Sierra Oncology (SRRA) 10-Q 2018 Q3 Quarterly report

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM10-Q

☒ Quarterly Report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the quarterly period ended September 30, 2018

OR

☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the transition period from            to            .

Commission File Number:001-37490

Sierra Oncology, Inc.

(Exact name of registrant as specified in its charter)

Delaware	20-0138994
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification Number)

Sierra Oncology, Inc.

c/o 2150 – 885 West Georgia Street

Vancouver, British Columbia, Canada V6C 3E8

(Address of principal executive offices and zip code)

(604)558-6536

(Registrant’s telephone number, including area code)

Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days:    Yes  ☒    No  ☐

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of RegulationS-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files).    Yes  ☒    No  ☐

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule12b-2 of the Exchange Act. (Check one):

Large accelerated filer	☐	Accelerated filer	☐
Non-accelerated filer	☐	Smaller reporting company	☒
		Emerging growth company	☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☒

Indicate by check mark whether the Registrant is a shell company (as defined in Rule12b-2 of the Exchange Act).    Yes  ☐    No  ☒

As of November 6, 2018, there were 74,365,965 shares of the Registrant’s Common Stock, $0.001 par value per share, outstanding.

TABLE OF CONTENTS

	Page
Part I. Financial Information
Item 1. Condensed Consolidated Financial Statements (unaudited)		2
Condensed Consolidated Balance Sheets		2
Condensed Consolidated Statements of Operations		3
Condensed Consolidated Statement of Stockholders’ Equity		4
Condensed Consolidated Statements of Cash Flows		5
Notes to Condensed Consolidated Financial Statements		6
Item  2. Management’s Discussion and Analysis of Financial Condition and Results of Operations		18
Item 3. Quantitative and Qualitative Disclosures About Market Risk		25
Item 4. Controls and Procedures		25
Part II. Other Information
Item 1. Legal Proceedings		27
Item 1A. Risk Factors		27
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds		61
Item 3. Defaults Upon Senior Securities		61
Item 4. Mine Safety Disclosures		61
Item 5. Other Information		61
Item 6. Exhibits		61
Signatures		63

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This quarterly report on Form10-Q (Quarterly Report) contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended (Exchange Act), and section 27A of the Securities Act of 1933, as amended (Securities Act). All statements contained in this Quarterly Report other than statements of historical fact are “forward-looking statements” for purposes of this Quarterly Report on Form10-Q. These forward-looking statements may include, but are not limited to, statements regarding our future clinical development activities, expected timing and results of clinical trials, future results of operations and financial position, our business strategy and plans and our objectives for future operations. The words “believe,” “may,” “will,” “potentially,” “estimate,” “continue,” “anticipate,” “intend,” “could,” “would,” “project,” “plan” “expect,” and similar expressions that convey uncertainty of future events or outcomes are intended to identify forward-looking statements.

We have based these forward-looking statements largely on our current expectations and projections about future events and trends that we believe may affect our financial condition, results of operations, business strategy, short-term and long-term business operations and objectives and financial needs. These forward-looking statements are subject to a number of risks, uncertainties and assumptions, including those described in the “Risk Factors” section and elsewhere in this Quarterly Report on Form10-Q. Moreover, we operate in a very competitive and rapidly changing environment, and new risks emerge from time to time. It is not possible for our management to predict all risks, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements we may make. In light of these risks, uncertainties and assumptions, the forward-looking events and circumstances discussed in this report may not occur and actual results could differ materially and adversely from those anticipated or implied in the forward-looking statements.

You should not rely upon forward-looking statements as predictions of future events. Although we believe that the expectations reflected in the forward-looking statements are reasonable, we cannot guarantee that the future results, levels of activity, performance or events and circumstances reflected in the forward-looking statements will be achieved or occur. We undertake no obligation to update publicly any forward-looking statements to conform these statements to actual results or to changes in our expectations, except as required by law. You should read this Quarterly Report with the understanding that our actual future results, levels of activity, performance and events and circumstances may be materially different from what we expect.

As used in this Quarterly Report on Form10-Q, the terms “Sierra Oncology,” “the Company,” “we,” “us” and “our” refer to Sierra Oncology, Inc., a Delaware corporation, and its subsidiaries taken as a whole, unless otherwise noted. Sierra Oncology is our registered trademark. The “Sierra Oncology” logo and all product names are our common law trademarks. This Quarterly Report may contain additional trade names, trademarks and service marks of other companies, which are the property of their respective owners. We do not intend our use or display of other companies’ trade names, trademarks or service marks to imply a relationship with, or endorsement or sponsorship of us by, these other companies.

1

PART I

ITEM 1. CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

SIERRA ONCOLOGY, INC.

Condensed Consolidated Balance Sheets

(unaudited)

(in thousands, except share and per share data)

	September 30, 2018			December 31, 2017
ASSETS
CURRENT ASSETS:
Cash and cash equivalents	$	116,128		$	100,348
Prepaid expenses and other current assets		3,203			1,377
Total current assets		119,331			101,725
Property and equipment, net		125			154
Other assets		596			319
TOTAL ASSETS	$	120,052		$	102,198
LIABILITIES AND STOCKHOLDERS’ EQUITY
CURRENT LIABILITIES:
Accrued liabilities	$	7,168		$	6,133
Accounts payable		962			1,339
Total current liabilities		8,130			7,472
Term loan		4,856			—
TOTAL LIABILITIES		12,986			7,472
Commitments and Contingencies (Note 7)
STOCKHOLDERS’ EQUITY:
Preferred stock, $0.001 par value; 10,000,000 shares authorized as of September 30, 2018 and December 31, 2017; nil shares issued and outstanding as of September 30, 2018 and December 31, 2017		—			—
Common stock, $0.001 par value; 500,000,000 shares authorized as of September 30, 2018 and December 31, 2017; 74,364,165 and 52,395,223 shares issued and outstanding as of September 30, 2018 and December 31, 2017		74			52
Additionalpaid-in capital		770,121			718,751
Accumulated deficit		(663,129	)		(624,077	)
TOTAL STOCKHOLDERS’ EQUITY		107,066			94,726
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$	120,052		$	102,198

The accompanying notes are an integral part of these condensed consolidated financial statements.

2

SIERRA ONCOLOGY, INC.

Condensed Consolidated Statements of Operations

(unaudited)

(in thousands, except share and per share data)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
Operating expenses:
Research and development	$	12,913		$	7,405		$	30,032		$	22,607
General and administrative		3,138			2,778			10,736			9,207
Total operating expenses		16,051			10,183			40,768			31,814
Loss from operations		(16,051	)		(10,183	)		(40,768	)		(31,814	)
Other income, net		479			225			1,333			506
Loss before provision for (benefit from) income taxes, net		(15,572	)		(9,958	)		(39,435	)		(31,308	)
Provision for (benefit from) income taxes, net		(5	)		37			(383	)		108
Net loss	$	(15,567	)	$	(9,995	)	$	(39,052	)	$	(31,416	)
Net loss per common share, basic and diluted	$	(0.21	)	$	(0.19	)	$	(0.56	)	$	(0.64	)
Weighted-average shares used in computing net loss per common share, basic and diluted		74,347,489			52,268,443			69,517,119			49,080,049

The accompanying notes are an integral part of these condensed consolidated financial statements.

3

SIERRA ONCOLOGY, INC.

Condensed Consolidated Statement of Stockholders’ Equity

(unaudited)

(in thousands, except share data)

	Common Stock				Additional Paid-In Capital		Accumulated Deficit			Total Stockholders’ Equity
	Shares		Amount
Balance—December 31, 2017		52,395,223	$	52	$	718,751	$	(624,077	)	$	94,726
Issuance of common stock for exercise of stock options		118,942		—		178		—			178
Stock-based compensation		—		—		5,102		—			5,102
Issuance of common stock, net of offering costs of $3.2 million		21,850,000		22		45,974		—			45,996
Issuance of common stock warrant		—		—		116		—			116
Net loss		—		—		—		(39,052	)		(39,052	)
Balance—September 30, 2018		74,364,165	$	74	$	770,121	$	(663,129	)	$	107,066

The accompanying notes are an integral part of these condensed consolidated financial statements.

4

SIERRA ONCOLOGY, INC.

Condensed Consolidated Statements of Cash Flows

(unaudited)

(in thousands)

	Nine Months Ended September 30,
	2018			2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$	(39,052	)	$	(31,416	)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation		5,102			4,498
Depreciation		85			228
Other		(167	)		30
Changes in operating assets and liabilities:
Prepaid expenses and other assets		(1,831	)		(483	)
Accrued liabilities		1,092			681
Accounts payable		(371	)		(2,093	)
Net cash used in operating activities		(35,142	)		(28,555	)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment		(59	)		(92	)
Net cash used in investing activities		(59	)		(92	)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock uponfollow-on offering, net of offering costs		45,996			27,422
Proceeds from issuance of term loan, net of issuance costs		4,955			—
Proceeds from exercise of common stock options		178			23
Net cash provided by financing activities		51,129			27,445
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash		(36	)		6
NET INCREASE / (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH		15,892			(1,196	)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH — Beginning of period		100,536			109,207
CASH, CASH EQUIVALENTS AND RESTRICTED CASH — End of period	$	116,428		$	108,011
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for income taxes, net	$	15		$	221
Cash paid for interest	$	9		$	—
SUPPLEMENTAL DISCLOSURES OFNON-CASH INVESTING AND FINANCING INFORMATION:
Property and equipment purchases included in accrued liabilities	$	—		$	5
Issuance of common stock warrant	$	116		$	—

The accompanying notes are an integral part of these condensed consolidated financial statements.

5

SIERRA ONCOLOGY, INC.

Notes to Condensed Consolidated Financial Statements

(unaudited)

1. The Company and Basis of Presentation

Organization and Description of Business

Sierra Oncology, Inc. (together with its subsidiaries, collectively referred to as the “Company”), a Delaware corporation, is a clinical stage drug development company advancing targeted therapeutics for the treatment of patients with unmet medical needs in hematology and oncology. Pursuant to an asset purchase agreement entered into in August 2018 (Note 7), Sierra Oncology acquired its lead drug candidate, momelotinib, a potent, selective and orally-bioavailable JAK1, JAK2 and ACVR1 inhibitor that has been investigated in two completed Phase 3 trials for the treatment of myelofibrosis and has demonstrated a potentially differentiated therapeutic profile encompassing anemia-related benefits, as well as achieving substantive spleen and constitutional symptom control. Sierra Oncology is also advancing SRA737 and SRA141. SRA737 is a potent, highly selective, orally bioavailable small molecule inhibitor of Checkpoint kinase 1 (Chk1), a key regulator of cell cycle progression and the DNA Damage Response (DDR) replication stress response. SRA141 is a potent, selective and orally bioavailable small molecule inhibitor of cell division cycle 7 kinase (Cdc7), a key regulator of DNA replication and involved in the DDR network.

The Company’s primary activities since inception have been conducting research and development activities, conducting preclinical and clinical testing, recruiting personnel, performing business and financial planning, identifying and evaluating additional drug candidates for potentialin-licensing or acquisition, and raising capital to support development activities.

The Company has not generated any product revenue related to its primary business purpose to date, nor has it generated any income, and is subject to a number of risks and uncertainties, which include dependence on key individuals, the need to identify and successfully develop commercially viable products, the need to obtain regulatory approval for its products and commercialize them, and the need to obtain adequate additional financing to fund the development of its product candidates.

As of September 30, 2018, the Company had $116.1 million of cash and cash equivalents. The Company believes that its balance of cash and cash equivalents as of the date of the issuance of these condensed consolidated financial statements is sufficient to fund its current operational plan for at least the next twelve months though it may pursue raising additional capital through equity financings or other arrangements.

Follow-On Offering

On March 6, 2018, the Company completed an underwritten public offering of an aggregate of 21,850,000 shares of common stock, including the underwriters’ exercise of their overallotment option, at a price to the public of $2.25 per share. The aggregate net proceeds received by the Company from the offering were $46.0 million, net of underwriting discounts and commissions and offering expenses of $3.2 million.

2. Summary of Significant Accounting Policies

Basis of Presentation

The condensed consolidated balance sheet as of September 30, 2018, the condensed consolidated statements of operations for the three and nine months ended September 30, 2018 and 2017, the condensed consolidated statements of cash flows for the nine months ended September 30, 2018 and 2017 and the condensed consolidated statement of stockholders’ equity as of September 30, 2018 are unaudited. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for the fair presentation of the Company’s condensed consolidated financial statements included in this report. The condensed consolidated financial data disclosed in these notes to the condensed consolidated financial statements related to the three-and nine-month periods are also unaudited. The condensed consolidated results of operations for the three and nine months ended September 30, 2018 are not necessarily indicative of the results to be expected for the year ending December 31, 2018, or for any other future annual or interim period. The condensed consolidated balance sheet as of December 31, 2017 included herein was derived from the audited consolidated financial statements as of that date. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements included in the Company’s Annual Report on Form10-K for the year ended December 31, 2017, filed with the SEC on February 27, 2018.

6

Use of Estimates

The preparation of the condensed consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of expense during the reporting period. Significant estimates and assumptions made in the accompanying condensed consolidated financial statements include, but are not limited to the fair value of stock options and the warrant issued, accruals such as research and development costs, and recoverability of the Company’s net deferred tax assets and related valuation allowance. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates.

Foreign Currency

The functional currency of the Company’s foreign subsidiaries is the U.S. Dollar. Transactions denominated in currencies other than the functional currency are recorded at prevailing exchange rates during the period. At the end of each reporting period, monetary assets and liabilities are remeasured to the functional currency using exchange rates in effect at the balance sheet date.Non-monetary assets and liabilities are recorded at historical exchange rates. Gains and losses related to remeasurement are recorded in other income, net in the condensed consolidated statements of operations. The net foreign exchange transaction gains (losses) included in other income, net in the accompanying condensed consolidated statements of operations was insignificant for the three and nine months ended September 30, 2018 and 2017.

Cash and Cash Equivalents

The Company considers all highly liquid investments with an original maturity of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents consist primarily of funds invested in readily available checking and savings accounts and highly liquid investments in money market funds.

Restricted Cash

Restricted cash, which consists of funds invested in a money market fund, represents collateral for a corporate credit card facility. Restricted cash at December 31, 2017 also included security deposits required for a facility lease that expired in February 2018.

Concentrations of Credit Risk

Financial instruments that subject the Company to significant concentrations of credit risk consist of cash, cash equivalents and restricted cash. All of the Company’s cash, cash equivalents and restricted cash are held at financial institutions in the United States and Canada that management believes to be of high credit quality. Deposits held in the United States and Canada with these financial institutions exceed federally insured limits.

The primary focus of the Company’s investment strategy is to preserve capital and meet liquidity requirements. The Company’s investment policy addresses the level of credit exposure by limiting the concentration in any one corporate issuer and establishing a minimum allowable credit rating.

Comprehensive Loss

The Company had no components of comprehensive loss other than net loss for all periods presented.

Fair Value of Financial Instruments

The Company’s cash and cash equivalents, restricted cash, other current assets, accounts payable, and accrued liabilities approximate their fair value due to their short duration. The term loan bears interest at prevailing market rates for instruments with similar characteristics, accordingly, the carrying value of this instrument approximates its fair value.

7

The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. The Company determines the fair value of its financial instruments based on assumptions that market participants would use in pricing an asset or liability in the principal or most advantageous market. When considering market participant assumptions in fair value measurements, the following fair value hierarchy distinguishes between observable and unobservable inputs, which are categorized in one of the following levels:

Level 1 – Inputs are unadjusted quoted prices in active markets for identical assets or liabilities at the measurement date;

Level 2 – Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and

Level 3 – Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data.

Property and Equipment, Net

Property and equipment, net are stated at cost, less accumulated depreciation. Depreciation on property and equipment, excluding leasehold improvements, is computed using the straight-line method over the estimated useful lives of the respective assets, generally three to five years. Depreciation begins at the time the asset is placed in service. Maintenance and repairs are charged to operations as incurred. Upon sale or retirement of assets, the cost and related accumulated depreciation are removed from the condensed consolidated balance sheet and the resulting gain or loss is reflected in the condensed consolidated statement of operations. Leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful lives of the assets or the remaining lease term.

Other Assets

Other assets consist primarily of restricted cash pledged as collateral for a corporate credit card facility, long-term prepaid rent and deferred income tax assets in foreign jurisdictions.

Research and Development Costs

Research and development costs are expensed as incurred. The Company accounts fornon-refundable advance payments for goods and services that will be used in future research and development activities as expenses when the goods have been received or when the service has been performed rather than when the payment is made. Depending on the timing of payments to service providers of research and development costs, the Company recognizes prepaid expenses or accrued expenses related to these costs. These prepaid or accrued expenses are based on management’s estimates of the work performed under service agreements and milestones achieved. In the event that a clinical trial is terminated early, the Company records an accrual for the estimated remaining costs to complete the trial in the period of termination.

Upfront payments made in connection with license and asset purchase agreements are expensed as research and developments costs, as the assets acquired do not have alterative future use. Contingent milestone payment obligations due to third parties under license and asset purchase agreements are expensed when the milestones are considered probable of occurring.

Research and development costs include fees incurred in connection with license and asset purchase agreements, compensation and other related costs for employees engaged in research and development, costs associated with research and preclinical studies, clinical trials, regulatory activities, manufacturing activities to support clinical activities, fees paid to external service providers that conduct certain research and development, clinical, and manufacturing activities on behalf of the Company and an allocation of overhead expenses.

Stock-Based Compensation

The Company accounts for stock-based payments at fair value, which is measured using the Black-Scholes option-pricing model. For stock-based awards that vest subject to the satisfaction of a service requirement, the fair value measurement date for employee stock-based compensation awards is the date of grant and the expense is recognized on a straight-line basis over the vesting period.

For stock-based awards that vest subject to the satisfaction of a service requirement and a performance component, the fair value measurement date is the date of grant and is recognized over the requisite service period as achievement of the performance objective becomes probable.

Stock-based compensation arrangements withnon-employees are recognized at the grant date and remeasured to fair value at each reporting period. The expense is recognized over the vesting period, which is generally the service period.

8

Income Taxes

The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Management makes an assessment of the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. Due to the Company’s historical operating performance and the recorded cumulative net losses in prior fiscal periods, the net U.S. deferred tax assets have been offset by a full valuation allowance.

The Company recognizes uncertain income tax positions at the largest amount that is more likely than not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. Changes in recognition or measurement are reflected in the period in which judgment occurs. The Company recognizes interest and penalties related to the underpayment of income taxes as a component of provision for (benefit from) income taxes, net.

Segment Information

Operating segments are components of an enterprise for which separate financial information is available and is evaluated regularly by the Company’s chief operating decision maker in deciding how to allocate resources and assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer.

The Company’s Chief Executive Officer views the Company’s operations and manages its business in one operating segment, which is the business of researching, developing and commercializing therapies for the treatment of patients with hematology and oncology. Accordingly, the Company has a single reporting segment.

Recent Accounting Pronouncements Not Yet Effective

In February 2016, the Financial Accounting Standards Board (FASB) issued FASB Accounting Standards Update (ASU)No. 2016-02,Leases (Topic 842). The amendments in this update require that organizations recognize lease assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. This ASU is effective for financial statements issued for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The Company will adopt the new standard effective January 1, 2019 and expects its operating leases, as disclosed in Note 7 “Commitments and Contingencies”, to be subject to the new standard. The Company willrecognize right-of-use assets and operating lease liabilities on its consolidated balance sheets upon adoption, which will increase its total assets and liabilities.

In June 2018, the FASB issued FASB ASUNo. 2018-07,Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting.This ASU is intended to simplify aspects of share-based compensation issued tonon-employees by making the guidance consistent with accounting for employee share-based compensation. This ASU is effective for financial statements issued for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The Company will adopt the new standard effective January 1, 2019 and does not expect that the adoption of this new accounting guidance will have a material impact on its consolidated financial statements.

3. Net Loss Per Share

Basic net loss per share is calculated by dividing net loss by the weighted-average number of common shares outstanding during the period without consideration for common stock equivalents. Diluted net loss per share is computed by dividing net loss by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method. For purposes of this calculation, stock options and the warrant for common stock are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive.

9

The following shares of common stock equivalents were excluded from the calculation of diluted net loss per share for the periods presented because including them would have been antidilutive:

	September 30, 2018		September 30, 2017
	(in thousands)
Options to purchase common stock		10,719,737		7,685,449
Warrant for common stock		73,529		—
Total potential dilutive shares		10,793,266		7,685,449

4. Fair Value Measurements

The Company measures and reports its cash equivalents and restricted cash at fair value. The following table sets forth the fair value of the Company’s financial assets measured on a recurring basis by level within the fair value hierarchy:

	September 30, 2018
	Level 1		Level 2		Level 3		Total
	(in thousands)
Financial Assets
Money market funds	$	115,019	$	—	$	—	$	115,019
Restricted money market funds		300		—		—		300
Total financial assets	$	115,319	$	—	$	—	$	115,319

	December 31, 2017
	Level 1		Level 2		Level 3		Total
	(in thousands)
Financial Assets
Money market funds	$	99,792	$	—	$	—	$	99,792
Restricted money market funds		187		—		—		187
Total financial assets	$	99,979	$	—	$	—	$	99,979

Money market funds and restricted money market funds are measured at fair value on a recurring basis using quoted prices and are classified as a Level 1 input.

There were no transfers between Levels 1, 2 or 3 during the nine months ended September 30, 2018.

5. Balance Sheet Components

Cash and Cash Equivalents

Cash and cash equivalents consist of the following:

	September 30, 2018		December 31, 2017
	(in thousands)
Cash	$	1,109	$	556
Cash equivalents:
Money market accounts		115,019		99,792
Total cash and cash equivalents	$	116,128	$	100,348

10

In November 2016, the FASB issued new guidance ASUNo. 2016-18,Statement of Cash Flows (Topic 230): Restricted Cash, which requires thebeginning-of-period andend-of-period totals on the statement of cash flows to include restricted cash and restricted cash equivalents, as well as disclosure of how the statement of cash flows reconciles to the balance sheet if restricted cash is shown separately from cash and cash equivalents on the balance sheet. The company adopted the guidance effective January 1, 2018 retrospectively to all periods presented. As a result, the condensed consolidated statement of cash flows no longer presents transfers to or from restricted cash.

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the condensed consolidated balance sheets to the amounts shown in the condensed consolidated statements of cash flows.

	September 30, 2018		September 30, 2017
	(in thousands)
Cash and cash equivalents	$	116,128	$	107,824
Restricted cash included in other assets		300		187
Total cash, cash equivalents and restricted cash shown in the condensed consolidated statement of cash flows	$	116,428	$	108,011

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following:

	September 30, 2018		December 31, 2017
	(in thousands)
Prepaid research and development project costs	$	1,106	$	549
Prepaid insurance		815		478
Other receivables		407		103
Income taxes receivable		294		—
Other		581		247
Total prepaid expenses and other current assets	$	3,203	$	1,377

Property and Equipment, net

Property and equipment, net consists of the following:

	September 30, 2018			December 31, 2017
	(in thousands)
Software	$	259		$	254
Leasehold improvements		108			79
Computer equipment		89			93
Furniture and fixtures		3			3
Property and equipment, gross		459			429
Less: accumulated depreciation		(334	)		(275	)
Total property and equipment, net	$	125		$	154

Depreciation related to the Company’s property and equipment was $26,000 and $0.1 million for the three and nine months ended September 30, 2018, and $0.1 million and $0.2 million for the three and nine months ended September 30, 2017.

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Accrued Liabilities

Accrued liabilities consist of the following:

	September 30, 2018		December 31, 2017
	(in thousands)
Accrued research and development costs	$	3,589	$	2,763
Accrued employee-related costs		2,133		2,699
Accrued professional fees		617		317
Accrued restructuring costs (Note 11)		71		137
Other		758		217
Total accrued liabilities	$	7,168	$	6,133

6. Term Loan

On August 21, 2018, the Company entered into a Loan and Security Agreement (Loan Agreement) with Silicon Valley Bank (SVB), pursuant to which the Company may obtain a loan of aggregate principal amount of up to $15.0 million (Term Loans), which becomes available in three tranches, each of an aggregate principal amount of up to $5.0 million. Contemporaneously with executing the Loan Agreement, the Company drew down the first $5.0 million tranche. The second and third $5.0 million tranches may be drawn only upon the achievement of certain development milestones. Borrowings under the Loan Agreement bear interest at the greater of (i) 6.0% or (ii) a floating per annum rate 1.0% above the prime rate (for an interest rate of 6.25% at September 30, 2018), with interest only due and payable monthly, until March 1, 2020 (unless extended under the conditions set forth in the Loan Agreement), at which time interest and principal will be due and payable monthly in equal monthly payments; are subject to a final payment fee equal to 6.75% of the aggregate principal amount.

The Company may prepay all, but not less than all, of the loaned amounts subject to a prepayment fee in the amount of 3.0% of the outstanding principal balance if such prepayment occurs prior to August 21, 2019; 2.0% of the outstanding principal balance if such prepayment occurs on or after August 21, 2019, but prior to August 21, 2020; or 1.0% of the outstanding principal balance if such prepayment occurs on August 21, 2020 or at any time thereafter prior to the maturity date of the Term Loans on August 1, 2022. The Loan Agreement is secured by substantially all of the Company’s personal property, except for its intellectual property and requires the Company to maintain the lesser of $10 million or 80% of its cash and cash equivalents with SVB. The Loan Agreement contains customary covenants that limit the Company’s ability to dispose of assets, enter into mergers or acquisitions, incur indebtedness, incur liens, pay dividends or make distributions on the Company’s capital stock, make investments or loans, and enter into certain affiliate transactions, among others. The Loan Agreement contains customary events of default that include, amongothers, non-payment defaults, covenant defaults, the occurrence of a material adverse change, and inaccuracy of representations and warranties. The occurrence of an event of default could result in an increase to the applicable interest rate of 5.0%, and the consequent obligation for the Company to repay all amounts outstanding under the Loan Agreement.

In connection with the Loan Agreement, the Company issued a warrant to SVB to purchase 73,529 of the Company’s common stock at a price per share of $1.87. The warrant was immediately exercisable, will expire on August 21, 2028, contains a cashless exercise provision and is classified as equity. If the Company is to draw the second or third tranche available under the Loan Agreement, the Company will grant an additional amount of common stock issuable upon exercise of the warrant based upon the principal amount advanced. In no event will the number of common stock issuable pursuant to the exercise of the warrant exceed 220,588 in aggregate.

The fair value of the warrant and the debt issuance costs were recorded as debt discounts and together with the final payment fee are being amortized using the effective interest rate method over the term of the loan. As of September 30, 2018, the effective interest rate on the initial tranche of the loan was 9.38% and the unamortized debt discount was $0.2 million. Amortization of the debt discount and accrual of final payment was $17,000 for the three months ended September 30, 2018.

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Scheduled payments due under the Loan Agreement, excluding the final payment fee of $0.3 million and interest payments, are as follows:

	September 30, 2018
	(in thousands)
2020	$	1,667
2021		2,000
2022		1,333
Total	$	5,000

During the three and nine months ended September 30, 2018, the Company recognized $0.1 million of interest expense related to the Loan Agreement.

7. Commitments and Contingencies

Asset Purchase Agreement

In August 2018, the Company entered into an asset purchase agreement with Gilead Sciences, Inc. (Gilead) whereby the Company acquired worldwide rights to the pharmaceutical product momelotinib, an investigational inhibitor of Janus kinase, together with all related intellectual property rights and certain other related assets. The Company paid Gilead an upfront payment of $3.0 million in August 2018. The related expense was included in research and development for the three and nine months ended September 30, 2018 in the accompanying condensed consolidated statement of operations. The Company will be required to pay Gilead milestone payments of up to an aggregate of $195.0 million upon the achievement of certain development, regulatory and commercial milestones events, including a milestone payment of $5.0 million upon the dosing of the first patient in a registrational clinical trial. These milestones will be accrued once they are considered probable of occurring. In addition, the Company is required to pay Gileadmid-teen to high twenty percent tiered royalties based upon net sales.

License Agreements

In September 2016, the Company entered into an exclusive license agreement with CRT Pioneer Fund LP (CPF) for worldwide rights,know-how and materials to develop SRA737, a small molecule inhibitor targeting Chk1, a promising therapeutic target to treat cancer. Pursuant to the agreement, the Company made aone-time upfront payment of $7.0 million to CPF in October 2016 and paid $2.0 million to CPF in January 2017 for the successful transfer of two ongoing Phase I clinical trials. The expense related to these payments was included in research and development for the year ended December 31, 2016. Additional milestone payments of up to an aggregate of $319.5 million may become payable to CPF upon the achievement of certain developmental, regulatory and commercial milestones, and will be accrued once they are considered probable of occurring. In addition, the Company is required to pay CPF, on aproduct-by-product andcountry-by-country basis, tiered high single-digit to low double-digit royalties on the net sales of any product successfully developed.

In May 2016, the Company entered into an exclusive license agreement (Carna License Agreement) with Carna Biosciences, Inc. (Carna) for worldwide rights to develop and commercialize SRA141, a small molecule kinase inhibitor targeting Cdc7. In exchange for this exclusive right, the Company paid Carna an upfront payment of $0.9 million in June 2016. The Company will be required to pay Carna milestone payments of up to an aggregate of $270.0 million upon achievement of certain developmental, regulatory and commercial milestone events, including a milestone payment of $4.0 million upon dosing of the first patient in the first Phase 1 clinical trial for SRA141. These milestones will be accrued once they are considered probable of occurring. As of September 30, 2018, the Company had not recorded any milestone payments to Carna. In addition, the Company is required to pay Carna tiered single-digit royalties on net sales of product candidates (as defined under the Carna License Agreement).

Lease Agreements

In February 2015, the Company entered into an operating lease agreement to sublease office space in Vancouver, Canada. Under the terms of the agreement, the Company issued a letter of credit to the sublessor on closing, which was collateralized by a restricted deposit. The operating lease agreement together with the restricted deposit expired on February 2018. In June 2017, the Company entered into a new operating lease agreement to continue leasing the office space in Vancouver, Canada commencing March 1, 2018. The new lease expires on February 28, 2023 and can be extended for an additional term of 5 years.

In January 2016, the Company entered into an operating lease agreement to lease office space near San Francisco, California. The operating lease agreement expires on April 30, 2019. In September 2017, the Company entered into a sublease agreement to sublet the premises to a third party until April 30, 2019. The fair value of the remaining contractual obligation, net of sublease income, was included in accrued liabilities in the accompanying condensed consolidated balance sheet as of September 30, 2018.

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In addition to base rent, these leases require payment of taxes and other operating costs. These operating costs are not included in the table below.

As of September 30, 2018, the aggregate futurenon-cancelable minimum lease payments associated with these operating leases are as follows:

Years Ending December 31:	Operating Leases
	(in thousands)
Remainder of 2018	$	102
2019		266
2020		219
2021		223
2022		178
Thereafter		—
Total(a)	$	988

(a) Minimum lease payments have not been reduced by minimum sublease rentals of $0.1 million due in the future under sublease.

The total rent expense was $0.1 million and $0.3 million for the three and nine months ended September 30, 2018, and $0.1 million and $0.4 million for the three and nine months ended September 30, 2017.

Legal

On November 9, 2016, a purported securities class action lawsuit was filed in the United States District Court for the Southern District of New York against the Company and certain of its executive officers (the New York Lawsuit). The New York Lawsuit was brought by purported stockholders of the Company seeking to represent a class consisting of stockholders who purchased stock between July 15, 2015 and June 6, 2016. The New York Lawsuit asserts claims under Sections 10(b) and 20(a) of the Exchange Act and seeks unspecified damages and other relief. On March 13, 2018, the United States District Court for the Southern District of New York granted the defendants’ motion to dismiss and entered a final judgment dismissing the New York Lawsuit with prejudice. Plaintiffs have filed an appeal. The Company believes that the claims in the New York Lawsuit are without merit and intends to defend the lawsuit vigorously. It is possible that additional similar lawsuits could be filed. Due to the early stage of the litigation, the Company is unable to predict the outcome of this matter. However, at this point in time, the Company does not expect the outcome of these claims will have a material impact on its condensed consolidated financial statements.

On November 18, 2016, a purported securities class action lawsuit was filed in the Superior Court of the State of California for the County of San Mateo against the Company, certain of its executive officers and directors, and the underwriters for the Company’s initial public offering of its common stock. On February 9, 2017, a substantially identical putative class action suit was filed in the Superior Court of the State of California for the County of San Mateo asserting the same claims on behalf of the same putative class (the two lawsuits together, the California Lawsuits). The California Lawsuits were brought by purported stockholders of the Company seeking to represent a class consisting of stockholders who purchased stock pursuant to and/or traceable to the Company’s Registration Statement on FormS-1. The lawsuits assert claims under Sections 11 and 15 of the Exchange Act and seek unspecified damages and other relief. On August 1, 2018, all parties reached a mutually acceptable resolution to the California Lawsuits by way of a mediated settlement, which is subject to the parties’ execution of final settlement documents and the approval of the court. While the Company believes that the claims are without merit, it believes settlement will reduce the ultimate cost and distraction of further litigation. The Company does not expect its portion of the settlement amount to have a material impact on its condensed consolidated financial statements.

From time to time, the Company may become subject to other legal proceedings, claims and litigation arising in the ordinary course of business. In addition, the Company may receive letters alleging infringement of patent or other intellectual property rights. The Company is not currently a party to any other material legal proceedings, nor is it aware of any pending or threatened litigation that, in the Company’s opinion, would have a material adverse effect on the business, operating results, cash flows or financial condition should such litigation be resolved unfavorably.

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8. Common Stock Reserved for Issuance

The Company is required to reserve and keep available out of its authorized but unissued shares of common stock a number of shares sufficient to effect the conversion of all outstanding options granted and available for grant under the incentive plans, shares reserved for issuance under the employee stock purchase plan and issued warrant.

	September 30, 2018		December 31, 2017
Outstanding stock options under the 2015 equity incentive plan		10,719,737		7,470,601
Shares reserved for future option grants under equity plans		1,731,500		1,503,770
Shares reserved under the 2015 employee stock purchase plan		700,000		700,000
Shares reserved under warrant upon contingent events		147,059		—
Outstanding warrant		73,529		—
Total common stock reserved for issuance		13,371,825		9,674,371

9. Stock-Based Compensation

In the accompanying condensed consolidated statements of operations, the Company recognized stock-based compensation expense for its employees andnon-employees as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
	(in thousands)
Research and development	$	1,168	$	1,003	$	3,330	$	3,024
General and administrative		653		457		1,772		1,474
Total stock-based compensation	$	1,821	$	1,460	$	5,102	$	4,498

Determination of Fair Value

The estimated grant-date fair values of all of the Company’s stock-based awards were calculated using the Black-Scholes option pricing model, based on assumptions as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Expected term (in years)		5.6 – 6.1		6.1		5.3 – 7.0		5.3 –7.0
Expected volatility		88 – 91%		87%		88 – 91%		86 – 96%
Risk-free interest rate		2.7 – 3.0%		1.8 – 2.1%		2.6 – 3.0%		1.8 – 2.3%
Expected dividend rate		—  %		—  %		—  %		—  %

Equity Incentive Plans

2018 Equity Inducement Plan

In September 2018, the Company’s Compensation Committee approved the 2018 Equity Inducement Plan (2018 Plan). The number of shares available for awards under the 2018 Plan was set to 1,500,000. The exercise price of each stock-based award issued under the 2018 Plan is required to be no less than the fair value of the Company’s capital stock. The vesting and exercise provisions of options or restricted awards granted are determined individually with each grant. Stock options have a10-year life and expire if not exercised within that period or if not exercised within three months of cessation of employment with the Company or such longer period of time as specified in the option agreement. As of September 30, 2018, there were no awards issued or outstanding under the 2018 Plan.

2015 Plan

The 2015 Equity Incentive Plan (2015 Plan) became effective on July 14, 2015. As of September 30, 2018, 8,636,226 shares were reserved for issuance under the 2015 Plan. The number of shares reserved for issuance under the 2015 Plan will increase automatically on January 1 of each calendar year 2016 through 2025 by the number of shares equal to 4% of the total outstanding shares of the Company’s common stock as of the immediately preceding December 31. The Company’s Board of Directors or Compensation Committee may reduce the amount of the increase in any particular year. The exercise price of each stock-based award issued under

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the 2015 Plan is required to be no less than the fair value of the Company’s capital stock. The vesting and exercise provisions of options or restricted awards granted are determined individually with each grant. Stock options have a10-year life and expire if not exercised within that period or if not exercised within three months of cessation of employment with the Company or such longer period of time as specified in the option agreement.

2008 Plan

The Company granted options under the 2008 Stock Plan (2008 Plan) until July 2015 when it was terminated as to future awards, although it continues to govern the terms of options that remain outstanding under the 2008 Plan. The 2008 Plan provided for the granting of Incentive Stock Options (ISO), nonqualified stock options and stock purchase rights. In connection with the Board of Director’s approval of the 2015 Plan, all remaining shares available for future award under the 2008 Plan were transferred to the 2015 Plan, and the 2008 Plan was terminated.

A summary of activity under the 2008 Plan, 2015 Plan and 2018 Plan and related information is as follows:

				Options Outstanding
	Shares Available for Grant			Number of Shares Outstanding			Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value of Outstanding Options (in thousands)
Outstanding — December 31, 2017		1,503,770			7,470,601		$	3.09		8.12	$	12,363
Awards authorized under the 2015 Plan		2,095,808
Awards authorized under the 2018 Plan		1,500,000
Options granted		(3,486,150	)		3,486,150			2.37
Options exercised		—			(118,942	)		1.50
Options forfeited/cancelled		118,072			(118,072	)		4.31
Outstanding — September 30, 2018		1,731,500			10,719,737		$	2.86		8.06	$	1,420
Exercisable — September 30, 2018					5,376,902		$	3.07		7.19	$	1,251
Vested and expected to vest — September 30, 2018					10,719,737		$	2.86		8.06	$	1,420

The weighted-average grant date fair values of options granted during the three and nine months ended September 30, 2018 was $1.56 and $1.76 per share, and $1.01 and $1.07 per share during the three and nine months ended September 30, 2017. The aggregate intrinsic value of options exercised was $21,000 and $0.2 million for the three and nine months ended September 30, 2018, and $0 and $0.1 million for the three and nine months ended September 30, 2017. The total grant date fair value of options vested for the three and nine months ended September 30, 2018 was $1.5 million and $4.6 million, and $1.4 million and $5.1 million during the three and nine months ended September 30, 2017.

As of September 30, 2018, total unrecognized stock-based compensation related to unvested stock options was $10.1 million. These costs are expected to be recognized over a remaining weighted-average period of 2.1 years as of September 30, 2018.

2015 Employee Stock Purchase Plan

The Company adopted the 2015 Employee Stock Purchase Plan (ESPP) and initially reserved 700,000 shares of common stock as of its effective date of July 15, 2015. The number of shares initially reserved for issuance under the ESPP will increase automatically on January 1 for nine years from the first offering date by the number of shares equal to 1% of the total outstanding shares of the Company’s common stock as of the immediately preceding December 31. The aggregate number of shares issued over the term of the 2015 Employee Stock Purchase Plan will not exceed 3,400,000 shares of common stock.

Under the ESPP, participants are offered the option to purchase shares of the Company’s common stock at a 15% discount during a series of discrete offering periods, subject to any plan limitations. The ESPP will not become effective until such time as the Compensation Committee determines in the future, and as of September 30, 2018, the initial offering periods had not commenced. As of September 30, 2018, no shares of common stock have been issued to employees participating in the ESPP and 700,000 shares were available for issuance under the ESPP.

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10. Income Taxes

The Company did not record a provision for U.S. federal income taxes for the three and nine months ended September 30, 2018 because it expects to generate a loss for the year ended December 31, 2018. The net income tax benefit of $5,000 and $0.4 million for the three and nine months ended September 30, 2018 primarily represented income tax benefit resulting from foreign research and development tax credits. Income tax expense of $37,000 and $0.1 million for the three and nine months ended September 30, 2017 represented foreign taxes. The Company’s net U.S. deferred tax assets continue to be offset by a full valuation allowance.

On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (Tax Act). The Tax Act significantly revises U.S. tax law by, among other provisions, lowering the U.S. federal statutory income tax rate from 35% to 21%, changing rules related to uses and limitations of net operating loss carryforwards created in tax years beginning after December 31, 2017 and eliminating or reducing certain income tax deductions.

The effects of changes in tax laws are required to be recognized in the period in which the legislation is enacted. However, due to the complexity and significance of the Tax Act’s provisions, the FASB issued ASUNo. 2018-06,Income Taxes (Topic 740)pursuant tothe SEC staff issued Staff Accounting Bulletin No. 118 (SAB 118), which allows companies to record the tax effects of the Tax Act on a provisional basis based on a reasonable estimate, and then, if necessary, subsequently adjust such amounts during a limited measurement period as more information becomes available. The measurement period ends when a company has obtained, prepared, and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year from enactment.

In connection with the Company’s initial analysis of the Tax Act, it recorded a decrease of its net deferred tax assets of $7.2 million for the period ended December 31, 2017, to account for the rate reduction. This did not have an impact on the Company’s condensed consolidated financial statements since its U.S. deferred tax assets are fully offset by a valuation allowance. The Company finalized the analysis during the three months ended September 30, 2018, with no material changes to the initial estimated decrease of its net deferred tax assets, and the accounting is now complete.

11. Restructuring Costs

In June 2016, the Company halted investment in PNT2258 and closed the related Phase 2 clinical trials to further enrollment. As a result, the Company closed its research facility in Plymouth, Michigan, renegotiated and terminated certain contracts, and implemented staff reductions in the United States and Canada.

The following table summarizes restructuring activities for the three months ended September 30, 2018 and 2017:

	Three Months Ended September 30,
	2018			2017
	(in thousands)
Beginning balance	$	86		$	206
Adjustments to research and development expense		(10	)		(38	)
Cash payments		(5	)		(58	)
Ending balance	$	71		$	110

The following table summarizes restructuring activities for the nine months ended September 30, 2018 and 2017:

	Nine Months Ended September 30,
	2018			2017
	(in thousands)
Beginning balance	$	137		$	763
Adjustments to research and development expense		(10	)		(112	)
Cash payments		(56	)		(541	)
Ending balance	$	71		$	110

The accrual balance is currently expected to be substantially paid by the end of 2018.

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ITEM 2. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following discussion contains management’s discussion and analysis of our financial condition and results of operations and should be read together with the unaudited condensed consolidated financial statements and the notes thereto included in Part I, Item 1 of this quarterly report and with our audited consolidated financial statements and related notes thereto for the year ended December 31, 2017, included in our Annual Report on Form10-K. This discussion and other parts of this quarterly report contain forward-looking statements that involve risks and uncertainties, such as our plans, objectives, expectations, intentions and beliefs. Our actual results could differ materially from those discussed in these forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those identified below and those discussed in the section entitled “Risk Factors” included elsewhere is this report.

Overview

We are a clinical stage drug development company advancing targeted therapeutics for the treatment of patients with unmet medical needs in hematology and oncology. We have a highly experienced management team with a proven track record of success in oncology drug development. We are an ambitious company, oriented towards achieving the successful registration and commercialization of our product candidates.

During the third quarter of 2018, we acquired from Gilead Sciences, Inc. (Gilead) our lead product candidate momelotinib, a potent, selective and orally-bioavailable JAK1, JAK2 and ACVR1 inhibitor. Momelotinib has been investigated in two completed Phase 3 trials for the treatment of myelofibrosis and has demonstrated a potentially differentiated therapeutic profile encompassing anemia-related benefits, as well as achieving substantive spleen and constitutional symptom control. We are currently preparing for discussions with regulators to determine the registration path for momelotinib and anticipate reporting next steps in the first half of 2019.

We are also advancing SRA737, our potent, highly selective, orally bioavailable small molecule inhibitor of Checkpoint kinase 1 (Chk1). Chk1 is a key regulator of cell cycle progression and the DDR replication stress response. In cancer cells, intrinsic replication stress is induced by factors such as oncogenes (e.g.,CCNE1 orMYC), genetic mutations in DNA repair machinery (e.g.,BRCA1 orFANCA), genetic mutations leading to a dysregulated cell cycle (e.g.,TP53 orRAD50) or other genomic alterations. This replication stress results in persistent DNA damage and genomic instability leading to an increased dependency on Chk1 for survival. Targeted inhibition of Chk1 by SRA737 may therefore be synthetically lethal to cancer cells with elevated intrinsic replication stress and have utility as a monotherapy in a range of tumor indications. The combination of SRA737 with other modalities, such as other agents that target the DDR network and certain chemotherapeutics, may also provide synergistic anti-tumor activity via a variety of potential biological mechanisms. Importantly, the oral bioavailability of SRA737 may afford greater dosing flexibility for both monotherapy and combination therapy settings than is possible with intravenously administered agents.

We are pursuing an innovative development plan for SRA737, which is currently being evaluated in two Phase 1/2 clinical trials in patients with advanced cancer. OurSRA737-01 trial is intended to evaluate SRA737’s potential to induce synthetic lethality as monotherapy, while theSRA737-02 trial is intended to evaluate the combination of SRA737 potentiated by subtherapeutic,low-dose gemcitabine.

During the second quarter of 2018, we further refined our SRA737-01 monotherapy study to focus on high grade serous ovarian cancer (HGSOC), supported by emerging data in the field that provides clinical validation for Chk1 inhibition in this indication. Accordingly, we are prioritizing the enrollment of genetically defined HGSOC patients into this trial, while continuing to enroll patients into the trial’s other indications, although with lower priority.

For theSRA737-02 Phase 1/2Low-Dose Gemcitabine Combination trial, during the second quarter of 2018, we commenced the Cohort Expansion Phase 2 portion of this trial, which is enrolling patients across four indications. We are also in the process of modifying this study to add and prioritize enrollment for a cohort of genetically defined HGSOC patients, replacing an originally proposed cohort of urothelial cancer patients.

We expect to report preliminary data from both trials in the first half of 2019.

Concurrently, we are designing clinical trials and conducting preclinical research evaluating SRA737 in combination with otherDDR-targeted agents, including polyADP-ribose polymerase (PARP) inhibitors, as well as with immuno-oncology therapeutics, that will guide the next planned wave of clinical development for our asset, potentially further broadening its therapeutic utility. In the first quarter of 2018, we announced an agreement with Janssen Research & Development, LLC (Janssen), under which they have agreed to supply us with TESARO’s ZEJULA^® (niraparib), facilitating the planned initiation of a PARP inhibitor combination trial with SRA737 for the treatment of prostate cancer. We are currently evaluating the optimal timing to commence this trial within the context of our recently expanded portfolio.

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Our pipeline also includes SRA141, a potent, selective, orally bioavailable small molecule inhibitor of cell division cycle 7 kinase (Cdc7). Cdc7 is a key regulator of DNA replication and is involved in the DDR network, making it a compelling emerging target for the potential treatment of a broad range of tumor types. During the third quarter of 2018, we successfully completed the Investigational New Drug Application (IND) filing process with the U.S. Food and Drug Administration (FDA) for SRA141 and we are planning for a Phase 1/2 trial with this drug candidate in patients with colorectal cancer. Upon dosing of the first patient in the first Phase 1 clinical trial of SRA141, a milestone payment of $4.0 million will be due to Carna Biosciences, Inc. (Carna), the licensor of this asset. We are currently evaluating the optimal timing to commence this trial within the context of our recently expanded portfolio.

We retain the global commercialization rights to momelotinib, SRA737 and SRA141.

Since inception, we have devoted substantially all of our resources to research and development activities, including the clinical development of our current product candidates momelotinib, SRA737, SRA141 and our former product candidate PNT2258, and providing general and administrative support for these operations. We have never generated revenue and have incurred significant net losses since inception. Our net losses were $15.6 million and $39.1 million for the three and nine months ended September 30, 2018 and $10.0 million and $31.4 million for the three and nine months ended September 30, 2017. As of September 30, 2018, we had an accumulated deficit of $663.1 million. We expect to incur significant expenses and increasing operating losses for the foreseeable future. We anticipate that our expenses will increase substantially as we:

• invest to further develop our product candidates, momelotinib, a small molecule inhibitor targeting JAK1, JAK2 and ACVR1; SRA737, a small molecule inhibitor targeting Chk1; and SRA141, a small molecule inhibitor targeting Cdc7;

• achieve development milestones that trigger payments due under certain agreements, including a milestone payment of $5.0 million that would be due to Gilead upon the dosing of the first patient in a registrational clinical trial for momelotinib and a milestone payment of $4.0 million that would be due to Carna upon dosing of the first patient in the first Phase 1 clinical trial for SRA141;

• acquire orin-license additional product candidates and technologies;

• develop additional product candidates;

• hire additional clinical, scientific, drug development and management personnel, as well as personnel to support any future commercialization efforts;

• invest in scaling our manufacturing capacity to support development and our global commercialization strategy;

• seek regulatory and marketing approvals for any product candidates that we may develop;

• ultimately establish a sales, marketing and distribution infrastructure to commercialize any drugs for which we may obtain marketing approval;

• defend against and resolve lawsuits or other legal issues;

• maintain, expand and protect our intellectual property portfolio; and

• add operational, financial and management information systems and personnel to continue to operate as a public company.

We have funded our operations to date primarily from the issuance and sale of our common stock through public offerings, and our convertible and redeemable convertible preferred stock in private financings and, to a lesser extent, through debt financings and exercises of our preferred stock warrants. As of September 30, 2018, we had cash and cash equivalents of $116.1 million.

Components of Statements of Operations

Operating Expenses

Research and Development

Research and development expenses consist primarily of the following:

• fees or milestone payments incurred in connection with license and asset purchase agreements;

• personnel-related costs, which include salaries, benefits, stock-based compensation, recruitment fees and travel costs;

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• costs associated with research and preclinical studies, clinical trials, regulatory activities and manufacturing activities to support clinical activities;

• fees paid to external service providers that conduct certain research and development, clinical and manufacturing activities on our behalf; and

• facility-related costs, which include direct and allocated expenses for rent and maintenance of facilities, depreciation and amortization expenses and other supplies.

The largest recurring component of our total operating expenses has historically been our investment in research and development activities, including the clinical development of our product candidates SRA737 and SRA141. We expect our research and development expenses will increase over the next few years as we advance our development programs, including our recently acquired product candidate momelotinib, achieve development milestones that trigger payments due under certain agreements, pursue regulatory approval of our product candidates in the United States and other jurisdictions, expand our portfolio of product candidates and prepare for potential commercialization, which will require a significant investment in areas related to contract manufacturing and inventory buildup.

The process of conducting clinical trials necessary to obtain regulatory approval is costly and time consuming. We may never succeed in achieving marketing approval for momelotinib, SRA737, SRA141 or any future product candidates. The probability of success of our product candidates may be affected by numerous factors, including clinical data, regulatory developments, competition, manufacturing capability and commercial viability. As a result, we are unable to determine the duration and completion costs of our research and development projects or when and to what extent we will generate revenue from the commercialization of momelotinib, SRA737, SRA141 or any future product candidates.

General and Administrative

General and administrative expenses consist of personnel-related costs, facility-related costs, allocated expenses and professional fees for services, including legal, patent prosecution and maintenance, human resources, audit and accounting services. Personnel-related costs consist of salaries, benefits, stock-based compensation, recruitment fees, severance costs and travel costs.

We expect to incur additional expenses associated with supporting our growing research and development activities, operating as a public company and other administration and professional services.

Other Income, net

Other income primarily consists of (i) interest and dividends earned on our cash and cash equivalents, (ii) interest expense associated with our term loan andnon-cash interest costs associated with the amortization of the debt discount and final payment fee, and (iii) foreign currency exchange gains and losses related to transactions and monetary asset and liability balances denominated in currencies other than the U.S. dollar. Foreign currency exchange gains and losses may also fluctuate in the future due to changes in foreign currency exchange rates.

Provision for (Benefit from) Income Taxes, net

Provision for (benefit from) income taxes, net consists of federal and state income taxes in the United States, income tax benefit resulting from research and development tax credits in Canada, income taxes in Canada and Australia, as well as deferred income taxes reflecting the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes, and changes in related valuation allowance.

We did not record a provision for U.S. federal income taxes for the three and nine months ended September 30, 2018 because we expect to generate a loss for the year ended December 31, 2018. Our tax benefit relates to research and development tax credits in Canada and our income tax provision relates to income taxes in Canada and Australia. Our net U.S. deferred tax assets continue to be offset by a full valuation allowance.

On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (Tax Act). The Tax Act significantly revises U.S. tax law by, among other provisions, lowering the U.S. federal statutory income tax rate from 35% to 21%, changing rules related to uses and limitations of net operating loss carryforwards created in tax years beginning after December 31, 2017 and eliminating or reducing certain income tax deductions.

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The effects of changes in tax laws are required to be recognized in the period in which the legislation is enacted. However, due to the complexity and significance of the Tax Act’s provisions, the Financial Accounting Standards Board (FASB) issued FASB Accounting Standards Update (ASU)No. 2018-06,Income Taxes (Topic 740)pursuant tothe SEC staff issued Staff Accounting Bulletin No. 118 (SAB 118), which allows companies to record the tax effects of the Tax Act on a provisional basis based on a reasonable estimate, and then, if necessary, subsequently adjust such amounts during a limited measurement period as more information becomes available. The measurement period ends when a company has obtained, prepared, and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year from enactment.

In connection with our initial analysis of the Tax Act, we recorded a decrease to our net deferred tax assets of $7.2 million for the period ended December 31, 2017, to account for the rate reduction. This did not have an impact on the condensed consolidated financial statements since our U.S. deferred tax assets are fully offset by a valuation allowance. We finalized the analysis during the three months ended September 30, 2018, with no material changes to the initial estimated decrease to our net deferred tax assets.

Results of Operations

Three Months Ended September 30, 2018 Compared to Three Months Ended September 30, 2017

	Three Months Ended September 30,						Change $
	2018			2017
	(in thousands)
Operating expenses:
Research and development	$	12,913		$	7,405		$	5,508
General and administrative		3,138			2,778			360
Total operating expenses		16,051			10,183			5,868
Loss from operations		(16,051	)		(10,183	)		(5,868	)
Other income, net		479			225			254
Loss before provision for (benefit from) income taxes, net		(15,572	)		(9,958	)		(5,614	)
Provision for (benefit from) income taxes, net		(5	)		37			(42	)
Net loss	$	(15,567	)	$	(9,995	)	$	(5,572	)

Research and Development

Research and development expenses increased $5.5 million, from $7.4 million for the three months ended September 30, 2017, to $12.9 million for the three months ended September 30, 2018. The increase was primarily due to a $3.0 million upfront fee paid to Gilead to acquire our lead product candidate momelotinib, an increase of $2.0 million in clinical trial costs and a $0.7 million increase in personnel-related and overhead costs for the three months ended September 30, 2018. These increased costs were partially offset by a $0.2 million decrease in research and preclinical costs related to SRA737 and SRA141 for the three months ended September 30, 2018.

General and Administrative

General and administrative expenses increased $0.4 million, from $2.8 million for the three months ended September 30, 2017 to $3.1 million for the three months ended September 30, 2018. The increase was primarily attributable to an increase in personnel-related costs, professional fees and allocated overhead for the three months ended September 30, 2018.

Other Income, net

Other income, net increased $0.3 million, from $0.2 million for the three months ended September 30, 2017 to $0.5 million for the three months ended September 30, 2018. The increase was primarily attributable to an increase in interest income as a result of higher balances of cash and cash equivalents and rising interest rates for the three months ended September 30, 2018.

Provision for (benefit from) income taxes, net

Net benefit from income taxes was $5,000 for the three months ended September 30, 2018, compared to provision for income taxes of $37,000 for the three months ended September 30, 2017.

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Nine Months Ended September 30, 2018 Compared to Nine Months Ended September 30, 2017

	Nine Months Ended September 30,						Change $
	2018			2017
	(in thousands)
Operating expenses:
Research and development	$	30,032		$	22,607		$	7,425
General and administrative		10,736			9,207			1,529
Total operating expenses		40,768			31,814			8,954
Loss from operations		(40,768	)		(31,814	)		(8,954	)
Other income, net		1,333			506			827
Loss before provision for (benefit from) income taxes, net		(39,435	)		(31,308	)		(8,127	)
Provision for (benefit from) income taxes, net		(383	)		108			(491	)
Net loss	$	(39,052	)	$	(31,416	)	$	(7,636	)

Research and Development

Research and development expenses increased $7.4 million, from $22.6 million for the nine months ended September 30, 2017, to $30.0 million for the nine months ended September 30, 2018. The increase was primarily due to a $3.0 million upfront fee paid to Gilead to acquire our lead product candidate, momelotinib, a $5.4 million increase in clinical trial costs and a $1.4 million increase in personnel-related costs for the nine months ended September 30, 2018. These increased costs were partially offset by a $1.5 million decrease in third-party manufacturing costs related to SRA737 and SRA141 and a $0.9 million decrease in research, preclinical and other support costs for the nine months ended September 30, 2018.

General and Administrative

General and administrative expenses increased $1.5 million, from $9.2 million for the nine months ended September 30, 2017 to $10.7 million for the nine months ended September 30, 2018. The increase was attributable to a $1.3 million increase in personnel-related costs, professional fees and allocated overhead and a $0.2 million increase in business development costs for the nine months ended September 30, 2018.

Other Income, net

Other income, net increased $0.8 million, from $0.5 million for the nine months ended September 30, 2017 to $1.3 million for the nine months ended September 30, 2018. The increase was primarily attributable to an increase in interest income as a result of higher cash balances of cash and cash equivalents and rising interest rates for the nine months ended September 30, 2018.

Provision for (benefit from) income taxes, net

Net benefit from income taxes was $0.4 million for the nine months ended September 30, 2018, compared to provision for income taxes of $0.1 million for the nine months ended September 30, 2017. The net benefit from income taxes for the nine months ended September 30, 2018 primarily represented benefit from foreign research and development tax credits.

Liquidity and Capital Resources

Capital Resources

Since our inception, we have never generated revenue and have incurred significant net losses. Our net losses for the three and nine months ended September 30, 2018 were $15.6 million and $39.1 million and for the three and nine months ended September 30, 2017 were $10.0 million and $31.4 million. As of September 30, 2018, we had an accumulated deficit of $663.1 million. Our principal sources of liquidity as of September 30, 2018 were cash and cash equivalents of $116.1 million.

On March 6, 2018, we completed an underwritten public offering of an aggregate of 21,850,000 shares of common stock at a price to the public of $2.25 per share. The aggregate net proceeds received by us from the offering were $46.0 million, net of underwriting discounts and commissions and offering expenses of $3.2 million.

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On August 21, 2018, we entered into a Loan and Security Agreement (Loan Agreement) with Silicon Valley Bank (SVB), pursuant to which we may obtain a loan of aggregate principal amount of up to $15.0 million. As of September 30, 2018, we borrowed $5.0 million under the first tranche, which bears interest at the greater of 6.0% or a floating per annum rate 1.0% above the prime rate (for an interest rate of 6.25% at September 30, 2018) and matures on August 1, 2022.

We expect to incur significant expenses and increasing operating losses for the foreseeable future. We anticipate that our expenses will increase substantially as we:

• invest to further develop our product candidates, momelotinib, a small molecule inhibitor targeting JAK1, JAK2 and ACVR1; SRA737, a small molecule inhibitor of Chk1; and SRA141, a small molecule inhibitor targeting Cdc7;

• achieve development milestones that trigger payments due under certain agreements, including a milestone payment of $5.0 million that would be due to Gilead upon the dosing of the first patient in a registrational clinical trial for momelotinib and a milestone payment of $4.0 million that would be due to Carna upon dosing of the first patient in the first Phase 1 clinical trial for SRA141;

• acquire orin-license additional product candidates and technologies;

• develop additional product candidates;

• hire additional clinical, scientific, drug development and management personnel, as well as personnel to support any future commercialization efforts;

• invest in scaling our manufacturing capacity to support development and our global commercialization strategy;

• seek regulatory and marketing approvals for any product candidates that we may develop;

• ultimately establish a sales, marketing and distribution infrastructure to commercialize any drugs for which we may obtain marketing approval;

• defend against and resolve lawsuits or other legal issues;

• maintain, expand and protect our intellectual property portfolio; and

• add operational, financial and management information systems and personnel to continue to operate as a public company.

To fund our current operating plans, we will need to raise additional capital. Our existing cash and cash equivalents will not be sufficient for us to complete development of our product candidates and, if applicable, to prepare for commercializing any product candidate that may receive approval. Accordingly, we will continue to require substantial additional capital to continue our clinical development and potential commercialization activities; however, we believe that our existing cash and cash equivalents will be sufficient to fund our current operating plans through at least the next twelve months. We cannot assure you that we will ever be profitable or generate positive cash flow from operating activities. However, our forecast for the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement that involves risks and uncertainties, and actual results could vary materially. The amount and timing of our future funding requirements will depend on many factors, including the pace and results of our preclinical and clinical development efforts.

We plan to continue to fund our current operating plans’ needs through equity financings or other arrangements. To the extent that we raise additional capital through future equity financings, the ownership interest of our stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our existing common stockholders. If we raise additional funds through the issuance of debt securities, these securities could contain covenants that would restrict our operations. There can be no assurance that such additional financing, if available, can be obtained on terms acceptable to us. If we are unable to obtain such additional financing, we would need to reevaluate our future operating plans.

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Cash Flows

The following table summarizes our cash flows for the periods indicated:

	Nine Months Ended September 30,
	2018			2017
	(in thousands)
Cash used in operating activities	$	(35,142	)	$	(28,555	)
Cash used in investing activities		(59	)		(92	)
Cash provided by financing activities		51,129			27,445
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash		(36	)		6
Net increase (decrease) in cash, cash equivalents and restricted cash	$	15,892		$	(1,196	)

Cash Flows from Operating Activities

For the nine months ended September 30, 2018, cash used in operating activities of $35.1 million was attributable to a net loss of $39.1 million, partially offset by $5.0 million innon-cash charges and a net change of $1.1 million in our net operating assets and liabilities. Thenon-cash charges consisted primarily of $5.1 million in stock-based compensation. The change in net operating assets and liabilities was primarily attributable to an increase in prepaid expenses and other assets of $1.8 million and a decrease in accounts payable of $0.4 million, partially offset by an increase in accrued liabilities of $1.1 million.

For the nine months ended September 30, 2017, cash used in operating activities of $28.6 million was attributable to a net loss of $31.4 million, partially offset by $4.8 million innon-cash charges and a net change of $1.9 million in our net operating assets and liabilities. Thenon-cash charges consisted primarily of $4.5 million in stock-based compensation. The change in net operating assets and liabilities was primarily attributable to a $2.0 million payment to CRT Pioneer Fund (CPF) pursuant to our license agreement with CPF upon the successful transfer of the SRA737 clinical trials to us.

Cash Flows from Investing Activities

For the nine months ended September 30, 2018 and 2017, cash used in investing activities was primarily attributable to the purchase of property and equipment.

Cash Flows from Financing Activities

For the nine months ended September 30, 2018 and 2017, cash provided by financing activities of $51.1 million and $27.4 million, respectively, was primarily attributable to net proceeds received from the sale and issuance of our common stock upon ourfollow-on offerings. For the nine months ended September 30, 2018, cash provided by financing activities also included borrowing under the Loan Agreement of $5.0 million.

Contractual Obligations and Commitments

In August 2018, we entered into a Loan Agreement with SVB, pursuant to which we may obtain a loan of aggregate principal amount of up to $15.0 million. As of September 30, 2018, we borrowed $5.0 million under the first tranche. Estimated principal payments (excluding interest and final payment fee) under the Loan Agreement as of September 30, 2018 are $3.2 million within 1 to 3 years and $1.8 million within 3 to 5 years.

Off-Balance Sheet Arrangements

We do not currently engage inoff-balance sheet financing arrangements. In addition, we do not have any interest in entities referred to as variable interest entities, which includes special purpose entities and other structure finance entities.

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Critical Accounting Policies and Estimates

Our condensed consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles (GAAP). The preparation of these condensed consolidated financial statements requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue, costs and expenses, and related disclosures. These estimates form the basis for judgments we make about the carrying values of our assets and liabilities, which are not readily apparent from other sources. We base our estimates and judgments on historical experience and on various other assumptions that we believe are reasonable under the circumstances. On an ongoing basis, we evaluate our estimates and assumptions. Our actual results may differ from these estimates under different assumptions or conditions.

We believe that the assumptions and estimates associated with research and development expenses and stock-based compensation have the most significant impact on our condensed consolidated financial statements. Therefore, we consider these to be our critical accounting policies and estimates.

There have been no significant changes in our critical accounting policies and estimates as compared to the critical accounting policies and estimates disclosed in Management’s Discussion and Analysis of Financial Condition and Operations included in our Annual Report on Form10-K for the year ended December 31, 2017.

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

We are exposed to market risks in the ordinary course of our business. These risks primarily include interest rate sensitivities and foreign currency risk.

Interest Rate Sensitivity

We had cash and cash equivalents of $116.1 million as of September 30, 2018, which consisted primarily of bank deposits and money market funds. Our primary exposure to market risk is interest income sensitivity, which is affected by changes in the general level of U.S. interest rates. However, because of the short-term nature of the instruments in our portfolio, a sudden change in market interest rates would not be expected to have a material impact on our condensed consolidated financial condition or results of operations. We do not believe that our cash or cash equivalents have significant risk of default or illiquidity.

In addition, we had an outstanding balance of $5.0 million under our Loan Agreement as of September 30, 2018. Borrowings under the Loan Agreement bear interest at the greater of 6% or a floating per annum rate of 1.0% above the prime rate (for an interest rate of 6.25% at September 30, 2018). The effect of a hypothetical 10% change in interest rates would not have a material impact on our operating loss.

Foreign Currency Risk

Our condensed consolidated results of operations and cash flows are subject to fluctuations due to changes in foreign currency exchange rates. A substantial majority of our expenses are denominated in U.S. Dollars, with the remainder in Canadian Dollars, British Pounds and Australian Dollars. Our condensed consolidated results of operations and cash flow are, therefore, subject to fluctuations due to changes in foreign currency exchange rates and may be adversely affected in the future due to changes in foreign exchange rates. To date, we have not entered into any hedging arrangements with respect to foreign currency risk or other derivative instruments. The effect of a hypothetical 10% change in foreign currency exchanges rates applicable to our business would not have a material impact on our operating loss.

ITEM 4. CONTROLS AND PROCEDURES

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer and our Chief Financial Officer, have performed an evaluation of the effectiveness of the design and operation of our disclosure controls and procedures (as defined in Rules13a-15(e) and15d-15(e) under the Exchange Act, as amended) as of the end of the period covered by this Quarterly Report on Form10-Q. Based on that evaluation, our Chief Executive Officer and Chief Financial Officer have concluded that our disclosure controls and procedures were effective as of September 30, 2018 to ensure that information required to be disclosed by us in the reports we file or submit under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms, and that such information is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate to allow timely discussion regarding required disclosures.

Any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objective and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures.

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Changes in Internal Control over Financial Reporting

There were no changes in our internal control over financial reporting identified in connection with the evaluation required by Rule13a-15(d) and15d-15(d) of the Exchange Act that occurred during the quarter ended September 30, 2018 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

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PART II

ITEM 1. LEGAL PROCEEDINGS

On November 9, 2016, a purported securities class action lawsuit was filed in the United States District Court for the Southern District of New York against us and certain of our executive officers (the New York Lawsuit). The New York Lawsuit was brought by purported stockholders of our company seeking to represent a class consisting of stockholders who purchased stock between July 15, 2015 and June 6, 2016. The New York Lawsuit asserts claims under Sections 10(b) and 20(a) of the Exchange Act and seeks unspecified damages and other relief. On March 13, 2018, the United States District Court for the Southern District of New York granted the defendants’ motion to dismiss and entered a final judgment dismissing the New York Lawsuit with prejudice. Plaintiffs have filed an appeal. We believe that the claims in the New York Lawsuit are without merit and intend to defend the lawsuit vigorously. Due to the early stage of the litigation, we are unable to predict the outcome of this matter. However, at this point in time, we do not expect the outcome of these claims will have a material impact on our condensed consolidated financial statements.

On November 18, 2016, a purported securities class action lawsuit was filed in the Superior Court of the State of California for the County of San Mateo against us, certain of our executive officers and directors, and the underwriters for our initial public offering of our common stock. On February 9, 2017, a substantially identical putative class action suit was filed in the Superior Court of the State of California for the County of San Mateo asserting the same claims on behalf of the same putative class (the two California lawsuits together, the California Lawsuits). The California Lawsuits were brought by purported stockholders of our company seeking to represent a class consisting of stockholders who purchased stock pursuant to and/or traceable to our Registration Statement on FormS-1. The lawsuits assert claims under Sections 11 and 15 of the Exchange Act and seek unspecified damages and other relief. On August 1, 2018, all parties reached a mutually acceptable resolution to the California Lawsuits by way of a mediated settlement, which is subject to the parties’ execution of final settlement documents and the approval of the court. While we believe that the claims are without merit, we believe settlement will reduce the ultimate cost and distraction of further litigation. We do not expect our portion of the settlement amount to have a material impact on our condensed consolidated financial statements.

From time to time, we may become involved in various other claims and legal proceedings relating to claims arising out of our operations. We are not currently a party to any other legal proceedings that, in the opinion of our management, are likely to have a material adverse effect on our business. Regardless of outcome, litigation can have an adverse impact on us because of defense and settlement costs, diversion of management resources and other factors.

ITEM 1A. RISK FACTORS

Investing in our common stock involves a high degree of risk. You should carefully consider the risks described below, as well as the other information in this report, including our consolidated financial statements and the related notes and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” before deciding whether to invest in our common stock. The occurrence of any of the events or developments described below could harm our business, financial condition, results of operations and growth prospects. In such an event, the market price of our common stock could decline, and you may lose all or part of your investment.

Risks Related to Our Business and Industry

We have incurred net losses in every year since our inception and anticipate that we will continue to incur net losses for the foreseeable future.

We are a clinical stage hematology and oncology company with a limited operating history. Since inception, we have incurred significant operating losses. Our net losses were $39.1 million and $42.0 million for the nine months ended September 30, 2018 and the year ended December 31, 2017, respectively. As of September 30, 2018, we had an accumulated deficit of $663.1 million. Investment in hematology and oncology product development is highly speculative because it entails substantial upfront capital expenditures and significant risk that any potential product candidate will fail to demonstrate adequate efficacy or an acceptable safety profile, gain regulatory approval and become commercially viable. For example, in June 2016 we decided to suspend the development of our former lead product candidate PNT2258 after an interim analysis of data from a Phase 2 clinical trial of PNT2258 indicated only modest efficacy. We have no products approved for commercial sale and have not generated any revenue to date, and we continue to incur significant research and development and other expenses related to our ongoing operations. We expect to continue to incur significant losses for the foreseeable future, and we expect these losses to increase as we continue the development of our product candidates, momelotinib, SRA737 and SRA141, fund research and preclinical studies and clinical trials, seek to identify additional product candidates,in-license additional products or technologies, seek regulatory approval, prepare for potential commercialization and continue to operate as a public company.

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Even if we succeed in commercializing momelotinib, SRA737, SRA141 or any future product candidates we may acquire or develop, we will continue to incur substantial research and development and other expenditures to develop and market these and other product candidates. We may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. The size of our future net losses will depend, in part, on the rate of future growth of our expenses and our ability to generate revenue. Our prior losses and expected future losses have had and will continue to have an adverse effect on our stockholders’ equity and working capital.

Our business is highly dependent on the success of our product candidates, momelotinib, SRA737 and SRA141. If we are unable to successfully develop, obtain regulatory approval for and commercialize momelotinib, SRA737 and SRA141, or experience significant delays in doing so, our business will be materially harmed.

Our business and future success depends on our ability to successfully develop, obtain regulatory approval for and commercialize our product candidates, momelotinib, a Phase 3 product candidate, and SRA737 and SRA141, which are both at earlier stages of development. We recently invested financial resources to acquire momelotinib from Gilead. While momelotinib is a late-stage product candidate for which previous Phase 3 clinical trial data suggest promising safety and efficacy in patients who have an inadequate response to, progression on or are intolerant of ruxolitinib, it will require additional clinical testing, including at least one additional adequate and well-controlled Phase 3 clinical trial, before we can seek regulatory approval and begin commercialization, if it all. We have also invested effort and financial resources in the research and development of SRA737 and SRA141, and both SRA737 and SRA141 will require significant additional preclinical and clinical testing before we can seek regulatory approval and potentially generate any commercial sales, if at all. Before we can generate any revenue from sales of momelotinib, SRA737, SRA141, or any other product candidate, we must complete additional development activities, submit INDs or foreign equivalents, as well as marketing applications such as New Drug Applications (NDAs) or foreign equivalents, for regulatory review and approval in multiple jurisdictions, make substantial investments, obtain access to sufficient commercial manufacturing capacity and engage in significant marketing and commercial access efforts.

We cannot commercialize product candidates in the United States without first obtaining regulatory approval for the product candidates from the FDA. Similarly, we cannot commercialize product candidates outside of the United States without obtaining regulatory approval from similar regulatory authorities outside of the United States, such as the European Medicines Agency (EMA) in Europe and the Medicines and Healthcare products Regulatory Agency (MHRA) in the United Kingdom. Even if momelotinib, SRA737, SRA141 or another product candidate were to be approved by the FDA or foreign regulatory authorities, any approval might contain significant limitations related to use restrictions for specified age groups, warnings, precautions or contraindications, or may be subject to burdensome post-approval study or risk management requirements. If we are unable to obtain regulatory approval for momelotinib, SRA737 or SRA141 in one or more jurisdictions, or if any approval contains significant limitations, we may not be able to obtain sufficient funding or generate sufficient revenue to continue the development, marketing or commercialization of momelotinib, SRA737, SRA141 or any other product candidate that we may acquire or develop in the future. If competitive products developed by third parties show significant benefit in the cancer indications in which we are developing our product candidates, any planned supportive or primary registration trials may be delayed, altered, terminated or not initiated and our other product candidates may never receive regulatory approval. Our clinical development programs for our product candidates may also not receive regulatory approval if we have inadequate financial or other resources to advance these product candidates through the clinical trial process. Furthermore, even if we obtain regulatory approval for any of our product candidates, we will still need to develop sales, marketing and commercialization infrastructure, or collaborate with a third party for the commercialization of our product candidates, establish commercially viable pricing and obtain approval for coverage and adequate reimbursement from third parties, including government payors. If we are unable to successfully commercialize any of our product candidates, we may not be able to generate sufficient revenues to continue our business.

If we are unable to successfully develop and commercialize our product candidates or experience significant delays in doing so, our business will be materially harmed.

We will be required to demonstrate, to the satisfaction of regulatory authorities, through clinical trials that our product candidates are safe and effective for use in their target indications before we can obtain regulatory approval for their marketing and commercial sale.

We recently acquired from Gilead our lead product candidate momelotinib, a potent, selective and orally-bioavailable JAK1, JAK2 and ACVR1 inhibitor. Momelotinib has been investigated in two completed Phase 3 trials for the treatment of myelofibrosis and has demonstrated a potentially differentiated therapeutic profile encompassing anemia-related benefits, as well as achieving substantive spleen and constitutional symptom control. We are currently preparing for discussions with regulators to determine the approval path forward for momelotinib and anticipate reporting next steps in the first half of 2019.

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Pursuant to Clinical Trial Authorizations (CTAs) granted by the MHRA in the United Kingdom for SRA737, two Phase 1 trials were initiated in the United Kingdom which were transferred to us in January 2017, both of which have been amended to Phase 1/2 trials. We plan to continue our SRA737 development efforts by continuing these clinical trials, including through potential expansion into other countries, and potentially conducting additional preclinical and clinical studies to further our understanding of SRA737.

SRA141 has never been evaluated in a clinical trial. We recently successfully completed the IND filing process with the FDA for SRA141 and we are planning for a Phase 1/2 trial with this drug candidate in patients with colorectal cancer.

The success of our product candidates and any future product candidates that we may acquire or develop will depend on many factors, including, but not limited to, the following:

• successful completion of preclinical studies;

• successful translation of preclinical results in human clinical trials;

• successful enrollment in, and completion of, clinical trials that produce data which adequately demonstrate the product candidate’s benefit and risk profile;

• successful transfer of existing trials;

• receipt of marketing approvals from applicable regulatory authorities;

• establishment of clinical trial material and commercial manufacturing capabilities, or arrangements with third-party manufacturers and suppliers on commercially reasonable terms;

• effective patent and trade secret protection and regulatory exclusivity;

• establishment of a commercial sales team, if and when approved, whether alone or in collaboration with others;

• acceptance, if and when approved, by patients, the medical community and third-party payors;

• coverage and adequate reimbursement by third-party payors, including government payors;

• successful competition with other therapies;

• continued acceptable safety profile following approval;

• enforcement and protection of intellectual property rights and claims;

• achievement of desirable medicinal properties for the intended indications; and

• effective growth of an organization of scientists and businesspeople who can develop and commercialize our products, if approved, and technology.

If we do not achieve one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to successfully develop and commercialize our product candidates, which would materially harm our business.

If further preclinical development or clinical trials of momelotinib, SRA737, SRA141 or future product candidates that we may develop or acquire fail to demonstrate acceptable safety and efficacy or do not otherwise produce positive results, we may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of momelotinib, SRA737, SRA141 or future product candidates.

Before obtaining marketing approval from regulatory authorities, including the FDA, for the sale of our product candidates, we must complete preclinical development and then conduct extensive clinical trials to demonstrate the safety and efficacy of our product candidates in humans.

The outcome of preclinical testing and early clinical trials may not be predictive of the success of later preclinical testing and clinical trials, and interim results of a clinical trial do not necessarily predict final results. Many companies in the biotechnology industry have suffered significant setbacks in later-stage clinical trials after achieving positive results in early-stage development, and there is a high failure rate for product candidates proceeding through clinical trials. For example, in June 2016, we announced that we decided to suspend the development of our former lead product candidate PNT2258 after an interim analysis of data from a Phase 2 clinical trial of PNT2258 indicated only modest efficacy. We cannot, therefore, guarantee that we will be successful in obtaining the required efficacy and safety profile from momelotinib, SRA737 or SRA141. A failure of one or more preclinical studies or clinical trials can occur at any stage of testing.

We recently acquired from Gilead our lead product candidate momelotinib, a potent, selective and orally-bioavailable JAK1, JAK2 and ACVR1 inhibitor. Momelotinib has been investigated in two completed Phase 3 trials for the treatment of myelofibrosis and has demonstrated a potentially differentiated therapeutic profile encompassing anemia-related benefits, as well as achieving substantive spleen and constitutional symptom control. We are currently preparing for discussions with regulators to determine the approval path forward for momelotinib and anticipate reporting next steps in the first half of 2019. While we believe the safety and efficacy profile of momelotinib in patients who have an inadequate response to, progress on or are intolerant of ruxolitinib appears promising based on the prior Phase 3 trial results, the likely Phase 3 trial we plan to commence in those patients may not be successful. For example, in theSIMPLIFY-1 Phase 3 trial conducted by Gilead in ruxolitinib-naive patients, the key secondary endpoint of total symptom score,

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which we might choose to use as the primary endpoint in a potential future Phase 3 trial, was not met. We may also fail to observe meaningful anemia benefits in a potential future Phase 3 trial, which could reduce the potential future value of momelotinib as we believe an anemia benefit could potentially provide a competitive advantage over existing therapies.

We are currently conducting preclinical assessments and two Phase 1/2 clinical trials of SRA737, which we believe will further inform our clinical development plans and patient selection strategies. Both of the current clinical studies for SRA737 are being conducted in the United Kingdom, with one of the clinical studies also being conducted in Spain and currently under consideration for expansion into France. We believe we have completed all necessary preclinical activities to support a potential future IND submission for SRA737 to the FDA. However, we have not yet discussed our plans for any IND submission with the FDA, and if pursued, we may receive feedback from the FDA that delays the submission or clearance of any IND.

SRA141 has never been evaluated in a clinical trial. We recently successfully completed the IND filing process with the FDA for SRA141 and we are planning for a Phase 1/2 trial with this drug candidate in patients with colorectal cancer.

Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and even if the trials are successfully completed, we cannot guarantee that the FDA or foreign regulatory authorities will interpret the results as we do, and more trials could be required before we submit our product candidates for approval. Many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their products. To the extent that the results of our studies and trials are not satisfactory to the FDA or foreign regulatory authorities for support of a marketing application, approval of our product candidates may be significantly delayed, or we may be required to expend significant additional resources, which may not be available to us, to conduct additional trials in support of potential approval of our product candidates.

We may experience numerous unforeseen events during, or as a result of, preclinical studies and clinical trials that could delay or prevent our ability to receive marketing approval or commercialize our product candidates, including, but not limited to:

• undesirable side effects or other unexpected characteristics of our product candidates, causing us or our investigators, regulators or institutional review boards (IRBs) to suspend or terminate the trials;

• regulators or IRBs may not authorize us or our investigators to initiate a clinical trial, conduct a clinical trial at a prospective trial site, or amend a clinical trial;

• government or regulatory delays and changes in regulatory requirements, policy and guidelines;

• delays in reaching or failure to reach agreement on acceptable clinical trial contracts or clinical trial protocols with prospective trial sites and contract research organizations (CROs), or failure by such CROs or trials sites to carry out the clinical trial in accordance with the terms of our agreements with them;

• negative or inconclusive results of preclinical studies or clinical trials;

• decision by us to conduct additional preclinical studies or clinical trials or abandon product development programs;

• a higher number of patients required for clinical trials, slower than expected enrollment, greater than expected competition for patients or higher than expected drop out rates;

• clinical sites electing to terminate their participation in one of our clinical trials, which would likely have a detrimental effect on subject enrollment;

• failure of third-party contractors to comply with regulatory requirements or meet their contractual obligations to us in a timely manner, or at all;

• inability or unwillingness of patients or medical investigators to follow our clinical trial protocols;

• suspension or termination of clinical trials for various reasons, including unacceptable health risks;

• imposition of a clinical hold for safety reasons or following an inspection of our clinical trial operations or site by the FDA or foreign regulatory authorities;

• greater than expected cost of clinical trials;

• insufficient supply or quality of product candidates or other materials necessary to conduct clinical trials;

• delays or additional costs as a result of the United Kingdom’s decision to leave the European Union and resulting need to decouple the United Kingdom’s regulatory system from that of the European Union; and

• revision of legal or regulatory requirements for approving our product candidates.

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If we are required to conduct additional preclinical studies or clinical trials or other testing of our product candidates beyond those that we currently contemplate, if we are unable to successfully complete preclinical studies and clinical trials of our product candidates or other testing, or if the results of these studies, trials or tests do not reflect an acceptable safety or efficacy profile, we may:

• be delayed or unable to submit an IND in the United States, or additional CTAs or equivalents in other countries;

• not have the permission of the FDA or other health authorities to commence clinical trials, or may have a clinical hold placed on one or more of our clinical trials;

• be delayed in obtaining marketing approval;

• not obtain marketing approval at all;

• obtain marketing approval in some countries and not in others;

• obtain approval for indications or patient populations that are not as broad as intended or desired;

• obtain approval with labeling that includes significant use or distribution restrictions or safety warnings, including boxed warnings;

• be subject to additional post-marketing testing requirements; or

• have the product removed from the market after obtaining marketing approval.

Product development costs will also increase if we experience delays in testing or marketing approvals. We do not know whether any preclinical studies or clinical trials will continue as planned, will need to be restructured or will be completed on schedule, or at all. Significant preclinical studies and clinical trial delays also could allow our competitors to bring products to market before we do and could impair our ability to successfully commercialize our product candidates, any of which may harm our business and results of operations.

Our preclinical and clinical development for SRA737 is focused on the development of targeted therapeutics for genetically-defined cancers, which is a rapidly evolving area of science, and the approach we are taking to develop drugs may not lead to marketable products. It is feasible that genetically-based patient selection strategies might also be employed in our SRA141 development programs.

The discovery and development of targeted therapeutics for genetically-defined cancers, including patients whose tumors harbor the applicable genetic alterations that we believe contribute to cancer, is an emerging field, and the scientific discoveries that form the basis for our efforts to develop genetically-selected product candidates are relatively new. The scientific evidence to support the feasibility of developing product candidates based on these discoveries is both preliminary and limited. Additionally, we may consider approaches such as a basket study in which enrollment is focused on a compilation of different tumor types that share a similar genetic signature. We cannot be sure that regulatory authorities, including the FDA and the EMA, will accept our trial designs or that we will be able to obtain approval for our product candidates.

We are currently developing our SRA737 product candidate for certain genetically-defined subpopulations of the general treated cancer population, and we are now enrolling selected patients into our Monotherapy andLow-Dose Gemcitabine combination studies of SRA737, based on genetic alterations in their tumors or other factors such as histology. In order to obtain marketing approval for SRA737 in the treatment of genetically-defined tumors and cancers, we will need to, among other things, demonstrate to the satisfaction of regulatory authorities that those genetic alterations have predictive clinical utility. We have started to apply our genetic selection criteria to patients in our Monotherapy and ourLow-Dose Gemcitabine combination clinical trials, and our approach may change based on our evolving knowledge of the field and on data obtained in our preclinical research and ongoing clinical trials. The goal of our genetic screening is to enroll patients who we believe have the highest probability of responding to the product candidate in order to show compelling evidence of clinical efficacy. Successful identification of patients is dependent on several factors, including, potentially, achieving certainty as to how specific genetic alterations respond to our product candidates and developing companion diagnostics to identify such genetic alterations as appropriate. For example, although we believe, based on scientific and medical literature, and preclinical research, that we have identified certain types and combinations of genetic alterations hypothesized to confer sensitivity to Chk1 inhibition that may be predictive of response to SRA737, we have only recently begun to assess activity of SRA737 in humans and have not discussed the validity of our genetic selection criteria with regulatory authorities, including MHRA, FDA or EMA.

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Our genetic selection strategy for SRA737 uses a novel algorithm and is not yet validated as predictive of clinical utility.

In order to obtain marketing approval for SRA737 in patients with genetic alterations hypothesized to confer sensitivity to Chk1 inhibition we will need to, among other things, demonstrate to the satisfaction of regulatory authorities that those genetic alterations have predictive clinical utility. It may be difficult for us to demonstrate the predictive clinical utility of our genetic selection criteria, which select for patients that have various combinations of genetic alterations across multiple gene panels. Although regulatory authorities, including FDA, have approved therapies for use in conjunction with companion diagnostic tests that aid in selecting patients for treatment based on genetic markers, to our knowledge neither the FDA nor the EMA has granted marketing approval for a therapy that requires the use of a companion diagnostic that uses broad gene panel testing to select for patients with various combinations of genetic alterations. The scientific evidence to support the feasibility of developing product candidates based on our selection criteria is both preliminary and limited. We have not discussed the validity of our genetic selection criteria with regulatory authorities, and we cannot be sure that regulatory authorities, including the FDA and EMA, will accept our genetic selection criteria.

Furthermore, we cannot be certain that the patient populations in our trials will be large enough to allow us to successfully determine efficacy of our product candidates, commercialize our product candidates, and achieve profitability. If we are unable to enroll sufficient numbers of patients whose tumors harbor the applicable genetic alterations, or if our product fails to work as we expect, or if we are unable to demonstrate the predictive clinical utility of our genetic selection criteria, our ability to assess and demonstrate the therapeutic effect of our product candidate(s) could be compromised, resulting in longer development times, larger trials, and a greater likelihood of not obtaining regulatory approval for our product candidates. In addition, regulatory authorities may require that we study our product candidates in clinical trials specific for a given tumor (i.e., tissue) type and this may result in increased time and cost. Even if our product candidates demonstrate efficacy in a particular tumor type, we cannot guarantee that any product candidate will behave similarly in multiple or all tumor types, and we may be required to obtain separate regulatory approvals for each tumor type we intend a product candidate to treat. We do not know if our approach will be successful, and if our approach is unsuccessful, our business will suffer.

Failure to successfully validate, develop and obtain regulatory approval for companion diagnostics for SRA737 and our other product candidates could harm our drug development strategy and operational results.

In any pivotal clinical trials of SRA737 we anticipate the potential requirement to screen and identify patients with specific genetic alterations who may derive meaningful benefit, as we have begun to do in our Monotherapy andLow-Dose Gemcitabine combination studies of SRA737. To achieve this, our product development programs for SRA737 and marketing approvals will be dependent on the development and commercialization of a companion diagnostic by us or by third party collaborators. It is feasible that a companion diagnostic might also be required in our SRA141 and other potential development programs.

Companion diagnostics are developed in conjunction with clinical programs for the associated product and are subject to regulation as medical devices by the FDA and comparable regulatory authorities, and, to date, the FDA has required premarket approval of all companion diagnostics for cancer therapies. Generally, when a companion diagnostic is essential to the safe and effective use of a therapeutic product, the FDA requires that the companion diagnostic be approved before or concurrent with approval of the therapeutic product and before a product can be commercialized. The approval of a companion diagnostic as part of the therapeutic product’s labeling limits the use of the therapeutic product to only those patients who express the specific genetic alteration that the companion diagnostic was developed to detect.

If FDA or a comparable regulatory authority requires approval of a companion diagnostic for any of our product candidates, whether before or after the product candidate obtains marketing approval, we, and/or third-party collaborators, may encounter difficulties in developing and obtaining approval for these companion diagnostics. Any delay or failure by us or third-party collaborators to develop or obtain regulatory approval of a companion diagnostic could delay or prevent approval or continued marketing of our related product candidates.

We may also experience delays in developing a sustainable, reproducible and scalable manufacturing process for the companion diagnostic or in transferring that process to commercial partners or negotiating insurance reimbursement plans, all of which may prevent us from completing our clinical trials or commercializing our products on a timely or profitable basis, if at all.

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We have acquired or licensed our product candidates from third parties that had already conducted or were in the process of conducting preclinical studies or clinical trials with our product candidates. We may discover that development efforts of third parties, including but not limited to historical studies and trials conducted by third parties, did not comply with all applicable rules and regulations, and we may experience difficulties or delays in assuming responsibility for or completing such ongoing or previously completed clinical development activities. Our acquisition of momelotinib has resulted in us being required to take over responsibility for conducting ongoing momelotinib trials. Further development and commercialization of momelotinib will require significant financial and operational resources from us.

Prior to our acquisition of momelotinib and licensing of SRA737, third parties had been responsible for all development activities for such product candidates, including drug process, preclinical and clinical development activities, submission of CTAs and INDs, development of the trial protocols, establishment and management of clinical and safety databases, submission of a pediatric investigation plan (PIP), and other activities. Although we believe the historical development activities were conducted in accordance with applicable rules and regulations in material respects, we cannot assure you that we will not discover inaccuracies or noncompliance in prior development activities that have an adverse effect on the future development of momelotinib or SRA737. For example, we will need to modify the PIP Gilead agreed to for momelotinib with European Union’s regulatory authorities and conduct the pediatric studies, unless a waiver or deferral is granted, before we can submit a marketing authorization application. Similarly, we will need to submit a pediatric study plan to FDA and conduct the pediatric study, unless a waiver or deferral is granted, prior to submission of an NDA. In addition, a foreign regulatory authority that inspected aSIMPLFY-1 investigational site and CRO concluded that the clinical trial at that site was not conducted in accordance with good clinical practices (GCPs). We do not know what effect, if any, this finding will have on review of any future marketing applications by the FDA or foreign regulatory authorities.

In connection with our acquisition of momelotinib, we assumed the responsibility for all currently ongoing clinical studies with momelotinib following a transition period, including related expenses and manufacturing and regulatory activities, which were previously managed and funded by Gilead. This includes responsibility for the ongoing Phase 3 extended access study, which provides extended access of momelotinib in certain patients enrolled in Gilead sponsored studies, who are currently receiving treatment with momelotinib and have not experienced progression of disease. If we are unable to successfully assume the responsibilities of these trials, if we experience delays in doing so, or if we encounter additional difficulties or delaysdue to deficiencies in the assumed trials prior to our acquisition of momelotinib, the development of momelotinib may be delayed or suspended. Further, extended access programs provide supportive safety information for regulatory review. Any adverse events or reactions experienced by subjects in the extended access program may be attributed to momelotinib and may limit our ability to obtain regulatory approval with labeling that we consider desirable, or at all.

From time to time we may amend the clinical protocols for our product candidates to include additional objectives that could yield important scientific information critical to our overall development strategy. The protocol amendment process requires review and approval by several review bodies, including regulatory agencies and scientific, regulatory and ethics boards. These protocol amendments may not be accepted by the review bodies in the form submitted, or at all, which may delay our planned enhancements to the clinical development and/or limit or change the type of information we may gather from those studies.

We have received approval from the MHRA for amendments to theSRA737-01 Monotherapy and theSRA737-02Low-Dose Gemcitabine combination clinical trial protocols. These amendments are designed to enhance the ongoing clinical trials including by expanding the enrollment of patients we predict may be most likely to benefit from SRA737, based on specific genetic alterations in their tumors. These amendments may provide us with the opportunity to more accurately and widely evaluate SRA737’s activity across a number of distinct cancer indications and genetic alterations. If the MHRA, FDA, EMA, an ethics committee or scientific review board, or another regulatory authority objects to or otherwise does not accept or approve any future protocols or protocol amendments or requires us to further modify trial protocols, our related planned clinical development program may be delayed or suspended and/or we may not be able to gather information we think would be useful to advance development of momelotinib, SRA737, SRA141, or other product candidates, and our development programs may be adversely affected.

For example, we are currently pursuing a development program for SRA737 that relies upon a seamless trial design, which presents additional risks compared to traditional three-phase development programs. In a seamless design, an early phase trial assesses clinical activity of a product candidate in a broad range of subjects, and the trial is later expanded to include additional cohorts (for example, including cohorts with entry criteria based in part on the characteristics of the subjects in whom clinical activity was observed during the initial period of the trial, such as genetic markers). The protocol may also be amended with regard to the expansion cohorts to focus, for example, on different treatment endpoints, different doses, or other trial parameters. Through this iterative process, the traditionally distinct Phase 1, Phase 2, and Phase 3 trials are combined into one or more adaptive, or combined-phase, trials.

Whereas the traditional three-phase development program provides for communication with regulatory agencies between each phase, and for the development and review of statistical plans for trials in each phase, a seamless design may require more frequent and fluid communication with regulators to vet the iterative protocol amendments, and new statistical plans may be necessary for each expansion cohort. If we are unable to receive timely or complete feedback to our frequent amendments to protocols and statistical plans from regulatory authorities, our development programs may be delayed and/or we may be required to conduct additional clinical trials.

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If we fail to obtain additional capital, we may be unable to acquire additional product candidates and complete the development and commercialization of our product candidates.

We expect to spend substantial capital to acquire additional product candidates and advance momelotinib, SRA737 and SRA141 in preclinical and clinical development, seek regulatory approvals for our product candidates, establish a commercial sales force to market and manufacture products, if any, that are approved for commercial sale. We also incur significant additional compliance and administrative costs as a result of operating as a public company.

Our future capital requirements will depend on many factors, including, but not limited to:

• the progress and results of our planned preclinical studies and clinical trials;

• the scope, progress, results and costs of product candidate discovery, preclinical development, laboratory testing and clinical trials for our future product candidates;

• the costs, timing and outcome of regulatory review of momelotinib, SRA737, SRA141 and any future product candidates;

• the costs of future commercialization activities, including drug sales, marketing, manufacturing and distribution, for any of our product candidates for which we receive marketing approval, to the extent that such sales, marketing, manufacturing and distribution are not the responsibility of any collaborator;

• the extent to which we acquire orin-license other drugs and technologies;

• our ability to establish and maintain collaborations on favorable terms, if at all;

• the success of any collaborations that we may enter into with third parties;

• the timing and amount of milestone and royalty payments;

• the amount of revenue, if any, received from commercial sales of our product candidates, should any of our drug candidates receive marketing approval; and

• the costs of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending intellectual property-related claims.

Identifying potential product candidates and conducting preclinical studies and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to obtain marketing approval and achieve drug sales. In addition, our product candidates, if approved, may not achieve commercial success. Our commercial revenues, if any, will be derived from sales of our product candidates, if approved, which we do not expect to be commercially available for many years, if at all. Accordingly, we will need to continue to rely on additional financing to achieve our business objectives.

We cannot be certain that additional funding will be available on acceptable terms, or at all. We have no committed source of additional capital and if we are unable to raise additional capital in sufficient amounts or on terms acceptable to us, we may have to significantly delay, scale back or discontinue the development or commercialization of our product candidates or other research and development initiatives. We could be required to seek collaborators for our product candidates at an earlier stage than otherwise would be desirable or on terms that are less favorable than might otherwise be available or relinquish or license on unfavorable terms our rights to our product candidates in markets where we otherwise would seek to pursue development or commercialization ourselves. We also may be unable to acquire additional promising product candidates.

If we encounter difficulties enrolling patients in our clinical trials, our clinical development activities could be delayed or otherwise adversely affected.

We may experience difficulties in patient enrollment in our clinical trials for a variety of reasons. The timely completion of clinical trials in accordance with their protocols depends, among other things, on our ability to enroll a sufficient number of patients who remain in the trial until its conclusion. The enrollment of patients depends on many factors, including, but not limited to:

• the number and size of clinical trials for other product candidates in the same therapeutic area that are currently in clinical development, and our ability to compete with such trials for patients and clinical trial sites;

• the patient eligibility criteria defined in the protocols;

• the size of the specific patient populations such as those whose tumors harbor the applicable genetic mutations, if required or other defined subsets of a larger patient population;

• the risk that disease progression will result in death or clinical deterioration before the patient can enroll in clinical trials or before sufficient data has been collected such that the patient contributes no meaningful information for the clinical trial in which the patient is enrolled;

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• the proximity and availability of clinical trial sites for prospective patients;

• the design of the trials;

• our ability to recruit clinical trial investigators with the appropriate competencies and experience;

• our ability to obtain and maintain patient consents; and

• the risk that patients enrolled in clinical trials will drop out of the trials before completion.

Our clinical trials compete with other clinical trials for product candidates that are in the same therapeutic areas as our product candidates. This competition reduces the number and types of patients and qualified clinical investigators available to us, because some patients who might have opted to enroll in our trials may instead opt to enroll in a trial being conducted by one of our competitors or clinical trial sites may not allow us to conduct our clinical trial at such site if competing trials are already being conducted there. Since the number of qualified clinical investigators is limited, we expect to conduct some of our clinical trials at the same clinical trial sites that some of our competitors use, which will reduce the number of patients who are available for our clinical trials in such clinical trial site. We may also encounter difficulties finding a clinical trial site at which to conduct our trials. Moreover, because our product candidates are experimental, potential patients and their doctors may be inclined to use conventional therapies, such as chemotherapy, radiation and other approved therapies, rather than enroll patients in any one of our clinical trials.

Delays in patient enrollment may result in increased costs or may affect the timing or outcome of our planned clinical trials, which could prevent completion of these clinical trials and adversely affect our ability to advance the development of our product candidates or any future product candidates we may develop.

We may expend our limited resources to pursue a particular product candidate and fail to capitalize on product candidates that may later prove to be more profitable or for which there is a greater likelihood of success. In addition, we may intentionally halt or terminate programs in order to conserve capital and focus on our remaining program or programs, which may increase our reliance on those programs to be successful.

Because we have limited financial and managerial resources, we focus our research and development efforts on certain selected product candidates. As a result, we may advertently or inadvertently forgo or delay pursuit of opportunities with other product candidates that later prove to have greater commercial potential. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. Our spending on current and future research and development programs and product candidates for specific indications may not yield any commercially viable product candidates. In addition, if we halt or terminate programs in order to conserve capital and focus on our remaining program or programs, it may increase our reliance on the success of such programs and raise our exposure to the risk of failure among any of our programs.

The manufacture of momelotinib, SRA737 and SRA141 requires outsourced, custom manufacturing and we may encounter difficulties in production, particularly with respect to formulation, process development or scaling up of our manufacturing capabilities. If our third-party manufacturers encounter such difficulties, our ability to provide supply of our product candidates for preclinical studies, clinical trials or our products for patients, if approved, could be delayed or stopped, or we may be unable to maintain a commercially viable cost structure.

As product candidates are developed, it is common that various aspects of the development program, such as manufacturing methods, are altered along the way in an effort to optimize processes and results. Such changes carry the risk that they will not achieve these intended objectives, and any of these changes could cause our product candidates to perform differently and affect the results of planned preclinical studies or future clinical trials.

Currently, SRA737 and SRA141 are manufactured using unoptimized processes by third-party manufacturers, and momelotinib is manufactured using an optimized drug substance process by third-party manufacturers. Although we have secured sufficient quantities of drug substance and drug product to supply our current momelotinib program, starting with the planned potential Phase 3 trial of momelotinib, we will need to obtain additional supplies from third-party manufacturers that we have engaged, or expect to engage. In addition, we may need to develop a pediatric formulation for momelotinib in the future. Although we are working to develop commercially viable manufacturing processes, doing so is a difficult and uncertain task, and there are risks associated with scaling to the level required for advanced clinical trials or commercialization, including, among others, cost overruns, potential problems with process scale up or formulation, process reproducibility, stability issues, lot consistency and timely availability of reagents or raw materials.

Any of these challenges could delay completion of preclinical studies or clinical trials, require bridging studies or trials, or the repetition of one or more studies or trials, increase development costs, delay approval of our product candidates, impair commercialization efforts, increase our cost of goods and have an adverse effect on our business, financial condition, results of operations and growth prospects.

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Our reliance on third-party manufacturing partners or suppliers may cause our supply of research and development, preclinical and clinical development materials to become limited or interrupted or fail to be of satisfactory quantity or quality.

We do not have any manufacturing facilities or personnel. We currently rely, and expect to continue to rely, on third parties for the manufacture and supply of preclinical study and clinical trial materials in relation to momelotinib, SRA737 and SRA141, including materials for any combination trials that we may undertake, and any future potential product candidates that we may develop for preclinical and clinical testing, as well as for commercial manufacture if our product candidates receive marketing approval. We have engaged, or expect to engage, third-party manufacturers to obtain materials and consumables necessary for the manufacture of momelotinib, SRA737 and SRA141.

We may be unable to establish further agreements with third-party manufacturers and suppliers or to do so on acceptable terms. Even if we are able to establish agreements with third-party manufacturers, reliance on third-party manufacturers and suppliers entails additional risks, including, but not limited to:

• reliance on the third party for sufficient quantity and quality;

• the possible breach of the manufacturing or supply agreement by the third party;

• failure to manufacture or supply the product according to our specifications;

• failure to manufacture or supply the product according to our schedule or at all;

• misappropriation of our proprietary information, including our trade secrets andknow-how;

• the possible termination or nonrenewal of the agreement by the third party at a time that is costly or inconvenient for us; and

• reliance on the third party for regulatory compliance, quality assurance and safety reporting.

While we require our third-party manufacturers and suppliers to comply with current good manufacturing practices (cGMPs) in the manufacture of clinical trial materials and commercial supply, should we obtain approval of any product candidates, these third-party manufacturers and suppliers may cease to continue to comply with cGMPs—which are FDA requirements for ensuring product quality control—or similar regulatory requirements outside the United States. Our contract manufacturers and suppliers are subject to continual review and periodic inspections to assess compliance with cGMPs. Accordingly, although we are not involved in theday-to-day operations of our contract manufacturers or suppliers, we are ultimately responsible for ensuring that our products and product candidates, and any other materials that may be used in our preclinical or clinical studies or trials, are manufactured or supplied in accordance with cGMPs. Therefore, we and others with whom we work must continue to expend time, money and effort in all areas of regulatory compliance, including manufacturing, production, quality control and quality assurance. Our failure, or the failure of our third-party manufacturers or suppliers, to comply with applicable regulations could result in our product candidates not being approved or sanctions being imposed on us, including fines, injunctions, civil penalties, delays, suspension or withdrawal of approvals, license revocation, seizures or recalls of product candidates or approved products, operating restrictions and criminal prosecutions, any of which could significantly and adversely affect supplies of our medicines and harm our business and results of operations.

Any performance failure on the part of our existing or future manufacturers or suppliers, or any interruption or poor yield or quality of manufactured or supplied materials, could delay development or marketing approval. We do not currently have arrangements in place for redundant supply. If any one of our current contract manufacturers or suppliers cannot perform as agreed, we may be required to replace that manufacturer or supplier. Although we believe that there are several potential alternative manufacturers or suppliers who could manufacture or supply our product candidates or the materials for trials relating to product candidates, we may incur added costs and delays in identifying and qualifying any such replacement.

If our third-party manufacturers or suppliers use hazardous and biological materials in a manner that causes injury or violates applicable law, we may be liable for damages. Our research and development activities involve the controlled use of potentially hazardous substances, including chemical and biological materials, by our third-party manufacturers or suppliers. Our manufacturers and suppliers are subject to federal, state and local laws and regulations in the United States governing the use, manufacture, storage, handling and disposal of medical and hazardous materials. Although we believe that our manufacturers’ and our suppliers’ procedures for using, handling, storing and disposing of these materials comply with legally prescribed standards, we cannot completely eliminate the risk of contamination or injury resulting from medical or hazardous materials. As a result of any such contamination or injury, we may incur liability or local, city, state or federal authorities may curtail the use of these materials and interrupt our business operations. In the event of an accident, we could be held liable for damages or penalized with fines, and the liability could exceed our resources. We do not have any insurance for liabilities arising from medical or hazardous materials. Compliance with applicable environmental laws and regulations is expensive, and current or future environmental regulations may impair our research, development and production efforts, which could harm our business, prospects, financial condition or results of operations.

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Thus, our current and anticipated future dependence upon others for the manufacture or supply of our product candidates or related medicines and materials may adversely affect our development timeline, our future profit margins or our ability to commercialize any product candidates that receive marketing approval on a timely and competitive basis.

Our product candidates may cause undesirable side effects or have other properties that could halt their development, prevent their regulatory approval, limit their commercial potential or result in significant negative consequences.

It is possible that the FDA or foreign regulatory authorities may not agree with any assessment of the safety profile of our product candidates. Undesirable side effects caused by any of our product candidates could cause us, IRBs, our CROs, the FDA or foreign regulatory authorities to interrupt, delay or discontinue development and could result in a clinical hold on any clinical trial, or the denial of regulatory approval by the FDA or foreign regulatory authorities for any or all targeted indications. This, in turn, could prevent us from commercializing our product candidates and generating revenues from their sale. In addition, if any of our products cause serious or unexpected side effects or are associated with other safety risks after receiving marketing approval, a number of potential significant negative consequences could result, including, but not limited to:

• regulatory authorities may withdraw their approval of this product;

• we may be required to recall the product, change the way it is administered, conduct additional clinical trials or change the labeling of the product;

• the product may be rendered less competitive and sales may decrease;

• our reputation may suffer generally both among clinicians and patients;

• we may be exposed to potential lawsuits and associated legal expenses, including costs of resolving claims;

• regulatory authorities may require certain labeling statements, such as warnings or contraindications or limitations on the indications for use, or impose restrictions on distribution in the form of a Risk Evaluation and Mitigation Strategy (REMS) in connection with approval, if any; or

• we may be required to change the way the product is administered or conduct additional preclinical studies or clinical trials.

If preliminary data demonstrate that any of our product candidates has an unfavorable safety profile and is unlikely to receive regulatory approval or be successfully commercialized, we may voluntarily suspend or terminate future development of such product candidate.

Any one or a combination of these events could prevent us from obtaining approval and achieving or maintaining market acceptance of the affected product or could substantially increase the costs and expenses of commercializing the product candidate, which in turn could delay or prevent us from generating significant revenues from the sale of the product.

We do not have our own laboratory facilities. We rely on third parties to conduct our preclinical studies and clinical trials. If these third parties do not successfully carry out their contractual duties or meet expected deadlines, we may not be able to obtain regulatory approval of or commercialize our product candidates.

We do not have our own laboratory facilities. We depend upon independent investigators and collaborators, such as universities, medical institutions, CROs and strategic partners to conduct our preclinical studies and clinical trials. We expect to have to negotiate budgets and contracts with CROs and trial sites, which may result in delays to our development timelines and increased costs. We will rely heavily on these third parties over the course of our preclinical studies and clinical trials, and we control only certain aspects of their activities. For example, the CRO of our current ongoing clinical trials of SRA737 was recently acquired by a large global CRO and there may be interruptions in service during their integration. Nevertheless, we are responsible for ensuring that each of our studies is conducted in accordance with applicable protocol, legal, regulatory and scientific standards, and our reliance on third parties does not relieve us of our regulatory responsibilities. We and these third parties are required to comply with GCPs and Good Laboratory Practices (GLPs), which are regulations and guidelines enforced by the FDA and comparable foreign regulatory authorities for clinical andnon-clinical research intended to support a submission or application to FDA or the comparable foreign authority. Regulatory authorities enforce these requirements through periodic inspections of trial sponsors, principal investigators and trial sites. If we or any of these third parties fail to comply with applicable requirements, the data generated in our studies and trials may be deemed unreliable and the FDA or foreign regulatory authorities may require us to perform additional studies or trials before approving our marketing applications. We cannot assure you that, upon inspection, such regulatory authorities will determine that any of our studies or trials comply with the GCP or GLP requirements. In addition, our studies and trials must be conducted with drug product produced under cGMPs. Our failure or any failure by these third parties to comply with these regulations or to recruit a sufficient number of patients may require us to repeat studies or trials, which would delay the regulatory approval process. Moreover, our business may be implicated if any of these third parties violates federal or state fraud and abuse or false claims laws and regulations or healthcare privacy and security laws.

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Any third parties conducting our preclinical studies and clinical trials will not be our employees and, except for remedies available to us under our agreements with such third parties, we cannot control whether or not they devote sufficient time and resources to our ongoing preclinical, clinical and nonclinical programs. These third parties may also have relationships with other commercial entities, including our competitors, for whom they may also be conducting clinical studies or other drug development activities, which could affect their performance on our behalf. If these third parties do not successfully carry out their contractual duties or obligations or meet expected deadlines, if they need to be replaced or if the quality or accuracy of the data they obtain is compromised due to the failure to adhere to our protocols or regulatory requirements or for other reasons, our studies and trials may be extended, delayed or terminated and we may not be able to complete development of, obtain regulatory approval of or successfully commercialize our product candidates. As a result, our financial results and the commercial prospects for our product candidates would be harmed, our costs could increase and our ability to generate revenue could be delayed.

We may be required to suspend, repeat or terminate our clinical trials if they are not conducted in accordance with regulatory requirements, the results are negative or inconclusive, or the trials are not well-designed.

Regulatory agencies, IRBs or data safety monitoring boards may at any time recommend the temporary or permanent discontinuation of our clinical trials or request that we cease using investigators in the clinical trials if they believe that the clinical trials are not being conducted in accordance with applicable regulatory requirements, or that they present an unacceptable safety risk to participants. Clinical trials must be conducted in accordance with GCPs, or other applicable foreign regulatory authority guidelines. Clinical trials are subject to oversight by the FDA, foreign regulatory authorities and IRBs at the study sites where the clinical trials are conducted. In addition, clinical trials must be conducted with product candidates produced in accordance with applicable cGMPs. Clinical trials may be suspended by the FDA, foreign regulatory authorities, or us for various reasons, including, but not limited to:

• deficiencies in the conduct of the clinical trials, including failure to conduct the clinical trial in accordance with regulatory requirements or clinical protocols;

• deficiencies in the clinical trial operations or trial sites;

• the product candidate may have unforeseen adverse side effects;

• deficiencies in the trial designs necessary to demonstrate efficacy;

• fatalities or other adverse events (AEs) arising during a clinical trial due to medical problems that may or may not be related to clinical trial treatments;

• the product candidates may not appear to be more effective than current therapies; or

• the quality or stability of the product candidates may fall below acceptable standards.

Although we have never been asked by a regulatory agency, IRB or data safety monitoring board to temporarily or permanently discontinue a clinical trial, if we elect or are forced to suspend or terminate a clinical trial of any of our current or future product candidates, the commercial prospects for that product will be harmed and our ability to generate product revenue from that product may be delayed or eliminated. For example, in June 2016 we decided to suspend the development of our former lead product candidate PNT2258 after an interim analysis of data from a Phase 2 clinical trial on PNT2258 indicated only modest efficacy. Furthermore, any of these events could prevent us or our partners from achieving or maintaining market acceptance of the affected product and could substantially increase the costs of commercializing our product candidates and impair our ability to generate revenue from the commercialization of these products either by us or by our collaboration partners.

Even if we receive regulatory approval to market our product candidates, the market may not be receptive to our products.

Even if we obtain regulatory approval for momelotinib or one of our other product candidates, they may not gain market acceptance among physicians, patients, healthcare payors and/or the medical community. We believe that the degree of market acceptance will depend on a number of factors, including, but not limited to:

• timing of market introduction of competitive products;

• safety and efficacy of our products;

• prevalence and severity of any side effects;

• potential advantages or disadvantages over alternative treatments;

• strength of marketing and distribution support;

• price of our products, both in absolute terms and relative to alternative treatments;

• availability of coverage and reimbursement from government and other third-party payors; and

• sequencing of available products.

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If our product candidates are approved for commercial sale and fail to achieve market acceptance, we may not be able to generate significant revenue or achieve or sustain profitability.

We may be subject to requests for access to our product candidates. Demand for compassionate use of our unapproved therapies could strain our resources, delay our drug development activities, negatively impact our regulatory approval or commercial activities, and result in losses.

We are developing product candidates, including momelotinib, to treat life-threatening illnesses for which there are currently limited therapeutic options. Other companies in our field have been the target of campaigns requesting access to unapproved drugs. If we experience similar request for access campaigns, we may experience significant disruption to our business which could result in losses. We are a small company with limited resources, and any unanticipated trials or access programs resulting from requests for access could deplete our drug supply, increase our capital expenditures, and otherwise divert our resources from our primary goals.

In addition, legislation referred to as “Right to Try” laws have been introduced at the local and national levels, which are intended to give patients access to unapproved therapies. New and emerging legislation regarding expanded access to unapproved drugs for life-threatening illnesses could negatively impact our business in the future. Either activism or legislation related to requests for access may require us to initiate an unanticipated expanded access program or to make our product candidates more widely available sooner than anticipated.

Patients who receive access to unapproved drugs through compassionate use or expanded access programs have life-threatening illnesses and generally have exhausted all other available therapies. The risk for serious adverse events, including those which may be unrelated to our product candidates, in this patient population is high and could have a negative impact on the safety profile of our product candidate, which could cause significant delays or an inability to successfully commercialize our product candidate and could materially harm our business. In addition, in order to perform the controlled clinical trials required for regulatory approval and successful commercialization of our product candidates, we may also need to restructure or pause any ongoing compassionate use and/or expanded access programs, which could prompt adverse publicity or other disruptions related to current or potential participants in such programs.

The terms of our Loan and Security Agreement require us to meet certain operating and financial covenants and place restrictions on our operating and financial flexibility. If we raise additional capital through debt financing, the terms of any new debt could further restrict our ability to operate our business.

Our Loan and Security Agreement is secured by a lien covering substantially all of our assets, excluding our intellectual property and certain other assets. Subject to the terms of the Loan and Security Agreement, we have the option to prepay all, but not less than all, of the amounts borrowed under the Loan and Security Agreement, subject to certain penalty payments, prior to the August 1, 2022 maturity date, at which time all amounts borrowed will be due and payable.

The Loan and Security Agreement contains customary covenants that include, among others, covenants that limit our (including our subsidiaries’) ability to dispose of assets, enter into mergers or acquisitions, incur indebtedness, incur liens, pay dividends or make distributions on our capital stock, make investments or loans, and enter into certain affiliate transactions, in each case subject to customary exceptions for a credit facility of this size and type.

The Loan and Security Agreement contains customary events of default that include, among others,non-payment defaults, covenant defaults, a default in the event a material adverse change occurs, defaults in the event our assets are attached or we are enjoined from doing business, bankruptcy and insolvency defaults, cross-defaults to certain other material indebtedness, material judgment defaults, and inaccuracy of representations and warranties. The occurrence of an event of default could result in an increase to the applicable interest rate of 5.0%, acceleration of and present occurrence of the maturity date, and the consequent obligation for us to repay in full in cash all amounts outstanding under the Loan and Security Agreement, and a right by the lender to exercise all remedies available to it under the Loan and Security Agreement and related agreements, including the right to dispose of the collateral as permitted under applicable law, The Loan and Security Agreement contains customary affirmative and negative covenants, indemnification provisions and events of default. The affirmative covenants include, among others, covenants requiring us to maintain our legal existence and governmental approvals, deliver certain financial reports and maintain certain intellectual property rights. The negative covenants include, among others, restrictions on transferring or licensing our assets, changing our business, incurring additional indebtedness, engaging in mergers or acquisitions, paying dividends or making other distributions, and creating other liens on our assets, in each case subject to customary exceptions. If we default under the Loan and Security Agreement, the lenders will be able to declare all obligations immediately due and payable and take control of our collateral, potentially requiring us to renegotiate our agreement on terms less favorable to us or to immediately cease operations. Further, if we are liquidated, the lender’s rights to repayment would be senior to the rights of the holders of our common shares to receive any proceeds from the liquidation. If we raise any additional debt financing, the terms of such additional debt could further restrict our operating and financial flexibility

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We do not have our own laboratory facilities or the ability to discover product candidates. We rely on licensing, acquisition and other forms of strategic relationship to grow our pipeline. Our efforts to acquire additional product candidates and grow our pipeline may be unsuccessful.

We do not have our own laboratory facilities or the ability to discover product candidates. We rely on licensing, acquisition and other forms of strategic relationship to grow our pipeline.We may acquire, or enter into strategic relationships to identify, license and develop, one or more additional product candidates to grow our pipeline. The identification, evaluation, development and potential acquisition or licensing of additional product candidates is expensive and time-consuming, and our efforts may not lead to the acquisition or licensing of any additional product candidates that can be successfully developed and commercialized. Competition for viable product candidates is intense, and the acquisition or licensing of product candidates may be more expensive than we are able to afford or may require us to seek additional financing. If our efforts do not lead to the acquisition or successful identification, development and licensing of suitable product candidates, we may be unable to grow our pipeline. In addition, if our efforts to grow our pipeline require us to pursue additional dilutive capital or debt financing strategies, we may experience harm to our financial position and stability.

Even if we are successful in continuing to build our pipeline, the potential product candidates that we identify may not be suitable for clinical development. For example, they may be shown to have harmful side effects or other characteristics that indicate that they are unlikely to be drugs that will receive marketing approval and achieve market acceptance. If we do not successfully develop and commercialize product candidates based upon our approach, we will not be able to obtain product revenue in future periods, which likely would result in significant harm to our financial position and adversely affect our stock price.

We face significant competition from other oncology companies, and our operating results will suffer if we fail to compete effectively.

The oncology industry is characterized by rapidly advancing technologies, intense competition and a strong emphasis on proprietary products. We may face potential competition from many different sources, including major pharmaceutical, specialty pharmaceutical and biotechnology companies, academic institutions and governmental agencies and public and private research institutions. Any product candidates that we successfully develop and commercialize will compete with existing therapies that are available for the indication or indications for which they are approved and new therapies that may become available in the future.

To our knowledge, there is currently one approved drug that specifically targets JAK inhibition, ruxolitinib, marketed by Incyte Corporation as Jakafi^® in the United States and by Novartis as Jakavi in rest of the world. In addition, there are a number of JAK inhibitor competitors in clinical development, at a similar state of development or more advanced than us. To our knowledge, Celgene Corporation is developing fedratinib, which has reported results from Phase 3 clinical trials, and CTI Biopharma Corporation is developing pacritinib, which has been submitted for regulatory approval in the European Union and is currently in a Phase 2 dose finding study in the United States. However, to our knowledge, there are no approved drugs that target both JAK and ACVR1 inhibition on the market, nor in development. Other competitors include Geron Corporation, which is developing imetelstat in a Phase 2 clinical trial for myelofibrosis, and Acceleron, which is developing luspatercept in a Phase 2 clinical trial for myelofibrosis. If momelotinib is approved, it will compete with existing therapies for the indication or indications for which it is approved. While we believe that momelotinib may have the ability to provide an anemia benefit, which we believe is unique to the JAK inhibition class of agents, the market for momelotinib is competitive, and physicians and other prescribers may not recommend or prescribe momelotinib over other competing products.

To our knowledge, there are no approved drugs that specifically target Chk1 on the market but there are a number of competitors in clinical development, at a similar state of development or more advanced than us. To our knowledge, Genentech, Inc. has conducted a Phase 1/2 clinical trial of an oral Chk1 inhibitor in patients with refractory solid tumors or lymphoma alone and in combination with gemcitabine. To our knowledge, Esperas Pharma is conducting a Phase 1/2 clinical trial of an oral Chk1 inhibitor as monotherapy and in combination with gemcitabine in patients with advanced or metastatic cancer. To our knowledge, Eli Lilly and Company is developing prexasertib, an intravenous Chk1/Chk2 inhibitor in several clinical settings, the most advanced of which are in Phase 2 clinical trials. There are also preclinical programs focused on developing Chk1 inhibitors. If SRA737 is approved, it will compete with existing therapies for the indication or indications for which it is approved.

Additionally, to our knowledge, there are no approved drugs that specifically target Cdc7. To our knowledge, Takeda Pharmaceutical Company is developing an oral Cdc7 inhibitor that is currently in a Phase 2 clinical trial for metastatic pancreatic and colorectal cancers and Eli Lily and Company has a Cdc7 inhibitor program that is currently in a Phase 1 clinical trial being conducted by Cancer Research UK. Other companies may be conducting preclinical studies of Cdc7 inhibitors as well. If SRA141 is approved, it will compete with existing therapies for the indication or indications for which it is approved.

Many of the companies against which we may compete have significantly greater financial and other resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals and marketing approved products than we do. Mergers and acquisitions in the oncology industry may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or that may be necessary for, our programs.

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Our commercial opportunity could be reduced or eliminated if any competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any drugs that we may develop. Our competitors also may obtain FDA or foreign regulatory approval for their product candidates more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market. In addition, our ability to compete may be affected in many cases by insurers or other third-party payors seeking to encourage the use of generic drugs. If we fail to complete effectively, our business and operating results would be harmed.

We are dependent on our key personnel, and if we are not successful in attracting and retaining highly qualified personnel, we may not be able to successfully implement our business strategy.

Our ability to compete in the highly competitive oncology industry depends upon our ability to attract and retain highly qualified managerial, scientific and medical personnel. We are dependent on our management, scientific and medical personnel, including Nick Glover, Ph.D., our President and Chief Executive Officer, Barbara Klencke, M.D., our Chief Development Officer and Mark Kowalski M.D., Ph.D., our Chief Medical Officer. The loss of the services of any of our executive officers, other key employees and other scientific and medical advisors, and our inability to find suitable replacements, could result in delays in product development and harm our business.

Our operations are conducted in regions where significant competition exists for key personnel and employees. Many other oncology companies and academic and research institutions are located in these regions. Competition for skilled personnel in these markets is intense and may limit our ability to hire and retain highly qualified personnel on acceptable terms or at all.

To induce valuable employees to remain at our company, in addition to salary and cash incentives, we have provided stock options that vest over time. The value to employees of stock options that vest over time may be significantly affected by movements in our stock price that are beyond our control, and may at any time be insufficient to counteract more lucrative offers from other companies. Despite our efforts to retain valuable employees, members of our management, scientific and development teams may terminate their employment with us on short notice. Although we have employment agreements with our key employees, these employment agreements provide forat-will employment, which means that any of our employees could leave our employment at any time, with or without notice. We do not maintain “key man” insurance policies on the lives of these individuals or the lives of any of our other employees.

Should momelotinib receive marketing approval in the United States, Canada, or elsewhere in the world, we would need to hire a substantial number of specialized personnel, including field-based personnel, unless we were to collaborate with a third party to commercialize momelotinib. If we are responsible for commercializing momelotinib, we would need to increase our administrative headcount to support such expanded development and commercialization operations with respect to our product candidates. Our ability to attract and retain qualified personnel in the future is subject to intense competition for qualified personnel among biotechnology, pharmaceutical and other businesses and our current financial position. The loss of the services of any of our senior management could delay or prevent the development and commercialization of our product candidates, or have other adverse effects on our business for an indefinite term. In particular, if we lose any members of our current senior management team, we may not be able to find suitable replacements in a timely fashion, if at all, and our business may be harmed as a result.

We may encounter difficulties in managing our expected growth and in expanding our operations successfully.

Prior to acquiring momelotinib, our most advanced product candidate was in Phase 1/2 development. As we advance momelotinib through Phase 3 development, we will need to develop or expand our development, regulatory, manufacturing, marketing and sales capabilities or contract with third parties to provide these capabilities for us. We must also successfully integrate the employees and operations related to the development of momelotinib. Maintaining additional relationships and managing our future growth will impose significant added responsibilities on members of our management. We must be able to manage our development efforts effectively, manage our clinical trials effectively, hire, train and integrate additional management, development, administrative and sales and marketing personnel, improve our managerial, development, operational and finance systems, and expand our facilities, all of which may impose a strain on our administrative and operational infrastructure. Our future financial performance will depend, in part, on our ability to manage this growth effectively. We may not be able to accomplish these tasks, which failure could prevent us from successfully developing our product candidates.

Raising additional capital may cause dilution to our existing stockholders, restrict our operations or require us to relinquish rights to our technologies or product candidates.

We may seek additional capital through a combination of public and private equity offerings, debt financings, strategic partnerships and alliances and licensing arrangements. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the ownership interests of our stockholders will be diluted, and the terms may include liquidation or other preferences that adversely affect the rights of our stockholders. The incurrence of indebtedness would result in increased fixed payment obligations

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and could involve certain restrictive covenants, such as limitations on our ability to incur additional debt, limitations on our ability to acquire or license intellectual property rights and other operating restrictions that could adversely impact our ability to conduct our business. If we raise additional funds through strategic partnerships and alliances and licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies or product candidates or grant licenses on terms unfavorable to us.

We may form or seek strategic alliances or collaborations in the future. We may be unable to form or enter into such alliances or collaboration arrangements, and we may not realize the expected benefits of any such transaction.

We may form or seek strategic alliances, or create joint ventures or collaborations with third parties that we believe will complement or augment our development and commercialization efforts with respect to our product candidates and any future product candidates that we may acquire or develop. Any of these transactions and relationships may require us to incurnon-recurring and other charges, increase our near and long-term expenditures, issue securities that dilute our existing stockholders, disrupt our management and business, forego potential future economic value or result in the loss of strategic value. These transactions and relationships also may result in a delay in the development of our product candidates if we become dependent upon the other party and such other party does not prioritize the development of our product candidates relative to its other development activities. In addition, we face significant competition in seeking appropriate strategic partners and the negotiation process is time-consuming and complex. Moreover, we may not be successful in our efforts to establish a strategic partnership or other alternative arrangements for our product candidates because our product candidates may be deemed to be at too early of a stage of development for collaborative effort and third parties may not view our product candidates as having the requisite potential to demonstrate safety and efficacy. We cannot be certain that, following a strategic transaction or license, we will achieve the revenue or specific net income that would justify such transaction.

Recent and future acquisitions could disrupt our business and harm our financial condition and operating results.

We may acquire additional businesses or product candidates from third parties that we believe will complement or augment our existing pipeline of product candidates, including, for example our recent acquisition of momelotinib from Gilead. Even if the assets we acquire have promising markets or technologies, we may not be able to realize the benefit of acquiring such assets if we are unable to successfully integrate them with our existing operations and company culture. We may encounter numerous difficulties in developing, manufacturing and marketing any new product candidates resulting from an acquisition, including momelotinib, which may delay or prevent us from realizing their expected benefits or enhancing our business. We cannot assure you that, following any such acquisition, we will achieve the expected synergies or benefits from the asset to justify the transaction. The risks we face in connection with acquisitions, including our recent acquisition of momelotinib, include, but are not limited to:

• diversion of management time and focus from operating our business to addressing acquisition integration challenges;

• integration of research and development efforts;

• hiring of key employees with knowledge regarding the acquired asset;

• changes in relationships with strategic partners as a result of product acquisitions or strategic positioning resulting from the acquisition;

• cultural challenges associated with integrating employees, knowledge and processes related to the acquired asset into our organization;

• unanticipated write-offs or charges; and

• litigation or other claims in connection with the acquired asset.

Our failure to address these risks or other problems encountered in connection with acquisitions could cause us to fail to realize the anticipated benefits of these transactions, cause us to incur unanticipated liabilities and harm the business generally. There is also a risk that future acquisitions will result in the incurrence of debt, contingent liabilities, amortization expenses or incremental operating expenses, any of which could harm our financial condition or operating results.

We currently have no marketing and sales organization and have no experience in marketing products. If we are unable to establish marketing and sales capabilities or enter into agreements with third parties to market and sell our product candidates, we may not be able to generate product revenue.

We currently have no sales, marketing or distribution capabilities and have no experience in marketing products. If any of our product candidates is approved for sale, we may develop anin-house marketing organization and sales force, which will require significant capital expenditures, management resources and time. We will have to compete with other companies to recruit, hire, train and retain qualified marketing and sales personnel.

If we are unable or decide not to establish internal sales, marketing and distribution capabilities, we will pursue collaborative arrangements regarding the sales and marketing of our products, however, there can be no assurance that we will be able to establish or maintain such collaborative arrangements on commercially reasonable terms, or if we are able to do so, that they will have effective

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sales forces. Any revenue we receive will depend upon the efforts of such third parties, which may not be successful. We may have little or no control over the marketing and sales efforts of such third parties and our revenue from product sales may be lower than if we had commercialized our product candidates ourselves. We also face competition in our search for third parties to assist us with the sales and marketing efforts of our product candidates.

We cannot guarantee that we will be able to developin-house sales and distribution capabilities or establish or maintain relationships with third-party collaborators to commercialize any product in the United States or overseas.

We depend on our information technology and infrastructure.

We rely on the efficient and uninterrupted operation of information technology systems, including mobile technologies, to manage our operations, to process, transmit and store electronic and financial information, and to comply with regulatory, legal and tax requirements. We also depend on our information technology infrastructure for communications among our personnel, contractors, consultants and vendors. System failures or outages could compromise our ability to perform these functions in a timely manner, which could harm our ability to conduct business or delay our financial reporting. Such failures could materially adversely affect our operating results and financial condition.

In addition, we depend on third parties to operate and support our information technology systems. These third parties vary from multi-disciplined to boutique providers, and they may or could have access to our computer networks, mobile networks, and our confidential information. Many of these third parties subcontract or outsource some of their responsibilities to other third parties. As a result, our information technology systems, including those functions that are performed by third parties who are involved with or have access to those systems, are very large and complex. Failure by any of these third-party providers to adequately deliver the contracted services, or maintain confidentiality, could have an adverse effect on our business, which in turn may materially adversely affect our operating results and financial condition. All information technology systems, despite implementation of security measures, may be vulnerable to disability, failures or unauthorized access. If our information technology systems were to fail or be breached, such failure or breach could materially adversely affect our ability to perform critical business functions and sensitive and confidential data could be compromised.

Our internal information technology systems, or those used by our CROs or other contractors or consultants, may fail or suffer security breaches.

Despite the implementation of what we believe are appropriate security measures on internal information technology systems, our internal information technology systems and those of our CROs and other contractors and consultants may become vulnerable to damage from security breaches and/or unauthorized access. The prevalent use of mobile devices also increases the risk of data security incidents. In the ordinary course of our business, we collect, store, process and transmit large amounts of sensitive information, including intellectual property, proprietary business information, personal information and other confidential information. It is critical that we do so in a secure manner in order to ensure the confidentiality, integrity and availability of such sensitive information. We have in the past experienced, and may in the future experience, a security breach. Any material system failure or security breach could cause interruptions in our operations, and could result in a material disruption of our development programs and our business operations. For example, the loss of data from completed or future preclinical studies or clinical trials could result in significant delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the data. Likewise, we rely on other third parties for the manufacture of our product candidates and to conduct studies and trials, and similar events relating to their information technology systems could also have a material adverse effect on our business. To the extent that any disruption or security breach were to result in a loss of, or damage to, our data or applications, or inappropriate disclosure of confidential or proprietary information, we could incur liability and the further development and commercialization of our product candidates could be significantly delayed.

We may be unable to adequately protect our information technology systems from cyberattacks, which could result in the disclosure of confidential information, damage our reputation, and subject us to significant financial and legal exposure.

Cyberattacks are frequent and may be sophisticated and intense to the point that they are difficult to detect. Cyberattacks could include wrongful conduct by hostile foreign governments, industrial espionage, the deployment of harmful malware,denial-of-service, and/or other means to threaten data confidentiality, integrity and availability. A successful cyberattack could cause serious negative consequences for us, including, without limitation, the disruption of operations, the misappropriation of confidential business information and trade secrets, and the disclosure of corporate strategic plans. We have in the past experienced, and may in the future experience, a compromise of our data or information technology systems that results in one or more third parties obtaining access to confidential information about our company. Although we devote resources to protect our information technology systems and continue to assess and, as necessitated, enhance our cybersecurity protection, we realize that cyberattacks are a threat, and there can be no assurance that our efforts will prevent information security breaches that would result in business, legal or reputational harm to us, or would have a material adverse effect on our operating results and financial condition. Confidential information obtained by third parties in connection with past or future attacks could be used in ways that adversely affect our company or our stockholders.

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Business disruptions could seriously harm our future revenue and financial condition and increase our costs and expenses.

Our operations, and those of our CROs and other contractors and consultants, could be subject to earthquakes, power shortages, telecommunications failures, water shortages, floods, hurricanes, typhoons, fires, extreme weather conditions, medical epidemics and other natural orman-made disasters or business interruptions, for which we may not have insurance coverage. The occurrence of any of these business disruptions could seriously harm our operations and financial condition and increase our costs and expenses. We rely on third-party manufacturers to produce and process our product candidates. Our ability to obtain supplies of our product candidates could be disrupted if the operations of these suppliers are affected by aman-made or natural disaster or other business interruption. Our corporate headquarters are located in Vancouver, British Columbia, which is near a major earthquake fault. Our operations and financial condition could suffer in the event of a major earthquake or other natural disaster near any of our locations.

Our employees, independent contractors, consultants, commercial partners and vendors may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements.

We are exposed to the risk of fraud or other illegal activity by our employees, independent contractors, consultants, commercial partners and vendors. Misconduct by such individuals could include intentional failures to comply with FDA or international regulations, provide accurate information to the FDA or foreign regulatory authorities, comply with manufacturing standards, comply with federal and state healthcare fraud and abuse laws and regulations, report financial information or data timely, completely and accurately or disclose unauthorized activities to us. In particular, sales, marketing and business arrangements in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Misconduct by third parties could also involve the improper use of information obtained in the course of clinical trials.

We have adopted a code of business conduct and ethics, but it is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent inappropriate conduct may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws or regulations. Efforts to ensure that our business arrangements will comply with applicable healthcare laws may involve substantial costs. It is possible that governmental and enforcement authorities will conclude that our business practices may not comply with current or future statutes, regulations or case law interpreting applicable fraud and abuse or other healthcare laws and regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, including the imposition of civil, criminal and administrative penalties, damages, disgorgement, monetary fines, possible exclusion from participation in Medicare, Medicaid and other federal healthcare programs, contractual damages, reputational harm, diminished profits and future earnings and curtailment of our operations, any of which could adversely affect our ability to operate our business and our results of operations. In addition, the approval and commercialization of any of our product candidates outside the United States will also likely subject us to foreign equivalents of the healthcare laws mentioned above, among other foreign laws.

If product liability lawsuits are brought against us, we may incur substantial liabilities and may be required to limit commercialization of our product candidates.

We face an inherent risk of product liability as a result of the testing of our product candidates and will face an even greater risk if we commercialize any products. For example, we may be sued if our product candidates cause or are perceived to cause injury or are found to be otherwise unsuitable during testing, manufacturing, marketing or sale. Any such product liability claims may include allegations of defects in manufacturing, defects in design, a failure to warn of dangers inherent in the product, negligence, strict liability or a breach of warranties. Claims could also be asserted under state consumer protection acts. If we cannot successfully defend ourselves against product liability claims, we may incur substantial liabilities or be required to limit commercialization of our product candidates. Even successful defense would require significant financial and management resources. Regardless of the merits or eventual outcome, liability claims may result in, but are not limited to:

• decreased demand for our product candidates;

• injury to our reputation;

• withdrawal of clinical trial participants;

• initiation of investigations by regulators;

• costs to defend the related litigation;

• a diversion of management’s time and our resources;

• substantial monetary awards to trial participants or patients;

• product recalls, withdrawals or labeling, marketing or promotional restrictions;

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• loss of revenue;

• exhaustion of any available insurance and our capital resources;

• the inability to commercialize any product candidate; and

• a decline in our stock price.

We currently hold liability insurance coverage, but that coverage may not be adequate to cover any and all liabilities that we may incur. We would need to increase our insurance coverage when we begin the commercialization of our product candidates, if ever. Insurance coverage is increasingly expensive. We may not be able to maintain insurance coverage at a reasonable cost or in an amount adequate to satisfy any liability that may arise.

Our ability to utilize our net operating loss carryforwards and certain other tax attributes may be significantly limited, or entirely restricted.

As of December 31, 2017, we had U.S. federal net tax operating loss carryforwards of $31.4 million expiring in 2037 and state operating loss carryforwards of $54.0 million expiring in years ranging from 2022 to 2037. We also had net tax credit carryforwards of $0.4 million which begin to expire in 2032. Under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, if a corporation undergoes an “ownership change,” the corporation’s ability to use itspre-change net operating loss carryforwards and otherpre-change tax attributes, such as research tax credits, to offset its post-change income and taxes may be limited. In general, an “ownership change” generally occurs if there is a cumulative change in our ownership by “5% stockholders” that exceeds 50 percentage points over a rolling three-year period. Similar rules may apply under state tax laws.

As a result of stock offerings that occurred prior to 2016, subsequent changes in the stock ownership, and the stock offering in February 2017, an ownership change under Section 382 is deemed to have occurred. As such, certain tax attributes existing as of the date of the ownership change are not available for future use. The loss of these attributes did not have any impact on the financial statements since our net U.S. deferred tax assets are offset by a full valuation allowance.

We have experienced ownership changes in the past and may experience ownership changes in the future as a result of future transactions in our stock, some of which may be outside our control. As a result, if we earn net taxable income, our ability to use ourpre-change net operating loss carryforwards, or otherpre-change tax attributes, to offset U.S. federal and state taxable income and taxes may be subject to limitations.

We are a U.S.-based multinational company subject to tax in certain U.S. and foreign tax jurisdictions. United States federal, state and local, as well as international tax laws and regulations are extremely complex and subject to varying interpretations. Although we believe that our tax estimates and tax positions are reasonable, there can be no assurance that our tax positions will not be challenged by relevant tax authorities or that we would be successful in any such challenge. If we are unsuccessful in such a challenge, the relevant tax authorities may assess additional taxes, which could result in adjustments to, or impact the timing or amount of, taxable income, deductions or other tax allocations, which may adversely affect our results of operations and financial position.

Unstable market and economic conditions may have adverse consequences on our business, financial condition and stock price.

Global credit and financial markets have experienced extreme volatility and disruptions in the past several years, including severely diminished liquidity and credit availability, declines in consumer confidence, declines in economic growth, increases in unemployment rates and uncertainty about economic stability. We cannot assure you that further deterioration in credit and financial markets and confidence in economic conditions will not occur. Our general business strategy and stock price may be adversely affected by any such economic downturn, volatile business environment or continued unpredictable and unstable market conditions. If the current equity and credit markets deteriorate, it may make any necessary debt or equity financing more difficult, more costly and more dilutive. Failure to secure any necessary financing in a timely manner and on favorable terms could have a material adverse effect on our growth strategy, financial performance and stock price and could require us to delay or abandon development plans. In addition, there is a risk that one or more of our current service providers, manufacturers and other partners may not survive these difficult economic times, which could directly affect our ability to attain our operating goals on schedule and on budget.

Our quarterly operating results may fluctuate significantly, which may cause our stock price to fluctuate or decline.

We expect our operating results to be subject to quarterly fluctuations. Our net loss and other operating results will be affected by numerous factors, including, but not limited to:

• variations in the level of expense related to our product candidates or future development programs;

• results of preclinical studies and clinical trials, or the addition or termination of preclinical studies, clinical trials or funding support;

• the timing of the release of results from any preclinical studies and clinical trials;

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• the timing and amount of milestone and royalty payments to our licensor;

• changes in the competitive landscape or market opportunity for our product candidates;

• our execution of any new collaboration, licensing or similar arrangement, and the timing of payments we may make or receive under such existing or future arrangements or the termination or modification of any such existing or future arrangements;

• any intellectual property infringement lawsuit or opposition, interference or cancellation proceeding in which we may become involved;

• any securities or other litigation in which we may become involved;

• additions and departures of key personnel;

• strategic decisions by us or our competitors, such as acquisitions, divestitures, spin-offs, joint ventures,

• strategic investments or changes in business strategy;

• the receipt by any of our product candidates of regulatory approval and market acceptance, and the demand for such product candidates;

• regulatory developments affecting our product candidates or those of our competitors; and

• changes in general market and economic conditions.

If our quarterly operating results or expected results from development of our product candidates fall outside the expectations of investors or securities analysts, the price of our common stock could decline substantially. Furthermore, any quarterly fluctuations in our operating results may, in turn, cause the price of our stock to fluctuate substantially. We believe that quarterly comparisons of our financial results are not necessarily meaningful and should not be relied upon as an indication of our future performance.

We face risks related to securities litigation that could result in significant legal expenses and settlement or damage awards.

We are currently and may in the future become subject to claims and litigation alleging violations of the securities laws or other related claims, which could harm our business and require us to incur significant costs. For example, on November 9, 2016, a purported securities class action lawsuit was filed in the United States District Court for the Southern District of New York against us and certain of our executive officers (the New York Lawsuit). The New York Lawsuit was brought by purported stockholders of our company seeking to represent a class consisting of stockholders who purchased stock between July 15, 2015 and June 6, 2016. The New York Lawsuit asserts claims under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and seeks unspecified damages and other relief. On March 13, 2018, the United States District Court for the Southern District of New York granted the defendants’ motion to dismiss and entered a final judgment dismissing the New York Lawsuit with prejudice. The plaintiffs have filed an appeal.

Also, on November 18, 2016, a purported securities class action lawsuit was filed in the Superior Court of the State of California for the County of San Mateo against us, certain of our executive officers and directors, and the underwriters for our initial public offering (IPO) of our common stock. On February 9, 2017, a substantially identical putative class action suit was filed in the Superior Court of the State of California for the County of San Mateo asserting the same claims on behalf of the same putative class (the two California lawsuits together, the California Lawsuits). The California Lawsuits were brought by purported stockholders of the company seeking to represent a class consisting of stockholders who purchased stock pursuant to and/or traceable to our Registration Statement on FormS-1. The lawsuits assert claims under Sections 11 and 15 of the Securities Exchange Act of 1934 and seek unspecified damages and other relief. On August 1, 2018, all parties reached a mutually acceptable resolution to the California Lawsuits by way of a mediated settlement, which is subject to the parties’ execution of final settlement documents and the approval of the court. The California Lawsuits remain pending. We are generally obliged, to the extent permitted by law, to indemnify our executive officers who are named as defendants in these types of lawsuits. Regardless of the outcome, this or future litigation may require significant attention from management and could result in significant legal expenses, settlement costs or damage awards that could have a material impact on our financial position, results of operations and cash flows.

Risks Related to Government Regulation

We may be unable to obtain U.S. or foreign regulatory approval of our product candidates, and, as a result, we may be unable to commercialize our product candidates.

Our product candidates are, and any future product candidates that we may develop will be, subject to extensive governmental regulations relating to, among other things, research, testing, development, manufacturing, safety, efficacy, approval, recordkeeping, import, export, reporting, labeling, storage, packaging, advertising and promotion, pricing, marketing, distribution, import and export of drugs. Rigorous preclinical testing and clinical trials and an extensive regulatory approval process are required to be successfully

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completed before a new drug can be marketed in the United States and in many foreign jurisdictions. Satisfaction of these and other regulatory requirements is costly, time-consuming, uncertain and subject to unanticipated delays. It is possible that none of the product candidates we may develop will obtain the regulatory approvals necessary for us or our collaborators to begin selling them.

As a company, we have very limited experience in conducting and managing the clinical trials necessary to obtain regulatory approvals, including approval by the FDA or foreign regulatory authorities, and, as a company, we have no experience in obtaining approval of any product candidates. The time required to obtain FDA and other approvals is unpredictable but typically takes many years following the initiation of clinical trials, depending upon the type, complexity and novelty of the product candidate. We may encounter delays or rejections during any stage of the regulatory review and approval process based upon the failure of clinical or laboratory data to demonstrate compliance with, or upon the failure of the product candidates to meet, the FDA’s or foreign regulatory authorities’ requirements for safety, efficacy and quality.

The standards that the FDA and foreign regulatory authorities use when regulating us are not always applied predictably or uniformly and can change. Because the product candidates we are developing may represent a new class of drug, the FDA and foreign regulatory authorities have not yet established any definitive policies, practices or guidelines in relation to these drugs. The lack of policies, practices or guidelines may hinder or slow review by the FDA or foreign regulatory authorities of any regulatory filings that we may submit. Moreover, the FDA or foreign regulatory authorities may respond to these submissions by defining requirements we may not have anticipated. Such responses could lead to significant delays in the development of our product candidates.

Any analysis we perform of data from preclinical and clinical activities is subject to confirmation and interpretation by regulatory authorities, which could delay, limit or prevent regulatory approval. We may also encounter unexpected delays or increased costs due to new government regulations, for example, from future legislation or administrative action, or from changes in FDA or foreign regulatory authority policy during the period of product development, clinical trials and regulatory review. It is impossible to predict whether legislative changes will be enacted, or whether FDA or foreign regulatory authority, guidance or interpretations will be changed, or what the impact of such changes, if any, may be.

In addition, the FDA and/or foreign regulatory authorities may delay, limit, or deny approval of a product candidate for many reasons, including, but not limited to:

• the FDA or foreign regulatory authorities may disagree with the design or implementation of our clinical trials;

• we may be unable to demonstrate to the satisfaction of the FDA or foreign regulatory authorities that a product candidate is safe and effective for any indication;

• we may be unable to demonstrate that a product candidate’s clinical and other benefits outweigh its safety risks;

• the FDA or foreign regulatory authorities may disagree with our interpretation of data from preclinical studies or clinical trials;

• the results of our clinical trials may not demonstrate the safety or efficacy required by the FDA or foreign regulatory authorities for approval;

• the FDA or foreign regulatory authorities may not approve our companion diagnostic, if a companion diagnostic is required;

• we may encounter difficulties coming to agreement with the FDA or foreign regulatory authorities on a pediatric investigation or study plan or may encounter difficulties meeting the terms of the plan, once agreed;

• the FDA or foreign regulatory authorities may find deficiencies in our manufacturing processes or facilities; and

• the FDA’s or foreign regulatory authorities’ approval policies or regulations may significantly change in a manner rendering our clinical data insufficient for approval.

Even if we comply with all of the regulatory requirements of the FDA and foreign regulatory authorities, we may not obtain regulatory approval for any of our product candidates in development. If we fail to obtain regulatory approval for any of our product candidates in development, we will have fewer commercialized products than we anticipate and correspondingly lower revenue.

In addition, because there may be approved treatments for some of the diseases for which we may seek approval, in order to receive regulatory approval, we may need to demonstrate through clinical trials that the product candidates we develop to treat these diseases, if any, are not only safe and effective, but safer or more effective than existing products. Furthermore, in recent years, there has been increased public and political pressure on the FDA with respect to the approval process for new drugs, and the FDA’s standards, especially regarding drug safety, appear to have become more stringent.

Any delay or failure in obtaining required approvals could have a material adverse effect on our ability to generate revenues from the particular product candidate for which we are seeking approval. Furthermore, any regulatory approval to market a product may be subject to limitations on the approved uses for which we may market the product or the labeling or other restrictions. In addition, the FDA has the authority to require a REMS plan as part of or after approval, which may impose further requirements or restrictions on

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the distribution or use of an approved product, such as limiting prescribing to certain physicians or medical centers that have undergone specialized training, limiting treatment to patients who meet certainsafe-use criteria and requiring treated patients to enroll in a registry. These limitations and restrictions may limit the size of the market for the product and affect reimbursement by third-party payors.

We are also subject to numerous foreign regulatory requirements governing, among other things, the conduct of clinical trials, manufacturing and marketing authorization, pricing and third-party reimbursement. The foreign regulatory approval process varies among countries and may include all of the risks associated with FDA approval described above as well as risks attributable to the satisfaction of local regulations in foreign jurisdictions. Moreover, the time required to obtain approval may differ from that required to obtain FDA approval. Approval by the FDA does not ensure approval by regulatory authorities outside the United States and vice versa.

If we or any collaborators, manufacturers or service providers fail to comply with applicable federal, state or foreign laws or regulations, we could be subject to enforcement actions, which could affect our ability to develop, market and sell our products successfully and could harm our reputation and lead to reduced acceptance of our products by the market. These enforcement actions include, among others:

• adverse regulatory inspection findings;

• warning letters;

• voluntary or mandatory product recalls or public notification or medical product safety alerts to healthcare professionals;

• restrictions on, or prohibitions against, marketing our products;

• restrictions on, or prohibitions against, importation or exportation of our products;

• suspension of review or refusal to approve pending applications or supplements to approved applications;

• exclusion from participation in government-funded healthcare programs;

• exclusion from eligibility for the award of government contracts for our products;

• suspension or withdrawal of product approvals;

• product seizures;

• injunctions; and

• civil and criminal penalties and fines.

In addition, negotiations around the United Kingdom’s exit from the European Union (Brexit) have caused uncertainty in the current regulatory framework in Europe. Brexit has resulted in a decision to move the EMA from the United Kingdom to the Netherlands, with operations currently scheduled to begin in the Netherlands by March 2019. In the United Kingdom, this transition may cause disruption in the administrative and medical scientific links between the EMA and MHRA, including delays in granting clinical trial authorization or marketing authorization, disruption of importation and export of active substance and other components of new drug formulations, and disruption of the supply chain for clinical trial product and final authorized formulations.

The cumulative effects of the disruption to the regulatory framework may add considerably to the development lead time to marketing authorization and commercialization of products in the European Union and/or the United Kingdom. In view of the current lack of detail and resolution with regard to the Brexit implementation, we are unable to confidently predict the effects of such disruption to the regulatory framework in Europe.

Even if we receive regulatory approval of our product candidates, we will be subject to ongoing regulatory obligations and continued regulatory review, which may result in significant additional expense and we may be subject to penalties if we fail to comply with regulatory requirements or experience unanticipated problems with our product candidates.

Any regulatory approvals that we receive for our product candidates will require surveillance to monitor the safety and efficacy of the product candidate, and may require us to conduct post-approval clinical studies. The FDA may also require a REMS in order to approve our product candidates, which could entail requirements for a medication guide, physician communication plans or additional elements to ensure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. In addition, if the FDA or a foreign regulatory authority approves our product candidates, the manufacturing processes, labeling, packaging, distribution, AE reporting, storage, advertising, promotion, import, export and recordkeeping for our product candidates will be subject to extensive and ongoing regulatory requirements. These requirements include submissions of safety and other post-marketing information and reports, registration, as well as continued compliance with cGMPs and cGCPs for any clinical trials that we conduct post-approval.

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Moreover, if we obtain regulatory approval for our product candidates, we will only be permitted to market our products for the indication approved by FDA or foreign regulatory authority, and such approval may involve limitations on the indicated uses or promotional claims we may make for our products, or otherwise not permit labeling that sufficiently differentiates our product candidates from competitive products with comparable therapeutic profiles. For example, we will not be able to claim that our products have fewer side effects, or improve compliance or efficacy unless we can demonstrate those attributes to FDA or foreign regulatory authority in comparative clinical trials.

Later discovery of previously unknown problems with our product candidates, including adverse effects of unanticipated severity or frequency, or with our third-party manufacturers or manufacturing processes, or failure to comply with regulatory requirements, may result in, among other things:

• restrictions on the marketing or manufacturing of our product candidates, withdrawal of the product from the market, or voluntary or mandatory product recalls;

• fines, warning letters, or untitled letters;

• holds on clinical trials;

• refusal by the FDA or foreign regulatory authorities to approve pending applications or supplements to approved applications filed by us or suspension or revocation of license approvals;

• product seizure or detention, or refusal to permit the import or export of our product candidates; and

• injunctions, the imposition of civil penalties or criminal prosecution.

The FDA’s and foreign regulatory authorities’ policies may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates. We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the United States or abroad. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we may have obtained and we may not achieve or sustain profitability.

If we or any of our independent contractors, consultants, collaborators, manufacturers, vendors or service providers fail to comply with healthcare and data privacy laws and regulations, we or they could be subject to enforcement actions, which could result in penalties and affect our ability to develop, market and sell our product candidates and may harm our reputation.

We are or may in the future be subject to federal, state, and foreign healthcare and data privacy laws and regulations pertaining to, among other things, fraud and abuse and patients’ rights. These laws and regulations include:

• the U.S. federal Anti-Kickback Statute, which prohibits, among other things, persons and entities from soliciting, receiving or providing remuneration, directly or indirectly, to induce either the referral of an individual for a healthcare item or service, or the purchasing or ordering of an item or service, for which payment may be made under a federal healthcare program such as Medicare or Medicaid;

• the U.S. federal false claims and civil monetary penalties laws, including the federal civil False Claims Act, which prohibit, among other things, individuals or entities from knowingly presenting or causing to be presented, claims for payment by government funded programs such as Medicare or Medicaid that are false or fraudulent, and which may apply to us by virtue of statements and representations made to customers or third parties;

• the U.S. federal Health Insurance Portability and Accountability Act (HIPAA), which created additional federal criminal statutes that prohibit, among other things, knowingly and willfully executing or attempting to execute a scheme to defraud healthcare programs;

• HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act (HITECH), which imposes requirements on certain types of people and entities relating to the privacy, security, and transmission of individually identifiable health information, and requires notification to affected individuals and regulatory authorities of certain breaches of security of individually identifiable health information;

• the federal Physician Payment Sunshine Act, which requires certain manufacturers of drugs, devices, biologics and medical supplies for which payment is available under Medicare, Medicaid, or the Children’s Health Insurance Program, to report annually to the Centers for Medicare & Medicaid Services (CMS) information related to payments and other transfers of value to physicians, other healthcare providers and teaching hospitals, and ownership and investment interests held by physicians and other healthcare providers and their immediate family members, which is published in a searchable form on an annual basis;

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• state laws comparable to each of the above federal laws, such as, for example, anti-kickback and false claims laws that may be broader in scope and also apply to commercial insurers and othernon-federal payors, requirements for mandatory corporate regulatory compliance programs, and laws relating to patient data privacy and security. Other state laws require pharmaceutical companies to comply with the pharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government; require drug manufacturers to report information related to payments and other transfers of value to physicians and other healthcare providers or marketing expenditures; and state and foreign laws govern the privacy and security of health information in some circumstances, many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts; and

• in the European Union, the General Data Protection Regulation (GDPR) – Regulation EU 2016/679 – which was adopted in May 2016 and took effect on May 25, 2018. The GDPR is intended to harmonize data protection requirements across the European Union member states by establishing new and expanded operational requirements for entities that process or control personal data generated in the European Union, including consent requirements for disclosing the way personal information will be used, information retention requirements, notification requirements in the event of a data breach, and other requirements.

If our operations are found to be in violation of any such health care laws and regulations, we may be subject to penalties, including administrative, civil and criminal penalties, monetary damages, disgorgement, imprisonment, the curtailment or restructuring of our operations, loss of eligibility to obtain approvals from the FDA or foreign regulatory authorities, or exclusion from participation in government contracting, healthcare reimbursement or other government programs, including Medicare and Medicaid, any of which could adversely our financial results. Although effective compliance programs can mitigate the risk of investigation and prosecution for violations of these laws, these risks cannot be entirely eliminated. Any action against us for an alleged or suspected violation could cause us to incur significant legal expenses and could divert our management’s attention from the operation of our business, even if our defense is successful. In addition, achieving and sustaining compliance with applicable laws and regulations may be costly to us in terms of money, time and resources.

Any products we develop may become subject to unfavorable pricing regulations, third-party coverage and reimbursement practices or healthcare reform initiatives, thereby harming our business.

The regulations that govern marketing approvals, pricing, coverage and reimbursement for new drugs vary widely from country to country. Many countries require approval of the sale price of a drug before it can be marketed. The pricing review period begins after marketing or product licensing approval is granted in most cases. In some foreign markets, prescription pharmaceutical pricing remains subject to continuing governmental control even after initial approval is granted. Although we intend to monitor these regulations, our programs are currently in the early stages of development and we will not be able to assess the impact of price regulations for a number of years. As a result, we might obtain regulatory approval for a product in a particular country, but then be subject to price regulations that delay our commercial launch of the product and negatively impact the revenues we are able to generate from the sale of the product in that country.

Our ability to commercialize any products successfully also will depend in part on the extent to which coverage and adequate reimbursement for these products and related treatments will be available from government health administration authorities, private health insurers and other third-party payors. In many jurisdictions, a product candidate must be approved for reimbursement before it can be approved for sale in that jurisdiction. Obtaining coverage and reimbursement approval of a product from a government or other third-party payor is a time-consuming and costly process that could require us to provide to the payor supporting scientific, clinical and cost-effectiveness data for the use of our products. If we are not currently capturing the scientific and clinical data that will be required for reimbursement approval, we may be required to conduct additional trials, which may delay or suspend reimbursement approval. Additionally, in the United States, no uniform policy of coverage and reimbursement for products exists among third-party payors. Therefore, coverage and reimbursement for products can differ significantly from payor to payor. As a result, the coverage determination process is often a time-consuming and costly process that will require us to provide scientific and clinical support for the use of our product candidates to each payor separately, with no assurance that coverage and adequate reimbursement will be obtained.

Even if we succeed in bringing one or more products to the market, these products may not be considered cost-effective, and the amount reimbursed for any products may be insufficient to allow us to sell our products on a competitive basis. Because our programs are in the early stages of development, we are unable at this time to determine their cost effectiveness or the likely level or method of reimbursement. Increasingly, the third-party payors, such as government and private insurance plans, who reimburse patients or healthcare providers, are requiring that drug companies provide them with predetermined discounts from list prices, and are seeking to reduce the prices charged or the amounts reimbursed for pharmaceutical products. If the coverage provided for any products we develop is inadequate in light of our development and other costs, our return on investment could be adversely affected.

The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 (MMA), established the Medicare Part D program to provide a voluntary prescription drug benefit to patients with disabilities and seniors. Under Part D, Medicare beneficiaries may enroll in prescription drug plans offered by private entities that will provide coverage of outpatient prescription drugs, such as momelotinib, if approved. Medicare Part D coverage is not standardized. Part D prescription drug plan sponsors are not required to pay for all covered Part D drugs, and each drug plan can develop its own drug formulary that identifies which drugs it will cover and

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at what tier or level. However, Part D prescription drug formularies must include drugs within each therapeutic category and class of covered Part D drugs, though not necessarily all the drugs in each category or class. Any formulary used by a Part D prescription drug plan must be developed and reviewed by a pharmacy and therapeutic committee. Government payment for some of the costs of prescription drugs may increase demand for products for which we receive regulatory approval. However, any negotiated prices for our products covered by a Part D prescription drug plan will likely be lower than the prices we might otherwise obtain. Moreover, while the MMA applies only to drug benefits for Medicare beneficiaries, private payers often follow Medicare coverage policy and payment limitations in setting their own payment rates. Any reduction in payment that results from the MMA may result in a similar reduction in payments fromnon-government payers.

Historically, Medicare Part D enrollees have had a partial gap in their coverage (known as the “coverage gap” or “donut hole”) wherein their coinsurance increases from 25% to a higher percentage (35% for brand drugs in 2018) after they reach an initial coverage limit, and remains at that level until they reach a catastrophic coverage threshold where the coinsurance is considerably reduced. However, beginning in 2019, Medicare Part D enrollees will continue to pay a 25% coinsurance during this interval – the same percentage that they were responsible for before they reached the initial coverage limit – thereby closing the coverage gap. The cost of closing the coverage gap is being borne by innovator companies and the government through subsidies. Beginning in 2011, each manufacturer of a drug approved under an NDA was required to enter into a Medicare Part D coverage gap discount agreement and provide a 50% discount on those drugs dispensed to Medicare Part D enrollees in the coverage gap, in order for its drugs to be reimbursed by Medicare Part D. The Bipartisan Budget Act of 2018 increased the manufacturer’s subsidy under this program from 50% to 70% of the negotiated price, beginning in 2019.

Certain products we develop, such as SRA737 and SRA141, if approved, may need to be administered under the supervision of a physician on an outpatient basis. Under applicable U.S. law, certain drugs that are not usually self-administered (including certain injectable drugs) may be eligible for coverage under the Medicare Part B program if:

• they are incident to a physician’s services;

• they are reasonable and necessary for the diagnosis or treatment of the illness or injury for which they are administered according to accepted standards of medical practice; and

• they have been approved by the FDA and meet other requirements of the statute.

There may be significant delays in obtaining coverage for newly-approved products, and coverage may be more limited than the purposes for which the drug is approved by the FDA or foreign regulatory authorities. Moreover, eligibility for coverage does not imply that any drug will be reimbursed in all cases or at a rate that covers our costs, including research, development, manufacture, sale and distribution. Interim payments for new drugs, if applicable, may also not be sufficient to cover our costs and may not be made permanent.

Reimbursement may be based on payments allowed for lower-cost products that are already reimbursed, may be incorporated into existing payments for other services and may reflect budgetary constraints or imperfections in Medicare data. Net prices for products may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and by any future relaxation of laws that presently restrict imports of products from countries where they may be sold at lower prices than in the United States. Third-party payors often rely upon Medicare Part D coverage policy and payment limitations in setting their own reimbursement rates. However, no uniform policy requirement for coverage and reimbursement for products exists among third-party payors in the United States. Therefore, coverage and reimbursement for products can differ significantly from payor to payor. As a result, the coverage determination process is often a time-consuming and costly process that will require us to provide scientific and clinical support for the use of our products to each payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance. Our inability to promptly obtain coverage and adequate reimbursement rates from both government-funded and private payors for new drugs that we develop and for which we obtain regulatory approval could have a material adverse effect on our operating results, our ability to raise capital needed to commercialize products and our financial condition.

We believe that the efforts of governments and third-party payors to contain or reduce the cost of healthcare and legislative and regulatory proposals to broaden the availability of healthcare will continue to affect the business and financial condition of oncology companies. A number of legislative and regulatory changes in the healthcare system in the United States and other major healthcare markets have been proposed in recent years, and such efforts have expanded substantially in recent years. These developments have included prescription drug benefit legislation that was enacted and took effect in January 2006, healthcare reform legislation enacted by certain states, and major healthcare reform legislation that was passed by Congress and enacted into law in the United States in 2010. The U.S. Congress and the Trump administration have similarly expressed concerns over the pricing of pharmaceutical products and there can be no assurance as to how this scrutiny will impact future pricing of pharmaceutical products generally. For example, President Trump outlined a blueprint of activities and proposals intended to lower prescription drug prices, which the Department of Health and Human Services is beginning to roll out. Future developments could, directly or indirectly, affect our ability to sell our products, if approved, at a favorable price.

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For example, the Patient Protection and Affordable Care Act of 2010, as amended by the Health Care and Education Reconciliation Act (PPACA), contains provisions that affect companies in the pharmaceutical industry and other healthcare related industries by imposing additional costs and changes to business practices. Provisions affecting pharmaceutical companies include the following.

• mandatory rebates for drugs sold into the Medicaid program were increased, and the rebate requirement was extended to drugs used in risk-based Medicaid managed care plans;

• the 340B Drug Pricing Program under the Public Health Services Act was extended to require mandatory discounts for drug products sold to certain critical access hospitals, cancer hospitals and other covered entities;

• expansion of eligibility criteria for Medicaid programs;

• expansion of entities eligible for discounts under the Public Health Service pharmaceutical pricing program;

• a new Patient Centered Outcomes Research Institute to oversee, identify priorities in, and conduct comparative clinical effectiveness research, along with funding for such research;

• pharmaceutical companies are required to offer discounts on brand-name drugs to patients who fall within the Medicare Part D coverage gap, commonly referred to as the “donut hole”; the Bipartisan Budget Act of 2018 increased the manufacturer’s subsidy under this program from 50% to 70% of the negotiated price, beginning in 2019; and

• pharmaceutical companies are required to pay an annualnon-tax deductible fee to the federal government based on each company’s market share of prior year total sales of branded products to certain federal healthcare programs, such as Medicare, Medicaid, Department of Veterans Affairs and Department of Defense. Since we expect our branded pharmaceutical sales, if any of our products are approved, to constitute a small portion of the total federal health program pharmaceutical market, we do not expect this annual assessment to have a material impact on our financial condition.

There have been judicial and Congressional challenges and amendments to certain aspects of the PPACA. President Trump has suggested that he plans to seek repeal of all or portions of the PPACA and indicated that Congress should replace the PPACA with new legislation, and in 2017, President Trump issued the Executive Order Promoting Healthcare Choice and Competition, directing certain federal agencies to modify their implementation of the PPACA. We expect there will be additional challenges, amendments and modifications to the PPACA in the future, including potential repeal of PPACA in full or in part. The full effect of the U.S. healthcare reform legislation on our business activities is unknown. The financial impact of the U.S. healthcare reform legislation will depend on a number of factors, including but not limited to, the policies reflected in implementing regulations and guidance and changes in sales volumes for products affected by the new system of rebates, discounts and fees. The legislation may also have a positive impact on our future net sales, if any, by increasing the aggregate number of persons with healthcare coverage in the United States. Further, new litigation is currently pending before the U.S. Supreme Court to invalidate certain provisions of the PPACA.

Moreover, we cannot predict what healthcare reform initiatives may be adopted in the future. Further federal and state legislative and regulatory developments are likely, and we expect ongoing initiatives in the United States to increase pressure on drug pricing. Such reforms could have an adverse effect on anticipated revenues from product candidates that we may successfully develop and for which we may obtain regulatory approval and may affect our overall financial condition and ability to develop product candidates.

Our ability to obtain services, reimbursement or funding may be impacted by possible reductions in federal spending in the United States as well as globally.

U.S. federal government agencies currently face potentially significant spending reductions. Under the Budget Control Act of 2011, the failure of Congress to enact deficit reduction measures of at least $1.2 trillion for the years 2013 through 2021 triggered automatic cuts to most federal programs. These cuts would include aggregate reductions to Medicare payments to providers of up to two percent per fiscal year, which went into effect beginning on April 1, 2013 and will stay in effect through 2025 unless additional Congressional action is taken. The American Taxpayer Relief Act of 2012, which was enacted on January 1, 2013, among other things, reduced Medicare payments to several providers, including hospitals and imaging centers. The full impact on our business of these automatic cuts is uncertain.

If government spending is reduced, anticipated budgetary shortfalls may also impact the ability of relevant agencies, such as the FDA or the National Institutes of Health to continue to function at current levels. Amounts allocated to federal grants and contracts may be reduced or eliminated. These reductions may also impact the ability of relevant agencies to timely review and approve drug research and development, manufacturing, and marketing activities, which may delay our ability to develop, market and sell any products we may develop. Any reductions in government spending in countries outside the United States may also impact us negatively, such as by limiting the functioning of international regulatory agencies in countries outside the United States or by eliminating programs on which we may rely.

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Obtaining and maintaining regulatory approval for our product candidates in one jurisdiction does not mean that we will be successful in obtaining regulatory approval of any of our product candidates in other jurisdictions.

Obtaining and maintaining regulatory approval for our product candidates in one jurisdiction does not guarantee that we will be able to obtain or maintain regulatory approval in any other jurisdiction, while a failure or delay in obtaining regulatory approval in one jurisdiction may have a negative effect on the regulatory approval process in others. For example, even if the FDA grants marketing approval for a product candidate, comparable regulatory authorities in foreign jurisdictions must also approve the manufacturing, marketing and promotion of the product candidate in those countries. Approval procedures vary among jurisdictions and can involve requirements and administrative review periods different from, and greater than, those in the United States, including additional preclinical studies or clinical trials as clinical studies conducted in one jurisdiction may not be accepted by regulatory authorities in other jurisdictions. In many jurisdictions outside the United States, a product candidate must be approved for reimbursement before it can be approved for sale in that jurisdiction. In some cases, the price that we intend to charge for our products is also subject to approval.

We may also submit marketing applications in other countries. Regulatory authorities in jurisdictions outside of the United States have requirements for approval of product candidates with which we must comply prior to marketing in those jurisdictions. Obtaining foreign regulatory approvals and compliance with foreign regulatory requirements could result in significant delays, difficulties and costs for us and could delay or prevent the introduction of our products in certain countries. If we fail to comply with the regulatory requirements in international markets or receive applicable marketing approvals, our target market will be reduced and our ability to realize the full market potential of our product candidates will be harmed.

If we or our third-party manufacturers fail to comply with environmental, health and safety laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on the success of our business.

Our research and development activities involve the controlled use of potentially hazardous substances, including chemical and biological materials, by ourselves and our third-party manufacturers. Our manufacturers are subject to federal, state and local laws and regulations in the United States and abroad governing laboratory procedures and the use, manufacture, storage, handling and disposal of medical and hazardous materials. Although we believe that our manufacturers’ procedures for using, handling, storing and disposing of these materials comply with legally prescribed standards, we cannot completely eliminate the risk of contamination or injury resulting from medical or hazardous materials. As a result of any such contamination or injury, we may incur liability or local, city, state or federal authorities may curtail the use of these materials and interrupt our business operations. In the event of an accident, we could be held liable for damages or penalized with fines, and the liability could exceed our resources. We do not have any insurance for liabilities arising from medical or hazardous materials. Compliance with applicable environmental, health and safety laws and regulations is expensive, and current or future environmental regulations may impair our research, development and production efforts, which could harm our business, prospects, financial condition or results of operations.

Although we maintain workers’ compensation insurance to cover us for costs and expenses we may incur due to injuries to our employees resulting from the use of hazardous materials, this insurance may not provide adequate coverage against potential liabilities. We do not maintain insurance for environmental liability or toxic tort claims that may be asserted against us in connection with our storage or disposal of biological, hazardous or radioactive materials.

In addition, we may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. These current or future laws and regulations may impair our research, development or production efforts. Failure to comply with these laws and regulations also may result in substantial fines, penalties or other sanctions.

Recently enacted comprehensive tax reform bill could increase our tax burden and adversely affect our business and financial condition.

The U.S. government has recently enacted comprehensive tax legislation that includes significant changes to the taxation of business entities. These changes include, among others, (i) a permanent reduction to the corporate income tax rate, (ii) revisions to uses and limitations of net operating loss carryforwards created in tax years beginning after December 31, 2017 (iii) a partial limitation on the deductibility of business interest expense, (iv) a shift of the U.S. taxation of multinational corporations from a tax on worldwide income to a participation exemption system (along with certain rules designed to prevent erosion of the U.S. income tax base) and (v) aone-time tax on accumulated offshore earnings held in cash and illiquid assets, with the latter taxed at a lower rate.

In addition, beginning in 2022, the newly enacted tax legislation will require U.S. research and experimental expenditures to be capitalized and amortized ratably over a five-year period. Any such expenditures attributable to research conducted outside the U.S. must be capitalized and amortized over a15-year period. Further, the comprehensive tax legislation, among other things, reduces the orphan drug credit from 50% to 25% of qualifying expenditures. When and if we become profitable, this amortization of research and experimental expenditures and reduction in orphan drug tax credits may result in an increased federal income tax burden, as it may cause us to pay federal income taxes earlier under the revised tax law than under the prior law and, despite being partiallyoff-set by a reduction in the corporate tax rate from a top marginal rate of 35% to a flat rate of 21%, may increase our total federal tax liability.

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Notwithstanding the reduction in the corporate income tax rate, the overall impact of this tax reform is uncertain, and our business and financial condition could be adversely affected. In addition, it is uncertain if and to what extent various states will conform to the newly enacted federal tax law.

Risks Related to Our Intellectual Property

We depend on intellectual property licensed from CPF and Carna, and the termination of these licenses could result in the loss of significant rights, which would harm our business.

Pursuant to a license agreement with CPF, we hold an exclusive license from CPF to use certain patented technology, including certain patent rights,know-how and materials related to SRA737. Either party may terminate the agreement if the other party materially breaches the agreement, subject to certain cure provisions, and CPF may terminate the agreement in certain limited circumstances. We may also terminate the agreement at any time upon 90 days’ prior written notice to CPF. Additionally, pursuant to a license agreement with Carna, we hold an exclusive license from Carna to use certain patented technology, including certain patent rights andknow-how related to SRA141. Carna may terminate the agreement in the event of our material breach, subject to certain cure provisions, and we may terminate the agreement at any time upon 30 days’ prior written notice to Carna.

Disputes may arise between us and our licensors regarding intellectual property subject to these license agreements, including with respect to:

• the scope of rights granted under the license agreement and other interpretation-related issues;

• whether and the extent to which our technology and processes infringe on intellectual property of the licensor that is not subject to the licensing agreement;

• the amount and timing of milestone and royalty payments;

• the rights of our licensors under the license agreements;

• our right to sublicense patent and other rights to third parties under collaborative development relationships;

• our diligence obligations with respect to the use of the licensed technology in relation to our development and commercialization of our product candidates, and what activities satisfy those diligence obligations; and

• the ownership of inventions andknow-how resulting from the joint creation or use of intellectual property by our licensors and us and our partners.

Any disputes with our licensors over intellectual property that we have licensed from them may prevent or impair our ability to maintain our current licensing arrangements. We depend on these licensed technologies and products to develop our product candidates. Termination of our license agreements could result in the loss of significant rights and could materially harm our ability to further develop and commercialize our product candidates.

If we are not able to obtain and enforce patent protection for our technologies or product candidates, development and commercialization of our product candidates may be adversely affected.

Our success depends in part on our ability to obtain and maintain patents and other forms of intellectual property rights, includingin-licenses of intellectual property rights of others, for our product candidates, methods used to manufacture our product candidates and methods for treating patients using our product candidates, as well as our ability to preserve our trade secrets, to prevent third parties from infringing upon our proprietary rights and to operate without infringing upon the proprietary rights of others. Our licensors have filed, and we will continue to file, patent applications directed to the compositions of matter and methods of use related to various aspects of our product candidates.

We and our current or future licensors and licenses may not be able to apply for or prosecute patents on certain aspects of our product candidates or technologies at a reasonable cost in a timely fashion or at all. It is also possible that we or our current licensors, or any future licensors or licensees, will fail to identify patentable aspects of inventions made in the course of development and commercialization activities before it is too late to obtain patent protection on them. Therefore, our patents and applications may not be prosecuted and enforced in a manner consistent with the best interests of our business. It is possible that defects of form in the preparation or filing of our patents or patent applications may exist, or may arise in the future, such as with respect to proper priority claims, inventorship, claim scope or patent term adjustments. If our current licensors, or any future licensors or licensees, are not fully cooperative or disagree with us as to the prosecution, maintenance or enforcement of any patent rights, such patent rights could be compromised and we might not be able to prevent third parties from making, using, and selling competing products. If there are material defects in the form or preparation of our patents or patent applications, such patents or applications may be invalid and unenforceable. Moreover, our competitors may independently develop equivalent knowledge, methods, andknow-how. Any of these outcomes could impair our ability to prevent competition from third parties, which may have an adverse impact on our business, financial condition and operating results.

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There is no guarantee that any of our pending patent applications will result in issued or granted patents, that any of our issued or granted patents will not later be found to be invalid or unenforceable or that any issued or granted patents will include claims that are sufficiently broad to cover our product candidates or technologies or to provide meaningful protection from our competitors. Moreover, the patent position of oncology companies can be highly uncertain because it involves complex legal and factual questions. We will be able to protect our proprietary rights from unauthorized use by third parties only to the extent that our current and future proprietary technology and product candidates are covered by valid and enforceable patents or are effectively maintained as trade secrets. If third parties disclose or misappropriate our proprietary rights, it may materially and adversely impact our position in the market.

The U.S. Patent and Trademark Office (USPTO) and various foreign governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other provisions during the patent process. There are situations in which noncompliance can result in abandonment or lapse of a patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. In such an event, competitors might be able to enter the market earlier than would otherwise have been the case. The standards applied by the USPTO and foreign patent offices in granting patents are not always applied uniformly or predictably. For example, there is no uniform worldwide policy regarding patentable subject matter or the scope of claims allowable in oncology patents. Moreover, changes in either the patent laws or in the interpretations of patent laws in the United States and other countries may diminish the value of our intellectual property. As such, we do not know the degree of future protection that we will have on our proprietary products and technology. While we will endeavor to try to protect our product candidates with intellectual property rights such as patents, as appropriate, the process of obtaining patents is time-consuming, expensive and sometimes unpredictable.

Further, patents have a limited lifespan. In the United States, the natural expiration of a patent is generally 20 years after it is filed (or 20 years after the filing date of the firstnon-provisional US patent application to which it claims priority). Various extensions may be available; however, the life of a patent, and the protection it affords, is limited. Without patent protection for our product candidates, we may be open to competition from generic versions of our product candidates. Further, the extensive period of time between patent filing and regulatory approval for a product candidate limits the time during which we can market a product candidate under patent protection, which may particularly affect the profitability of our early-stage product candidates.

If we are unable to protect the confidentiality of our trade secrets our business and competitive position would be harmed.

In addition to seeking patent protection for certain aspects of our product candidates and technologies, we also consider trade secrets, including confidential and unpatentedknow-how important to the maintenance of our competitive position. We protect trade secrets and confidential and unpatentedknow-how, in part, by entering intonon-disclosure and confidentiality agreements with parties who have access to such knowledge, such as our employees, outside scientific collaborators, CROs, contract manufacturers, consultants, advisors and other third parties. We also enter into confidentiality and invention or patent assignment agreements with our employees and consultants that obligate them to maintain confidentiality and assign their inventions to us.

Despite these efforts, any of these parties may breach the agreements and disclose our proprietary information, including our trade secrets, and we may not be able to obtain adequate remedies for such breaches. Enforcing a claim that a party illegally disclosed or misappropriated a trade secret is difficult, expensive and time-consuming, and the outcome is unpredictable. In addition, some courts in the United States and certain foreign jurisdictions are less willing or unwilling to protect trade secrets. If any of our trade secrets were to be lawfully obtained or independently developed by a competitor, we would have no right to prevent them from using that technology or information to compete with us. If any of our trade secrets were to be disclosed to or independently developed by a competitor, our competitive position would be harmed.

Changes in patent law could diminish the value of patents in general, thereby impairing our ability to protect our product candidates.

Numerous recent changes to the patent laws and proposed changes to the rules of the USPTO may have a significant impact on our ability to protect our technology and enforce our intellectual property rights. For example, the Leahy-Smith America Invents Act (AIA) enacted in 2011 involves significant changes in patent legislation. An important change introduced by the AIA is that, as of March 16, 2013, the United States transitioned to a“first-to-file” system for deciding which party should be granted a patent when two or more patent applications are filed by different parties claiming the same invention. A third party that files a patent application in the USPTO after that date but before us could therefore be awarded a patent covering an invention of ours even if we had made the invention before it was made by the third party. This will require us to be cognizant going forward of the time from invention to filing of a patent application.

Further, the Supreme Court has ruled on several patent cases in recent years, some of which cases either narrow the scope of patent protection available in certain circumstances or weaken the rights of patent owners in certain situations. These changes have led to increasing uncertainty with regard to the scope and value of our issued patents and to our ability to obtain patents in the future.

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Among some of the other changes introduced by the AIA are changes that limit where a patentee may file a patent infringement suit and providing opportunities for third parties to challenge any issued patent in the USPTO. This applies to all of our U.S. patents, even those issued before March 16, 2013. Because of a lower evidentiary standard in USPTO proceedings compared to the evidentiary standard in United States federal court necessary to invalidate a patent claim, a third party could potentially provide evidence in a USPTO proceeding sufficient for the USPTO to hold a claim invalid even though the same evidence would be insufficient to invalidate the claim if first presented in a district court action. Accordingly, a third party may attempt to use the USPTO procedures to invalidate our patent claims that would not have been invalidated if first challenged by the third party as a defendant in a district court action.

Depending on decisions by the U.S. Congress, the U.S. federal courts, the USPTO or similar authorities in foreign jurisdictions, the laws and regulations governing patents could change in unpredictable ways that may weaken our and our licensors’ ability to obtain new patents or to enforce existing patents we and our licensors or partners may obtain in the future.

Once granted, patents may remain open to opposition, interference,re-examination, post-grant review, inter partes review, nullification derivation and opposition proceedings in court or before patent offices or similar proceedings for a given period after allowance or grant, during which time third parties can raise objections against such initial grant. In the course of such proceedings, which may continue for a protracted period of time, the patent owner may be compelled to limit the scope of the allowed or granted claims thus attacked, or may lose the allowed or granted claims altogether.

We, our licensors or any future strategic partners may become subject to third-party claims or litigation alleging infringement of patents or other proprietary rights or seeking to invalidate patents or other proprietary rights.

We, our licensors or any future strategic partners may be subject to third-party claims for infringement or misappropriation of patent or other proprietary rights that prevent us from developing and commercializing our products. If we, our licensors or any future strategic partners are found to infringe a third-party patent or other intellectual property rights, we could be required to pay substantial damages, potentially including treble damages and attorneys’ fees, if we are found to have willfully infringed. In addition, we, our licensors or any future strategic partners may choose to seek, or be required to seek, a license from a third party, which may not be available on acceptable terms, if at all. Even if a license can be obtained on acceptable terms, the rights may benon-exclusive, which could give our competitors access to the same technology or intellectual property rights licensed to us. If we fail to obtain a required license, we may be unable to effectively market product candidates, which could limit our ability to generate revenue or achieve profitability and possibly prevent us from generating revenue sufficient to sustain our operations. Alternatively, we may need to redesign our infringing products, which may be impossible or require substantial time and monetary expenditure. In addition, we may find it necessary to pursue claims or initiate lawsuits to protect or enforce our patent or other intellectual property rights. The cost to us in defending or initiating any litigation or other proceeding relating to patent or other proprietary rights, even if resolved in our favor, could be substantial, and litigation would divert our management’s attention. Some of our competitors may be able to sustain the costs of complex patent litigation more effectively than we can because they have substantially greater resources. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could delay our research and development efforts and limit our ability to continue our operations.

We may be involved in lawsuits to protect or enforce our patents or the patents of our licensors, which could be expensive, time-consuming and unsuccessful.

Competitors may infringe our patents or the patents of our licensors. To counter infringement or unauthorized use, we may be required to file infringement claims, which can be expensive and time-consuming. If we were to initiate legal proceedings against a third party to enforce a patent covering one of our products or our technology, the defendant could counterclaim that our patent is invalid or unenforceable. In patent litigation in the United States, defendant counterclaims alleging invalidity or unenforceability are commonplace. Grounds for a validity challenge could be an alleged failure to meet any of several statutory requirements, for example, lack of novelty, obviousness ornon-enablement. Grounds for an unenforceability assertion could be an allegation that someone connected with prosecution of the patent withheld relevant information from the USPTO, or made a misleading statement, during prosecution. The outcome following legal assertions of invalidity and unenforceability during patent litigation is unpredictable. With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art, of which we and the patent examiner were unaware during prosecution. If a defendant were to prevail on a legal assertion of invalidity or unenforceability, we would lose at least part, and perhaps all, of the patent protection on one or more of our products or certain aspects of our platform technology. Such a loss of patent protection could have a material adverse impact on our business. Patents and other intellectual property rights also will not protect our technology if competitors design around our protected technology without legally infringing our patents or other intellectual property rights.

In addition, in an infringement proceeding, a court may refuse to stop the other party from using the technology at issue on the grounds that our patents do not cover the technology in question. An adverse result in any litigation or defense proceedings could put one or more of our patents at risk of being invalidated, held unenforceable, or interpreted narrowly and could put our patent applications at risk of not issuing. Defense of these claims, regardless of their merit, would involve substantial litigation expense and would be a substantial diversion of employee resources from our business.

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Interference proceedings provoked by third parties or brought by the USPTO may be necessary to determine the priority of inventions with respect to our patents or patent applications or those of our licensors. An unfavorable outcome could result in a loss of our current patent rights and could require us to cease using the related technology or to attempt to license rights to it from the prevailing party. Our business could be harmed if the prevailing party does not offer us a license on commercially reasonable terms. Litigation or interference proceedings may result in a decision adverse to our interests and, even if we are successful, may result in substantial costs and distract our management and other employees. We may not be able to prevent, alone or with our licensors, misappropriation of our trade secrets or confidential information, particularly in countries where the laws may not protect those rights as fully as in the United States.

Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be compromised by disclosure during this type of litigation. In addition, there could be public announcements of the results of hearings, motions or other interim proceedings or developments. If securities analysts or investors perceive these results to be negative, it could have a substantial adverse effect on the price of our common stock.

Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment and other requirements imposed by governmental patent agencies, and our patent protection could be reduced or eliminated fornon-compliance with these requirements.

We have limited foreign intellectual property rights and may not be able to protect our intellectual property rights throughout the world.

We have limited intellectual property rights outside the United States. Filing, prosecuting and defending patents on product candidates in all countries throughout the world would be prohibitively expensive, and our intellectual property rights in some countries outside the United States can be less extensive than those in the United States. In addition, the laws of some foreign countries do not protect intellectual property rights to the same extent as federal and state laws in the United States. Consequently, we may not be able to prevent third parties from practicing our inventions in all countries outside the United States, or from selling or importing products made using our inventions in and into the United States or other jurisdictions. Competitors may use our technologies in jurisdictions where we have not obtained patent protection to develop their own products and further, may export otherwise infringing products to territories where we have patent protection, but enforcement is not as strong as that in the United States. These products may compete with our products and our patents or other intellectual property rights may not be effective or sufficient to prevent them from competing.

Many companies have encountered significant problems in protecting and defending intellectual property rights in foreign jurisdictions. The legal systems of certain countries, particularly certain developing countries, do not favor the enforcement of patents, trade secrets and other intellectual property protection, particularly those relating to oncology products, which could make it difficult for us to stop the infringement of our patents or marketing of competing products in violation of our proprietary rights generally. Proceedings to enforce our patent rights in foreign jurisdictions could result in substantial costs and divert our efforts and attention from other aspects of our business, could put our patents at risk of being invalidated or interpreted narrowly and our patent applications at risk of not issuing and could provoke third parties to assert claims against us. We may not prevail in any lawsuits that we initiate and the damages or other remedies awarded, if any, may not be commercially meaningful. Accordingly, our efforts to enforce our intellectual property rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we develop or license.

If we fail to comply with our obligations under any license, collaboration or other agreements, we may be required to pay damages and could lose intellectual property rights that are necessary for developing and protecting our product candidates and technologies or we could lose certain rights to grant sublicenses.

In connection with our recent acquisition of momelotinib from Gilead, we are required to make aggregate milestone payments of up to $195.0 million to Gilead upon the achievement of certain development, regulatory and commercial milestones, including a milestone payment of $5.0 million upon the initiation of a registrational clinical trial, as well asmid-teen to high twenty percent tiered royalties based upon net sales and additional tiered milestone payments upon reaching certain sales milestones. If we breach any of these obligations, we may be required to indemnify the Seller, subject to certain limitations set forth in the momelotinib purchase.

Additionally, our current license agreements impose, and any future licenses we enter into are likely to impose, various development, commercialization, funding, milestone, royalty, diligence, sublicensing, insurance, patent prosecution and enforcement, and other obligations on us. For example, we are required to use commercially reasonable efforts to develop and commercialize licensed products, and are required to pay CPF and Carna milestone payments in an aggregate amount of up to $319.5 and $270.0 million, respectively, based upon the achievement of certain developmental, regulatory and commercial milestones of SRA737 and SRA141, including a milestone payment of $4.0 million to Carna upon dosing of the first patient in the first Phase 1 clinical trial for SRA141. We are also required to pay CPF tiered high single-digit to low double-digit royalties on the net sales of SRA737 and to pay Carna tiered single-digit royalties on the net sales of SRA141. If we breach any of these obligations, or use the intellectual property licensed to us in an unauthorized manner, we may be required to pay damages and the licensor may have the right to terminate the license, which could result in us being unable to develop, manufacture and sell products that are covered by the licensed technology or enable

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a competitor to gain access to the licensed technology. We may also be required to negotiate to return our licensed intellectual property related to SRA737 to CPF if we cease or scale back development and commercialization of SRA737 for oncology-related indications. Moreover, our licensors may own or control intellectual property that has not been licensed to us and, as a result, we may be subject to claims, regardless of their merit, that we are infringing or otherwise violating the licensor’s rights. In addition, we may be required to pay significant milestone and royalty payments, depending on the technology and intellectual property we use in products that we successfully develop and commercialize, if any. Therefore, even if we successfully develop and commercialize products, we may be unable to achieve or maintain profitability.

We may be subject to claims that our employees, consultants or independent contractors have wrongfully used or disclosed confidential information of third parties.

We have received confidential and proprietary information from third parties. In addition, we employ individuals who were previously employed at other oncology companies. We may be subject to claims that we or our employees, consultants or independent contractors have inadvertently or otherwise used or disclosed confidential information of these third parties or our employees’ former employers. Litigation may be necessary to defend against these claims. Even if we are successful in defending against these claims, litigation could result in substantial cost and be a distraction to our management and employees.

Risks Related to Ownership of Our Common Stock

The market price of our common stock has been and may continue to be volatile, and you may be unable to sell your shares at or above the price at which you purchased them.

The market price of our common stock has been and may continue to be subject to wide fluctuations. For example, we experienced a significant decrease in our stock price after we announced the suspension of the development of our former lead product candidate PNT2258 and the DNAi platform in June 2016. Factors affecting the market price of our common stock include, but are not limited to:

• the timing and results of development activities related to our product candidates;

• the commencement, enrollment or results of future clinical trials we may conduct, or changes in the development status of our product candidates;

• any delay in our regulatory filings for our product candidates and any adverse development or perceived adverse development with respect to the applicable regulatory authority’s review of such filings;

• disputes with CPF or Carna regarding our licensed technology and products, or with Gilead regarding our acquisition of momelotinib and assumption of the related clinical trials;

• our ability to acquire orin-license new product candidates to grow our pipeline;

• adverse results or delays in preclinical studies or clinical trials;

• changes in laws or regulations applicable to our product candidates, including but not limited to clinical trial requirements for approvals;

• adverse developments concerning our manufacturers;

• our inability to obtain adequate product supply for any approved product or inability to do so at acceptable prices;

• our inability to establish collaborations if needed;

• our failure to commercialize our product candidates;

• additions or departures of key scientific or management personnel;

• unanticipated serious safety concerns related to the use of our product candidates;

• announcements of significant acquisitions, strategic partnerships, joint ventures or capital commitments by us or our competitors;

• the size and growth of our initial target markets;

• our ability to successfully treat additional types of cancers or at different stages;

• actual or anticipated variations in quarterly operating results;

• our failure to meet the estimates and projections of the investment community or that we may otherwise provide to the public;

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• publication of research reports about us or our industry, or immunotherapy in particular, or positive or negative recommendations or withdrawal of research coverage by securities analysts;

• changes in the market valuations of similar companies;

• overall performance of the equity markets;

• sales of our common stock by us or our stockholders in the future;

• disputes or other developments relating to proprietary rights, including patents, litigation matters and our ability to obtain patent protection for our technologies;

• significant lawsuits, including patent or stockholder litigation;

• general political and economic conditions; and

• other events or factors, many of which are beyond our control.

In addition, the stock market in general, and oncology companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our common stock, regardless of our actual operating performance. Securities class action litigation is often instituted against companies following periods of volatility in the market price of a company’s securities. For example, we are currently vigorously defending purported securities class action lawsuits against us and certain of our executive officers. This type of litigation could result in substantial costs and a diversion of management’s attention and resources, which could harm our business, operating results or financial condition.

We do not intend to pay dividends on our common stock so any returns will be limited to the value of our stock.

We currently anticipate that we will retain future earnings for the development, operation and expansion of our business and do not anticipate declaring or paying any cash dividends for the foreseeable future. Any return to stockholders will therefore be limited to the appreciation of their stock.

We are an emerging growth company, and we cannot be certain if the reduced reporting requirements applicable to emerging growth companies will make our common stock less attractive to investors.

We are an emerging growth company, as defined in the Jumpstart Our Business Startups Act (JOBS Act) enacted in April 2012. For as long as we continue to be an emerging growth company, we may take advantage of exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies, including not being required to comply with the auditor attestation requirements of Section 404 (Section 404) of the Sarbanes-Oxley Act of 2002, as amended (Sarbanes-Oxley Act), reduced disclosure obligations regarding executive compensation in our periodic reports and proxy statements and exemptions from the requirements of holding nonbinding advisory stockholder votes on executive compensation and stockholder approval of any golden parachute payments not previously approved. We cannot predict if investors will find our common stock less attractive because we may rely on these exemptions. If some investors find our common stock less attractive as a result, there may be a less active trading market for our common stock and our stock price may be more volatile.

We will remain an emerging growth company until the earlier of (i) the last day of the fiscal year (a) following the fifth anniversary of the completion of our IPO, (b) in which we have total annual gross revenue of at least $1.07 billion or (c) in which we are deemed to be a large accelerated filer, which requires the market value of our common stock that is held bynon-affiliates to exceed $700 million as of the prior June 30th, whichever is earliest; and (ii) the date on which we have issued more than $1 billion innon-convertible debt during the prior three-year period.

Under the JOBS Act, emerging growth companies can also delay adopting new or revised accounting standards until such time as those standards apply to private companies. We have irrevocably elected not to avail ourselves of this exemption from new or revised accounting standards and, therefore, are subject to the same new or revised accounting standards as other public companies that are not emerging growth companies. As a result, changes in rules of U.S. generally accepted accounting principles or their interpretation, the adoption of new guidance or the application of existing guidance to changes in our business could significantly affect our financial position and results of operations.

We incur significantly increased costs and devote substantial management time as a result of operating as a public company.

As a public company, we incur significant legal, accounting and other expenses that we did not incur as a private company. The Sarbanes-Oxley Act, the Dodd-Frank Wall Street Reform and Consumer Protection Act, the listing requirements of the stock exchange upon which our common stock is listed and other applicable securities rules and regulations impose various requirements on public companies, including establishment and maintenance of effective disclosure and financial controls and corporate governance practices. Our management and other personnel devote a substantial amount of time to these compliance initiatives. Moreover, these

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rules and regulations increase our legal and financial compliance costs and make some activities more time-consuming and costly. However, these rules and regulations are often subject to varying interpretations, in many cases due to their lack of specificity, and, as a result, their application in practice may evolve over time as new guidance is provided by regulatory and governing bodies. This could result in continuing uncertainty regarding compliance matters and higher costs necessitated by ongoing revisions to disclosure and governance practices.

Pursuant to Section 404, we are required to furnish a report by our management on our internal control over financial reporting. However, while we remain an emerging growth company, we will not be required to include an attestation report on internal control over financial reporting issued by our independent registered public accounting firm. To achieve compliance with Section 404 within the prescribed period, we are engaged in a process to document and evaluate our internal control over financial reporting, which is both costly and challenging. In this regard, we will need to continue to dedicate internal resources, potentially engage outside consultants and adopt a detailed work plan to assess and document the adequacy of internal control over financial reporting, continue steps to improve control processes as appropriate, validate through testing that controls are functioning as documented and implement a continuous reporting and improvement process for internal control over financial reporting. Despite our efforts, there is a risk that we will not be able to conclude, within the prescribed timeframe or at all, that our internal control over financial reporting is effective as required by Section 404.

Additionally, we have in the past and may in the future identify material weaknesses or significant deficiencies in internal control over financial reporting. Under standards established by the Public Company Accounting Oversight Board, a deficiency in internal control over financial reporting exists when the design or operation of a control does not allow management or personnel, in the normal course of performing their assigned functions, to prevent or detect misstatements on a timely basis. A material weakness is a deficiency or combination of deficiencies in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of our annual or interim financial statements will not be prevented or detected and corrected on a timely basis. We cannot assure you that there will not be additional material weaknesses or significant deficiencies that our independent registered public accounting firm or we will identify. If we identify such issues or if we are unable to produce accurate and timely financial statements, our stock price may be adversely affected and we may be unable to maintain compliance with the Nasdaq Stock Market listing requirements.

Provisions in our restated certificate of incorporation and restated bylaws and Delaware law might discourage, delay or prevent a change in control of our company or changes in our management and, therefore, depress the market price of our common stock.

Our restated certificate of incorporation and restated bylaws contain provisions that could depress the market price of our common stock by acting to discourage, delay or prevent a change in control of our company or changes in our management that the stockholders of our company may deem advantageous. These provisions, among other things:

• establish a classified board of directors so that not all members of our board are elected at one time;

• permit only the board of directors to establish the number of directors and fill vacancies on the board;

• provide that directors may only be removed “for cause” and only with the approval oftwo-thirds of our stockholders;

• require super-majority voting to amend some provisions in our restated certificate of incorporation and restated bylaws;

• authorize the issuance of “blank check” preferred stock that our board could use to implement a stockholder rights plan (also known as a “poison pill”);

• eliminate the ability of our stockholders to call special meetings of stockholders;

• prohibit stockholder action by written consent, which requires all stockholder actions to be taken at a meeting of our stockholders;

• prohibit cumulative voting; and

• establish advance notice requirements for nominations for election to our board or for proposing matters that can be acted upon by stockholders at annual stockholder meetings.

In addition, Section 203 of the Delaware General Corporation Law may discourage, delay or prevent a change in control of our company. Section 203 imposes certain restrictions on mergers, business combinations and other transactions between us and holders of 15% or more of our common stock.

If securities or industry analysts do not publish research, or publish inaccurate or unfavorable research, about our business, our stock price and trading volume could decline.

The trading market for our common stock depends in part on the research and reports that securities or industry analysts publish about us or our business. If one or more of the securities or industry analysts who publish research about us downgrade our stock or publish inaccurate or unfavorable evaluations of our company or our stock, the price of our stock could decline. If one or more of these analysts cease coverage of our company, our stock may lose visibility in the market, which in turn could cause our stock price to decline.

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ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

Unregistered Sale of Equity Securities

On August 21, 2018, the Company granted a warrant to Silicon Valley Bank to purchase 73,529 shares of the Company’s common stock at a price per share of $1.87. Additional shares may be issued upon each draw of any tranche B advance as determined by the principal advance amount, but not to exceed 73,529 shares and upon each draw of any tranche C advance as determined by the principal advance amount, but not to exceed 73,530. In no event will the number of common stock issuable pursuant to the exercise of the warrant exceed 220,588 in the aggregate. The warrant is immediately exercisable and will expire on August 21, 2028.

The issuance of the warrant was exempt from registration under the Securities Act of 1933, as amended, under Section 4(a)(2) thereof as a transaction by an issuer not involving a public offering.

Use of Proceeds

On July 15, 2015, our Registration Statement on FormS-1 (FileNo. 333-204921) relating to the IPO of our common stock was declared effective by the SEC. Pursuant to such Registration Statement, we sold an aggregate of 9,315,000 shares of our common stock at a price of $17.00 per share for aggregate cash proceeds of approximately $143.6 million, net of underwriting discounts and commissions and offering costs.

In June 2016, we halted investment in PNT2258, our former lead product candidate, based on our review of the interim results from a Phase 2 trial of PNT2258. Accordingly, we now intend to use the remaining net proceeds from our IPO to advance the development of product candidates momelotinib, SRA737 and SRA141, acquire orin-license additional product candidates and technologies and for other general corporate purposes.

ITEM 3. DEFAULTS UPON SENIOR SECURITIES

Not applicable.

ITEM 4. MINE SAFETY DISCLOSURES

Not applicable.

ITEM 5. OTHER INFORMATION

None.

ITEM 6. EXHIBITS

The exhibits filed or furnished as part of this Quarterly Report on Form10-Q are set forth below. Where so indicated, exhibits that were previously filed are incorporated by reference. For exhibits incorporated by reference, the location of the exhibit in the previous filing is indicated.

			Incorporated by Reference
Exhibit Number	Exhibit Description	Form	File No.	Exhibit No.	Exhibit Filing Date	Filed/Furnished Herewith
2.1#†	Asset Purchase Agreement dated August 20, 2018 by and between the Registrant and YM Biosciences Australia Pty Ltd, and Gilead Sciences, Inc.					X
4.1	Warrant dated August 21, 2018 issued to Silicon Valley Bank.					X
10.1#	Loan and Security Agreement dated August 21, 2018, by and between the Registrant and Silicon Valley Bank.					X

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			Incorporated by Reference
Exhibit Number	Exhibit Description	Form	File No.	Exhibit No.	Exhibit Filing Date	Filed/Furnished Herewith
10.2	2018 Equity Inducement Plan and forms of award agreements thereunder.					X
31.1	Certification of Principal Executive Officer, pursuant to Rule13a-14(a)/15d-14(a), as adopted pursuant to Section  302 of the Sarbanes-Oxley Act of 2002.					X
31.2	Certification of Principal Financial Officer, pursuant to Rule13a-14(a)/15d-14(a), as adopted pursuant to Section  302 of the Sarbanes-Oxley Act of 2002.					X
32.1*	Certification of Chief Executive Officer, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.					X
32.2*	Certification of Chief Financial Officer, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.					X
101.INS	XBRL Instance Document.					X
101.SCH	XBRL Taxonomy Extension Schema Document.					X
101.CAL	XBRL Taxonomy Extension Calculation Linkbase Document.					X
101.DEF	XBRL Taxonomy Extension Definition Linkbase Document.					X
101.LAB	XBRL Taxonomy Extension Labels Linkbase Document.					X
101.PRE	XBRL Taxonomy Extension Presentation Linkbase Document.					X

* This certification is deemed not filed for purpose of section 18 of the Exchange Act or otherwise subject to the liability of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act or the Exchange Act.

# Portions of this exhibit have been omitted based on an application for confidential treatment submitted to the SEC. The omitted portions of this exhibit have been filed separately with the SEC.

† Schedules and similar attachments to the agreement have been omitted pursuant to Item 601(b)(2) of RegulationS-K. The Company will furnish supplementally a copy of any omitted schedule or similar attachment to the SEC upon request.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	SIERRA ONCOLOGY, INC.
Date: November 8, 2018	By:	/s/ Nick Glover
		Dr. Nick Glover
		President and Chief Executive Officer
		(Principal Executive Officer)
Date: November 8, 2018	By:	/s/ Sukhi Jagpal
		Sukhi Jagpal
		Chief Financial Officer
		(Principal Financial Officer)

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