Leap Therapeutics (LPTX) 10-K16 Mar 202019 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2019	Mar. 11, 2020	Jun. 28, 2019
Document and Entity Information
Entity Registrant Name	LEAP THERAPEUTICS, INC.
Entity Central Index Key	0001509745
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Public Float			$ 28.2
Entity Common Stock, Shares Outstanding		35,799,488
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 3,891	$ 16,284
Research and development incentive receivable	185	836
Prepaid expenses and other current assets	165	202
Total current assets	4,241	17,322
Property and equipment, net	124	86
Right of use asset	1,026
Deferred tax assets	127	124
Deferred offering costs	831	162
Deposits	1,099	1,380
Total assets	7,448	19,074
Current liabilities:
Accounts payable	4,571	3,579
Accrued expenses	3,441	2,872
Lease liability - current portion	474
Total current liabilities	8,486	6,451
Non current liabilities:
Warrant liability		3,448
Restricted stock liability	159
Lease liability, net of current portion	552
Total liabilities	9,197	9,899
Stockholders' equity (deficiency):
Common stock, $0.001 par value; 100,000,000 shares authorized, 24,194,877 and 14,703,159 shares issued and outstanding as of December 31, 2019 and 2018, respectively	24	15
Additional paid-in capital	193,319	162,393
Accumulated other comprehensive income	76	302
Accumulated deficit	(195,168)	(153,535)
Total stockholders' equity (deficiency)	(1,749)	9,175
Total liabilities and stockholders' equity (deficiency)	$ 7,448	$ 19,074

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
CONSOLIDATED BALANCE SHEETS
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized shares	100,000,000	100,000,000
Common stock, issued shares	24,194,877	14,703,159
Common stock, outstanding shares	24,194,877	14,703,159

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating expenses:
Research and development	$ 24,366	$ 21,830
General and administrative	9,085	8,921
Total operating expenses	33,451	30,751
Loss from operations	(33,451)	(30,751)
Interest income	313	447
Interest expense	(23)	(19)
Australian research and development incentives	132	756
Foreign currency gains (loss)	126	(835)
Change in fair value of warrant liability		7,284
Loss before income taxes	(32,903)	(23,118)
Income taxes	3	(20)
Net loss	(32,900)	(23,138)
Dividend attributable to down round feature of warrants	(359)
Net loss attributable to common stockholders	$ (33,259)	$ (23,138)
Net loss per share
Basic (in dollars per share)	$ (1.47)	$ (1.64)
Diluted (in dollars per share)	$ (1.47)	$ (2.11)
Weighted average common shares outstanding
Basic (in shares)	22,582,687	14,144,287
Diluted (in shares)	22,582,687	14,412,695

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Net loss	$ (32,900)	$ (23,138)
Other comprehensive income (loss):
Foreign currency translation adjustments	(226)	570
Comprehensive loss	$ (33,126)	$ (22,568)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIENCY) - USD ($) $ in Thousands	Common StockCommon Stock Offering under the Lincoln Park Capital Registered Offering Purchase Agreement	Common Stock	Additional Paid-in CapitalCommon Stock Offering under the Lincoln Park Capital Registered Offering Purchase Agreement	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Common Stock Offering under the Lincoln Park Capital Registered Offering Purchase Agreement	Total
Balance at the beginning of the period at Dec. 31, 2017		$ 12		$ 141,770	$ (268)	$ (130,397)		$ 11,117
Balance at the beginning of the period (in shares) at Dec. 31, 2017		12,354,014
Increase (Decrease) in Stockholders' Equity
Issuance of common stock, net of issuance costs		$ 3		14,793				14,796
Issuance of common stock (in shares)		2,146,667
Issuance of common stock upon exercise of warrants				2,347				2,347
Issuance of common stock upon exercise of warrants (in shares)		200,000
Issuance of common stock upon exercise of stock options				14				$ 14
Exercised (in shares)		2,478						2,478
Foreign currency translation adjustment					570			$ 570
Stock-based compensation				3,469				3,469
Net loss						(23,138)		(23,138)
Balance at the end of the period at Dec. 31, 2018		$ 15		162,393	302	(153,535)		9,175
Balance at the end of the period (in shares) at Dec. 31, 2018		14,703,159
Increase (Decrease) in Stockholders' Equity
Issuance of common stock, net of issuance costs	$ 1	$ 7	$ 999	12,115			$ 1,000	12,122
Issuance of common stock (in shares)	571,429	7,557,142
Issuance of common stock through ATM sales		$ 1		1,922				1,923
Issuance of common stock through ATM sales (in shares)		1,033,147
ATM issuance costs				(13)				(13)
Commitment purchase agreement (in shares)		330,000
Lincoln Park issuance costs				(10)				(10)
Foreign currency translation adjustment					(226)			(226)
Reclassification of 2017 warrants from liability to equity				11,822		(8,374)		3,448
Dividend attributable to down round feature of warrants				359		(359)		(359)
Stock-based compensation				3,732				3,732
Net loss						(32,900)		(32,900)
Balance at the end of the period at Dec. 31, 2019		$ 24		$ 193,319	$ 76	$ (195,168)		$ (1,749)
Balance at the end of the period (in shares) at Dec. 31, 2019		24,194,877

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Public Offering
CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIENCY)
Issuance of common stock, issuance costs	$ 1,102	$ 1,304

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (32,900)	$ (23,138)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	47	49
Change in right of use assets.	729
Stock-based compensation expense	3,732	3,469
Change in fair value of restricted stock liability	159
Change in fair value of warrant liability		(7,284)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	302	(297)
Deferred tax assets	(3)	20
Research and development incentive receivable	643	780
Accounts payable and accrued expenses	1,084	368
Lease liability	(695)
Net cash used in operating activities	(26,902)	(26,033)
Cash flows from investing activities:
Purchases of property and equipment	(100)
Proceeds from sale of property and equipment	15
Net cash used in investing activities	(85)
Cash flows from financing activities:
Proceeds from the issuance of common stock, net of underwriter commissions and discounts	12,331	15,034
Proceeds from issuance of common stock from ATM sales	1,923
Proceeds from issuance of common stock in connection with July 2019 Lincoln Park Capital Registered Offering Purchase Agreement	1,000
Proceeds from the exercise of common stock warrants		1,217
Proceeds from the exercise of stock options		14
Payment of deferred offering costs	(437)	(359)
Net cash provided by financing activities	14,817	15,906
Effect of exchange rate changes on cash and cash equivalents	(223)	674
Net decrease in cash and cash equivalents	(12,393)	(9,453)
Cash and cash equivalents at beginning of period	16,284	25,737
Cash and cash equivalents at end of period	3,891	16,284
Supplemental disclosure of non-cash financing activities:
Reduction in fair value of warrant liability as a result of exercise of common stock warrants		1,130
Reclassification of 2017 Warrants from liability to equity	3,448
Dividend attributable to down round feature of warrants	359
Offering costs included in accounts payable and accrued expenses	444	$ 41
Right-of-use asset recorded upon adoption of ASU 2016-02	1,755
Lease liability recorded upon adoption of ASU 2016-02	1,720
Accrued rent reclassified upon adoption of ASU 216-02	$ 35

Nature of Business, Basis of Pr

Nature of Business, Basis of Presentation and Liquidity	12 Months Ended
Nature of Business, Basis of Presentation and Liquidity	Dec. 31, 2019
Nature of Business, Basis of Presentation and Liquidity
Nature of Business, Basis of Presentation and Liquidity	1. Nature of Business, Basis of Presentation and Liquidity Nature of Business Leap Therapeutics, Inc. was incorporated in the state of Delaware as Dekkun Corporation on January 3, 2011 and changed its name to HealthCare Pharmaceuticals, Inc. effective May 29, 2014, and then to Leap Therapeutics, Inc. effective November 16, 2015 (the “Company”). During 2015, HealthCare Pharmaceuticals Pty Ltd (“HCP Australia”) was formed and is a wholly owned subsidiary of the Company. During 2017, the Company merged with Macrocure Ltd. (now “Leap Therapeutics Ltd.”) and its wholly owned subsidiary Macrocure, Inc. The Company is a biopharmaceutical company acquiring and developing novel therapeutics at the leading edge of cancer biology. The Company’s approach is designed to target compelling tumor-promoting and immuno-oncology pathways to gene rate durable clinical benefit and enhanced outcomes for patients. The Company’s programs are monoclonal antibodies that target key cellular pathways that enable cancer to grow and spread and specific mechanisms that activate the body’s immune system to identify and attack cancer. Basis of Presentation The accompanying consolidated financial statements of the Company include the accounts of its wholly owned subsidiaries and have been prepared in conformity with accounting principles generally accepted in the United States of America. All inter-company accounts and transactions are eliminated upon consolidation. Liquidity Since inception, the Company has been engaged in organizational activities, including raising capital, and research and development activities. The Company does not yet have a product that has been approved by the Food and Drug Administration (the “FDA”), has not generated any revenues and has not yet achieved profitable operations, nor has it ever generated positive cash flows from operations. There is no assurance that profitable operations, if achieved, could be sustained on a continuing basis. Further, the Company’s future operations are dependent on the success of the Company’s efforts to raise additional capital, its research and commercialization efforts, regulatory approval, and, ultimately, the market acceptance of the Company’s products. In accordance with ASC 205‑40, Going Concern, the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the consolidated financial statements are issued. As of December 31, 2019, the Company had an accumulated deficit of $195,168. During the year ended December 31, 2019, the Company incurred a loss of $32,900 and used $26,902 of cash in operations. The Company expects to continue to generate operating losses in the foreseeable future. On January 3, 2020, the Company entered into a Securities Purchase Agreement (the “Securities Purchase Agreement”) with institutional investors named therein (collectively, the “Purchasers,” and each, a “Purchaser”), providing for a private placement transaction exempt from the registration requirements of the Securities Act of 1933, as amended (the “Securities Act”), pursuant to which the Company issued and sold 1,421,801 shares of the Company’s Series A Mandatorily Convertible Cumulative Non-Voting Perpetual Preferred Stock, par value $0.001 per share (the “Series A Preferred Stock”), at a purchase price of $10.54 per share, and 1,137,442 shares of the Company’s Series B Mandatorily Convertible Cumulative Non-Voting Perpetual Preferred Stock, par value $0.001 per share (the “Series B Preferred Stock”) at a purchase price of $10.55 per share, and one (1) share of the Company’s Special Voting Stock, par value $0.001 (the “Special Voting Stock”) entitling the Purchaser of Series A Preferred Stock to elect one member of the Company’s Board of Directors for aggregate net proceeds to the Company of approximately $25,300 (the “Transaction”). On January 3, 2020, the Company entered into an exclusive option and license agreement (the “BeiGene Agreement”) with BeiGene, Ltd. (“BeiGene”) for the clinical development and commercialization of DKN-01, the Company’s anti-Dickkopf-1 (DKK1) antibody, in Asia (excluding Japan), Australia, and New Zealand. The Company retains exclusive rights for the development, manufacturing, and commercialization of DKN-01 for the rest of the world. Pursuant to the BeiGene Agreement, the Company received an upfront cash payment of $3,000 from BeiGene in exchange for granting BeiGene an option to an exclusive license to develop and commercialize DKN-01 in Asia (excluding Japan), Australia, and New Zealand, and will be eligible to receive an additional payment upon BeiGene’s exercise of the option. Additionally, the Company is eligible to receive additional payments based upon the achievement of certain development, regulatory, and sales milestones as well as tiered royalties on any product sales of DKN-01 in the licensed territory. The Company believes that its cash and cash equivalents of $3,891 as of December 31, 2019, together with the $25,300 in net proceeds from the January 2020 private placement and the $3,000 upfront cash payment received from BeiGene, will be sufficient to fund its operating expenses for at least the next 12 months from issuance of these financial statements. In addition, the Company will seek additional funding through public or private equity financings or government programs and will seek funding or development program cost-sharing through collaboration agreements or licenses with larger pharmaceutical or biotechnology companies. If the Company does not obtain additional funding or development program cost-sharing, or exceeds its current spending forecasts or fails to receive the research and development tax incentive payment, the Company has the ability and would be forced to: delay, reduce or eliminate certain clinical trials or research and development programs, reduce or eliminate discretionary operating expenses, and delay company and pipeline expansion, any of which would adversely affect its business prospects. The inability to obtain funding, as and when needed, would have a negative impact on the Company’s financial condition and ability to pursue its business strategies.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2019
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Principles of Consolidation The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions are eliminated upon consolidation. Use of Estimates The presentation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) 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 consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Research and Development Expense Research and development costs are expensed as incurred. Research and development expenses include personnel costs associated with research and development activities, including noncash share-based compensation and costs for third-party contractors to perform research, conduct clinical trials and manufacture drug supplies and materials. The Company accrues for costs incurred by external service providers, including contract research organizations and clinical investigators, based on its estimates of service performed and costs incurred. These estimates include the level of services performed by the third parties, patient enrollment in clinical trials, administrative costs incurred by the third parties, and other indicators of the services completed. Based on the timing of amounts invoiced by service providers, the Company may also record payments made to those providers as prepaid expenses that will be recognized as expense in future periods as the related services are rendered. Research and development incentive income and receivable The Company recognizes other income from Australian research and development incentives when there is reasonable assurance that the income will be received, the relevant expenditure has been incurred, and the consideration can be reliably measured. The research and development incentive is one of the key elements of the Australian Government’s support for Australia’s innovation system and is supported by legislative law primarily in the form of the Australian Income Tax Assessment Act 1997 as long as eligibility criteria are met. Management has assessed the Company’s research and development activities and expenditures to determine which activities and expenditures are likely to be eligible under the research and development incentive regime described above. At each period end management estimates the refundable tax offset available to the Company based on available information at the time. This estimate is also reviewed by external tax advisors on an annual basis. Under the program, a percentage of eligible research and development expenses incurred by the Company through its subsidiary in Australia are reimbursed. The percentage was 43.5% for the years ended December 31, 2019 and 2018. The research and development incentive receivable represents an amount due in connection with the above program. The Company has recorded a research and development incentive receivable of $185 and $836 as of December 31, 2019 and 2018, respectively, in the consolidated balance sheets and other income from Australian research and development incentives of $132 and $756, in the consolidated statements of operations for the years ended December 31, 2019 and 2018, respectively, related to refundable research and development incentive program payments in Australia. The following table shows the change in the research and development incentive receivable from January 1, 2018 to December 31, 2019: Balance at January 1, 2018 $ 1,744 Australian research and development incentive income 756 Cash received for 2016 eligible overseas research and development expenses (740) Cash received for 2017 eligible expenses (793) Foreign currency translation (131) Balance at December 31, 2018 836 Australian research and development incentive income, net 132 Cash received for 2018 eligible expenses (757) Foreign currency translation (26) Balance at December 31, 2019 $ 185 Concentration of Credit Risk Financial instruments which potentially subject the Company to credit risk consist principally of cash and cash equivalents. All cash and cash equivalents are held in United States financial institutions and money market funds. At times, the Company may maintain cash balances in excess of the federally insured amount. Income Taxes The Company accounts for income taxes using the asset and liability method. Under the asset and liability method, deferred income taxes are recognized for differences between the financial reporting and tax bases of assets and liabilities at enacted statutory tax rates in effect for the years in which the differences are expected to reverse. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. The Company follows accounting guidance concerning provisions for uncertainty in income tax positions. This guidance clarifies the accounting for income taxes by prescribing a minimum probability threshold that an uncertain tax position must meet before a financial statement benefit is recognized. The minimum threshold is defined as a tax position that is more likely than not to be sustained upon examination by the applicable taxing authority, of any related appeals or litigation processes, based on the technical merits of the position. The tax benefit to be recognized is measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. The Company recognizes accrued interest and penalties associated with uncertain tax position as part of the income tax provision. There were no uncertain tax positions or income tax related interest and penalties recorded for the years ended December 31, 2019 and 2018. The income tax returns of the Company for the year ended December 31, 2016 and subsequent years are subject to examination by the Internal Revenue Service and other taxing authorities, generally for three years after the returns were filed. Foreign Currency Translation The financial statements of the Company’s foreign subsidiary are measured using the local currency as the functional currency. Assets and liabilities of this subsidiary are translated into U.S. dollars at exchange rates as of the consolidated balance sheet date. Equity is translated at historical exchange rates. Revenues and expenses are translated into U.S. dollars at average rates of exchange in effect during the year. The resulting cumulative translation adjustments have been recorded as a separate component of stockholders’ deficiency. Foreign currency transaction gains and losses are included in the results of operations. Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset. Computer equipment is depreciated over three years. Laboratory equipment, office equipment and furniture and fixtures are depreciated over five years. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the asset. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in loss from operations. Expenditures for repairs and maintenance are charged to expense as incurred. Impairment of Long-Lived Assets Long-lived assets consist of property and equipment. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset group for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset group to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset group over its fair value. The Company has not recorded any impairment losses on long-lived assets during 2019 and 2018. Deferred Offering Costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ equity (deficiency) as a reduction of additional paid-in capital generated as a result of the offering. As of December 31, 2019 and 2018 there was $831 and $162, respectively, of deferred offering costs. Deposits Deposits as of December 31, 2019 and 2018, included $1,099 and $1,380, respectively, of deposits made by the Company with certain service providers that are to be applied to future payments due under the service agreements or returned to the Company if not utilized. Fair Value of Financial Instruments Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: · Level 1—Quoted prices in active markets for identical assets or liabilities. · Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. · Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. During the years presented, the Company has not changed the manner in which it values assets and liabilities that are measured at fair value using Level 3 inputs. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. There were no transfers within the hierarchy during the years ended December 31, 2019 and 2018. A summary of the assets and liabilities carried at fair value in accordance with the hierarchy defined above is as follows (in thousands): Total Level 1 Level 2 Level 3 December 31, 2019 Assets: Cash equivalents $ 3,891 $ 3,891 $ — $ — Total assets $ 3,891 $ 3,891 $ — $ — December 31, 2018 Assets: Cash equivalents $ 16,284 $ 16,284 $ — $ — Total assets $ 16,284 $ 16,284 $ — $ — Liabilities: Warrant liability $ 3,448 $ — $ — $ 3,448 Total liabilities $ 3,448 $ — $ — $ 3,448 Cash equivalents of $3,891 and $16,284 as of December 31, 2019 and 2018, respectively, consisted of overnight investments and money market funds and are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices in active markets. The carrying value of the research and development incentive receivable, accounts payable and accrued expenses approximate their fair value due to the short-term nature of these assets and liabilities. A roll-forward of the recurring fair value measurements of the warrant liability categorized with Level 3 inputs are as follows (in thousands): Warrant Liability Balance-January 1, 2018 $ 11,862 Exercise of warrants (1,130) Change in Fair value (7,284) Balance-December 31, 2018 $ 3,448 Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11 (3,448) Balance-January 1, 2019 $ — The warrant liability in the table above is composed of the fair value of warrants (the “2017 Warrants”) to purchase common shares that the Company issued in connection with a private placement (the“November 2017 Private Placement”). The fair value of the warrant liability was determined based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. The Company utilized a Monte Carlo simulation, which is a statistical method used to generate a defined number of share price paths to develop a reasonable estimate of the range of the future expected share prices, to value the warrant liability. The Monte Carlo simulation incorporated assumptions and estimates to value the warrant liability. Estimates and assumptions impacting the fair value measurement included the estimated probability of adjusting the exercise price of the warrants, the number of shares for which the warrants will be exercisable, the remaining contractual term of the warrants, the risk-free interest rate, the expected dividend yield, and the expected volatility of the price of the underlying common shares. The Company historically had been a private company and lacks company-specific historical and implied volatility information of its shares. Therefore, it estimated its expected share volatility based on the historical volatility of publicly traded peer companies for a term equal to the remaining contractual term of the warrants. The risk-free interest rate was determined by reference to the U.S. Treasury yield curve for time periods approximately equal to the remaining contractual term of the warrants. The Company estimated a 0% expected dividend yield based on the fact that the Company has never paid or declared dividends and does not intend to do so in the foreseeable future. Leases In February 2016, the FASB issued ASU 2016-02, Leases, or ASU 2016-02, to enhance the transparency and comparability of financial reporting related to leasing arrangements. The Company adopted ASU 2016-02 on January 1, 2019, the effective date, and used the effective date as its date of initial application. At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present. Most leases with a term greater than one year are recognized on the balance sheet as right-of-use assets, lease liabilities and, if applicable, long-term lease liabilities. The Company has elected not to recognize on the balance sheet leases with terms at commencement of one year or less. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected remaining lease term. The Company has determined that the rate implicit in the lease is not determinable and the Company does not have borrowings with similar terms and collateral. Therefore, the Company considered a variety of factors, including observable debt yields from comparable companies and the volatility in the debt market for securities with similar terms, in determining that 8% was reasonable to use as the incremental borrowing rate for purposes of the calculation of lease liabilities. In accordance with the guidance in ASU 2016-02, components of a lease should be split into three categories: lease components (e.g. land, building, etc.), non-lease components (e.g. common area maintenance, maintenance, consumables, etc.), and non-components (e.g. property taxes, insurance, etc.). Then the fixed and in-substance fixed contract consideration (including any related to non-components) must be allocated based on fair values to the lease components and non-lease components. Although separation of lease and non-lease components is required, certain practical expedients are available. Entities may elect the practical expedient to not separate lease and non-lease components. Rather, they would account for each lease component and the related non-lease component together as a single component. The Company has elected to account for the lease and non-lease components of each of its operating leases as a single lease component and allocate all of the contract consideration to the lease component only. The lease component results in an operating right-of-use asset being recorded on the consolidated balance sheets and amortized such that lease expense is recorded on a straight line basis over the term of the lease. Segment Information The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is developing novel, targeted drugs for the treatment of cancer. Substantially all of the Company’s tangible assets are held in the United States. Patent Costs All patent related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses. Stock-Based Compensation The Company measures all stock options and other stock-based awards granted to employees based on the fair value on the date of the grant and recognizes compensation expense of those awards, net of estimated forfeitures, over the requisite service period, which is generally the vesting period of the respective award. Generally, the Company issues stock options to employees with only service-based vesting conditions and records the expense for these awards using the straight-line method. The Company measures stock-based awards granted to consultants and nonemployees based on the fair value of the award on the date on which the related service is complete. Compensation expense is recognized over the period during which services are rendered by such consultants and nonemployees until completed. At the end of each financial reporting period prior to completion of the service, the fair value of these awards is remeasured using the then current fair value of the Company’s common stock and updated assumption inputs in the Black-Scholes option-pricing model. Stock-based compensation is classified in the accompanying consolidated statements of operations based on the function to which the related services are provided. The Company recognizes compensation expense for only the portion of awards that are expected to vest. In developing a forfeiture rate estimate, the Company has considered its historical experience to estimate pre-vesting forfeitures for service-based awards. The impact of a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual forfeiture rate is materially different from the Company’s estimate, the Company may be required to record adjustments to stock-based compensation expense in future periods. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The Company historically has been a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The expected term of stock options granted to nonemployees is equal to the contractual term of the option award. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends on common stock and does not expect to pay any cash dividends in the foreseeable future. Net Loss per Share Basic net loss per share is computed using the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential shares of common stock, including the assumed exercise of stock options. Reclassifications Certain prior period amounts have been reclassified for consistency with the current period presentation. These reclassifications had no effect on previously reported results of operations. Warrant Liability In connection with entering into the November 2017 Private Placement, the Company issued the 2017 Warrants with each share of common stock sold in the November 2017 Private Placement. The Company classified the 2017 Warrants as a liability on its consolidated balance sheet prior to January 1,2019, because each warrant represented a freestanding financial instrument that is not indexed to the Company’s own shares. The warrant liability was initially recorded at fair value upon entering into the November 2017 Private Placement agreement and was subsequently remeasured to fair value at each reporting date. Changes in the fair value of the warrant liability were recognized as gains (losses) in the consolidated statements of operations through the year ended December 31,2018. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board, or FASB, and are early adopted by the Company or adopted as of the specified effective date. In June 2018, the FASB issued ASU No. 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, which is intended to simplify the accounting for share-based payments to nonemployees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The new guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted this standard effective January 1, 2019, which had no impact on the Company's consolidated financial statements. In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), and Derivatives and Hedging (Topic 815) ("ASU 2017-11"), which changes the classification analysis of certain equity-linked financial instruments (or embedded features) with down round features. The amendments require entities that present earnings per share ("EPS") in accordance with Topic 260 to recognize the effect of the down round feature when triggered with the effect treated as a dividend and as a reduction of income available to common shareholders in basic EPS. The new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted this standard effective January 1, 2019 and concluded that the 2017 Warrants qualified for equity classification. The Company applied the guidance retrospectively to the 2017 Warrants by means of a cumulative-effect adjustment to its statement of financial position as of the beginning of the interim and annual period beginning January 1, 2019. The Company performed a final remeasurement of the warrant liability as of January 1, 2019 and reclassified $3,448 to stockholders’ equity. In February 2016, the FASB issued ASU 2016-02, Leases, or ASU 2016-02. ASU 2016-02 requires a lessee to recognize on its balance sheet (for both finance and operating leases) a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for the lease term. ASU 2016-02 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company adopted ASU 2016-02 on January 1, 2019, the effective date, and used the effective date as its date of initial application. As such, the Company did not adjust prior period amounts. The Company also elected to adopt the practical expedients upon transition, which permit companies to not reassess lease identification, classification, and initial direct costs under ASU 2016-02 for leases that commenced prior to the effective date (see Note 5).

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
Property and Equipment, Net	Dec. 31, 2019
Property and Equipment, Net
Property and Equipment, Net	3. Property and Equipment, Net Property and equipment, net consisted of the following: December 31, 2019 2018 Computer office equipment $ 51 $ 51 Leasehold improvements 69 69 Lab equipment 113 58 Furnitures and fixtures 30 30 263 208 Less: accumulated depreciation (139) (122) Property and equipment, net $ 124 $ 86 Depreciation expense was $47 and $49 for the years ended December 31, 2019 and 2018, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
Accrued Expenses	Dec. 31, 2019
Accrued Expenses
Accrued Expenses	4. Accrued Expenses Accrued expenses consist of the following: December 31, 2019 2018 Clinical trials $ 1,828 $ 1,745 Professional fees 609 219 Payroll and related expenses 1,004 908 Accrued expenses $ 3,441 $ 2,872

Leases

Leases	12 Months Ended
Leases	Dec. 31, 2019
Leases
Leases	5. Leases Effective January 1, 2017, the Company entered into an assignment agreement to assume an operating lease for its office space in Cambridge, Massachusetts. Annual rent under the lease, exclusive of operating expenses and real estate taxes, was $289 for the 12-month period ending July 31, 2017, $297 for the 12-month period ending July 31, 2018 and $305 for the 12-month period ending April 30, 2019. During the year ended December 31, 2018, the Company extended the term through April 30, 2022. Annual rent, exclusive of operating expenses and real estate taxes, for the 12-month periods ending April 30, 2020, April 30, 2021 and April 30, 2022, is $422, $429 and $437, respectively. Effective July 15, 2018, the Company entered into an agreement to assume an operating lease for its research laboratory in Cambridge, Massachusetts. Annual rent under the lease, exclusive of operating expenses and real estate taxes, is $420. The lease expires on April 30, 2020. Future lease payments under non-cancelable operating leases as of December 31, 2019 are detailed as follows: Future Operating Lease Payments 2020 532 2021 434 2022 146 Total Lease Payments 1,112 Less: imputed interest (86) Total operating lease liabilities $ 1,026 In February 2016, the FASB issued ASU 2016-02 as amended, Leases Topic 842. Topic 842 requires a lessee to recognize on its balance sheet (for both finance and operating leases) a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for the lease term. The Company adopted Topic 842 on January 1, 2019, the effective date, and used the effective date as its date of initial application. As such, the Company did not adjust prior period amounts. The Company also elected to adopt the practical expedients upon transition, which permit companies to not reassess lease identification, classification, and initial direct costs under Topic 842 for leases that commenced prior to the effective date. The Company has operating leases for real estate in the United States and does not have any finance leases. The Company’s leases may contain options to renew and extend lease terms and options to terminate leases early. Reflected in the right-of-use asset and lease liability on the Company’s consolidated balance sheets are the periods provided by renewal and extension options that the Company is reasonably certain to exercise, as well as the periods provided by termination options that the Company is reasonably certain to not exercise. The Company has existing leases that include variable lease and non-lease components that are not included in the right-of-use asset and lease liability and are reflected as an expense in the period incurred. Such payments primarily include common area maintenance charges and increases in rent payments that are driven by factors such as future changes in an index (e.g., the Consumer Price Index). In calculating the present value of future lease payments, the Company utilized its incremental borrowing rate based on the remaining lease term at the date of adoption. The Company has elected to account for each lease component and its associated non-lease components as a single lease component and has allocated all of the contract consideration across lease components only. This will potentially result in the initial and subsequent measurement of the balances of the right-of-use asset and lease liability for leases being greater than if the policy election was not applied. The Company has existing net leases in which the non-lease components (e.g. common area maintenance, maintenance, consumables, etc.) are paid separately from rent based on actual costs incurred and therefore are not included in the right-of-use asset and lease liability and are reflected as an expense in the period incurred. On January 1, 2019, the Company recorded a right-of-use asset of $1,755 and a lease liability of $1,755 on its consolidated balance sheet. As of December 31, 2019, a right-of-use asset of $1,026 and lease liability of $1,026 are reflected on the consolidated balance sheets. The Company recorded rent expense of $837 and $690 during the years ended December 31, 2019 and 2018, respectively.

Warrants

Warrants	12 Months Ended
Warrants	Dec. 31, 2019
Warrants
Warrants	6. Warrants As of December 31, 2019, outstanding warrants to purchase common stock consisted of the following: December 31, 2019 Number of Shares Date Exercisable Issuable Exercise Price Exercisable for Classification Penny Warrants 54,516 $ 0.01 Common Stock Equity 2017 Warrants 2,758,094 $ 1.75 Common Stock Equity 2019 Warrants 7,557,142 $ 1.95 Common Stock Equity 10,369,752 2017 Warrants The 2017 Warrants contain full ratchet anti-dilution protection provisions. Prior to January 1, 2019, the Company classified the 2017 Warrants as a liability on its consolidated balance sheet because each warrant represented a freestanding financial instrument that, due to the potential variable nature of the exercise price, is not considered to be indexed to the Company’s own shares. The warrant liability was initially recorded at fair value upon entering into the Private Placement and has been subsequently remeasured to fair value at each reporting date. Changes in the fair value of the warrant liability were recognized as gains (losses) in the Company’s consolidated statement of operations. On January 1, 2019, the Company adopted ASU 2017-11 and concluded that the 2017 Warrants now qualify for equity classification. The Company applied the guidance retrospectively to the 2017 Warrants by means of a cumulative-effect adjustment to its statement of financial position as of the beginning of the interim and annual period beginning January 1, 2019. The Company performed a final remeasurement of the warrant liability as of January 1, 2019 and reclassified $3,448 to stockholders’ equity. The Company will recognize on a prospective basis the value of the effect of the down round feature in the warrant when it is triggered (i.e., when the exercise price is adjusted downward). This value is measured as the difference between (1) the financial instrument’s fair value (without the down round feature) using the pre-trigger exercise price and (2) the financial instrument’s fair value (with the down round feature) using the reduced exercise price. The value of the effect of the down round feature will be treated as a dividend and a reduction to income available to common shareholders in the basic EPS calculation. In connection with the public offering in February 2019, when the 2017 Warrants were repriced from $6.085 to $1.75, the Company recorded a dividend of $359 during the year ended December 31, 2019. 2019 Warrants On February 5, 2019, in connection with the 2019 Public Offering, the Company issued immediately exercisable warrants (the “2019 Warrants”) to purchase 7,557,142 shares of common stock to investors. The 2019 Warrants have an exercise price of $1.95 per share and expire on February 5, 2026. The 2019 Warrants qualify for equity classification.

Common Stock

Common Stock	12 Months Ended
Common Stock	Dec. 31, 2019
Common Stock
Common Stock	7. Common Stock Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, if any, subject to the preferential dividend rights of the preferred stockholders. Through December 31, 2019, no dividends have been declared. As of December 31, 2019, the Company had reserved shares of common stock for the exercise of outstanding stock options and warrants, and for the number of shares remaining for grant under the Company's 2012 and 2016 Equity Incentive Plans (see Note 8). Public Offering of Common Stock — March 2018 On March 27, 2018, the Company completed a public offering whereby the Company issued 2,146,667 shares of its common stock at a price of $7.50 per share, which included 280,000 shares issued pursuant to the underwriters’ exercise of their option to purchase additional shares of common stock. The aggregate net proceeds received by the Company from the offering were approximately $14,796, net of underwriting discounts and commissions and estimated offering expenses payable by the Company. Public Offering of Common Stock - February 2019 On February 5, 2019, the Company completed the 2019 Public Offering whereby the Company issued 7,557,142 shares of its common stock at a price of $1.75 per share, which included 985,714 shares issued pursuant to the underwriters’ exercise of their option to purchase additional shares of common stock, each share issued with a warrant to purchase one share of common stock. Each warrant has an exercise price of $1.95 per share with an exercise period expiring seven years from the date of issuance. The aggregate net proceeds received by the Company from the 2019 Public Offering were approximately $12,122, net of underwriting discounts and commissions and estimated offering expenses payable by the Company. Issuance of Common Stock under Distribution Agreement - 2019 On September 7, 2018, the Company filed a Prospectus Supplement to register the offer and sale of shares of common stock having an aggregate offering price of up to $30,000 pursuant to the terms of a distribution agreement, or the Distribution Agreement, with Raymond James & Associates, Inc. During the year ended December 31, 2019, the Company issued 1,033,147 shares under the Distribution Agreement, for net proceeds of $1,923. Lincoln Park Purchase Agreements - July 2019 On July 10, 2019, the Company entered into a Commitment Purchase Agreement and a Registration Rights Agreement with Lincoln Park, pursuant to which the Company has the right to sell to Lincoln Park up to $20,000 in shares of its Common Stock, $0.001 par value per share, subject to certain limitations and conditions set forth in the Commitment Purchase Agreement. As consideration for Lincoln Park’s commitment to purchase shares of Common Stock pursuant to the Commitment Purchase Agreement, the Company issued to Lincoln Park 330,000 shares of Common Stock. The Company did not receive any cash proceeds from the issuance of such shares. On July 11, 2019, the Company entered into a Registered Offering Purchase Agreement and together with the Commitment Purchase Agreement, under which the Company agreed to sell to Lincoln Park, and Lincoln Park agreed to purchase 571,429 shares of its Common Stock, at a price of $1.75 per share for an aggregate purchase price of $1,000.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
Stock-Based Compensation	Dec. 31, 2019
Stock-Based Compensation
Stock-Based Compensation	8. Stock-Based Compensation Equity Incentive Plans In September 2012, the Company adopted the 2012 Equity Incentive Plan, as amended (the "Plan"), which provides designated employees of the Company and its affiliates, certain consultants and advisors who perform services for the Company and its affiliates, and nonemployee members of the Board of Directors of the Company and its affiliates with the opportunity to receive grants of incentive stock options, nonqualified stock options and stock awards. On January 20, 2017, the Company's stockholders approved the 2016 Equity Incentive Plan (the "2016 Plan"). Beginning on January 1, 2018, the number of shares of common stock authorized for issuance pursuant to the 2016 Plan was increased each January 1 by an amount equal to four percent (4%) of the Company's outstanding common stock as of the end of the immediately preceding calendar year or such other amount as determined by the compensation committee of the Company's Board of Directors. During the year ended December 31, 2019, the compensation committee of the board of directors authorized an additional 3,000,000 shares of Common Stock to be added to the shares authorized for issuance under the 2016 Plan. In connection with the merger with Macrocure in January 2017, the Company assumed the Macrocure 2013 Share Incentive Plan (the “2013 Plan”), the Macrocure 2008 Stock Option Plan (the “2008 Plan”) and all stock options outstanding under each of the 2013 Plan and the 2008 Plan immediately prior to the consummation of the merger. As of December 31, 2019, there were 2,459,373 shares available for grant under the Company’s Equity Incentive Plans. A summary of activity under the Company’s Equity Incentive Plans is as follows: Weighted Average Weighted Aggregate Exercise Price Average Remaining Intrinsic Options Per Share Life in Years Value Outstanding at December 31, 2017 2,257,621 $ 12.38 8.66 $ 68 Granted 599,050 $ 6.68 Exercised (2,478) $ 5.56 Forfeited (92,281) $ 7.89 Outstanding at December 31, 2018 2,761,912 $ 11.30 8.01 $ — Granted 1,481,975 $ 1.48 Forfeited (219,321) $ 15.14 Outstanding at December 31, 2019 4,024,566 $ 7.48 7.98 $ 2 Options exercisable at December 31, 2019 2,398,685 $ 10.48 7.25 $ — Options vested and expected to vest at December 31, 2019 4,024,566 $ 7.48 7.98 $ 2 During the years ended December 31, 2019 and 2018 the Company recognized $3,732 and $3,469 respectively, of stock-based compensation expense. The grant date fair value of the options granted during the years ended December 31, 2019 and 2018, was estimated at the date of grant using the Black-Scholes option valuation model. The expected life was estimated using the “simplified” method. The expected volatility was based on the historical volatility of comparable public companies from a representative peer group selected based on industry and market capitalization data. The risk-free interest rate was based on the continuous rates provided by the U.S. Treasury with a term approximating the expected life of the option. The expected dividend yield was 0% because the Company does not expect to pay any dividends for the foreseeable future. The Company elected the straight-line attribution method in recognizing the grant date fair value of options issued over the requisite service periods of the awards, which are generally the vesting periods. The assumptions that the Company used to determine the grant-date fair value of stock options granted to employees and directors were as follows, presented on a weighted average basis: Year Ended Year Ended December 31, December 31, 2019 2018 Expected volatility % 66.94 % Weighted average risk-free interest rate % 2.80 % Expected dividend yield % % Expected term (in years) 6.95 Stock options generally vest over a three or four year period, as determined by the Compensation Committee of the Board of Directors at the time of grant. The options expire ten years from the grant date. As of December 31, 2019, there was approximately $3,059 of unrecognized compensation cost related to non-vested stock options, which is expected to be recognized over a remaining weighted-average period of approximately 2.19 years. Stock-based compensation expense was classified in the consolidated statements of operations as follows: Year Ended December 31, 2019 2018 Research and development $ 714 $ 625 General and administrative 3,018 2,844 Total $ 3,732 $ 3,469 Restricted Stock Units During the year ended December 31, 2019, the Company issued 181,000 restricted stock units (“RSUs”) to employees under the 2016 Plan. Upon vesting of the RSUs, the Company has the option to settle the award by either issuing shares of the Company’s common stock or paying an amount of cash equal to the fair value of the Company’s common stock on the settlement date. In October 2019, the Company cash settled 90,500 RSUs. As of December 31, 2019, the Company recorded a restricted stock liability on its consolidated balance sheet of $159. The following table presents a summary of outstanding RSU’s under the 2016 Plan as of December 31, 2019: Weighted Number of Average Shares Fair Value Outstanding at December 31, 2018 — $ — Awarded 181,000 $ Settled in cash (90,500) $ Outstanding at December 31, 2019 90,500 $ As of December 31, 2019, there were 90,500 shares outstanding covered by RSUs which were fully vested. The weighted average grant date fair value of these shares of restricted stock was $1.74 per share and the fair value of these shares of restricted stock was approximately $159 as of December 31, 2019.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2019
Income Taxes
Income Taxes	9. Income Taxes The Company had federal, state and foreign net operating loss carryforwards of approximately $135,890, $117,579 and $83,950, respectively, as of December 31, 2019. The U.S. tax losses begin to expire in 2030. The foreign losses are primarily from Israel and have an indefinite carryforward. The Company’s federal net operating losses include $54,581 which can also be carried forward indefinitely. The Company may be able to utilize its net operating loss carryforwards to reduce future federal and State income tax liabilities. However, these net operating losses are subject to various limitations under Internal Revenue Code section 382, which limit the use of net operating loss carryforwards to the extent there has been in ownership change of more than 50 percentage points. In addition, the net operating loss carryforwards are subject to examination by the taxing authorities and could be adjusted or disallowed due to such exams. Although the Company has not undergone an IRC section 382 analysis, it is possible that the utilization of the Company’s net operating loss carryforwards may be limited. In addition, the Company has federal and state research and development tax credits of approximately $3,770 and $645, respectively, that begin expiring in 2030 for federal and state tax purposes and whose future usage may also be limited to the extent there has been an ownership change of more than 50 percentage points. There is no provision for income taxes in the United States or Israel, because the Company has historically incurred operating losses and maintains a full valuation allowance against its deferred tax assets in these jurisdictions. The deferred tax asset recorded in the consolidated balance sheets relates to the Company’s Australian operations. Income (loss) before income taxes consisted of the following: Year Ended December 31, 2019 2018 U.S. $ (32,875) $ (21,378) Foreign (28) (1,740) Loss before income taxes $ (32,903) $ (23,118) A summary of the Company’s current and deferred expense for income tax is as follows: Year Ended December 31, 2019 2018 Current expense (benefit): Federal $ — $ — State — — Foreign — — Total current expense (benefit): $ — $ — Deferred expense (benefit): Federal $ — $ — State — — Foreign (3) 20 Total deferred expense (benefit): $ (3) $ 20 Total income tax expense (benefit): $ (3) $ 20 A reconciliation of the Company’s statutory income tax rate to the Company’s effective income tax rate is as follows: Year Ended December 31, 2019 2018 Federal statutory income tax rate 21.00 % 21.00 % State taxes, net of federal benefit 6.79 % 7.76 % Permanent differences (0.33) % 2.38 % Tax credits 3.30 % 6.94 % Foreign rate differential 0.07 % 0.68 % Valuation allowance (40.18) % (38.26) % Other 9.35 % (0.59) % 0.01 % (0.09) % The significant components of the Company’s deferred tax assets as of December 31, 2019 and 2018 were as follows: Year Ended December 30, 2019 2018 Federal net operating loss carryforwards $ 47,845 $ 38,531 State net operating loss carryforwards 7,431 5,553 Stock Options 2,584 1,632 Federal research tax credits 3,770 2,811 State research tax credits 510 382 License fees 1,332 1,495 Accrued expenses 277 88 Other 115 149 Total deferred tax assets $ 63,864 $ 50,641 Valuation allowance (63,737) (50,517) Net deferred tax asset (liability) $ 127 $ 124 As of December 31, 2019 and 2018, the Company had provided a full valuation allowance against its net deferred tax assets, except for its Australian deferred tax assets, because realization of any future tax benefit cannot be reasonably assured. The valuation allowance increased during the years ended December 31, 2019 and 2018, by $13,220 and $8,181, respectively. The Company follows the authoritative guidance on accounting for and disclosure of uncertainty in tax positions, which requires the Company to determine whether a tax position of the Company is more likely than not to be sustained upon examination, including resolution of any related appeals of litigation processes, based on the technical merits of the position. For tax positions meeting the more likely than not threshold, the tax amount recognized in the financial statements is reduced by the largest benefit that has a greater than 50% likelihood of being realized upon the ultimate settlement with the relevant taxing authority. The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business the Company is subject to examination by federal and state jurisdictions, where applicable. There are currently no pending tax examinations. The earliest tax years that may be subject to examination by jurisdiction are 2016 for both federal and state purposes. In addition, the NOL carryforwards are subject to examination by the taxing authority and could be adjusted or disallowed due to such exams. The Company’s policy is to record interest and penalties related to income taxes as part of the tax provision. There were no interest and penalties pertaining to uncertain tax positions for the years ended December 31, 2019 or 2018.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
Net Loss Per Share	Dec. 31, 2019
Net Loss Per Share
Net Loss Per Share	10. Net Loss Per Share Basic and diluted net loss per share for the years ended December 31, 2019 and 2018 was calculated as follows: Year Ended Year Ended December 31, December 31, 2019 2018 Numerator: Net loss $ (32,900) $ (23,138) Dividend attributable to down round feature of warrants (359) — Net loss attributable to common stockholders for basic loss per share $ (33,259) $ (23,138) Less change in fair value of warrant liability — 7,284 Net loss attributable to common stockholders for diluted loss per share $ (33,259) $ (30,422) Denominator: Weighted average number of common shares outstanding-basic 22,582,687 14,144,287 Assumed conversion of dilutive securities: Private Placement Warrants — 268,408 Denominator for diluted loss per share-adjusted weighted average shares 22,582,687 14,412,695 Net loss per share attributable to common stockholders-basic $ (1.47) $ (1.64) Net loss per share attributable to common stockholders-diluted $ (1.47) $ (2.11) The Company’s potentially dilutive securities include stock options and warrants. These securities were excluded from the computations of diluted net loss per share for the years ended December 31, 2019 and 2018, as the effect would be to reduce the net loss per share. During the year ended December 31, 2018, the outstanding warrants issued with the Private Placement is reflected in the diluted net loss per share computation by applying the treasury stock method. The following table includes the potential common shares, presented based on amounts outstanding at each period end, that were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Year Ended December 31, 2019 2018 Options to purchase common stock 4,024,566 2,761,912 Warrants to purchase common stock 10,369,752 54,516 Restricted stock units 90,500 — 14,394,318 2,816,428

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2019
Commitments and Contingencies
Commitments and Contingencies	11. Commitments and Contingencies Manufacturing Agreements —The Company is party to manufacturing agreements with vendors to manufacture TRX518 and DKN‑01, our lead product candidates, for use in clinical trials. As of December 31, 2019, noncancelable commitments under these agreements totaled $207. License and Service Agreements —On January 3, 2011, the Company entered into a license agreement with Eli Lilly and Company (“Lilly”) to grant a license to the Company for certain intellectual property rights relating to pharmaceutically active compounds that may be useful in the treatment of bone healing, cancer and, potentially, other medical conditions. The Company issued 9,000,000 shares of Series A Stock to Lilly in consideration for the grant of the license. As defined in the license agreement, the Company would be required to pay royalties to Lilly based upon a percentage in the low single digits of net sales of developed products, if and when achieved. However, there can be no assurance that clinical or commercialization success of developed products will occur, and no royalties have been paid or accrued through December 31, 2019. License Agreement —On May 28, 2015, the Company entered into a license agreement with Lonza Sales AG (“Lonza”), pursuant to which Lonza granted the Company a world-wide, non-exclusive license for certain intellectual property relating to a gene expression system for manufacturing DKN‑01. As defined in the license agreement, the Company would be required to pay royalties to Lonza based on a percentage in the low single digits of net sales of DKN‑01, if and when achieved. However, there can be no assurance that clinical or commercialization success will occur, and no royalties have been paid or accrued through December 31, 2019. Legal Proceedings —At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. The Company expenses as incurred the costs related to its legal proceedings. A patent covering the TRX518 antibody and its uses in methods of inducing or enhancing an immune response in a subject was granted in 2013 to the Company by the European Patent Office (EPO). Three notices of opposition to this patent were filed: two by major pharmaceutical companies and a third by an individual, possibly on behalf of a major pharmaceutical company. At the conclusion of the opposition proceedings before the Opposition Division of the EPO, the Opposition Division issued a decision indicating that the Company’s patent was maintained with narrowed claims that differ from the claims as originally granted. These narrowed claims cover the TRX518 antibody and uses of the TRX518 antibody in methods of inducing or enhancing an immune response in a subject. The Company has filed an appeal of the decision of the Opposition Division seeking to obtain broader claims that more closely reflect the claims as granted in the patent. The EPO Board of Appeal has issued a Summons to Oral Proceedings setting a date of March 31, 2020 for the appeal hearing. In 2016, a patent covering the use of the TRX518 antibody in combination with a chemotherapeutic agent for treating cancer was granted to the Company by the EPO. In March 2017, notices of opposition to this patent were filed at the EPO by ten different entities, including several major pharmaceutical companies. Oral proceedings at the EPO took place on December 4 and 5, 2018. At the conclusion of the oral proceedings, the Opposition Division decided that the patent should be revoked in its entirety on the ground that the claims as granted contained added matter. Subsequently, the Opposition Division issued an interlocutory decision restating its conclusion that the claims as granted contain added matter and revoking the patent. The Company has filed an appeal of the decision of the Opposition Division seeking to obtain a reversal of the Opposition Division’s decision on added matter. A statement of our grounds of appeal was filed on May 31, 2019. The EPO Board of Appeal has not yet scheduled a date for the appeal hearing. Indemnification Agreements —In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not aware of any claims under indemnification arrangements, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of December 31, 2019 and 2018.

Defined Contribution Plan

Defined Contribution Plan	12 Months Ended
Defined Contribution Plan	Dec. 31, 2019
Defined Contribution Plan
Defined Contribution Plan	12. Defined Contribution Plan The Company has a 401(k) defined contribution plan (the "401(k) Plan") for substantially all of its employees. Eligible employees may make pretax contributions to the 401(k) Plan up to statutory limits. The Company makes matching employee contributions in cash to the 401(k) Plan at a rate of 100% of the first 3% of earnings contributed and 50% of the next 2% of earnings contributed. Employees participating in the 401(k) Plan are fully vested in the Company matching contributions, and investments are directed by participants. The Company made matching contributions of $170 and $148 for the years ended December 31, 2019 and 2018, respectively.

Related Party Transactions

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2019
Related Party Transactions
Related Party Transactions	13. Related Party Transactions The Company has a license agreement with a stockholder (See Note 10). On February 5, 2019, the Company completed the 2019 Public Offering pursuant to which the Company issued 7,557,142 shares of its common stock at a price of $1.75 per share, which included 985,714 shares issued pursuant to the underwriters’ exercise of their option to purchase additional shares of common stock, each share issued with a warrant to purchase one share of common stock. Each warrant has an exercise price of $1.95 per share with an exercise period expiring seven years from the date of issuance. The aggregate net proceeds received by the Company from the offering were approximately $12,122, net of underwriting discounts and commissions and estimated offering expenses payable by the Company. HealthCare Ventures IX, L.P. purchased common stock and warrants in the 2019 Public Offering on the same terms and conditions as the other Purchasers. Three of the Company’s directors and executive officers are affiliated with HealthCare Ventures IX, L.P. and its affiliates.

Subsequent Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2019
Subsequent Events
Subsequent Events	14. Subsequent Events BeiGene Exclusive Option and License Agreement On January 3, 2020, the Company entered into a Exclusive Option and License Agreement with BeiGene for the clinical development and commercialization of DKN-01, the Company’s anti-Dickkopf-1 (DKK1) antibody, in Asia (excluding Japan), Australia, and New Zealand. The Company will retain exclusive rights for the development, manufacturing, and commercialization of DKN-01 for the rest of the world. Pursuant to the Exclusive Option and License Agreement, the Company received an upfront cash payment of $3,000 from BeiGene in exchange for granting BeiGene an option to an exclusive license to develop and commercialize DKN-01 in Asia (excluding Japan), Australia, and New Zealand, and will be eligible to receive an additional payment upon BeiGene’s exercise of the option following initial proof-of-concept studies. Additionally, the Company is eligible to receive additional payments based upon the achievement of certain development, regulatory, and sales milestones as well as tiered royalties on any product sales of DKN-01 in the licensed territory. Private Placement – January 2020 On January 3, 2020, the Company entered into a Securities Purchase Agreement with the Purchasers, providing for a private placement transaction exempt from the Securities Act, pursuant to which the Company issued and sold 1,421,801 shares of its Series A Preferred Stock, at a purchase price of $10.54 per share, and 1,137,442 shares of its Series B Preferred Stock at a purchase price of $10.55 per share, and one (1) share of the Company’s Special Voting Stock entitling the Purchaser of Series A Preferred Stock to elect one member of the Company’s Board of Directors for aggregate net proceeds to the Company of approximately $25,300. On March 5, 2020, the Company’s stockholders approved the conversion of the Series A preferred stock into a pre-funded warrant to purchase 14,413,902 shares of common stock and the conversion of the Series B preferred stock into 11,531,133 shares of common stock. Each investor also received a warrant to purchase an equal number of shares at an exercise price of $2.11 per share. Warrants Subsequent to December 31, 2019, there were 65,700 warrants exercised for cash resulting in gross proceeds to the Company of $128. Stock option grants On March 2, 2020, the Company made a stock option grant to its directors and employees to purchase 765,000 shares of common stock, pursuant to the Company’s 2016 Plan, at an exercise price of $2.94 per share. Each option grant to directors will vest quarterly over a one year period and each option grant to employees will vest in equal monthly installments over a three year period.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2019
Summary of Significant Accounting Policies
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions are eliminated upon consolidation.
Use of Estimates	Use of Estimates The presentation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) 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 consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents.
Research and Development Expense	Research and Development Expense Research and development costs are expensed as incurred. Research and development expenses include personnel costs associated with research and development activities, including noncash share-based compensation and costs for third-party contractors to perform research, conduct clinical trials and manufacture drug supplies and materials. The Company accrues for costs incurred by external service providers, including contract research organizations and clinical investigators, based on its estimates of service performed and costs incurred. These estimates include the level of services performed by the third parties, patient enrollment in clinical trials, administrative costs incurred by the third parties, and other indicators of the services completed. Based on the timing of amounts invoiced by service providers, the Company may also record payments made to those providers as prepaid expenses that will be recognized as expense in future periods as the related services are rendered.
Research and development incentive income and receivable	Research and development incentive income and receivable The Company recognizes other income from Australian research and development incentives when there is reasonable assurance that the income will be received, the relevant expenditure has been incurred, and the consideration can be reliably measured. The research and development incentive is one of the key elements of the Australian Government’s support for Australia’s innovation system and is supported by legislative law primarily in the form of the Australian Income Tax Assessment Act 1997 as long as eligibility criteria are met. Management has assessed the Company’s research and development activities and expenditures to determine which activities and expenditures are likely to be eligible under the research and development incentive regime described above. At each period end management estimates the refundable tax offset available to the Company based on available information at the time. This estimate is also reviewed by external tax advisors on an annual basis. Under the program, a percentage of eligible research and development expenses incurred by the Company through its subsidiary in Australia are reimbursed. The percentage was 43.5% for the years ended December 31, 2019 and 2018. The research and development incentive receivable represents an amount due in connection with the above program. The Company has recorded a research and development incentive receivable of $185 and $836 as of December 31, 2019 and 2018, respectively, in the consolidated balance sheets and other income from Australian research and development incentives of $132 and $756, in the consolidated statements of operations for the years ended December 31, 2019 and 2018, respectively, related to refundable research and development incentive program payments in Australia. The following table shows the change in the research and development incentive receivable from January 1, 2018 to December 31, 2019: Balance at January 1, 2018 $ 1,744 Australian research and development incentive income 756 Cash received for 2016 eligible overseas research and development expenses (740) Cash received for 2017 eligible expenses (793) Foreign currency translation (131) Balance at December 31, 2018 836 Australian research and development incentive income, net 132 Cash received for 2018 eligible expenses (757) Foreign currency translation (26) Balance at December 31, 2019 $ 185
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments which potentially subject the Company to credit risk consist principally of cash and cash equivalents. All cash and cash equivalents are held in United States financial institutions and money market funds. At times, the Company may maintain cash balances in excess of the federally insured amount.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method. Under the asset and liability method, deferred income taxes are recognized for differences between the financial reporting and tax bases of assets and liabilities at enacted statutory tax rates in effect for the years in which the differences are expected to reverse. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. The Company follows accounting guidance concerning provisions for uncertainty in income tax positions. This guidance clarifies the accounting for income taxes by prescribing a minimum probability threshold that an uncertain tax position must meet before a financial statement benefit is recognized. The minimum threshold is defined as a tax position that is more likely than not to be sustained upon examination by the applicable taxing authority, of any related appeals or litigation processes, based on the technical merits of the position. The tax benefit to be recognized is measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. The Company recognizes accrued interest and penalties associated with uncertain tax position as part of the income tax provision. There were no uncertain tax positions or income tax related interest and penalties recorded for the years ended December 31, 2019 and 2018. The income tax returns of the Company for the year ended December 31, 2016 and subsequent years are subject to examination by the Internal Revenue Service and other taxing authorities, generally for three years after the returns were filed.
Foreign Currency Translation	Foreign Currency Translation The financial statements of the Company’s foreign subsidiary are measured using the local currency as the functional currency. Assets and liabilities of this subsidiary are translated into U.S. dollars at exchange rates as of the consolidated balance sheet date. Equity is translated at historical exchange rates. Revenues and expenses are translated into U.S. dollars at average rates of exchange in effect during the year. The resulting cumulative translation adjustments have been recorded as a separate component of stockholders’ deficiency. Foreign currency transaction gains and losses are included in the results of operations.
Property and Equipment	Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset. Computer equipment is depreciated over three years. Laboratory equipment, office equipment and furniture and fixtures are depreciated over five years. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the asset. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in loss from operations. Expenditures for repairs and maintenance are charged to expense as incurred.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets consist of property and equipment. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset group for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset group to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset group over its fair value. The Company has not recorded any impairment losses on long-lived assets during 2019 and 2018.
Deferred Offering Costs	Deferred Offering Costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ equity (deficiency) as a reduction of additional paid-in capital generated as a result of the offering. As of December 31, 2019 and 2018 there was $831 and $162, respectively, of deferred offering costs.
Other Assets	Deposits Deposits as of December 31, 2019 and 2018, included $1,099 and $1,380, respectively, of deposits made by the Company with certain service providers that are to be applied to future payments due under the service agreements or returned to the Company if not utilized.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: · Level 1—Quoted prices in active markets for identical assets or liabilities. · Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. · Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. During the years presented, the Company has not changed the manner in which it values assets and liabilities that are measured at fair value using Level 3 inputs. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. There were no transfers within the hierarchy during the years ended December 31, 2019 and 2018. A summary of the assets and liabilities carried at fair value in accordance with the hierarchy defined above is as follows (in thousands): Total Level 1 Level 2 Level 3 December 31, 2019 Assets: Cash equivalents $ 3,891 $ 3,891 $ — $ — Total assets $ 3,891 $ 3,891 $ — $ — December 31, 2018 Assets: Cash equivalents $ 16,284 $ 16,284 $ — $ — Total assets $ 16,284 $ 16,284 $ — $ — Liabilities: Warrant liability $ 3,448 $ — $ — $ 3,448 Total liabilities $ 3,448 $ — $ — $ 3,448 Cash equivalents of $3,891 and $16,284 as of December 31, 2019 and 2018, respectively, consisted of overnight investments and money market funds and are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices in active markets. The carrying value of the research and development incentive receivable, accounts payable and accrued expenses approximate their fair value due to the short-term nature of these assets and liabilities. A roll-forward of the recurring fair value measurements of the warrant liability categorized with Level 3 inputs are as follows (in thousands): Warrant Liability Balance-January 1, 2018 $ 11,862 Exercise of warrants (1,130) Change in Fair value (7,284) Balance-December 31, 2018 $ 3,448 Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11 (3,448) Balance-January 1, 2019 $ — The warrant liability in the table above is composed of the fair value of warrants (the “2017 Warrants”) to purchase common shares that the Company issued in connection with a private placement (the“November 2017 Private Placement”). The fair value of the warrant liability was determined based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. The Company utilized a Monte Carlo simulation, which is a statistical method used to generate a defined number of share price paths to develop a reasonable estimate of the range of the future expected share prices, to value the warrant liability. The Monte Carlo simulation incorporated assumptions and estimates to value the warrant liability. Estimates and assumptions impacting the fair value measurement included the estimated probability of adjusting the exercise price of the warrants, the number of shares for which the warrants will be exercisable, the remaining contractual term of the warrants, the risk-free interest rate, the expected dividend yield, and the expected volatility of the price of the underlying common shares. The Company historically had been a private company and lacks company-specific historical and implied volatility information of its shares. Therefore, it estimated its expected share volatility based on the historical volatility of publicly traded peer companies for a term equal to the remaining contractual term of the warrants. The risk-free interest rate was determined by reference to the U.S. Treasury yield curve for time periods approximately equal to the remaining contractual term of the warrants. The Company estimated a 0% expected dividend yield based on the fact that the Company has never paid or declared dividends and does not intend to do so in the foreseeable future.
Leases	Leases In February 2016, the FASB issued ASU 2016-02, Leases, or ASU 2016-02, to enhance the transparency and comparability of financial reporting related to leasing arrangements. The Company adopted ASU 2016-02 on January 1, 2019, the effective date, and used the effective date as its date of initial application. At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present. Most leases with a term greater than one year are recognized on the balance sheet as right-of-use assets, lease liabilities and, if applicable, long-term lease liabilities. The Company has elected not to recognize on the balance sheet leases with terms at commencement of one year or less. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected remaining lease term. The Company has determined that the rate implicit in the lease is not determinable and the Company does not have borrowings with similar terms and collateral. Therefore, the Company considered a variety of factors, including observable debt yields from comparable companies and the volatility in the debt market for securities with similar terms, in determining that 8% was reasonable to use as the incremental borrowing rate for purposes of the calculation of lease liabilities. In accordance with the guidance in ASU 2016-02, components of a lease should be split into three categories: lease components (e.g. land, building, etc.), non-lease components (e.g. common area maintenance, maintenance, consumables, etc.), and non-components (e.g. property taxes, insurance, etc.). Then the fixed and in-substance fixed contract consideration (including any related to non-components) must be allocated based on fair values to the lease components and non-lease components. Although separation of lease and non-lease components is required, certain practical expedients are available. Entities may elect the practical expedient to not separate lease and non-lease components. Rather, they would account for each lease component and the related non-lease component together as a single component. The Company has elected to account for the lease and non-lease components of each of its operating leases as a single lease component and allocate all of the contract consideration to the lease component only. The lease component results in an operating right-of-use asset being recorded on the consolidated balance sheets and amortized such that lease expense is recorded on a straight line basis over the term of the lease.
Segment Information	Segment Information The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is developing novel, targeted drugs for the treatment of cancer. Substantially all of the Company’s tangible assets are held in the United States.
Patent Costs	Patent Costs All patent related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses.
Stock-Based Compensation	Stock-Based Compensation The Company measures all stock options and other stock-based awards granted to employees based on the fair value on the date of the grant and recognizes compensation expense of those awards, net of estimated forfeitures, over the requisite service period, which is generally the vesting period of the respective award. Generally, the Company issues stock options to employees with only service-based vesting conditions and records the expense for these awards using the straight-line method. The Company measures stock-based awards granted to consultants and nonemployees based on the fair value of the award on the date on which the related service is complete. Compensation expense is recognized over the period during which services are rendered by such consultants and nonemployees until completed. At the end of each financial reporting period prior to completion of the service, the fair value of these awards is remeasured using the then current fair value of the Company’s common stock and updated assumption inputs in the Black-Scholes option-pricing model. Stock-based compensation is classified in the accompanying consolidated statements of operations based on the function to which the related services are provided. The Company recognizes compensation expense for only the portion of awards that are expected to vest. In developing a forfeiture rate estimate, the Company has considered its historical experience to estimate pre-vesting forfeitures for service-based awards. The impact of a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual forfeiture rate is materially different from the Company’s estimate, the Company may be required to record adjustments to stock-based compensation expense in future periods. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The Company historically has been a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The expected term of stock options granted to nonemployees is equal to the contractual term of the option award. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends on common stock and does not expect to pay any cash dividends in the foreseeable future.
Net Loss per Share	Net Loss per Share Basic net loss per share is computed using the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential shares of common stock, including the assumed exercise of stock options.
Reclassification	Reclassifications Certain prior period amounts have been reclassified for consistency with the current period presentation. These reclassifications had no effect on previously reported results of operations.
Warrant Liability	Warrant Liability In connection with entering into the November 2017 Private Placement, the Company issued the 2017 Warrants with each share of common stock sold in the November 2017 Private Placement. The Company classified the 2017 Warrants as a liability on its consolidated balance sheet prior to January 1,2019, because each warrant represented a freestanding financial instrument that is not indexed to the Company’s own shares. The warrant liability was initially recorded at fair value upon entering into the November 2017 Private Placement agreement and was subsequently remeasured to fair value at each reporting date. Changes in the fair value of the warrant liability were recognized as gains (losses) in the consolidated statements of operations through the year ended December 31,2018.
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board, or FASB, and are early adopted by the Company or adopted as of the specified effective date. In June 2018, the FASB issued ASU No. 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, which is intended to simplify the accounting for share-based payments to nonemployees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The new guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted this standard effective January 1, 2019, which had no impact on the Company's consolidated financial statements. In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), and Derivatives and Hedging (Topic 815) ("ASU 2017-11"), which changes the classification analysis of certain equity-linked financial instruments (or embedded features) with down round features. The amendments require entities that present earnings per share ("EPS") in accordance with Topic 260 to recognize the effect of the down round feature when triggered with the effect treated as a dividend and as a reduction of income available to common shareholders in basic EPS. The new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted this standard effective January 1, 2019 and concluded that the 2017 Warrants qualified for equity classification. The Company applied the guidance retrospectively to the 2017 Warrants by means of a cumulative-effect adjustment to its statement of financial position as of the beginning of the interim and annual period beginning January 1, 2019. The Company performed a final remeasurement of the warrant liability as of January 1, 2019 and reclassified $3,448 to stockholders’ equity. In February 2016, the FASB issued ASU 2016-02, Leases, or ASU 2016-02. ASU 2016-02 requires a lessee to recognize on its balance sheet (for both finance and operating leases) a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for the lease term. ASU 2016-02 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company adopted ASU 2016-02 on January 1, 2019, the effective date, and used the effective date as its date of initial application. As such, the Company did not adjust prior period amounts. The Company also elected to adopt the practical expedients upon transition, which permit companies to not reassess lease identification, classification, and initial direct costs under ASU 2016-02 for leases that commenced prior to the effective date (see Note 5).

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2019
Summary of Significant Accounting Policies
Schedule of change in the research and development incentive receivable	The following table shows the change in the research and development incentive receivable from January 1, 2018 to December 31, 2019: Balance at January 1, 2018 $ 1,744 Australian research and development incentive income 756 Cash received for 2016 eligible overseas research and development expenses (740) Cash received for 2017 eligible expenses (793) Foreign currency translation (131) Balance at December 31, 2018 836 Australian research and development incentive income, net 132 Cash received for 2018 eligible expenses (757) Foreign currency translation (26) Balance at December 31, 2019 $ 185
Summary of assets and liabilities carried at fair value in accordance with the hierarchy	A summary of the assets and liabilities carried at fair value in accordance with the hierarchy defined above is as follows (in thousands): Total Level 1 Level 2 Level 3 December 31, 2019 Assets: Cash equivalents $ 3,891 $ 3,891 $ — $ — Total assets $ 3,891 $ 3,891 $ — $ — December 31, 2018 Assets: Cash equivalents $ 16,284 $ 16,284 $ — $ — Total assets $ 16,284 $ 16,284 $ — $ — Liabilities: Warrant liability $ 3,448 $ — $ — $ 3,448 Total liabilities $ 3,448 $ — $ — $ 3,448
Schedule of the recurring fair value measurements of the warrant derivative liability categorized with Level 3 inputs	A roll-forward of the recurring fair value measurements of the warrant liability categorized with Level 3 inputs are as follows (in thousands): Warrant Liability Balance-January 1, 2018 $ 11,862 Exercise of warrants (1,130) Change in Fair value (7,284) Balance-December 31, 2018 $ 3,448 Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11 (3,448) Balance-January 1, 2019 $ —

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
Property and Equipment, Net (Tables)	Dec. 31, 2019
Property and Equipment, Net
Schedule of property and equipment, net	December 31, 2019 2018 Computer office equipment $ 51 $ 51 Leasehold improvements 69 69 Lab equipment 113 58 Furnitures and fixtures 30 30 263 208 Less: accumulated depreciation (139) (122) Property and equipment, net $ 124 $ 86

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
Accrued Expenses (Tables)	Dec. 31, 2019
Accrued Expenses
Schedule of accrued expenses	December 31, 2019 2018 Clinical trials $ 1,828 $ 1,745 Professional fees 609 219 Payroll and related expenses 1,004 908 Accrued expenses $ 3,441 $ 2,872

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Dec. 31, 2019
Leases
Schedule of future minimum lease payments	Future Operating Lease Payments 2020 532 2021 434 2022 146 Total Lease Payments 1,112 Less: imputed interest (86) Total operating lease liabilities $ 1,026

Warrants (Tables)

Warrants (Tables)	12 Months Ended
Warrants (Tables)	Dec. 31, 2019
Warrants
Schedule of warrants	December 31, 2019 Number of Shares Date Exercisable Issuable Exercise Price Exercisable for Classification Penny Warrants 54,516 $ 0.01 Common Stock Equity 2017 Warrants 2,758,094 $ 1.75 Common Stock Equity 2019 Warrants 7,557,142 $ 1.95 Common Stock Equity 10,369,752

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
Stock-Based Compensation (Tables)	Dec. 31, 2019
Stock-Based Compensation
Schedule of stock option activity under the Company's Equity Incentive Plans	Weighted Average Weighted Aggregate Exercise Price Average Remaining Intrinsic Options Per Share Life in Years Value Outstanding at December 31, 2017 2,257,621 $ 12.38 8.66 $ 68 Granted 599,050 $ 6.68 Exercised (2,478) $ 5.56 Forfeited (92,281) $ 7.89 Outstanding at December 31, 2018 2,761,912 $ 11.30 8.01 $ — Granted 1,481,975 $ 1.48 Forfeited (219,321) $ 15.14 Outstanding at December 31, 2019 4,024,566 $ 7.48 7.98 $ 2 Options exercisable at December 31, 2019 2,398,685 $ 10.48 7.25 $ — Options vested and expected to vest at December 31, 2019 4,024,566 $ 7.48 7.98 $ 2
Schedule of assumptions used to determine grant-date fair value of stock options	Year Ended Year Ended December 31, December 31, 2019 2018 Expected volatility % 66.94 % Weighted average risk-free interest rate % 2.80 % Expected dividend yield % % Expected term (in years) 6.95
Schedule of stock-based compensation expense classified in the consolidated statements of operations and comprehensive loss	Year Ended December 31, 2019 2018 Research and development $ 714 $ 625 General and administrative 3,018 2,844 Total $ 3,732 $ 3,469
Summary of outstanding RSU's under the 2016 Plan	Weighted Number of Average Shares Fair Value Outstanding at December 31, 2018 — $ — Awarded 181,000 $ Settled in cash (90,500) $ Outstanding at December 31, 2019 90,500 $

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2019
Income Taxes
Schedule of income (loss) before income taxes	Year Ended December 31, 2019 2018 U.S. $ (32,875) $ (21,378) Foreign (28) (1,740) Loss before income taxes $ (32,903) $ (23,118)
Schedule of Company's current and deferred expense for income tax	Year Ended December 31, 2019 2018 Current expense (benefit): Federal $ — $ — State — — Foreign — — Total current expense (benefit): $ — $ — Deferred expense (benefit): Federal $ — $ — State — — Foreign (3) 20 Total deferred expense (benefit): $ (3) $ 20 Total income tax expense (benefit): $ (3) $ 20
Schedule of reconciliation of the Company's statutory income tax rate to the Company's effective income tax rate	Year Ended December 31, 2019 2018 Federal statutory income tax rate 21.00 % 21.00 % State taxes, net of federal benefit 6.79 % 7.76 % Permanent differences (0.33) % 2.38 % Tax credits 3.30 % 6.94 % Foreign rate differential 0.07 % 0.68 % Valuation allowance (40.18) % (38.26) % Other 9.35 % (0.59) % 0.01 % (0.09) %
Schedule of significant components of the Company's deferred tax assets	Year Ended December 30, 2019 2018 Federal net operating loss carryforwards $ 47,845 $ 38,531 State net operating loss carryforwards 7,431 5,553 Stock Options 2,584 1,632 Federal research tax credits 3,770 2,811 State research tax credits 510 382 License fees 1,332 1,495 Accrued expenses 277 88 Other 115 149 Total deferred tax assets $ 63,864 $ 50,641 Valuation allowance (63,737) (50,517) Net deferred tax asset (liability) $ 127 $ 124

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
Net Loss Per Share (Tables)	Dec. 31, 2019
Net Loss Per Share
Schedule of basic and diluted net loss per share	Year Ended Year Ended December 31, December 31, 2019 2018 Numerator: Net loss $ (32,900) $ (23,138) Dividend attributable to down round feature of warrants (359) — Net loss attributable to common stockholders for basic loss per share $ (33,259) $ (23,138) Less change in fair value of warrant liability — 7,284 Net loss attributable to common stockholders for diluted loss per share $ (33,259) $ (30,422) Denominator: Weighted average number of common shares outstanding-basic 22,582,687 14,144,287 Assumed conversion of dilutive securities: Private Placement Warrants — 268,408 Denominator for diluted loss per share-adjusted weighted average shares 22,582,687 14,412,695 Net loss per share attributable to common stockholders-basic $ (1.47) $ (1.64) Net loss per share attributable to common stockholders-diluted $ (1.47) $ (2.11)
Schedule of potentially anti-dilutive securities excluded from calculation of diluted net loss per share	Year Ended December 31, 2019 2018 Options to purchase common stock 4,024,566 2,761,912 Warrants to purchase common stock 10,369,752 54,516 Restricted stock units 90,500 — 14,394,318 2,816,428

Nature of Business, Basis of _2

Nature of Business, Basis of Presentation and Liquidity - Liquidity (Details) $ / shares in Units, $ in Thousands	Jan. 03, 2020USD ($)director$ / sharesshares	Mar. 27, 2018USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Accumulated deficit			$ 195,168	$ 153,535
Net loss			32,900	23,138
Net cash used in operating activities			(26,902)	(26,033)
Cash and cash equivalents			$ 3,891	$ 16,284
Preferred stock, proceeds	$ 25,300	$ 14,796
Exclusive Option and License Agreement
Consideration received for rights	$ 3,000
Series A Preferred Stock
Preferred stock, shares issued \| shares	1,421,801
Preferred stock par value (per share) \| $ / shares	$ 0.001
Sale price per share \| $ / shares	$ 10.54
Series B Preferred Stock
Preferred stock, shares issued \| shares	1,137,442
Preferred stock par value (per share) \| $ / shares	$ 0.001
Sale price per share \| $ / shares	10.55
Special Voting Stock
Preferred stock par value (per share) \| $ / shares	$ 0.001
Board seats \| director	1

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accounting policies:
Eligible for reimbursement (as a percent of R&D expense)	43.50%	43.50%
Research and development incentive income and receivable
Balance at the beginning of the period	$ 836	$ 1,744
Australian research and development incentives	132	756
Cash received eligible overseas research and development expenses		(740)
Cash received for eligible expenses	(757)	(793)
Foreign currency translation	(26)	(131)
Balance at the end of the period	185	836
Other Assets
Deposits	1,099	1,380
Deferred offering costs	831	162
Uncertain tax positions	0	0
Service agreements
Other Assets
Deposits	$ 1,099	$ 1,380
Office equipment
Other Assets
Useful life (in years)	5 years
Computer equipment
Other Assets
Useful life (in years)	3 years
Lab equipment
Other Assets
Useful life (in years)	5 years
Furnitures and fixtures
Other Assets
Useful life (in years)	5 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Warrants and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	12 Months Ended		24 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019
Warrants
Warrant, equity component	$ 3,448
Assets:
Cash & cash equivalents	3,891	$ 16,284	$ 3,891
Total assets	3,891	16,284	3,891
Liabilities:
Warrant liability		3,448
Total liabilities		3,448
Fair value measurements of the warrant liability
Beginning Balance	3,448	11,862	11,862
Exercise of warrants	(3,448)	(1,130)
Change in fair value of warrant liability		(7,284)
Warrant, equity component	$ 3,448
Ending Balance		$ 3,448
Expected dividend yield (as a percentage)	0.00%	0.00%
Level 1
Assets:
Cash & cash equivalents	$ 3,891	$ 16,284	3,891
Total assets	$ 3,891	16,284	$ 3,891
Level 3
Liabilities:
Warrant liability		3,448
Total liabilities		$ 3,448

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property and Equipment, Net
Property and equipment, gross	$ 263	$ 208
Less: accumulated depreciation	(139)	(122)
Property and equipment, net	124	86
Depreciation expense	47	49
Office equipment
Property and Equipment, Net
Property and equipment, gross	51	51
Leasehold improvements
Property and Equipment, Net
Property and equipment, gross	69	69
Lab equipment
Property and Equipment, Net
Property and equipment, gross	113	58
Furnitures and fixtures
Property and Equipment, Net
Property and equipment, gross	$ 30	$ 30

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued Expenses
Clinical trials	$ 1,828	$ 1,745
Professional fees	609	219
Payroll and related expenses	1,004	908
Accrued expenses	$ 3,441	$ 2,872

Leases - Annual rent (Details)

Leases - Annual rent (Details) - USD ($) $ in Thousands	Apr. 30, 2019	Jul. 31, 2018	Jul. 15, 2018	Jul. 31, 2017	Jan. 01, 2017
Leases
Annual rent	$ 305	$ 297		$ 289
2020					$ 422
2021					429
2022					$ 437
Research laboratory
Leases
Annual rent			$ 420

Leases - Future minimum lease p

Leases - Future minimum lease payments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Leases
2020	$ 532
2021	434
2022	146
Total Lease Payments	1,112
Less: imputed interest	(86)
Total operating lease liabilities	$ 1,026	$ 1,755

Leases - (Details)

Leases - (Details) - USD ($) $ in Thousands	12 Months Ended
Leases - (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Leases
Right of use asset	$ 1,026		$ 1,755
Lease liability	1,026		$ 1,755
Rent expense	837	$ 690
Accrued rent reclassified upon adoption of ASU 216-02	$ 35

Warrants (Details)

Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Feb. 05, 2019
Warrants
Warrants outstanding (in warrants)	10,369,752
Warrant, equity component	$ 3,448
Dividend attributable to down round feature of warrants	$ 359
Penny Warrants
Warrants
Warrants outstanding (in warrants)	54,516
Exercise price (per warrant)	$ 0.01
2017 Warrants
Warrants
Warrants outstanding (in warrants)	2,758,094
Exercise price (per warrant)	$ 1.75	$ 6.085
2019 Warrants
Warrants
Warrants outstanding (in warrants)	7,557,142
Exercise price (per warrant)	$ 1.95	$ 1.95
Warrants (issued)		7,557,142

Common Stock (Details)

Common Stock (Details) $ in Thousands	12 Months Ended
Common Stock (Details) $ in Thousands	Dec. 31, 2019USD ($)
Common Stock
Votes (per share)	one
Dividend declared	$ 0

Common Stock - Public Offering

Common Stock - Public Offering (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 11, 2019	Feb. 05, 2019	Mar. 27, 2018	Dec. 31, 2019	Dec. 31, 2018
Common stock, par value (in dollars per share)				$ 0.001	$ 0.001
Issuance of common stock (value)		$ 12,122		$ 12,122	$ 14,796
Issuance of common stock (in shares)		7,557,142	2,146,667
Price per share		$ 1.75	$ 7.50
Proceeds from issuance of common stock from ATM sales				1,923
Proceeds from issuance of common stock in connection with July 2019 Lincoln Park Capital Registered Offering Purchase Agreement				$ 1,000
Lincoln Park Purchase Agreements
Common stock, par value (in dollars per share)	$ 0.001
Issuance of common stock (in shares)	571,429
Price per share	$ 1.75
Authorized amount for issuance of common stock for ATM sales	$ 20,000
Issuance of stock in consideration for license (in shares)	330,000
Proceeds from issuance of common stock in connection with July 2019 Lincoln Park Capital Registered Offering Purchase Agreement	$ 1,000
Distribution Agreement
Issuance of common stock (in shares)				1,033,147
Authorized amount for issuance of common stock for ATM sales				$ 30,000
Proceeds from issuance of common stock from ATM sales				$ 1,923
2019 Warrants
Exercise price (per warrant)		$ 1.95		$ 1.95
Warrants and Rights Outstanding, Term		7 years
Underwriters' exercise
Issuance of common stock (in shares)		985,714	280,000

Stock-Based Compensation - Equi

Stock-Based Compensation - Equity Incentive Plans (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-Based Compensation
Options outstanding (in shares)	4,024,566	2,761,912	2,257,621
Available for grant (in shares)	2,459,373
2016 Plan
Stock-Based Compensation
Annual increase (as percent of outstanding common stock)	(4.00%)
Additional shares authorized (in shares)	3,000,000

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended			24 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Options
Outstanding balance at the beginning of the period (in shares)	2,761,912	2,257,621		2,257,621
Granted (in shares)	1,481,975	599,050
Exercised (in shares)		2,478
Forfeited (in shares)	(219,321)	(92,281)
Outstanding balance at the end of the period (in shares)	4,024,566	2,761,912	2,257,621	4,024,566
Options exercisable at the end of the period (in shares)	2,398,685			2,398,685
Options vested and expected to vest at end of period (in shares)	4,024,566			4,024,566
Options unvested at end of period (in shares)	90,500			90,500
Weighted Average Exercise Price Per Share
Outstanding balance at the beginning of the period (in dollars per share)	$ 11.30	$ 12.38		$ 12.38
Granted (in dollars per share)	1.48	6.68
Exercised (in dollars per share)		5.56
Forfeited (in dollars per share)	15.14	7.89
Outstanding balance at the end of the period (in dollars per share)	7.48	$ 11.30	$ 12.38	7.48
Exercisable at the end of the period (in dollars per share)	10.48			10.48
Options vested and expected to vest at end of the period (in dollars per share)	$ 7.48			$ 7.48
Weighted Average Remaining Life in Years
Outstanding balance	7 years 11 months 23 days	8 years 4 days	8 years 7 months 28 days
Options exercisable at end of period	7 years 3 months
Options vested and expected to vest at end of the period	7 years 11 months 23 days
Aggregate Intrinsic Value
Outstanding balance	$ 2		$ 68	$ 2
Options vested and expected to vest at end of the period	2			2
Stock-based compensation expense	$ 3,732	$ 3,469
Assumptions used to determine grant-date fair value
Expected Volatility	66.94%	66.94%
Weighted average risk-free interest rate	2.07%	2.80%
Expected dividend yield (as a percentage)	0.00%	0.00%
Expected term (in years)	6 years 9 months 7 days	6 years 11 months 12 days
Unrecognized costs	$ 3,059			$ 3,059
Research and development
Aggregate Intrinsic Value
Stock-based compensation expense	714	$ 625
General and administrative
Aggregate Intrinsic Value
Stock-based compensation expense	$ 3,018	$ 2,844
Weighted average
Assumptions used to determine grant-date fair value
Unrecognized costs weighted-average period	2 years 2 months 9 days
Weighted average \| Options to purchase common stock
Assumptions used to determine grant-date fair value
Expected dividend yield (as a percentage)				0.00%
Minimum
Assumptions used to determine grant-date fair value
Vesting period	3 years
Maximum
Assumptions used to determine grant-date fair value
Vesting period	4 years

Stock-Based Compensation - Outs

Stock-Based Compensation - Outstanding RSU's under the 2016 Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Number of shares
Awarded	181,000
Settled in cash	(90,500)
Outstanding at the end	90,500
Weighted average fair value
Awarded (in dollars per share)	$ 1.74
Settled in cash (in dollars per share)	1.17
Outstanding at the end (in dollars per share)	$ 1.76
Fair value	$ 159
Restricted stock liability	$ 159

Income Taxes - Operating Loss C

Income Taxes - Operating Loss Carryforwards (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Federal
Operating Loss Carryforwards
Operating loss carryforward	$ 135,890
Research tax credits	3,770
State
Operating Loss Carryforwards
Operating loss carryforward	117,579
Research tax credits	645
Foreign
Operating Loss Carryforwards
Operating loss carryforward	83,950
Indefinite federal net operating loss carryforward	$ 54,581

Income Taxes - (Details)

Income Taxes - (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes - (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income (Loss) before income taxes
U.S.	$ (32,875)	$ (21,378)
Foreign	(28)	(1,740)
Loss before income taxes	$ (32,903)	$ (23,118)

Income Taxes - Current and defe

Income Taxes - Current and deferred expense for income tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deferred expense (benefit):
Foreign	$ (3)	$ 20
Total deferred expense (benefit):	(3)	20
Income taxes	$ (3)	$ 20

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Statutory and Effective Tax Rates (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of the statutory tax rate to the Company's effective tax rate
Federal statutory income tax rate	21.00%	21.00%
State taxes, net of federal benefit	6.79%	7.76%
Permanent differences	(0.33%)	2.38%
Tax credits	3.30%	6.94%
Foreign rate differential	0.07%	0.68%
Valuation allowance	(40.18%)	(38.26%)
Other	9.35%	(0.59%)
Effective income tax rate	0.01%	(0.09%)

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred Tax Assets
Federal net operating loss carryforwards	$ 47,845	$ 38,531
State net operating loss carryforwards	7,431	5,553
Stock Options	2,584	1,632
License fees	1,332	1,495
Accrued expenses	277	88
Other	115	149
Total deferred tax assets	63,864	50,641
Valuation allowance	(63,737)	(50,517)
Net deferred tax assets (liability)	127	124
Federal
Deferred Tax Assets
Research tax credits	3,770	2,811
State
Deferred Tax Assets
Research tax credits	$ 510	$ 382

Income Taxes - Valuation Allowa

Income Taxes - Valuation Allowance and Tax Reforms (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Taxes
Increase in valuation allowance	$ 13,220	$ 8,181
Interest and penalties pertaining to uncertain tax positions	$ 0	$ 0

Net Loss Per Share - Basic and

Net Loss Per Share - Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net loss	$ (32,900)	$ (23,138)
Dividend attributable to down round feature of warrants	(359)
Net loss attributable to common stockholders	(33,259)	(23,138)
Change in fair value of warrant liability		7,284
Net loss attributable to common stockholders for diluted loss per share	$ (33,259)	$ (30,422)
Denominator:
Weighted average number of common shares outstanding - basic (in shares)	22,582,687	14,144,287
Assumed conversion of dilutive securities:
Private Placement Warrants (in shares)		268,408
Denominator for diluted loss per share - adjusted weighted (in shares)	22,582,687	14,412,695
Net loss per share attributable to common stockholders - basic (in dollars per share)	$ (1.47)	$ (1.64)
Net loss per share attributable to common stockholders - diluted (in dollars per share)	$ (1.47)	$ (2.11)

Net Loss Per Share - Antidiluti

Net Loss Per Share - Antidilutive (Details) - shares	12 Months Ended
Net Loss Per Share - Antidilutive (Details) - shares	Dec. 31, 2019	Dec. 31, 2018
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	14,394,318	2,816,428
Options to purchase common stock
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	4,024,566	2,761,912
Warrants to purchase common stock
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	10,369,752	54,516
Restricted stock units
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	90,500

Commitments and Contingencies -

Commitments and Contingencies - Manufacturing, License and Other Agreements (Details) - USD ($) $ in Thousands	Jan. 03, 2011	Dec. 31, 2019
Commitments and Contingencies
Manufacturing commitments		$ 207
License And Service Agreements
Commitments and Contingencies
Issuance of stock in consideration for license (in shares)	9,000,000
Royalties paid or accrued		0
Licensing Agreement
Commitments and Contingencies
Royalties paid or accrued		$ 0

Commitments and Contingencies_2

Commitments and Contingencies - Legal Proceedings (Details)	1 Months Ended	12 Months Ended
Commitments and Contingencies - Legal Proceedings (Details)	Mar. 31, 2017entity	Dec. 31, 2019companyclaim
Commitments and Contingencies
Number filing notice of opposition	10	2
Notices of opposition		3

Defined Contribution Plan (Deta

Defined Contribution Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Plan
Contributions to the 401(k) Plan	$ 170	$ 148
Layering first
Defined Contribution Plan
Eligible Employees to contribute (as a percent)	3.00%
Company's match (as a percent)	100.00%
Layering second
Defined Contribution Plan
Eligible Employees to contribute (as a percent)	2.00%
Company's match (as a percent)	50.00%

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 03, 2020	Feb. 05, 2019	Mar. 27, 2018	Dec. 31, 2019	Dec. 31, 2018
Related Party Transactions
Issuance of common stock (in shares)		7,557,142	2,146,667
Price per share		$ 1.75	$ 7.50
Number of warrants issued per common stock		1
Issuance of common stock (value)		$ 12,122		$ 12,122	$ 14,796
Proceeds from issuance, net underwriting discounts and commissions	$ 25,300		$ 14,796
Common Stock
Related Party Transactions
Issuance of common stock (in shares)				7,557,142	2,146,667
Issuance of common stock (value)				$ 7	$ 3
Underwriters' exercise
Related Party Transactions
Issuance of common stock (in shares)		985,714	280,000
2019 Warrants
Related Party Transactions
Exercise price (per warrant)		$ 1.95		$ 1.95
Warrant expiring period		7 years

Subsequent Events - (Details)

Subsequent Events - (Details) $ / shares in Units, $ in Thousands	Mar. 05, 2020$ / sharesshares	Mar. 02, 2020$ / sharesshares	Jan. 03, 2020USD ($)director$ / sharesshares	Jan. 01, 2020USD ($)shares	Mar. 27, 2018USD ($)$ / shares	Dec. 31, 2019$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Feb. 05, 2019$ / shares
Subsequent Events
Price per share \| $ / shares					$ 7.50			$ 1.75
Preferred stock, proceeds \| $			$ 25,300		$ 14,796
Proceeds from exercise of warrants \| $							$ 1,217
Granted (in shares) \| shares						1,481,975	599,050
Exercise price (per share) \| $ / shares						$ 1.48	$ 6.68
Exclusive Option and License Agreement
Subsequent Events
Asset, consideration \| $			$ 3,000
Series A Preferred Stock
Subsequent Events
Preferred stock, shares issued \| shares			1,421,801
Price per share \| $ / shares			$ 10.54
Purchase price per share \| $ / shares			$ 10.54
Series B Preferred Stock
Subsequent Events
Preferred stock, shares issued \| shares			1,137,442
Purchase price per share \| $ / shares			$ 10.55
Special Voting Stock
Subsequent Events
Board seats \| director			1
Common Stock
Subsequent Events
Shares issued on conversion of Series B preferred stock \| shares	11,531,133
Subsequent event
Subsequent Events
Exercise price (per warrant) \| $ / shares	$ 2.11
Proceeds from exercise of warrants \| $				$ 128
Warrants, Exercised \| shares				65,700
Subsequent event \| Common Stock
Subsequent Events
Pre-funded warrant on conversion of Series A preferred stock \| shares	14,413,902
2016 Plan \| Subsequent event \| Directors and employees
Subsequent Events
Granted (in shares) \| shares		765,000
Exercise price (per share) \| $ / shares		$ 2.94
2016 Plan \| Subsequent event \| Directors
Subsequent Events
Vesting period		1 year
2016 Plan \| Subsequent event \| Employees
Subsequent Events
Vesting period		3 years