Ardelyx (ARDX) 10-Q 9 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 02, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Trading Symbol	ARDX
Entity Registrant Name	Ardelyx, Inc.
Entity Central Index Key	1,437,402
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		47,445,139

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	[1]
Current assets:
Cash and cash equivalents	$ 63,636	$ 74,598
Short-term investments	85,088	126,225
Prepaid expenses and other current assets	5,221	3,169
Total current assets	153,945	203,992
Property and equipment, net	9,335	8,991
Other assets	842	148
Total assets	164,122	213,131
Current liabilities:
Accounts payable	4,713	5,635
Accrued compensation and benefits	2,599	3,161
Accrued and other liabilities	11,076	10,405
Total current liabilities	18,388	19,201
Other long-term liabilities	756	779
Total liabilities	19,144	19,980
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.0001 par value; 5,000,000 shares authorized as of June 30, 2017 and December 31, 2016, respectively; no shares issued and outstanding as of June 30, 2017 and December 31, 2016, respectively.
Common stock, $0.0001 par value; 300,000,000 shares authorized as of June 30, 2017 and December 31, 2016, respectively; 47,442,639 and 47,309,422 shares issued and outstanding as of June 30, 2017 and December 31, 2016, respectively.	5	5
Additional paid-in capital	412,617	407,092
Accumulated deficit	(267,604)	(213,875)
Accumulated other comprehensive loss	(40)	(71)
Total stockholders' equity	144,978	193,151
Total liabilities and stockholders' equity	$ 164,122	$ 213,131
[1]	Derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2016.

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2017	Dec. 31, 2016	[1]
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	47,442,639	47,309,422
Common stock, shares outstanding	47,442,639	47,309,422
[1]	Derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2016.

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Operating expenses:
Research and development	$ 20,572	$ 23,838	$ 42,960	$ 43,091
General and administrative	5,846	4,852	11,892	9,130
Total operating expenses	26,418	28,690	54,852	52,221
Loss from operations	(26,418)	(28,690)	(54,852)	(52,221)
Other income, net	697	77	1,123	139
Loss before provision for income taxes	(25,721)	(28,613)	(53,729)	(52,082)
Provision for income taxes	0	0	0	0
Net loss	$ (25,721)	$ (28,613)	$ (53,729)	$ (52,082)
Net loss per common share, basic and diluted	$ (0.54)	$ (0.83)	$ (1.13)	$ (1.53)
Weighted-average number of common shares used in computing net loss per share, basic and diluted	47,403,243	34,636,559	47,373,404	34,051,785

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (25,721)	$ (28,613)	$ (53,729)	$ (52,082)
Unrealized gain on available-for-sale securities, net of tax	9		31
Comprehensive loss	$ (25,712)	$ (28,613)	$ (53,698)	$ (52,082)

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017		Jun. 30, 2016
Operating activities
Net loss	$ (53,729)		$ (52,082)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	1,242		631
Amortization of deferred financing costs	325		174
Amortization of deferred compensation for services	91		101
Amortization of premium on investment securities	1
Stock-based compensation	4,899		2,476
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(3,163)		1,073
Accounts payable	(451)		1,717
Accrued compensation and benefits	(562)		(328)
Accrued and other liabilities	498		5,089
Net cash used in operating activities	(50,849)		(41,149)
Investing activities
Proceeds from maturities of short-term investments	75,434
Sales of short-term investments	10,482
Purchases of short-term investments	(44,748)
Purchases of property and equipment	(1,907)		(495)
Net cash provided by (used in) investing activities	39,261		(495)
Financing activities
Proceeds from issuance of common stock, net of issuance costs			80,837
Proceeds from issuance of common stock under stock plans	626		472
Net cash provided by financing activities	626		81,309
Net (decrease) increase in cash and cash equivalents	(10,962)		39,665
Cash and cash equivalents at beginning of period	74,598	[1]	107,004
Cash and cash equivalents at end of period	$ 63,636		$ 146,669
[1]	Derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2016.

Organization and Basis of Prese

Organization and Basis of Presentation	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Organization and Basis of Presentation	NOTE 1. ORGANIZATION AND BASIS OF PRESENTATION Ardelyx, Inc., or “the Company,” is focused on enhancing the way patients with cardiorenal and gastrointestinal, or GI, diseases are treated by using the gut as the gateway to delivering medicines that matter. The Company has pioneered the development of small molecule therapeutics that act predominantly in the GI tract, thereby avoiding potentially negative side effects on the rest of the body. The Company’s strategy is to evolve from a research and development-focused company to an integrated biotechnology company, by establishing regional and global partnerships to leverage its own commercial capabilities and experience to help build its cardiorenal and GI portfolios. The Company is developing several products and programs focused on underserved medical needs including the following: Cardiorenal Portfolio • Tenapanor: Phase 3 for treatment of end-stage renal disease, or ESRD, patients on dialysis suffering from elevated serum phosphorous, or hyperphosphatemia • RDX7675: Phase 3 to treat patients with hyperkalemia, a severe disorder of elevated serum potassium common in patients with chronic kidney disease, or CKD, and/or heart failure • Research Programs: Development of unique, small-molecule approaches to treat hyperkalemia to improve efficacy and compliance significantly reducing pill burden Gastrointestinal Portfolio • Tenapanor: Phase 3 clinical development for treatment of patients with irritable bowel syndrome with constipation, or IBS-C, a highly prevalent disorder with symptoms of both constipation and abdominal pain • RDX8940: Investigational New Drug Application, or IND, filed in late 2016 for various indications • Research Programs: Gut biased farnesoid X receptor, or FXR, agonists for the treatment of various GI disorders, and efforts that leverage its knowledge of the mechanisms of tenapanor in order to discover new agents that modulate transport of ions and other processes in the gut. The Company operates in only one business segment, which is the development of biopharmaceutical products. Basis of Presentation These unaudited condensed consolidated financial statements and the related footnote information of the Company have been prepared pursuant to the requirements of the Securities and Exchange Commission, or the SEC, for interim reporting. As permitted under those rules and regulations, certain footnotes or other financial information that are normally required by U.S. generally accepted accounting principles, or U.S. GAAP, have been condensed or omitted pursuant to such rules and regulations. In the opinion of the Company’s management, the accompanying interim unaudited condensed consolidated financial statements include all adjustments (consisting only of normal recurring adjustments) necessary for a fair presentation of the information for the periods presented. The results for the three and six months ended June 30, 2017 are not necessarily indicative of results to be expected for the entire year ending December 31, 2017 or future operating periods. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2016, included in the Company’s Annual Report on Form 10-K filed with the SEC (the “2016 Form 10-K”). The balance sheet at December 31, 2016 has been derived from the audited financial statements at that date, as filed with the 2016 Form 10-K. The accompanying condensed consolidated financial statements include the accounts of Ardelyx, Inc. and its wholly-owned subsidiary, Ardelyx Cayman Islands, and have been prepared in accordance with U.S. GAAP. Intercompany transactions and balances have been eliminated in consolidation.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Although management believes these estimates are based upon reasonable assumptions within the bounds of its knowledge of the Company’s business and operations, actual results could differ materially from those estimates. Accrued Research and Development Expenses As part of the process of preparing its financial statements, the Company is required to estimate its accrued expenses. This process involves reviewing open contracts and purchase orders, communicating with its personnel to identify services that have been performed on its behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of the actual cost. The majority of the Company’s service providers submit its monthly invoices in arrears for services performed or when contractual milestones are met. The Company makes estimates of its accrued expenses as of each balance sheet date in its financial statements based on facts and circumstances known to the Company at that time. The Company periodically confirms the accuracy of its estimates with the service providers and makes adjustments if necessary. Examples of estimated accrued research and development expenses include fees paid to: • contract research organizations (“CROs”) in connection with clinical studies; • investigative sites in connection with clinical studies; • vendors related to product manufacturing, development and distribution of clinical supplies; and • vendors in connection with preclinical development activities. The Company records expenses related to clinical studies and manufacturing development activities based on its estimates of the services received and efforts expended pursuant to contracts with multiple CROs and manufacturing vendors that conduct and manage these activities on its behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract, and may result in uneven payment flows. There may be instances in which payments made to the Company’s vendors will exceed the level of services provided and result in a prepayment of the expense. Payments under some of these contracts depend on factors such as the successful enrollment of subjects and the completion of clinical trial milestones. In accruing service fees, the Company estimates the time period over which services will be performed, enrollment of subjects, number of sites activated and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the Company’s estimate, the Company will adjust the accrued or prepaid expense balance accordingly. To date, there have been no material differences from the Company’s estimates to the amounts actually incurred. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers - Revenue from Contracts with Customers In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) In October 2016, the FASB issued ASU No. 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory In May 2017, FASB issued ASU No. 2017-09, Compensation-Stock Compensation (Topic 718)- Scope of Modification Accounting The Company has reviewed all other significant newly-issued accounting pronouncements and concluded that they either are not applicable to the Company’s operations or no material effect is expected on its condensed consolidated financial statements as a result of future adoption.

Cash, Cash Equivalents and Inve

Cash, Cash Equivalents and Investments	6 Months Ended
	Jun. 30, 2017
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Investments	NOTE 3. CASH, CASH EQUIVALENTS AND INVESTMENTS Securities classified as cash, cash equivalents and short-term investments as of June 30, 2017 and December 31, 2016 are summarized below (in thousands). Estimated fair value is based on quoted market prices for these investments. June 30, 2017 Amortized Gross Unrealized Fair Value Gains Losses Cash and cash equivalents: Cash $ 8,290 $ — $ — $ 8,290 Money market funds 54,249 — — 54,249 Commercial paper 1,097 — — 1,097 Total cash and cash equivalents $ 63,636 $ — $ — $ 63,636 Short-term investments Corporate bonds 42,782 1 (27 ) $ 42,756 Commercial paper 24,399 2 (6 ) 24,395 Asset-backed securities 17,947 — (10 ) $ 17,937 Total short-term investments $ 85,128 $ 3 $ (43 ) $ 85,088 Total $ 148,764 $ 3 $ (43 ) $ 148,724 December 31, 2016 Amortized Gross Unrealized Fair Value Gains Losses Cash and cash equivalents: Cash $ 3,638 $ — $ — $ 3,638 Money market funds 68,561 — — 68,561 Commercial paper 2,399 — — 2,399 Total cash equivalents and investments $ 74,598 $ — $ — $ 74,598 Short-term investments Corporate bonds $ 58,464 $ 2 $ (56 ) $ 58,410 Commercial paper 62,946 5 (20 ) 62,931 Asset-backed securities 4,886 — (2 ) 4,884 Total short-term investments $ 126,296 $ 7 $ (78 ) $ 126,225 Total $ 200,894 $ 7 $ (78 ) $ 200,823 Cash equivalents consist of money market funds and commercial paper with original maturities of three months or less at the time of purchase, and the carrying amount is a reasonable approximation of fair value. The Company invests its cash in high quality securities of financial and commercial institutions. These securities are carried at fair value, which is based on readily available market information, with unrealized gains and losses included in “accumulated other comprehensive gain (loss)” within stockholders’ equity on the Company’s condensed consolidated balance sheets. The Company uses the specific identification method to determine the amount of realized gains or losses on sales of marketable securities. Realized gains or losses have been insignificant and are included in “other income, net” in the consolidated condensed statement of operations. All available-for-sale securities held as of June 30, 2017 had contractual maturities of less than one year. Investments that have maturities beyond one year as of the end of the reporting period are classified as non-current. The Company’s available-for-sale securities are subject to a periodic impairment review. The Company considers a debt security to be impaired when its fair value is less than its carrying cost, in which case the Company would further review the investment to determine whether it is other-than-temporarily impaired. When the Company evaluates an investment for other-than-temporary impairment, the Company reviews factors such as the length of time and extent to which fair value has been below cost basis, the financial condition of the issuer and any changes thereto, intent to sell, and whether it is more likely than not the Company will be required to sell the investment before the recovery of it cost basis. If an investment is other-than-temporarily impaired, the Company writes it down through the statement of operations to its fair value and establishes that value as a new cost basis for the investment. The Company did not identify any of its available-for-sale securities as other-than-temporarily impaired in any of the periods presented. As of June 30, 2017, no investment was in a continuous unrealized loss position for more than one year, the unrealized losses were not due to a change in credit risk, and the Company believes that is more likely than not the investments will be held until maturity or a forecasted recovery of fair value.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 4. FAIR VALUE MEASUREMENTS 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. The three-level hierarchy for the inputs to valuation techniques is briefly summarized as follows: Level 1 – Valuations are based on quoted prices in active markets for identical assets or liabilities and readily accessible by the Company at the reporting date. Examples of assets and liabilities utilizing Level 1 inputs are certain money market funds, U.S. Treasuries and trading securities with quoted prices on active markets. Level 2 – Valuations based on inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Examples of assets and liabilities utilizing Level 2 inputs are U.S. government agency bonds, corporate bonds, commercial paper, certificates of deposit and over-the-counter derivatives. Level 3 – Valuations based on unobservable inputs in which there is little or no market data, which require the Company to develop its own assumptions. The following table sets forth the fair value of the Company’s financial assets measured on a recurring basis by level within the fair value hierarchy (in thousands): June 30, 2017 Total Level 1 Level 2 Level 3 Assets: Money market funds $ 54,249 $ 54,249 $ — $ — Corporate bonds 42,756 — 42,756 — Commercial paper 25,492 — 25,492 — Asset-backed securities 17,937 — 17,937 — Total $ 140,434 $ 54,249 $ 86,185 $ — December 31, 2016 Total Level 1 Level 2 Level 3 Assets: Money market funds $ 68,561 $ 68,561 $ — $ — Corporate bonds 58,410 — 58,410 — Commercial paper 65,330 — 65,330 — Asset-backed securities 4,884 — 4,884 Total $ 197,185 $ 68,561 $ 128,624 $ — Where quoted prices are available in an active market, securities are classified as Level 1. The Company classifies money market funds as Level 1. When quoted market prices are not available for the specific security, then the Company estimates fair value by using benchmark yields, reported trades, broker/dealer quotes, and issuer spreads. The Company classifies corporate bonds, commercial paper and asset-backed securities as Level 2. In certain cases where there is limited activity or less transparency around inputs to valuation, securities are classified as Level 3. There were no transfers between Level 1 and Level 2 during the periods presented. The carrying amounts reflected in the balance sheets for cash equivalents, short-term investments, prepaid expenses and other current assets, accounts payable and accrued expenses approximate their fair values at June 30, 2017 and December 31, 2016, due to their short-term nature.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	NOTE 5. STOCK-BASED COMPENSATION The following table presents stock-based compensation expense recognized for stock options, restricted stock units, or RSUs, performance-based restricted stock units, or PRSUs, and the Company’s employee stock purchase program, or ESPP, in the Company’s statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Research and development $ 1,414 $ 681 $ 2,445 $ 1,306 General and administrative 1,376 605 2,454 1,170 Total $ 2,790 $ 1,286 $ 4,899 $ 2,476 In January 2017, the Company granted PRSU awards to certain employees which vest upon the achievement of certain performance conditions, subject to the employees’ continued service relationship with the Company. None vested during the three and six months ended June 30, 2017. However, the related compensation cost is recognized as an expense over the estimated vesting period when achievement of the milestone is considered probable. The expense recognized for these awards is based on the grant date fair value of the Company’s common stock multiplied by the number of units granted. The Company recognized $0.6 million of related expense during the three and six months ended June 30, 2017. At June 30, 2017, the Company had $20.2 million, $1.8 million, $1.6 million and $0.1 million of total unrecognized compensation expense, net of estimated forfeitures, related to stock option grants, RSU grants, PRSUs and ESPP, respectively, that will be recognized over an average vesting period of 3.0 years, 2.2 years, 1.3 years and 0.2 years, respectively.

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Net Loss Per Share	NOTE 6. NET LOSS PER SHARE Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per common share is computed giving effect to all potential dilutive common shares, including common stock issuable upon exercise of stock options, and unvested restricted common stock and stock units. The Company uses the treasury-stock method to compute diluted earnings per share with respect to its stock options and common stock equivalents. For purposes of this calculation, options to purchase stock are considered to be potential common shares and are only included in the calculation of diluted net loss per share when their effect is dilutive. Basic and diluted loss per share are calculated as follows (in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Numerator: Net loss $ (25,721 ) $ (28,613 ) $ (53,729 ) $ (52,082 ) Denominator: Weighted average common shares outstanding - basic and diluted 47,403,243 34,636,559 47,373,404 34,051,785 Net loss per share - basic and diluted $ (0.54 ) $ (0.83 ) $ (1.13 ) $ (1.53 ) For the three and six months ended June 30, 2017, the total number of anti-dilutive outstanding common stock equivalents excluded from the net loss per common share computation was 6.6 million and 6.4 million, respectively. For the three and six months ended June 30, 2016, the total number of anti-dilutive outstanding common stock equivalents excluded from the net loss per common share computation was 4.7 million and 4.6 million, respectively.

Accrued and Other Liabilities

Accrued and Other Liabilities	6 Months Ended
	Jun. 30, 2017
Payables and Accruals [Abstract]
Accrued and Other Liabilities	NOTE 7. ACCRUED AND OTHER LIABILITIES Accrued liabilities and other liabilities consist of the following (in thousands) June 30, 2017 December 31, 2016 Accrued clinical and non-clinical expenses $ 7,271 $ 6,694 Accrued contract manufacturing 2,580 2,705 Accrued professional and consulting services 370 322 Other 855 684 $ 11,076 $ 10,405

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Stockholders' Equity	NOTE 8. STOCKHOLDERS’ EQUITY Option Exercises For the three and six months ended June 30, 2017, employees exercised options to purchase 9,025 and 28,326 shares, respectively, of the Company’s common stock with insignificant net proceeds to the Company. For the three and six months ended June 30, 2016, employees exercised options to purchase zero and 6,250 shares, respectively, of the Company’s common stock with insignificant net proceeds to the Company. Restricted Stock Units For the three and six months ended June 30, 2017, the Company issued zero and 15,188 shares, respectively, of the Company’s common stock due to vesting of restricted stock units. For the three and six ended June 30, 2016, the Company issued zero shares of the Company’s common stock due to vesting of restricted stock units. Employee Stock Purchase Plan In February 2017, the Company sold 42,845 shares under the ESPP. The shares were purchased at a purchase price of $8.77 per share with proceeds to the Company of approximately $0.4 million. Issuance of Common Stock for Services For the three and six months ended June 30, 2017, the Company issued 46,858 shares of common stock in exchange for services performed. The shares issued were valued at $0.2 million based on the fair value of the common stock on the date of grant. For the three and six months ended June 30, 2016, the Company issued 20,118 shares of common stock in exchange for services performed. The shares issued were valued at $0.2 million based on the fair value of the common stock on the date of grant.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	NOTE 9. SUBSEQUENT EVENTS In August 2017, we announced a corporate restructuring plan that included the immediate reduction of approximately 28% of our workforce, primarily including research and certain development and general administrative personnel. As a result, we expect to record restructuring charges in the third quarter for one-time employee severance benefits and related costs totaling approximately $0.8 million. The majority of the charges are expected to be paid by the end of the third quarter ending September 30, 2017.

Summary of Significant Accoun16

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Although management believes these estimates are based upon reasonable assumptions within the bounds of its knowledge of the Company’s business and operations, actual results could differ materially from those estimates.
Accrued Research and Development Expenses	Accrued Research and Development Expenses As part of the process of preparing its financial statements, the Company is required to estimate its accrued expenses. This process involves reviewing open contracts and purchase orders, communicating with its personnel to identify services that have been performed on its behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of the actual cost. The majority of the Company’s service providers submit its monthly invoices in arrears for services performed or when contractual milestones are met. The Company makes estimates of its accrued expenses as of each balance sheet date in its financial statements based on facts and circumstances known to the Company at that time. The Company periodically confirms the accuracy of its estimates with the service providers and makes adjustments if necessary. Examples of estimated accrued research and development expenses include fees paid to: • contract research organizations (“CROs”) in connection with clinical studies; • investigative sites in connection with clinical studies; • vendors related to product manufacturing, development and distribution of clinical supplies; and • vendors in connection with preclinical development activities. The Company records expenses related to clinical studies and manufacturing development activities based on its estimates of the services received and efforts expended pursuant to contracts with multiple CROs and manufacturing vendors that conduct and manage these activities on its behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract, and may result in uneven payment flows. There may be instances in which payments made to the Company’s vendors will exceed the level of services provided and result in a prepayment of the expense. Payments under some of these contracts depend on factors such as the successful enrollment of subjects and the completion of clinical trial milestones. In accruing service fees, the Company estimates the time period over which services will be performed, enrollment of subjects, number of sites activated and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the Company’s estimate, the Company will adjust the accrued or prepaid expense balance accordingly. To date, there have been no material differences from the Company’s estimates to the amounts actually incurred.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers - Revenue from Contracts with Customers In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) In October 2016, the FASB issued ASU No. 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory In May 2017, FASB issued ASU No. 2017-09, Compensation-Stock Compensation (Topic 718)- Scope of Modification Accounting The Company has reviewed all other significant newly-issued accounting pronouncements and concluded that they either are not applicable to the Company’s operations or no material effect is expected on its condensed consolidated financial statements as a result of future adoption.
Fair Value Measurements	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. The three-level hierarchy for the inputs to valuation techniques is briefly summarized as follows: Level 1 – Valuations are based on quoted prices in active markets for identical assets or liabilities and readily accessible by the Company at the reporting date. Examples of assets and liabilities utilizing Level 1 inputs are certain money market funds, U.S. Treasuries and trading securities with quoted prices on active markets. Level 2 – Valuations based on inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Examples of assets and liabilities utilizing Level 2 inputs are U.S. government agency bonds, corporate bonds, commercial paper, certificates of deposit and over-the-counter derivatives. Level 3 – Valuations based on unobservable inputs in which there is little or no market data, which require the Company to develop its own assumptions.

Cash, Cash Equivalents and In17

Cash, Cash Equivalents and Investments (Tables)	6 Months Ended
	Jun. 30, 2017
Cash and Cash Equivalents [Abstract]
Schedule of Securities Classified as Cash, Cash Equivalents and Short-term Investments	Securities classified as cash, cash equivalents and short-term investments as of June 30, 2017 and December 31, 2016 are summarized below (in thousands). Estimated fair value is based on quoted market prices for these investments. June 30, 2017 Amortized Gross Unrealized Fair Value Gains Losses Cash and cash equivalents: Cash $ 8,290 $ — $ — $ 8,290 Money market funds 54,249 — — 54,249 Commercial paper 1,097 — — 1,097 Total cash and cash equivalents $ 63,636 $ — $ — $ 63,636 Short-term investments Corporate bonds 42,782 1 (27 ) $ 42,756 Commercial paper 24,399 2 (6 ) 24,395 Asset-backed securities 17,947 — (10 ) $ 17,937 Total short-term investments $ 85,128 $ 3 $ (43 ) $ 85,088 Total $ 148,764 $ 3 $ (43 ) $ 148,724 December 31, 2016 Amortized Gross Unrealized Fair Value Gains Losses Cash and cash equivalents: Cash $ 3,638 $ — $ — $ 3,638 Money market funds 68,561 — — 68,561 Commercial paper 2,399 — — 2,399 Total cash equivalents and investments $ 74,598 $ — $ — $ 74,598 Short-term investments Corporate bonds $ 58,464 $ 2 $ (56 ) $ 58,410 Commercial paper 62,946 5 (20 ) 62,931 Asset-backed securities 4,886 — (2 ) 4,884 Total short-term investments $ 126,296 $ 7 $ (78 ) $ 126,225 Total $ 200,894 $ 7 $ (78 ) $ 200,823

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Summary of Fair Value Measurements of Company's Financial Assets	The following table sets forth the fair value of the Company’s financial assets measured on a recurring basis by level within the fair value hierarchy (in thousands): June 30, 2017 Total Level 1 Level 2 Level 3 Assets: Money market funds $ 54,249 $ 54,249 $ — $ — Corporate bonds 42,756 — 42,756 — Commercial paper 25,492 — 25,492 — Asset-backed securities 17,937 — 17,937 — Total $ 140,434 $ 54,249 $ 86,185 $ — December 31, 2016 Total Level 1 Level 2 Level 3 Assets: Money market funds $ 68,561 $ 68,561 $ — $ — Corporate bonds 58,410 — 58,410 — Commercial paper 65,330 — 65,330 — Asset-backed securities 4,884 — 4,884 Total $ 197,185 $ 68,561 $ 128,624 $ —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock-Based Compensation Recognized	The following table presents stock-based compensation expense recognized for stock options, restricted stock units, or RSUs, performance-based restricted stock units, or PRSUs, and the Company’s employee stock purchase program, or ESPP, in the Company’s statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Research and development $ 1,414 $ 681 $ 2,445 $ 1,306 General and administrative 1,376 605 2,454 1,170 Total $ 2,790 $ 1,286 $ 4,899 $ 2,476

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Computation of Basic and Diluted Loss Per Share Attributable to Common Stockholders	Basic and diluted loss per share are calculated as follows (in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Numerator: Net loss $ (25,721 ) $ (28,613 ) $ (53,729 ) $ (52,082 ) Denominator: Weighted average common shares outstanding - basic and diluted 47,403,243 34,636,559 47,373,404 34,051,785 Net loss per share - basic and diluted $ (0.54 ) $ (0.83 ) $ (1.13 ) $ (1.53 )

Accrued and Other Liabilities (

Accrued and Other Liabilities (Tables)	6 Months Ended
	Jun. 30, 2017
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities and Other Liabilities	Accrued liabilities and other liabilities consist of the following (in thousands) June 30, 2017 December 31, 2016 Accrued clinical and non-clinical expenses $ 7,271 $ 6,694 Accrued contract manufacturing 2,580 2,705 Accrued professional and consulting services 370 322 Other 855 684 $ 11,076 $ 10,405

Organization and Basis of Pre22

Organization and Basis of Presentation - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2017Segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segments	1

Cash Equivalents and Investment

Cash Equivalents and Investments - Schedule of Securities Classified as Cash, Cash Equivalents and Short-term Investments (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016		Jun. 30, 2016	Dec. 31, 2015
Cash Cash Equivalents And Short Term Investments [Line Items]
Cash and cash equivalents, Amortized Cost	$ 63,636	$ 74,598	[1]	$ 146,669	$ 107,004
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	0	0
Cash and cash equivalents, Fair Value	63,636	74,598
Short-term investments, Amortized Cost	85,128	126,296
Short-term investments, Gross Unrealized Gains	3	7
Short-term investments, Gross Unrealized Losses	(43)	(78)
Short-term investments, Fair Value	85,088	126,225
Cash equivalents and short-term investments, Amortized Cost	148,764	200,894
Cash equivalents and short-term investments, Gross Unrealized Gains	3	7
Cash equivalents and short-term investments, Gross Unrealized Losses	(43)	(78)
Cash equivalents and short-term investments, Fair Value	148,724	200,823
Cash [Member]
Cash Cash Equivalents And Short Term Investments [Line Items]
Cash and cash equivalents, Amortized Cost	8,290	3,638
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	0	0
Cash and cash equivalents, Fair Value	8,290	3,638
Money Market Funds [Member]
Cash Cash Equivalents And Short Term Investments [Line Items]
Cash and cash equivalents, Amortized Cost	54,249	68,561
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	0	0
Cash and cash equivalents, Fair Value	54,249	68,561
Commercial Paper (Cash Equivalents) [Member]
Cash Cash Equivalents And Short Term Investments [Line Items]
Cash and cash equivalents, Amortized Cost	1,097	2,399
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	0	0
Cash and cash equivalents, Fair Value	1,097	2,399
Corporate Bonds (Investments) [Member]
Cash Cash Equivalents And Short Term Investments [Line Items]
Short-term investments, Amortized Cost	42,782	58,464
Short-term investments, Gross Unrealized Gains	1	2
Short-term investments, Gross Unrealized Losses	(27)	(56)
Short-term investments, Fair Value	42,756	58,410
Commercial Paper (Investments) [Member]
Cash Cash Equivalents And Short Term Investments [Line Items]
Short-term investments, Amortized Cost	24,399	62,946
Short-term investments, Gross Unrealized Gains	2	5
Short-term investments, Gross Unrealized Losses	(6)	(20)
Short-term investments, Fair Value	24,395	62,931
Asset-Backed Securities [Member]
Cash Cash Equivalents And Short Term Investments [Line Items]
Short-term investments, Amortized Cost	17,947	4,886
Short-term investments, Gross Unrealized Losses	(10)	(2)
Short-term investments, Fair Value	$ 17,937	$ 4,884
[1]	Derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2016.

Cash Equivalents and Investme24

Cash Equivalents and Investments - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2017USD ($)
Cash Cash Equivalents And Short Term Investments [Line Items]
Investment in continuous unrealized loss position for more than one year	$ 0
Maximum [Member]
Cash Cash Equivalents And Short Term Investments [Line Items]
Available for sale securities contractual maturity period	1 year

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value Measurements of Company's Financial Assets (Detail) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets:
Assets at fair value	$ 140,434	$ 197,185
Level 1 [Member]
Assets:
Assets at fair value	54,249	68,561
Level 2 [Member]
Assets:
Assets at fair value	86,185	128,624
Money Market Funds [Member]
Assets:
Assets at fair value	54,249	68,561
Money Market Funds [Member] | Level 1 [Member]
Assets:
Assets at fair value	54,249	68,561
Corporate Bonds [Member]
Assets:
Assets at fair value	42,756	58,410
Corporate Bonds [Member] | Level 2 [Member]
Assets:
Assets at fair value	42,756	58,410
Commercial Paper [Member]
Assets:
Assets at fair value	25,492	65,330
Commercial Paper [Member] | Level 2 [Member]
Assets:
Assets at fair value	25,492	65,330
Asset-Backed Securities [Member]
Assets:
Assets at fair value	17,937	4,884
Asset-Backed Securities [Member] | Level 2 [Member]
Assets:
Assets at fair value	$ 17,937	$ 4,884

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail)	Jun. 30, 2017USD ($)
Fair Value Disclosures [Abstract]
Transfer of assets from Level 1 to Level 2	$ 0
Transfer of assets from Level 2 to Level 1	$ 0

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-Based Compensation Expense Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$ 2,790	$ 1,286	$ 4,899	$ 2,476
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	1,414	681	2,445	1,306
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$ 1,376	$ 605	$ 2,454	$ 1,170

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2017USD ($)shares	Jun. 30, 2017USD ($)shares
Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock based compensation expense	$ 20.2	$ 20.2
Unrecognized stock based compensation expense, weighted-average remaining recognition period		3 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock based compensation expense	$ 1.8	$ 1.8
Unrecognized stock based compensation expense, weighted-average remaining recognition period		2 years 2 months 12 days
Performance-Based Restricted Stock Units (PSRUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vested shares | shares	0	0
Recognized stock-based compensation related expense in connection with vesting of award granted	$ 0.6	$ 0.6
Unrecognized stock based compensation expense	1.6	$ 1.6
Unrecognized stock based compensation expense, weighted-average remaining recognition period		1 year 3 months 19 days
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock based compensation expense	$ 0.1	$ 0.1
Unrecognized stock based compensation expense, weighted-average remaining recognition period		2 months 12 days

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Basic and Diluted Loss Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator:
Net loss	$ (25,721)	$ (28,613)	$ (53,729)	$ (52,082)
Denominator:
Weighted average common shares outstanding - basic and diluted	47,403,243	34,636,559	47,373,404	34,051,785
Net loss per share - basic and diluted	$ (0.54)	$ (0.83)	$ (1.13)	$ (1.53)

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Anti-dilutive securities excluded from computation of diluted net loss per share attributable to common stockholders	6.6	4.7	6.4	4.6

Accrued and Other Liabilities -

Accrued and Other Liabilities - Schedule of Accrued Liabilities and Other Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accrued clinical and non-clinical expenses	$ 7,271	$ 6,694
Accrued contract manufacturing	2,580	2,705
Accrued professional and consulting services	370	322
Other	855	684
Accrued liabilities and other liabilities	$ 11,076	$ 10,405	[1]
[1]	Derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2016.

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock for services (Shares)		46,858	20,118	46,858	20,118
Issuance of common stock for services, amount		$ 0.2	$ 0.2	$ 0.2	$ 0.2
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares sold under ESPP	42,845
Purchase price of common shares	$ 8.77
Proceeds from issuance of shares under the ESPP	$ 0.4
Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares purchased by employees on exercise of options		9,025	0	28,326	6,250
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, restricted stock units		0	0	15,188	0

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Employee Severance [Member] - USD ($) $ in Millions	Aug. 09, 2017	Jun. 30, 2017
Subsequent Event [Line Items]
Restructuring activities completion date		Sep. 30, 2017
Subsequent Event [Member]
Subsequent Event [Line Items]
Percentage of workforce reduction	28.00%
Employee severance benefits and related costs	$ 0.8