Aceragen (ACGN) 10-Q 6 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 15, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Trading Symbol	IDRA
Entity Registrant Name	IDERA PHARMACEUTICALS, INC.
Entity Central Index Key	861,838
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		118,350,364

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 27,996	$ 19,971
Short-term investments	38,028	21,256
Prepaid expenses and other current assets	2,358	1,203
Total current assets	68,382	42,430
Long-term investments	28,670	7,344
Property and equipment, net	1,685	1,306
Restricted cash and other assets	347	346
Total assets	99,084	51,426
Current liabilities:
Accounts payable	881	2,458
Accrued expenses	4,571	4,460
Current portion of note payable	254	128
Total current liabilities	5,706	7,046
Note payable, net of current portion	569	742
Other liabilities	151	236
Total liabilities	$ 6,426	$ 8,024
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.01 par value, Authorized - 5,000 shares
Common stock, $0.001 par value, Authorized - 280,000 shares; Issued and outstanding - 118,340 and 94,829 shares at September 30, 2015 and December 31, 2014, respectively	$ 118	$ 95
Additional paid-in capital	580,658	494,850
Accumulated deficit	(488,091)	(451,526)
Accumulated other comprehensive loss	(27)	(17)
Total stockholders' equity	92,658	43,402
Total liabilities and stockholders' equity	99,084	51,426
Series E Preferred Stock [Member]
Stockholders' equity:
Preferred stock, $0.01 par value	0	0
Series A Preferred Stock [Member]
Stockholders' equity:
Preferred stock, $0.01 par value	$ 0	$ 0

Condensed Balance Sheets (Unau3

Condensed Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	280,000,000	280,000,000
Common stock, shares issued	118,340,000	94,829,000
Common stock, shares outstanding	118,340,000	94,829,000
Series E Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares designated	0	424,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Series A Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares designated	1,500,000	1,500,000
Preferred stock, shares issued	1,000	1,000
Preferred stock, shares outstanding	1,000	1,000

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Alliance revenue	$ 20	$ 30	$ 59	$ 71
Operating expenses:
Research and development	7,454	6,678	25,134	19,248
General and administrative	4,030	2,873	11,688	7,646
Total operating expenses	11,484	9,551	36,822	26,894
Loss from operations	(11,464)	(9,521)	(36,763)	(26,823)
Other income (expense):
Investment income	123	14	239	45
Interest expense	(27)		(81)
Foreign currency exchange gain	3	52	40	54
Net loss	(11,365)	(9,455)	(36,565)	(26,724)
Preferred stock dividends		119		422
Net loss applicable to common stockholders	$ (11,365)	$ (9,574)	$ (36,565)	$ (27,146)
Basic and diluted net loss per common share applicable to common stockholders (Note 13)	$ (0.10)	$ (0.11)	$ (0.32)	$ (0.33)
Shares used in computing basic and diluted net loss per common share applicable to common stockholders	118,248	84,527	113,821	81,200
Net loss	$ (11,365)	$ (9,455)	$ (36,565)	$ (26,724)
Unrealized gain (loss) on available-for-sale securities	50	(5)	(10)	5
Comprehensive loss	$ (11,315)	$ (9,460)	$ (36,575)	$ (26,719)

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash Flows from Operating Activities:
Net loss	$ (36,565)	$ (26,724)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	4,013	2,086
Depreciation and amortization expense	346	135
Amortization of investment premiums	397	149
Issuance of common stock for services rendered	90	62
Non-employee stock option expense	142	(8)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(1,163)	(228)
Accounts payable, accrued expenses, and other liabilities	(1,590)	2,718
Net cash used in operating activities	(34,330)	(21,810)
Cash Flows from Investing Activities:
Purchases of available-for-sale securities	(63,106)	(2,619)
Maturities of available-for-sale securities	23,602	2,000
Sales of available-for-sale securities	999
Purchases of property and equipment	(659)	(891)
Net cash used in investing activities	(39,164)	(1,510)
Cash Flows from Financing Activities:
Proceeds from equity financings, net of issuance costs	80,599	37,137
Proceeds from issuance of note payable		850
Dividends paid		(582)
Proceeds from exercise of common stock warrants and options and employee stock purchases	987	8,132
Payments on note payable	(59)
Payments on capital lease	(8)	(4)
Net cash provided by financing activities	81,519	45,533
Net increase in cash and cash equivalents	8,025	22,213
Cash and cash equivalents, beginning of period	19,971	26,278
Cash and cash equivalents, end of period	$ 27,996	$ 48,491

Organization

Organization	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	(1) Organization Idera Pharmaceuticals, Inc. (“Idera” or the “Company”) is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel therapeutics for oncology and rare diseases. The Company uses two distinct proprietary drug discovery technology platforms to design and develop drug candidates: its Toll-like receptor (“TLR”) targeting technology and its third-generation antisense program, which the Company previously referred to as its GSO program. The Company developed these platforms based on its scientific expertise and pioneering work with synthetic oligonucleotides as therapeutic agents. Using its TLR targeting technology, the Company designs synthetic oligonucleotide-based drug candidates to modulate the activity of specific TLRs. In addition, using its third-generation antisense technology, the Company is developing drug candidates to turn off the messenger RNA (“mRNA”) associated with disease causing genes. The Company believes that its third-generation antisense technology may potentially reduce the immunotoxicity and increase the potency of earlier generation antisense and RNA interference (“RNAi”) technologies. Idera is currently conducting a Phase 1/2 clinical trial of IMO-8400, a novel synthetic oligonucleotide antagonist of TLR7, TLR8 and TLR9, in patients with Waldenström’s macroglobulinemia and a Phase 1/2 clinical trial of IMO-8400 in patients with diffuse large B-cell lymphoma (“DLBCL”) who harbor the MYD88 L265P oncogenic mutation. The Company is also developing IMO-8400 for the treatment of rare diseases and has selected dermatomyositis and Duchenne muscular dystrophy (“DMD”) as the first non-cancer rare diseases for which it plans to develop IMO-8400. The Company believes it can develop and commercialize therapies on its own in these disease indications, which are characterized by small, well-defined patient populations with serious unmet medical needs. The Company also evaluated a second novel synthetic oligonucleotide antagonist of TLR7, TLR8 and TLR9, IMO-9200, as a drug candidate for potential use in inflammatory bowel disease (“IBD”). The Company has also conducted a Phase 1 clinical trial of subcutaneously injected IMO-9200 in healthy subjects and preclinical studies using oral administration of IMO-9200 in mouse models of colitis. The Company is currently reviewing its strategic options in relation to the advancement of IMO-9200, as IBD falls outside of the core focus of oncology and rare diseases. In the second quarter of 2015, the Company entered into a strategic clinical research alliance with MD Anderson Cancer Center (“MD Anderson”) to advance clinical development of a TLR9 agonist administered in combination with checkpoint inhibitors. The Company plans to initiate the first trial from the research alliance, a Phase 1/2 clinical trial of IMO-2125, one of the Company’s clinical-stage TLR9 agonists, administered intra-tumorally in combination with ipilimumab, a CTLA4 antibody, in patients with metastatic melanoma in the fourth quarter of 2015. The Company is also developing its third-generation antisense drug candidates to specifically address challenges associated with earlier generation antisense. Although currently used technologies to silence RNA have demonstrated the ability to inhibit the expression of disease-associated proteins, the Company believes that to reach their full therapeutic potential, gene silencing technologies need to achieve an improved therapeutic index through reduced immunotoxicity and increased potency. The Company is conducting preclinical studies in the field of oncology and rare diseases where there is an unmet medical need. The company has selected NLRP3 (NOD-like receptor family, pyrin domain containing protein 3) and DUX4 (Double Homeobox 4) as gene targets to advance into IND-enabling activities. Potential disease indications include, but are not limited to interstitial cystitis, uveitis and facioscapulohumeral muscular dystrophy (FSHD), respectively. Concurrently, the Company is engaging in academic collaborations to further evaluate the application of this third-generation antisense technology platform in additional gene targets and exploring development opportunities with third parties for applications outside of the Company’s current focus areas. As of September 30, 2015, the Company had an accumulated deficit of $488,091,000. The Company expects to incur substantial operating losses in future periods. The Company does not expect to generate significant product revenue, sales-based milestones or royalties until the Company successfully completes development and obtains marketing approval for drug candidates, either alone or in collaborations with third parties, which the Company expects will take a number of years. In order to commercialize its drug candidates, the Company needs to complete clinical development and comply with comprehensive regulatory requirements. The Company is subject to a number of risks and uncertainties similar to those of other companies of the same size within the biotechnology industry, such as uncertainty of clinical trial outcomes, uncertainty of additional funding, and history of operating losses.

New Accounting Pronouncements -

New Accounting Pronouncements - Recently Issued	9 Months Ended
	Sep. 30, 2015
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements - Recently Issued	(2) New Accounting Pronouncements - Recently Issued In May 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606), which was amended by ASU No. 2015-14. ASU No. 2014-09, as amended by ASU No. 2015-14, requires an entity to recognize revenue from the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In particular, this ASU addresses contracts with more than one performance obligation, as well as the accounting for some costs to obtain or fulfill a contract with a customer, and provides for additional disclosures with respect to revenues and cash flows arising from contracts with customers. This ASU will be effective for fiscal years beginning after December 15, 2017, including interim periods within that fiscal year. Early adoption of this ASU is permitted only for fiscal years beginning after December 15, 2016, including interim periods within that fiscal year. The Company is currently evaluating the effect that the adoption of this ASU will have on its financial statements. In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). ASU 2014-15 amends FASB ASC 205-40, Presentation of Financial Statements – Going Concern, by providing guidance on determining when and how reporting entities must disclose going-concern uncertainties in their financial statements, including requiring management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements and providing certain disclosures if there is substantial doubt about the entity’s ability to continue as a going concern. ASU 2014-15 will be effective for fiscal years ending after December 15, 2016 and for interim periods thereafter. Early adoption of ASU 2014-15 is permitted. The Company is currently evaluating the effect that the adoption of ASU 2014-15 will have on its financial statements.

Unaudited Interim Financial Sta

Unaudited Interim Financial Statements	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Unaudited Interim Financial Statements	(3) Unaudited Interim Financial Statements The accompanying unaudited financial statements included herein have been prepared by the Company in accordance with United States Generally Accepted Accounting Principles (“U.S. GAAP”) for interim financial information and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. In the opinion of management, all adjustments, consisting of normal recurring adjustments, and disclosures considered necessary for a fair presentation of interim period results have been included. Interim results for the nine months ended September 30, 2015 are not necessarily indicative of results that may be expected for the year ending December 31, 2015. For further information, refer to the financial statements and footnotes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2014, which was filed with the SEC on March 12, 2015.

Financial Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2015
Investments, All Other Investments [Abstract]
Financial Instruments	(4) Financial Instruments The fair value of the Company’s financial instruments is determined and disclosed in accordance with the three-tier fair value hierarchy specified in Note 6, “Fair Value of Assets and Liabilities.” The Company is required to disclose the estimated fair values of its financial instruments. The Company’s financial instruments consist of cash, cash equivalents, available-for-sale investments, receivables and a note payable. The estimated fair values of these financial instruments approximate their carrying values as of September 30, 2015 and December 31, 2014. As of September 30, 2015 and December 31, 2014, the Company did not have any derivatives, hedging instruments or other similar financial instruments except for the note issued under the Company’s loan and security agreement, which is discussed in Note 5(a) to the financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, including put and call features which the Company determined are clearly and closely associated with the debt host and do not require bifurcation as a derivative liability, or the fair value of the feature is immaterial.

Cash and Cash Equivalents

Cash and Cash Equivalents	9 Months Ended
	Sep. 30, 2015
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents	(5) Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of 90 days or less when purchased to be cash equivalents. Cash and cash equivalents at September 30, 2015 and December 31, 2014 consisted of cash, commercial paper and money market funds.

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities	(6) Fair Value of Assets and Liabilities The Company measures fair value at the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date using assumptions that market participants would use in pricing the asset or liability (the “inputs”) into a three-tier fair value hierarchy. This fair value hierarchy gives the highest priority (Level 1) to quoted prices in active markets for identical assets or liabilities and the lowest priority (Level 3) to unobservable inputs in which little or no market data exists, requiring companies to develop their own assumptions. Observable inputs that do not meet the criteria of Level 1, and include quoted prices for similar assets or liabilities in active markets or quoted prices for identical assets and liabilities in markets that are not active, are categorized as Level 2. Level 3 inputs are those that reflect the Company’s estimates about the assumptions market participants would use in pricing the asset or liability, based on the best information available in the circumstances. Valuation techniques for assets and liabilities measured using Level 3 inputs may include unobservable inputs such as projections, estimates and management’s interpretation of current market data. These unobservable Level 3 inputs are only utilized to the extent that observable inputs are not available or cost-effective to obtain. The Company applies ASU No. 2011-04, Fair Value Measurement (Topic 820), in its fair value measurements and disclosures. The table below presents the assets and liabilities measured and recorded in the financial statements at fair value on a recurring basis at September 30, 2015 and December 31, 2014 categorized by the level of inputs used in the valuation of each asset and liability. (In thousands) Total Quoted Prices Significant Significant September 30, 2015 Assets Money market funds $ 27,890 $ 27,890 $ — $ — Short-term investments – commercial paper 6,470 — 6,470 — Short-term investments – corporate bonds 25,366 — 25,366 — Short-term investments – municipal bonds 6,192 — 6,192 — Long-term investments – corporate bonds 22,812 — 22,812 — Long-term investments – municipal bonds 5,858 — 5,858 — Total assets $ 94,588 $ 27,890 $ 66,698 $ — Total liabilities $ — $ — $ — $ — December 31, 2014 Assets Money market funds $ 17,156 $ 17,156 $ — $ — Other cash equivalents – commercial paper 2,500 — 2,500 — Short-term investments – commercial paper 4,494 — 4,494 — Short-term investments – certificate of deposit 500 — 500 — Short-term investments – corporate bonds 14,357 — 14,357 — Short-term investments – municipal bonds 1,905 — 1,905 — Long-term investments –corporate bonds 7,344 — 7,344 — Total assets $ 48,256 $ 17,156 $ 31,100 $ — Total liabilities $ — $ — $ — $ — The Level 1 assets consist of money market funds, which are actively traded daily. The Level 2 assets consist of corporate bond, commercial paper, certificate of deposit and municipal bond investments whose fair value may not represent actual transactions of identical securities. The fair value of corporate and municipal bonds is generally determined from quoted market prices received from pricing services based upon quoted prices from active markets and/or other significant observable market transactions at fair value. The fair value of commercial paper is generally determined based on the relationship between the investment’s discount rate and the discount rates of the same issuer’s commercial paper available in the market which may not be actively traded daily. The fair value of certificates of deposit approximates carrying value. Since these fair values may not be based upon actual transactions of identical securities, they are classified as Level 2. Since any investments are classified as available-for-sale securities, any unrealized gains or losses are recorded in accumulated other comprehensive income or loss within stockholders’ equity on the balance sheet. The Company did not elect to measure any other financial assets or liabilities at fair value at September 30, 2015 or December 31, 2014.

Investments

Investments	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Investments	(7) Investments The Company’s available-for-sale investments at fair value consisted of the following at September 30, 2015 and December 31, 2014: September 30, 2015 Cost Gross Gross Estimated (In thousands) Short-term investments – commercial paper $ 6,465 $ — $ 5 $ 6,470 Short-term investments – corporate bonds 25,371 (8 ) 3 25,366 Short-term investments – municipal bonds 6,189 — 3 6,192 Total short-term investments 38,025 (8 ) 11 38,028 Long-term investments – corporate bonds 22,856 (48 ) 4 22,812 Long-term investments – municipal bonds 5,844 — 14 5,858 Total long-term investments 28,700 (48 ) 18 28,670 Total investments $ 66,725 $ (56 ) $ 29 $ 66,698 December 31, 2014 Cost Gross Gross Estimated (In thousands) Short-term investments – commercial paper $ 4,493 $ — $ 1 $ 4,494 Short-term investments – certificate of deposit 500 — — 500 Short-term investments – corporate bonds 14,364 (7 ) — 14,357 Short-term investments – municipal bonds 1,906 (1 ) — 1,905 Total short-term investments 21,263 (8 ) 1 21,256 Long-term investments – corporate bonds 7,354 (10 ) — 7,344 Total long-term investments 7,354 (10 ) — 7,344 Total investments $ 28,617 $ (18 ) $ 1 $ 28,600 The Company had no realized gains or losses from available-for-sale securities in the nine months ended September 30, 2015 and 2014. There were no losses or other-than-temporary declines in value included in “Investment income, net” on the Company’s condensed statements of operations and comprehensive loss for any securities for the nine months ended September 30, 2015 and 2014. The Company had no auction rate securities as of September 30, 2015 and December 31, 2014. See Note 4, “Financial Instruments,” and Note 6, “Fair Value of Assets and Liabilities” for additional information related to the Company’s investments.

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment	(8) Property and Equipment At September 30, 2015 and December 31, 2014, net property and equipment at cost consisted of the following: (In thousands) September 30, December 31, Leasehold improvements $ 594 $ 525 Laboratory equipment and other 4,420 3,884 Total property and equipment, at cost 5,014 4,409 Less: accumulated depreciation 3,329 3,103 Property and equipment, net $ 1,685 $ 1,306 Depreciation and amortization expense on property and equipment was approximately $126,000 and $57,000 in the three months ended September 30, 2015 and 2014, respectively, and approximately $329,000 and $135,000 in the nine months ended September 30, 2015 and 2014, respectively.

Restricted Cash

Restricted Cash	9 Months Ended
	Sep. 30, 2015
Cash and Cash Equivalents [Abstract]
Restricted Cash	(9) Restricted Cash As part of the Company’s lease arrangement for its office and laboratory facility in Cambridge, Massachusetts, the Company is required to restrict cash held in a certificate of deposit securing a line of credit for the lessor. As of September 30, 2015 and December 31, 2014, the restricted cash amounted to $311,000 held in certificates of deposit securing a line of credit for the lessor.

Exton Office Lease

Exton Office Lease	9 Months Ended
	Sep. 30, 2015
Leases [Abstract]
Exton Office Lease	(10) Exton Office Lease On April 1, 2015, the Company entered into a lease of approximately 4,300 square feet of office space in Exton, Pennsylvania. The term of the lease ends on April 30, 2020, with one five-year renewal option exercisable by the Company. On September 23, 2015, the Company entered into an amendment to the lease for an additional approximately 6,700 square feet of office space adjacent and connected to the original 4,300 square feet of office space in Exton, Pennsylvania. The Company classifies the lease as an operating lease. Future minimum commitments as of September 30, 2015 under the Company’s Exton office lease agreement are approximately: December 31, Operating (In thousands) 2015 $ 24 2016 168 2017 190 2018 200 2019 209 2020 88 $ 879

Comprehensive Loss

Comprehensive Loss	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Comprehensive Loss	(11) Comprehensive Loss Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Comprehensive loss for the nine months ended September 30, 2015 and 2014 is comprised of reported net loss and any change in net unrealized gains and losses on investments during each period, which is included in accumulated other comprehensive gain (loss) on the accompanying balance sheets. The Company applies ASU No. 2011-05, Comprehensive Income, by presenting the components of net income and other comprehensive income as one continuous statement. The following table includes the changes in the accumulated balance of the component of other comprehensive gain (loss) for the nine months ended September 30, 2015 and 2014: Nine Months Nine Months (In thousands) Ended Sept. 30, Ended Sept. 30, Accumulated unrealized loss on available-for-sale securities at beginning of period $ (17 ) $ (7 ) Change during the period (10 ) 5 Accumulated unrealized loss on available-for-sale securities at end of period $ (27 ) $ (2 )

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	(12) Stock-Based Compensation The Company recognizes all stock-based payments to employees and directors as expense in the statements of operations and comprehensive loss based on their fair values. The Company records compensation expense over an award’s requisite service period, or vesting period, based on the award’s fair value at the date of grant. The Company’s policy is to charge the fair value of stock options as an expense, adjusted for forfeitures, on a straight-line basis over the vesting period, which is generally four years for employees and three years for directors. The Company recorded charges of $1,144,000 and $766,000 in its statements of operations and comprehensive loss for the three months ended September 30, 2015 and 2014, respectively, and $4,013,000 and $2,086,000 in its statements of operations and comprehensive loss for the nine months ended September 30, 2015 and 2014, respectively, for stock-based compensation expense attributable to stock-based payments made to employees and directors. The stock-based compensation for the nine months ended September 30, 2015 includes approximately $329,000 for the recognition of additional cost associated with the acceleration of vesting and extension of the exercise period of a retiring director’s stock options due to a modification. The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model. The following assumptions apply to the options to purchase 2,228,250 and 2,518,500 shares of common stock granted to employees and directors during the nine months ended September 30, 2015 and 2014, respectively: Nine Months Ended September 30, 2015 2014 Average risk free interest rate 1.3 % 1.6 % Expected dividend yield — — Expected lives (years) 4.3 4.8 Expected volatility 92.0 % 83.0 % Weighted average grant date fair value of options granted during the period (per share) $ 2.57 $ 2.47 Weighted average exercise price of options granted during the period (per share) $ 3.85 $ 3.80 The expected lives and the expected volatility of the options granted during the nine months ended September 30, 2015 and 2014 are based on historical experience. All options granted during the nine months ended September 30, 2015 and 2014 were granted at exercise prices equal to the fair market value of the common stock on the dates of grant.

Net Loss per Common Share Appli

Net Loss per Common Share Applicable to Common Stockholders	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Loss per Common Share Applicable to Common Stockholders	(13) Net Loss per Common Share Applicable to Common Stockholders For the three and nine months ended September 30, 2015 and 2014, basic and diluted net loss per common share applicable to common stockholders is computed using the weighted average number of shares of common stock outstanding during the period. Diluted net loss per common share applicable to common stockholders is the same as basic net loss per common share applicable to common stockholders as the effects of the Company’s potential common stock equivalents are antidilutive. Total antidilutive securities were 73,444,753 and 78,349,485 for the nine months ended September 30, 2015 and 2014, respectively, and consist of stock options, preferred stock and warrants. For the three months ended September 30, 2014, net loss per common share applicable to common stockholders reflects $119,000 in dividends accrued on shares of the Series E convertible preferred stock (“Series E preferred stock”). For the nine months ended September 30, 2014, net loss per common share applicable to common stockholders reflects $422,000 in dividends accrued on shares of the Company’s Series D convertible preferred stock (“Series D preferred stock”) and the Series E preferred stock. There were no dividends accrued on the Series D preferred stock and Series E preferred stock during the three and nine months ended September 30, 2015 because the Series D preferred stock and Series E preferred stock were converted to common stock during February 2014 and December 2014, respectively.

Common Stock Warrant and Option

Common Stock Warrant and Option Exercises and Employee Stock Purchases	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
Common Stock Warrant and Option Exercises and Employee Stock Purchases	(14) Common Stock Warrant and Option Exercises and Employee Stock Purchases The Company issued 487,153 and 5,398,609 shares of common stock and received total proceeds of $987,000 and $8,132,000 for warrant and stock option exercises and employee stock purchases under the Company’s 1995 Employee Stock Purchase Plan during the nine months ended September 30, 2015 and 2014, respectively, as follows: Nine Months Ended Nine Months Ended September 30, 2015 September 30, 2014 (In thousands) Shares Proceeds Shares Proceeds Warrant exercises 136 $ 503 5,044 $ 7,299 Stock option exercises 332 431 346 811 Employee stock purchases 19 53 9 22 Total 487 $ 987 5,399 $ 8,132

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions	(15) Related Party Transactions February 2014 Conversion of Series D Preferred Stock On January 10, 2014, the Company notified Pillar Pharmaceuticals I, L.P. (“Pillar I”), an investment partnership managed by one of the Company’s directors and significant stockholders and the holder of all 1,124,260 shares of the Company’s issued and outstanding Series D preferred stock, of its intention to redeem the Series D preferred stock on February 10, 2014 in accordance with the terms of the Certificate of Designations, Preferences and Rights of Series D Preferred Stock (the “Series D Certificate of Designations”). Following this notice, Pillar I had the right to convert its Series D preferred stock into shares of the Company’s common stock at any time prior to the close of business on February 9, 2014. On February 6, 2014, Pillar I converted such shares into 6,266,175 shares of the Company’s common stock in accordance with the terms of the Series D Certificate of Designations. As a result of the conversion, no shares of Series D preferred stock remain outstanding. On March 28, 2014, the Company filed a Certificate of Elimination of Number of Shares of Preferred Stock Designated as Series D Convertible Preferred Stock with the State of Delaware Secretary of State which eliminated the designation of the shares of Series D preferred stock. December 2014 Conversion of Series E Preferred Stock In December 2014, the holders of Series E preferred stock converted such shares into 8,484,840 shares of common stock in accordance with the terms of the Certificate of Designations, Preferences and Rights of Series E Preferred Stock. As a result of this conversion, no shares of Series E preferred stock remain outstanding. On March 12, 2015, the Company filed a Certificate of Elimination of Number of Shares of Preferred Stock Designated as Series E Convertible Preferred Stock with the State of Delaware Secretary of State which eliminated the designation of the shares of Series E preferred stock. Director Stock Purchases The Company issued 23,689 and 17,753 shares of common stock in lieu of director board and committee fees of approximately $90,000 and $62,000 pursuant to the Company’s director compensation program during the nine months ended September 30, 2015 and 2014, respectively. See also Note 16, “Registration Rights Agreement,” and Note 17, “Financing” for additional information on related party transactions.

Registration Rights Agreement

Registration Rights Agreement	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Registration Rights Agreement	(16) Registration Rights Agreement On February 9, 2015, the Company entered into a registration rights agreement with investment funds (the “Selling Stockholders”) affiliated with Baker Bros. Advisors LP and two members of the Company’s board of directors, relating to the registration for resale of the shares of the Company’s common stock held by the Selling Stockholders, including the shares of the Company’s common stock that may be issued upon the exercise of warrants held by the Selling Stockholders (collectively, the “Registrable Shares”). Under the registration rights agreement, the Company has agreed to file a registration statement on Form S-3 with the SEC within 60 days after demand by any of the Selling Stockholders, to register for resale the Registrable Shares. The Company has agreed to use its reasonable best efforts to cause the registration statement to become effective as promptly as practicable after filing, and to remain effective until the shares being registered thereunder have been sold or may be sold freely without limitations or restrictions as to volume or manner of sale pursuant to Rule 144. The Company has agreed to pay for all expenses incurred in connection with the registration of these shares. The Company expects to file this registration statement in the fourth quarter of 2015. The registration rights agreement contains customary covenants and agreements by the Company and customary indemnification obligations of the Company and the Selling Stockholders.

Financing

Financing	9 Months Ended
	Sep. 30, 2015
Disclosure Text Block Supplement [Abstract]
Financing	(17) Financing February 19, 2015 Follow-on Underwritten Public Offering On February 19, 2015, the Company closed a follow-on underwritten public offering, in which it sold 23,000,000 shares of common stock at a price to the public of $3.75 per share for aggregate gross proceeds of $86.3 million. The net proceeds to the Company from the offering, after deducting underwriters’ discounts and commissions and other offering costs and expenses, were $80.6 million. Investment funds affiliated with Baker Bros. Advisors LP and two members of the Company’s board of directors purchased 5,333,333 shares in this offering at the $3.75 per share purchase price. On February 19, 2015, Baker Bros. Advisors LP and certain of its affiliated funds (which include the Selling Stockholders) (collectively, “Baker Brothers”) held 6,965,432 shares of the Company’s common stock, warrants to purchase up to 20,316,327 shares of the Company’s common stock at an exercise price of $0.47 per share and pre-funded warrants to purchase up to 22,151,052 shares of the Company’s common stock at an exercise price of $0.01 per share. February 10, 2014 Follow-on Underwritten Public Offering On February 10, 2014, the Company closed a follow-on underwritten public offering, in which it sold 7,867,438 shares of common stock at a price to the public of $4.00 per share and pre-funded warrants to purchase up to 2,158,750 shares of common stock at a price to the public of $3.99 per share for aggregate gross proceeds of $40.1 million. The pre-funded warrants have an exercise price of $0.01 per share and will expire if not exercised by February 10, 2021. The net proceeds to the Company from the offering, after deducting underwriters’ discounts and commissions and other offering costs and expenses and excluding the proceeds of the exercise of the pre-funded warrants, if any, were approximately $37.2 million.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Events	(18) Subsequent Events The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure.

New Accounting Pronouncements24

New Accounting Pronouncements - Recently Issued (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
New Accounting Pronouncements - Recently Issued	In May 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606), which was amended by ASU No. 2015-14. ASU No. 2014-09, as amended by ASU No. 2015-14, requires an entity to recognize revenue from the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In particular, this ASU addresses contracts with more than one performance obligation, as well as the accounting for some costs to obtain or fulfill a contract with a customer, and provides for additional disclosures with respect to revenues and cash flows arising from contracts with customers. This ASU will be effective for fiscal years beginning after December 15, 2017, including interim periods within that fiscal year. Early adoption of this ASU is permitted only for fiscal years beginning after December 15, 2016, including interim periods within that fiscal year. The Company is currently evaluating the effect that the adoption of this ASU will have on its financial statements. In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). ASU 2014-15 amends FASB ASC 205-40, Presentation of Financial Statements – Going Concern, by providing guidance on determining when and how reporting entities must disclose going-concern uncertainties in their financial statements, including requiring management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements and providing certain disclosures if there is substantial doubt about the entity’s ability to continue as a going concern. ASU 2014-15 will be effective for fiscal years ending after December 15, 2016 and for interim periods thereafter. Early adoption of ASU 2014-15 is permitted. The Company is currently evaluating the effect that the adoption of ASU 2014-15 will have on its financial statements.
Fair Value Measurement Policies	The Company measures fair value at the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date using assumptions that market participants would use in pricing the asset or liability (the “inputs”) into a three-tier fair value hierarchy. This fair value hierarchy gives the highest priority (Level 1) to quoted prices in active markets for identical assets or liabilities and the lowest priority (Level 3) to unobservable inputs in which little or no market data exists, requiring companies to develop their own assumptions. Observable inputs that do not meet the criteria of Level 1, and include quoted prices for similar assets or liabilities in active markets or quoted prices for identical assets and liabilities in markets that are not active, are categorized as Level 2. Level 3 inputs are those that reflect the Company’s estimates about the assumptions market participants would use in pricing the asset or liability, based on the best information available in the circumstances. Valuation techniques for assets and liabilities measured using Level 3 inputs may include unobservable inputs such as projections, estimates and management’s interpretation of current market data. These unobservable Level 3 inputs are only utilized to the extent that observable inputs are not available or cost-effective to obtain. The Company applies ASU No. 2011-04, Fair Value Measurement (Topic 820), in its fair value measurements and disclosures. The Level 1 assets consist of money market funds, which are actively traded daily. The Level 2 assets consist of corporate bond, commercial paper, certificate of deposit and municipal bond investments whose fair value may not represent actual transactions of identical securities. The fair value of corporate and municipal bonds is generally determined from quoted market prices received from pricing services based upon quoted prices from active markets and/or other significant observable market transactions at fair value. The fair value of commercial paper is generally determined based on the relationship between the investment’s discount rate and the discount rates of the same issuer’s commercial paper available in the market which may not be actively traded daily. The fair value of certificates of deposit approximates carrying value. Since these fair values may not be based upon actual transactions of identical securities, they are classified as Level 2. Since any investments are classified as available-for-sale securities, any unrealized gains or losses are recorded in accumulated other comprehensive income or loss within stockholders’ equity on the balance sheet. The Company did not elect to measure any other financial assets or liabilities at fair value at September 30, 2015 or December 31, 2014.
Stock-based Payments Policy	The Company recognizes all stock-based payments to employees and directors as expense in the statements of operations and comprehensive loss based on their fair values. The Company records compensation expense over an award’s requisite service period, or vesting period, based on the award’s fair value at the date of grant. The Company’s policy is to charge the fair value of stock options as an expense, adjusted for forfeitures, on a straight-line basis over the vesting period, which is generally four years for employees and three years for directors. The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model. The expected lives and the expected volatility of the options granted during the nine months ended September 30, 2015 and 2014 are based on historical experience. All options granted during the nine months ended September 30, 2015 and 2014 were granted at exercise prices equal to the fair market value of the common stock on the dates of grant.

Fair Value of Assets and Liab25

Fair Value of Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The table below presents the assets and liabilities measured and recorded in the financial statements at fair value on a recurring basis at September 30, 2015 and December 31, 2014 categorized by the level of inputs used in the valuation of each asset and liability. (In thousands) Total Quoted Prices Significant Significant September 30, 2015 Assets Money market funds $ 27,890 $ 27,890 $ — $ — Short-term investments – commercial paper 6,470 — 6,470 — Short-term investments – corporate bonds 25,366 — 25,366 — Short-term investments – municipal bonds 6,192 — 6,192 — Long-term investments – corporate bonds 22,812 — 22,812 — Long-term investments – municipal bonds 5,858 — 5,858 — Total assets $ 94,588 $ 27,890 $ 66,698 $ — Total liabilities $ — $ — $ — $ — December 31, 2014 Assets Money market funds $ 17,156 $ 17,156 $ — $ — Other cash equivalents – commercial paper 2,500 — 2,500 — Short-term investments – commercial paper 4,494 — 4,494 — Short-term investments – certificate of deposit 500 — 500 — Short-term investments – corporate bonds 14,357 — 14,357 — Short-term investments – municipal bonds 1,905 — 1,905 — Long-term investments –corporate bonds 7,344 — 7,344 — Total assets $ 48,256 $ 17,156 $ 31,100 $ — Total liabilities $ — $ — $ — $ —

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Summary of Available-for-Sale Investments at Fair Value	The Company’s available-for-sale investments at fair value consisted of the following at September 30, 2015 and December 31, 2014: September 30, 2015 Cost Gross Gross Estimated (In thousands) Short-term investments – commercial paper $ 6,465 $ — $ 5 $ 6,470 Short-term investments – corporate bonds 25,371 (8 ) 3 25,366 Short-term investments – municipal bonds 6,189 — 3 6,192 Total short-term investments 38,025 (8 ) 11 38,028 Long-term investments – corporate bonds 22,856 (48 ) 4 22,812 Long-term investments – municipal bonds 5,844 — 14 5,858 Total long-term investments 28,700 (48 ) 18 28,670 Total investments $ 66,725 $ (56 ) $ 29 $ 66,698 December 31, 2014 Cost Gross Gross Estimated (In thousands) Short-term investments – commercial paper $ 4,493 $ — $ 1 $ 4,494 Short-term investments – certificate of deposit 500 — — 500 Short-term investments – corporate bonds 14,364 (7 ) — 14,357 Short-term investments – municipal bonds 1,906 (1 ) — 1,905 Total short-term investments 21,263 (8 ) 1 21,256 Long-term investments – corporate bonds 7,354 (10 ) — 7,344 Total long-term investments 7,354 (10 ) — 7,344 Total investments $ 28,617 $ (18 ) $ 1 $ 28,600

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Tabular Disclosure of Major Components of Property and Equipment and Related Accumulated Depreciation	At September 30, 2015 and December 31, 2014, net property and equipment at cost consisted of the following: (In thousands) September 30, December 31, Leasehold improvements $ 594 $ 525 Laboratory equipment and other 4,420 3,884 Total property and equipment, at cost 5,014 4,409 Less: accumulated depreciation 3,329 3,103 Property and equipment, net $ 1,685 $ 1,306

Exton Office Lease (Tables)

Exton Office Lease (Tables)	9 Months Ended
	Sep. 30, 2015
Leases [Abstract]
Schedule of Future Minimum Commitments	Future minimum commitments as of September 30, 2015 under the Company’s Exton office lease agreement are approximately: December 31, Operating (In thousands) 2015 $ 24 2016 168 2017 190 2018 200 2019 209 2020 88 $ 879

Comprehensive Loss (Tables)

Comprehensive Loss (Tables)	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Changes in Accumulated Balance of the Component of Other Comprehensive Gain (Loss)	The following table includes the changes in the accumulated balance of the component of other comprehensive gain (loss) for the nine months ended September 30, 2015 and 2014: Nine Months Nine Months (In thousands) Ended Sept. 30, Ended Sept. 30, Accumulated unrealized loss on available-for-sale securities at beginning of period $ (17 ) $ (7 ) Change during the period (10 ) 5 Accumulated unrealized loss on available-for-sale securities at end of period $ (27 ) $ (2 )

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Assumptions Used to Determine Fair Value of Stock Options Granted During Period	The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model. The following assumptions apply to the options to purchase 2,228,250 and 2,518,500 shares of common stock granted to employees and directors during the nine months ended September 30, 2015 and 2014, respectively: Nine Months Ended September 30, 2015 2014 Average risk free interest rate 1.3 % 1.6 % Expected dividend yield — — Expected lives (years) 4.3 4.8 Expected volatility 92.0 % 83.0 % Weighted average grant date fair value of options granted during the period (per share) $ 2.57 $ 2.47 Weighted average exercise price of options granted during the period (per share) $ 3.85 $ 3.80

Common Stock Warrant and Opti31

Common Stock Warrant and Option Exercises and Employee Stock Purchases (Tables)	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
Schedule of Common Stock Warrant and Option Exercises and Employee Stock Purchases	The Company issued 487,153 and 5,398,609 shares of common stock and received total proceeds of $987,000 and $8,132,000 for warrant and stock option exercises and employee stock purchases under the Company’s 1995 Employee Stock Purchase Plan during the nine months ended September 30, 2015 and 2014, respectively, as follows: Nine Months Ended Nine Months Ended September 30, 2015 September 30, 2014 (In thousands) Shares Proceeds Shares Proceeds Warrant exercises 136 $ 503 5,044 $ 7,299 Stock option exercises 332 431 346 811 Employee stock purchases 19 53 9 22 Total 487 $ 987 5,399 $ 8,132

Organization - Additional Infor

Organization - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)Platform	Dec. 31, 2014USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of technology platform to develop drug candidates	2
Accumulated deficit | $	$ (488,091)	$ (451,526)

Fair Value of Assets and Liab33

Fair Value of Assets and Liabilities - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	$ 94,588	$ 48,256
Total liabilities	0	0
Money Market Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	27,890	17,156
Other Cash Equivalents - Commercial Paper [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets		2,500
Long-term Investments - Municipal Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	5,858
Short-term Investments [Member] | Commercial Paper [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	6,470	4,494
Short-term Investments [Member] | Certificates of Deposit [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets		500
Short-term Investments [Member] | Corporate Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	25,366	14,357
Short-term Investments [Member] | Municipal Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	6,192	1,905
Long-term Investments - Corporate Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	22,812	7,344
Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	27,890	17,156
Total liabilities	0	0
Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member] | Money Market Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	27,890	17,156
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	66,698	31,100
Total liabilities	0	0
Significant Other Observable Inputs (Level 2) [Member] | Other Cash Equivalents - Commercial Paper [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets		2,500
Significant Other Observable Inputs (Level 2) [Member] | Long-term Investments - Municipal Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	5,858
Significant Other Observable Inputs (Level 2) [Member] | Short-term Investments [Member] | Commercial Paper [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	6,470	4,494
Significant Other Observable Inputs (Level 2) [Member] | Short-term Investments [Member] | Certificates of Deposit [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets		500
Significant Other Observable Inputs (Level 2) [Member] | Short-term Investments [Member] | Corporate Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	25,366	14,357
Significant Other Observable Inputs (Level 2) [Member] | Short-term Investments [Member] | Municipal Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	6,192	1,905
Significant Other Observable Inputs (Level 2) [Member] | Long-term Investments - Corporate Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total assets	22,812	7,344
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total liabilities	$ 0	$ 0

Investments - Summary of Availa

Investments - Summary of Available-for-Sale Investments at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 66,725	$ 28,617
Gross Unrealized (Losses)	(56)	(18)
Gross Unrealized Gains	29	1
Estimated Fair Value	66,698	28,600
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	38,025	21,263
Gross Unrealized (Losses)	(8)	(8)
Gross Unrealized Gains	11	1
Estimated Fair Value	38,028	21,256
Short-term Investments [Member] | Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	6,465	4,493
Gross Unrealized Gains	5	1
Estimated Fair Value	6,470	4,494
Short-term Investments [Member] | Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	25,371	14,364
Gross Unrealized (Losses)	(8)	(7)
Gross Unrealized Gains	3
Estimated Fair Value	25,366	14,357
Short-term Investments [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	6,189	1,906
Gross Unrealized (Losses)		(1)
Gross Unrealized Gains	3
Estimated Fair Value	6,192	1,905
Short-term Investments [Member] | Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost		500
Estimated Fair Value		500
Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	28,700	7,354
Gross Unrealized (Losses)	(48)	(10)
Gross Unrealized Gains	18
Estimated Fair Value	28,670	7,344
Long-term Investments [Member] | Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	22,856	7,354
Gross Unrealized (Losses)	(48)	(10)
Gross Unrealized Gains	4
Estimated Fair Value	22,812	$ 7,344
Long-term Investments [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	5,844
Gross Unrealized Gains	14
Estimated Fair Value	$ 5,858

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Realized gains or losses from available-for-sale securities	$ 0	$ 0
Auction rate securities, noncurrent	0		$ 0
Losses from investments	$ 0	$ 0

Property and Equipment - Tabula

Property and Equipment - Tabular Disclosure of Major Components of Property and Equipment and Related Accumulated Depreciation (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Leasehold improvements	$ 594	$ 525
Laboratory equipment and other	4,420	3,884
Total property and equipment, at cost	5,014	4,409
Less: accumulated depreciation	3,329	3,103
Property and equipment, net	$ 1,685	$ 1,306

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense on property and equipment	$ 126,000	$ 57,000	$ 329,000	$ 135,000

Restricted Cash - Additional In

Restricted Cash - Additional Information (Detail) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Restricted Cash [Abstract]
Total restricted cash	$ 311,000	$ 311,000

Exton Office Lease - Additional

Exton Office Lease - Additional Information (Detail) - Exton [Member] - ft²	Sep. 23, 2015	Apr. 01, 2015
Property Subject to or Available for Operating Lease [Line Items]
Area of leased office space		4,300
Lease maturity date		Apr. 30, 2020
Operating lease renewal term		5 years
Amendment To Lease Agreement [Member]
Property Subject to or Available for Operating Lease [Line Items]
Additional area of leased office space	6,700

Exton Office Lease - Schedule o

Exton Office Lease - Schedule of Future Minimum Commitments (Detail) - Exton [Member] $ in Thousands	Sep. 30, 2015USD ($)
Operating Leases Future Minimum Payments Due [Line Items]
2,015	$ 24
2,016	168
2,017	190
2,018	200
2,019	209
2,020	88
Total	$ 879

Comprehensive Loss - Change in

Comprehensive Loss - Change in Accumulated Balance of the Component of Other Comprehensive Gain (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Comprehensive Income (Loss) After Tax [Abstract]
Accumulated unrealized loss on available-for-sale securities at beginning of period			$ (17)	$ (7)
Change during the period	$ 50	$ (5)	(10)	5
Accumulated unrealized loss on available-for-sale securities at end of period	$ (27)	$ (2)	$ (27)	$ (2)

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recorded charges in statement of operations	$ 1,144	$ 766	$ 4,013	$ 2,086
Options to purchase common stock granted to employees and directors			2,228,250	2,518,500
Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period			4 years
Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period			3 years
Retiring Director's Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recorded charges in statement of operations			$ 329

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Assumptions Used to Determine Fair Value of Stock Options Granted During Period (Detail) - $ / shares	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Average risk free interest rate	1.30%	1.60%
Expected dividend yield	0.00%	0.00%
Expected lives (years)	4 years 3 months 18 days	4 years 9 months 18 days
Expected volatility	92.00%	83.00%
Weighted average grant date fair value of options granted during the period (per share)	$ 2.57	$ 2.47
Weighted average exercise price of options granted during the period (per share)	$ 3.85	$ 3.80

Net Loss per Common Share App44

Net Loss per Common Share Applicable to Common Stockholders - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total antidilutive securities			73,444,753	78,349,485
Preferred stock dividends		$ 119,000		$ 422,000
Series E Preferred Stock [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Preferred stock dividends		$ 119,000
Series D and E Preferred Stock [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Preferred stock dividends	$ 0		$ 0	$ 422,000

Common Stock Warrant and Opti45

Common Stock Warrant and Option Exercises and Employee Stock Purchases - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Warrant and Option Exercises and Employee Stock Purchases [Line Items]
Number of shares of common stock issued for stock warrants and stock options exercised and ESPP purchases	487,000	5,399,000
Proceeds from stock issued for warrant and option exercises & ESPP purchases	$ 987	$ 8,132
Common Stock Warrants and Option Exercises and Employee Stock Purchases [Member]
Warrant and Option Exercises and Employee Stock Purchases [Line Items]
Number of shares of common stock issued for stock warrants and stock options exercised and ESPP purchases	487,153	5,398,609
Proceeds from stock issued for warrant and option exercises & ESPP purchases	$ 987	$ 8,132

Common Stock Warrant and Opti46

Common Stock Warrant and Option Exercises and Employee Stock Purchases - Schedule of Common Stock Warrant and Option Exercises and Employee Stock Purchases (Detail) - USD ($) shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Warrant and Option Exercises and Employee Stock Purchases [Line Items]
Total, Shares	487	5,399
Total, Proceeds	$ 987	$ 8,132
Warrant Exercises [Member]
Warrant and Option Exercises and Employee Stock Purchases [Line Items]
Total, Shares	136	5,044
Total, Proceeds	$ 503	$ 7,299
Stock Option Exercises [Member]
Warrant and Option Exercises and Employee Stock Purchases [Line Items]
Total, Shares	332	346
Total, Proceeds	$ 431	$ 811
Employee Stock Purchases [Member]
Warrant and Option Exercises and Employee Stock Purchases [Line Items]
Total, Shares	19	9
Total, Proceeds	$ 53	$ 22

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	Feb. 06, 2014	Dec. 31, 2014	Sep. 30, 2015	Sep. 30, 2014	Jan. 10, 2014
Directors [Member]
Related Party Transaction [Line Items]
Common stock issued in lieu of board fees			23,689	17,753
Value of common stock issued			$ 90,000	$ 62,000
Series D Preferred Stock [Member]
Related Party Transaction [Line Items]
Preferred stock, shares issued					1,124,260
Preferred stock, shares outstanding	0				1,124,260
Shares of common stock issued upon conversion	6,266,175
Series E Preferred Stock [Member]
Related Party Transaction [Line Items]
Preferred stock, shares issued		0	0
Preferred stock, shares outstanding		0	0
Shares of common stock issued upon conversion		8,484,840

Registration Rights Agreement -

Registration Rights Agreement - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Registration rights agreement date	Feb. 9, 2015
Registration statement filing period with SEC	60 days

Financing - Additional Informat

Financing - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Feb. 19, 2015	Feb. 10, 2014
Class of Stock [Line Items]
Stock issued, shares	23,000,000
Common stock, price per share	$ 3.75
Gross proceeds from offering of common stock	$ 86.3
Net proceeds from offering of common stock	$ 80.6
Gross proceeds from sale of common stock and warrants excluding the proceeds from exercise of the warrants, if any		$ 40.1
Sales price per share of pre-funded warrants		$ 3.99
Net proceeds from sale of common stock and warrants excluding the proceeds from exercise of the warrants, if any		$ 37.2
Investment Funds [Member] | Directors [Member]
Class of Stock [Line Items]
Stock issued, shares	5,333,333
Common stock, price per share	$ 3.75
Baker Bros. Advisors LP [Member]
Class of Stock [Line Items]
Common stock held, shares	6,965,432
Shares of common stock that may be purchased upon exercise of warrants held	20,316,327
Exercise price of warrants	$ 0.47
Common Stock [Member]
Class of Stock [Line Items]
Stock issued, shares		7,867,438
Price to the public per share of common stock		$ 4
Pre-funded Warrants [Member]
Class of Stock [Line Items]
Exercise price of warrants		$ 0.01
Shares of common stock that may be purchased upon exercise of warrants issued		2,158,750
Pre-funded warrants expiration date		Feb. 10, 2021
Pre-funded Warrants [Member] | Baker Bros. Advisors LP [Member]
Class of Stock [Line Items]
Exercise price of warrants	$ 0.01
Shares of common stock that may be purchased upon exercise of warrants issued	22,151,052