Eiger BioPharmaceuticals (EIGRQ) 10-Q 11 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 31, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Trading Symbol	CLDN
Entity Registrant Name	CELLADON CORPORATION
Entity Central Index Key	1,305,253
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		23,913,263

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 50,041	$ 14,435
Short-term investments	8,004	70,513
Prepaid expenses and other assets	1,165	3,135
Total current assets	59,210	88,083
Property and equipment, net	616	763
Other assets	127	264
Total assets	59,953	89,110
Current liabilities:
Accounts payable and accrued expenses	3,446	5,803
Accrued restructuring charges	2,392
Accrued clinical expenses	342	731
Accrued interest	69	71
Current portion of long-term obligations	10,587	1
Total current liabilities	16,836	6,606
Long-term obligations, net of discount	10	10,102
Non-current liabilities	$ 283	$ 298
Commitments and contingencies (Note 5)
Stockholders' equity:
Preferred stock, $0.001 par value; authorized shares - 10,000,000 at June 30, 2015 and December 31, 2014, respectively; no shares issued and outstanding
Common stock, $0.001 par value; authorized shares - 200,000,000 at June 30, 2015 and December 31, 2014, respectively; issued and outstanding - 23,913,263 and 23,490,737 at June 30, 2015 and December 31, 2014, respectively	$ 24	$ 23
Additional paid-in capital	222,510	218,528
Accumulated other comprehensive loss		(8)
Accumulated deficit	(179,710)	(146,439)
Total stockholders' equity	42,824	72,104
Total liabilities and stockholders' equity	$ 59,953	$ 89,110

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	23,913,263	23,490,737
Common stock, shares outstanding	23,913,263	23,490,737

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Operating expenses:
Research and development	$ 9,501	$ 4,981	$ 21,019	$ 10,199
General and administrative	3,493	2,024	8,272	3,730
Restructuring charges	3,081		3,081
Total operating expenses	16,075	7,005	32,372	13,929
Loss from operations	(16,075)	(7,005)	(32,372)	(13,929)
Other income (expense):
Interest income	14	21	54	29
Interest expense	(445)		(955)	(59)
Other income (expense)	(19)	(8)	2	(12)
Change in fair value of warrant liability				(183)
Consolidated net loss	(16,525)	(6,992)	(33,271)	(14,154)
Other comprehensive loss:
Unrealized gain on investments	1	18	8	16
Comprehensive loss	$ (16,524)	$ (6,974)	$ (33,263)	$ (14,138)
Net loss per share attributable to common stockholders, basic and diluted	$ (0.69)	$ (0.38)	$ (1.40)	$ (0.94)
Weighted-average shares outstanding, basic and diluted	23,906,032	18,511,889	23,787,620	15,092,098

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities
Consolidated net loss	$ (33,271)	$ (14,154)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	153	60
Asset impairments	213
Stock-based compensation	3,201	1,267
Noncash interest expense	536	59
Amortization of investment premium	190	49
Change in fair value of warrant liability		183
Loss on disposal of property and equipment	6
Deferred rent	(9)	22
Changes in operating assets and liabilities:
Prepaid expenses and other assets	2,064	(546)
Accounts payable and accrued expenses	(439)	11
Net cash used in operating activities	(27,356)	(13,049)
Cash flows from investing activities
Purchases of investment securities		(38,067)
Proceeds from maturities of investment securities	62,327	10,700
Purchases of property and equipment	(156)	(270)
Proceeds from sale of property and equipment	8
Net cash provided by (used in) investing activities	62,179	(27,637)
Cash flows from financing activities
Proceeds from issuance of common stock	783	50,804
Costs paid in connection with common stock offering		(4,650)
Net cash provided by financing activities	783	46,154
Net increase in cash and cash equivalents	35,606	5,468
Cash and cash equivalents, beginning of period	14,435	7,903
Cash and cash equivalents, end of period	$ 50,041	$ 13,371

Basis of Presentation, Organiza

Basis of Presentation, Organization and Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation, Organization and Summary of Significant Accounting Policies	1. Basis of Presentation, Organization and Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited consolidated financial statements of Celladon Corporation (Celladon or the Company) should be read in conjunction with the audited financial statements and notes thereto as of and for the year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K (Annual Report) filed with the Securities and Exchange Commission (SEC). The accompanying financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, since they are interim statements, the accompanying financial statements do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, the accompanying financial statements reflect all adjustments (consisting of normal recurring adjustments) that are necessary for a fair statement of the financial position, results of operations and cash flows for the interim periods presented. Interim results are not necessarily indicative of results for a full year. The preparation of the Company’s consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimates in the Company’s consolidated financial statements relate to the fair value of equity awards and clinical trial expense accruals. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Organization Celladon was incorporated in California on December 21, 2000 (inception) and reincorporated in Delaware in April 2012. The Company is a biotechnology company that has been focused on the development of cardiovascular gene therapy. As a result of the negative results from the Phase 2b clinical trial of its lead product candidate, MYDICAR (AAV1/SERCA2a), the Company is evaluating its strategic opportunities to maximize shareholder value, including the possibility of seeking a merger, sale of the Company or all or some of its assets, and/or a liquidation, and has suspended further research and development activities to reduce operating expenses while it evaluates these opportunities. As of June 30, 2015, the Company has devoted substantially all of its efforts to product development, raising capital and building infrastructure and has not generated revenues from its planned principal operations. Principles of Consolidation The financial statements of the Company’s former subsidiary Celladon Europe B.V. (Celladon Europe) were consolidated with those of the Company through Celladon Europe’s dissolution on December 30, 2014. All intercompany transactions and balances were eliminated in consolidation. Investment Securities Investment securities primarily consist of investment grade corporate debt securities. The Company classifies all investment securities as available-for-sale. Investments with maturity dates greater than 12 months from the end of each reporting period are classified as long-term. Investment securities are carried at fair value, with the unrealized gains and losses reported as a component of other comprehensive income (loss) in stockholders’ equity (deficit) until realized. Realized gains and losses from the sale of investment securities, if any, are determined on a specific identification basis. A decline in the market value of any investment security below cost that is determined to be other than temporary will result in an impairment charge to earnings and a new cost basis for the security is established. No such impairment charges were recorded for any period presented. As of June 30, 2015 and December 31, 2014, none of the investment securities have been in an unrealized loss position for more than 12 months. Premiums and discounts are amortized or accreted over the life of the related security as an adjustment to yield using the straight-line method and are included in interest income. Interest income is recognized when earned. The following table sets forth the composition of the Company’s investment securities (in thousands): Unrealized As of June 30, 2015 Maturity in Years Amortized Gains Losses Fair Corporate debt securities Less than 1 year $ 8,004 $ — $ — $ 8,004 Unrealized As of December 31, 2014 Maturity in Years Amortized Gains Losses Fair Corporate debt securities Less than 1 year $ 70,521 $ — $ (8 ) $ 70,513 Net Loss Per Share Attributable to Common Stockholders Basic and diluted net loss per common share is calculated by dividing net loss applicable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents. Potentially dilutive shares, which include convertible preferred stock and rights to acquire convertible preferred stock (non-controlling interest), warrants for the purchase of common stock and options outstanding under the Company’s equity incentive plans, are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive. Potentially dilutive securities not included in the calculation of diluted net loss per share attributable to common stockholders because to do so would be anti-dilutive are as follows (in common stock equivalent shares): Six Months Ended 2015 2014 Warrants for common stock 152,735 206,340 Common stock options and restricted stock units 2,544,854 2,510,828 2,697,589 2,717,168 Recent Accounting Pronouncements In April 2015, the FASB issued ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. The amendments in this ASU require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The amendments in this ASU are effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption of the amendments is permitted. The new guidance shall be applied on a retrospective basis, wherein the balance sheet of each individual period presented should be adjusted to reflect the period-specific effects of applying the new guidance. The Company is currently evaluating the impact of the adoption of this standard on its consolidated financial statements. In August 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2014-15, which defined management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related disclosure. ASU 2014-15 defined the term substantial doubt and requires an assessment for a period of one year after the date of the issuance of the financial statements. It requires certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans and requires an express statement and other disclosures when substantial doubt is not alleviated. The guidance becomes effective for reporting periods beginning after December 15, 2016, with early adoption permitted. The Company does not believe that the adoption of this guidance will have a material impact on its consolidated financial statements.

Balance Sheet Details

Balance Sheet Details	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Details	2. Balance Sheet Details Prepaid expenses and other assets consist of the following (in thousands): June 30, December 31, Prepaid expenses 874 756 Commercial manufacturing costs (1) — 1,751 Other receivables 185 628 Debt issue costs, current 106 — $ 1,165 $ 3,135 (1) The commercial manufacturing costs consisted mainly of design and engineering services for commercial drug manufacturing capabilities. The Company determined that it was probable that it would not complete the commercial manufacturing project in light of the CUPID 2 clinical data announced in April 2015 (see Note 7). The Company therefore recorded the costs accumulated as of December 31, 2014 and activity in the first half of 2015 as a period expense in the consolidated financial statements in the six month period ending June 30, 2015. Property and equipment consist of the following (in thousands): June 30, December 31, Office furniture and other equipment (1) $ 520 $ 881 Leasehold improvements 246 246 Accumulated depreciation (1) (150 ) (364 ) $ 616 $ 763 (1) Equipment and related accumulated depreciation related to MYDICAR manufacturing assets were reduced by $0.5 and $0.3, respectively, for a net impairment of $0.2 million in the six months ended June 30, 2015 following the CUPID 2 trial results and suspension of further development of the MYDICAR program (see Note 7). Accounts payable and accrued expenses consist of the following (in thousands): June 30, December 31, Accounts payable $ 2,761 $ 3,293 Accrued compensation 268 1,909 Accrued other 406 596 Current portion of deferred rent 11 5 $ 3,446 $ 5,803

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The Company’s financial instruments primarily consist of cash and cash equivalents, investment securities, accounts payable and accrued liabilities. The carrying value of these financial instruments generally approximates fair value due to their short-term nature. Investment securities are recorded at fair value. The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets; Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions As of June 30, 2015 and December 31, 2014, cash and cash equivalents consist primarily of bank deposits with third-party financial institutions and highly liquid money market securities with original maturities at date of purchase of 90 days or less and are stated at cost which approximate fair value and are classified within the Level 1 designation discussed above. Marketable securities are recorded at fair value, defined as the exit price in the principal market in which the Company would transact, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Level 2 securities are valued using quoted market prices for similar instruments, non-binding market prices that are corroborated by observable market data, or discounted cash flow techniques and include the Company’s investments in corporate debt securities and commercial paper. Financial liabilities that were measured or disclosed at fair value on a recurring basis, and were classified within the Level 3 designation, included the warrant liability and convertible notes prior to their conversion to equity upon the Company’s initial public offering in February 2014. None of the Company’s non-financial assets and liabilities are recorded at fair value on a non-recurring basis. No transfers between levels have occurred during the periods presented. Cash equivalents measured at fair value as of June 30, 2015 and December 31, 2014 are all classified within Level 1. Below is a summary of other assets and liabilities measured at fair value (in thousands): Fair Value Measurements at As of Quoted Prices Significant Significant Assets: Corporate debt securities $ 8,004 $ — $ 8,004 $ — Fair Value Measurements at As of Quoted Prices (Level 1) Significant Significant Assets: Corporate debt securities $ 70,513 $ — $ 70,513 $ —

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	4. Commitments and Contingencies Sublicense Agreement and Amended and Restated License Agreement with AmpliPhi Sublicense Agreement In June 2012, the Company entered into a sublicense agreement (the AmpliPhi Sublicense) with AmpliPhi Biosciences Corporation (AmpliPhi), pursuant to which AmpliPhi sublicensed to the Company certain rights under a separate agreement which AmpliPhi entered into in 2009 with the Trustees of University of Pennsylvania (UPenn). Under the terms of the AmpliPhi Sublicense, the Company obtained an exclusive, worldwide sublicense from AmpliPhi under certain UPenn patents related to AAV1 vectors for the development, manufacture, use and sale of companion diagnostics to MYDICAR. In addition, the Company is required to use commercially reasonable efforts to meet certain developmental, regulatory and commercial milestones with respect to companion diagnostics under the agreement. Following the recent suspension of further development of MYDICAR and its companion diagnostic, the Company may not currently be in compliance with these milestone requirements and will consider whether to terminate the agreement at the appropriate time following its review of strategic alternatives. In consideration for the sublicense granted to the Company under the agreement, the Company paid to AmpliPhi a sublicense initiation fee of $310,000, and the Company is obligated to pay to AmpliPhi an annual sublicense maintenance fee of $310,000. The Company is also required to pay to AmpliPhi a low single-digit percentage royalty based on net sales of any companion diagnostic covered by a licensed patent sold by the Company, its affiliates or its sublicensees. The Company’s royalty obligations continue on a companion diagnostic-by-companion diagnostic and country-by-country basis until the expiration of the last-to-expire valid claim in a licensed patent covering the applicable companion diagnostic in such country. Finally, the Company is obligated to pay to AmpliPhi all royalty and milestone payments that become due and payable by AmpliPhi to UPenn under AmpliPhi’s agreement with UPenn as a result of the Company’s exercise of the sublicense granted under the Company’s agreement with AmpliPhi, including a low single-digit tiered percentage royalty on net sales of any companion diagnostic sold by the Company, its affiliates or its sublicensees, which royalty is separate from and in addition to the royalty payable to AmpliPhi described above, and up to an aggregate of $850,000 in potential milestone payments per product covered by the licensed patents. The Company may unilaterally terminate the agreement upon 30 days’ written notice to AmpliPhi. Absent early termination, the agreement will automatically terminate upon the expiration of the last-to-expire licensed patent, which is expected to be in 2019. The Company recorded $0.3 million in each of the six month periods ended June 30, 2015 and June 30, 2014. Through June 30, 2015, no milestone obligations were incurred under the agreement. Amended and Restated License Agreement The Company entered into an amended and restated license agreement with AmpliPhi concurrently with the AmpliPhi Sublicense that both amended the terms of the license agreement which the Company entered into with AmpliPhi in 2009 and terminated its manufacturing agreement with AmpliPhi which the Company entered into in 2009. Under the agreement, the Company obtained an exclusive, worldwide license under certain patents and know-how related to AmpliPhi’s AAV vector and manufacturing technology for the development, manufacture, use and sale of MYDICAR. In addition, the Company has agreed to use commercially reasonable efforts to meet certain diligence milestones with respect to the development and commercialization of at least one product covered by the UPenn patent rights licensed to AmpliPhi by UPenn under the Company’s agreement with UPenn. Following the recent suspension of further development of MYDICAR, the Company may not currently be in compliance with these milestone requirements and will consider whether to seek termination of the agreement at the appropriate time following its review of strategic alternatives. During the term of the agreement, the Company is not obligated to make annual license or maintenance payments, but is obligated to pay to AmpliPhi all royalty and milestone payments that become due and payable by AmpliPhi to UPenn under AmpliPhi’s agreement with UPenn as a result of the Company’s exercise of the sublicense granted under the Company’s agreement with AmpliPhi. This includes a low single-digit tiered percentage royalty on net sales of MYDICAR and any other product covered by the licensed patents sold by the Company, its affiliates or its sublicensees, and up to $850,000 in milestone payments upon the achievement of certain developmental and regulatory milestones related to MYDICAR and any other product covered by the licensed patents. Through June 30, 2015, no milestone obligations were incurred under the agreement. The agreement does not provide either party with termination rights and does not have a provision for expiration or automatic termination. Exclusive Patent License with the Regents of the University of Minnesota In May 2009, the Company entered into an exclusive patent license agreement with the Regents of the University of Minnesota (UMinn) under which it obtained an exclusive license to UMinn’s joint ownership interest in a patent application related to screening technology for isolation of small molecule modulators of SERCA enzymes. The agreement does not encompass a manufacturing agreement. The Company has agreed to meet certain performance milestones under the agreement, the deadline for which may be extended at the Company’s request provided that the Company has used commercially reasonable efforts to achieve such milestones by the applicable deadlines. The Company recently suspended further development of the small molecule program and will consider whether to terminate the agreement at the appropriate time following its review of strategic alternatives. The Company has the first right to prosecute and maintain the applicable patent family. The Company made an upfront payment to UMinn of $120,000. In addition, the Company is obligated to pay to UMinn an annual license fee of $120,000. The annual license fee will increase to $325,000 if the Company (1) undergoes a change of control, (2) assigns the agreement, any of its rights or obligations under the agreement or as joint ownership interest in the licensed technology, (3) receives a certain amount in license and sublicense revenues under the agreement, (4) files an investigational new drug application (IND), new drug application, biologic license application or orphan drug application (or a foreign equivalent of any such application) for a product covered by the licensed technology, or (5) enters into any agreement with a third party to market or use the licensed technology, subject to certain exceptions. The Company may unilaterally terminate the agreement upon 90 days’ written notice to UMinn. UMinn may terminate the agreement upon 10 days’ written notice to the Company upon the Company’s insolvency or for its breach of the agreement if such breach remains uncured for 90 days after the Company receives notice of such breach, or 30 days in the case of a non-payment breach. Absent early termination, the agreement will automatically terminate upon the expiration of all active claims in any licensed patent or patent application, which is expected to occur no earlier than January 2030. The Company recorded $0.1 million in each of the six month periods ended June 30, 2015 and June 30, 2014. Through June 30, 2015, no milestone obligations were incurred under the agreement. Material Transfer and Exclusivity Agreement In February 2014, the Company and Les Laboratoires Servier (Servier) entered into a material transfer and exclusivity agreement, pursuant to which the Company agreed to transfer to Servier samples of certain proprietary compounds from the Company’s small molecule SERCA2b modulator program and granted to Servier a non-exclusive, non-sublicensable, royalty-free license to conduct certain studies of the samples for the purpose of evaluating Servier’s interest in negotiating a potential license and research collaboration agreement with the Company relating to small molecule SERCA2b modulators (Compounds), for the treatment of type 2 diabetes and other metabolic diseases. In 2015 the Company concluded certain pre-clinical studies in coordination with Servier and the evaluation period has expired. License Agreement with Enterprise On July 18, 2014, the Company and Enterprise Partners Management, LLC (Enterprise), an affiliate of Enterprise Partners Venture Capital, entered into an Assignment and License Agreement (the Enterprise License Agreement), pursuant to which Enterprise granted to the Company an exclusive, worldwide license and the assignment of patents held by Enterprise relating to certain gene therapy applications of the membrane-bound form of the Stem Cell Factor gene (mSCF) for treatment of cardiac ischemia. The Company has the right to grant sublicenses to third parties under the Enterprise License Agreement. Entities affiliated with Enterprise beneficially owned more than 10% of the Company’s stock as of the date the Enterprise License Agreement was executed. In consideration for the rights granted to the Company under the Enterprise License Agreement, the Company paid an upfront fee to Enterprise of $160,000. The Company is also obligated to pay to Enterprise a milestone payment in the amount of $1,000,000 upon the grant to the Company, a Company affiliate or a Company sublicensee of the first regulatory approval in the United States of a product that is covered by the licensed patents. In addition, the Company is required to pay to Enterprise a 2% royalty on net sales of products sold by the Company, Company affiliates and Company sublicensees that are covered by the licensed patents. The Company’s royalty obligations continue on a product-by-product and country-by-country basis until the expiration of the last-to-expire valid claim in the licensed patents covering a licensed product in such country. The Company may unilaterally terminate the Enterprise License Agreement upon written notice to Enterprise. Enterprise may terminate the agreement in the event of the Company’s material breach of the Enterprise License Agreement if such breach remains uncured for 90 days following receipt of written notice of such breach. Absent early termination, the Enterprise License Agreement will automatically terminate upon the expiration of the last-to-expire of the licensed patents containing a valid claim. Other License Agreements The Company has entered into various license agreements pursuant to which the Company acquired certain intellectual property. Pursuant to each agreement the Company paid a license fee and reimbursed historical patent costs. Additionally, under each agreement, the Company may be required to pay annual maintenance fees, royalties, milestone payments and sublicensing fees. Each of the license agreements is generally cancelable by the Company, given appropriate prior written notice. The Company cancelled certain license agreements following the CUPID 2 clinical trial results in April 2015 (see Note 7). Minimum annual payments to maintain these cancelable licenses total an aggregate of approximately $0.1 million and potential future milestone payments total an aggregate of approximately $0.9 million. The Company has recorded research and development expense related to license and annual maintenance fees under the agreements of $0.1 million and $0.2 million for the six month periods ended June 30, 2015 and June 30, 2014, respectively. Through June 30, 2015, the Company has recorded research and development expense of $0.1 million related to milestone obligations incurred under the agreements. Leases The Company leases office space in San Diego, California under long-term operating leases that expire in October 2017 and September 2021. In March 2015, the Company entered into a short-term lease for approximately 7,000 square feet of office space in Seattle, Washington that expires in June 2016. The Company also has a short-term lease for satellite office space in Seattle, Washington that expires in 2015. Rent expense for the three months and six months ended June 30, 2015 was $0.2 million and $0.3 million, respectively. Rent expense for the three months and six months ended June 30, 2014 was $21,000 and $42,000, respectively. Future minimum payments under the long-term operating leases net of contractual sublease payments total $2.8 million.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Stockholders' Equity	5. Stockholders’ Equity Common Stock Warrants The following table summarizes the fully exercisable warrants outstanding for the purchase of common stock as of June 30, 2015 and December 31, 2014: June 30, 2015 December 31, 2014 Exercise Price Expiration Date 152,735 206,340 $ 5.61 October 2018 Stock Options Options granted under the Company’s equity incentive plans generally expire no more than ten years from the date of grant and generally vest and become exercisable over a period not to exceed four years, as determined by the Company’s board of directors. Recipients of stock options are eligible to purchase shares of the Company’s common stock at an exercise price equal to no less than the estimated fair market value of such stock on the date of grant. The Company has also granted inducement stock options outside an equity incentive plan that are subject to the terms and conditions of the Company’s 2013 Equity Incentive Plan. Prior Plans In December 2001, the Company adopted its 2001 Stock Option Plan (the 2001 Plan) and in January 2012 adopted its 2012 Equity Incentive Plan (the 2012 Plan, and together with the 2001 Plan, the Prior Plans). The Prior Plans have terminated and no further shares may be granted under the Prior Plans. 2013 Equity Incentive Plan The 2013 Equity Incentive Plan became effective in February 2014. Under the 2013 Equity Incentive Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units (RSUs), performance-based stock awards and other awards to individuals who are then employees, officers, non-employee directors or consultants of the Company and its affiliates. Additionally, the 2013 Equity Incentive Plan provides for the grant of performance cash awards. The number of shares of common stock reserved for issuance under the 2013 Equity Incentive Plan will automatically increase on January 1 of each year continuing through and including January 1, 2023 by 5% of the total number of shares of the Company’s capital stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares determined by the Company’s board of directors. A summary of the Company’s stock option and RSU activity is as follows: Options and RSUs Outstanding at December 31, 2014 2,408,634 Granted 1,342,750 Exercised (380,253 ) Cancelled (826,277 ) Outstanding at June 30, 2015 2,544,854 2013 Employee Stock Purchase Plan The 2013 Equity Stock Purchase Plan (ESPP) became effective in January 2014. The number of shares of common stock reserved for issuance will automatically increase on January 1 of each calendar year through January 1, 2023 by the least of (1) 1% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, (2) 384,307 shares, or (3) a number determined by the Company’s board of directors that is less than (1) and (2). Stock-Based Compensation Expense The allocation of stock-based compensation for all equity awards is as follows (in thousands): Three Months Six Months 2015 2014 2015 2014 Research and development $ 681 $ 441 $ 1,591 $ 784 General and administrative 415 307 1,610 483 $ 1,096 $ 748 $ 3,201 $ 1,267 As of June 30, 2015 the unrecognized compensation cost related to outstanding employee options was $14.9 million and is expected to be recognized as expense over approximately 3.2 years.

Long-Term Obligations

Long-Term Obligations	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Long-Term Obligations	6. Long-Term Obligations Hercules Loan Agreement On July 31, 2014, the Company entered into a Loan and Security Agreement (the Loan Agreement) with Hercules Technology III, L.P. and Hercules Technology Growth Capital, Inc. (as agent and as a lender, and together with Hercules Technology III, L.P., the Lenders) under which up to $25.0 million was available for the Company to borrow in two tranches (the Loan). The Company borrowed the first tranche of $10.0 million on August 1, 2014. The Loan accrued interest at a rate equal to the greater of either (i) 8.25% plus the prime rate as reported from time to time in The Wall Street Journal minus 5.25%, and (ii) 8.25%. Contractual payments under the Loan Agreement were interest only until August 1, 2015 followed by equal monthly payments of principal and interest, through the scheduled maturity date on February 1, 2018. In addition, a final payment equal to $1,750,000 was due at such time as the Loan was prepaid or became due and payable in full as specified in the Loan Agreement. The second tranche of up to $15.0 million was available to be drawn through June 30, 2015, but only if the Company provided the Lenders with notice that data from the Company’s Phase 2b clinical trial for MYDICAR supported the continued development of MYDICAR for its Breakthrough Therapy designation to either a Phase 3 clinical trial or for registration for approval, as reasonably determined by the Company’s senior management and board of directors (the Milestone). In April 2015, the Company’s senior management and board of directors determined that the Company did not achieve the Milestone (see Note 7). Accordingly, the Company could not draw down the second tranche of $15.0 million. In June 2015 the Company announced it would prepay the outstanding amounts due under the Loan Agreement and on August 3, 2015, the Company paid the Lenders (i) the $10,000,000 outstanding principal balance, (ii) $75,625 in accrued and unpaid interest, and (iii) an end of term charge of $1,750,000, for a total payment of $11,825,625. Upon the prepayment on August 3, 2015, the Company’s obligations, covenants, debts and liabilities under the Loan Agreement were satisfied in full and the Lender’s commitments to extend further credit to the Company were terminated. Capital Lease In 2014 the Company entered into a capital lease arrangement for office equipment in the Company’s San Diego, California office. The Company is obligated to make 60 payments of approximately $600. Contractual Payments and Carrying-Value Reconciliation The following table provides a reconciliation of our future contractual principal and final fee payments on our debt and capital lease obligations to the reported carrying value (in thousands): June 30, December 31, Total loan debt and capital lease obligations $ 11,762 $ 11,762 Less: Debt discount (1,165 ) (1,659 ) Total carrying value: 10,597 10,103 Less: Carrying value of current portion of long-term obligations (10,587 ) (1 ) Carrying value of long-term obligations, less current portion $ 10 $ 10,102

Restructuring charges

Restructuring charges	6 Months Ended
	Jun. 30, 2015
Restructuring and Related Activities [Abstract]
Restructuring charges	7. Restructuring charges On April 26, 2015, the Company announced that its Phase 2b CUPID 2 trial did not meet its primary and secondary endpoints. No safety issues were noted. In light of the CUPID 2 results and following analysis of the CUPID 2 data, the Company’s board of directors, in two phases, approved an approximately 70% aggregate reduction of the Company’s peak workforce of 34 employees to reduce operating expenses and conserve cash resources. The Company has also committed to retention payments payable to certain key employees if such employees remain with the Company until December 31, 2015 or are terminated by the Company without cause prior to such date. The Company has suspended further research or development activities while it evaluates its strategic alternatives. The Company also engaged a financial advisor and is evaluating strategic alternatives to maximize shareholder value, including a potential merger, sale or liquidation of the Company. Restructuring charges for each period were as follows (in thousands): Three Months Six Months 2015 2014 2015 2014 Employee severance and related costs $ 2,868 $ — $ 2,868 $ — Asset impairments 213 — 213 — Total restructuring and asset impairment charges $ 3,081 $ — $ 3,081 $ — The accrued restructuring activity during the six months ended June 30, 2015 was as follows: Employee Severance Accrued restructuring balance as of December 31, 2014 $ — Additional accruals 2,868 Cash payments (476 ) Accrued restructuring balance as of June 30, 2015 $ 2,392 The Company recorded the additional accruals as restructuring charges in the consolidated statements of operations. The charges incurred during the six months ended June 30, 2015, included $2.4 million related to employee severance costs, which impacted 24 employees, and $0.5 million related to retention payment accruals. Eleven employees related to the restructuring activity separated from the Company in the second quarter of 2015 and the other 13 employees are expected to separate from the Company in the third quarter of 2015. The accrued restructuring balance as of June 30, 2015, relates to employee severance and related costs which are expected to be paid within the next six months and was recorded as a current liability in the consolidated balance sheets. The Company has committed to approximately $3.8 million in aggregate charges related to employee severance and related costs which are expected to be settled in 2015. Following the announcement on June 26, 2015, that the Company had suspended further research and development of its MYDICAR programs, the Company’s officers determined that certain equipment used in the MYDICAR manufacturing process were impaired and an asset impairment charge of $0.2 million was recorded to restructuring charges in the consolidated statements of operations for the six months ended June 30, 2015.The Company may incur additional charges in the future for employee severance and related costs as well as asset-related or other restructuring activities, as it continues to evaluate its strategic alternatives.

Subsequent Event

Subsequent Event	6 Months Ended
	Jun. 30, 2015
Subsequent Events [Abstract]
Subsequent Event	8. Subsequent Event In July 2015, following the Company’s announcements of the negative CUPID 2 data and the suspension of further research and development activities and the subsequent declines of the price of the Company’s common stock, three putative securities class action complaints (captioned Fialkov v. Celladon Corporation, Case No. 15-cv-1458-AJB-DHB, Lorusso v. Celladon Corporation, Case No. 15-cv-1501-L-JLB and Jacobs v. Celladon Corporation, Case No. 15-cv-1529-AJB-MDD ) were filed in the U.S. District Court for the Southern District of California against the Company and certain of the Company’s current and former officers. The complaints generally allege that the defendants violated Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 by making materially false and misleading statements regarding the clinical trial program for MYDICAR, thereby artificially inflating the price of the Company’s common stock. The complaints seek unspecified monetary damages and other relief, including attorneys’ fees. The Company expects the court to consolidate the three putative securities class actions and to appoint a lead plaintiff to represent the putative class. The Company then expects the lead plaintiff to file a consolidated complaint. It is possible that additional suits will be filed, or allegations made by stockholders, with respect to these same or other matters and also naming the Company and/or the Company’s officers and directors as defendants. The Company believes that it has meritorious defenses and intends to defend these lawsuits vigorously. Due to the early stage of these proceedings, the Company is not able to predict or reasonably estimate the ultimate outcome or possible losses relating to these claims.

Basis of Presentation, Organi14

Basis of Presentation, Organization and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated financial statements of Celladon Corporation (Celladon or the Company) should be read in conjunction with the audited financial statements and notes thereto as of and for the year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K (Annual Report) filed with the Securities and Exchange Commission (SEC). The accompanying financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, since they are interim statements, the accompanying financial statements do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, the accompanying financial statements reflect all adjustments (consisting of normal recurring adjustments) that are necessary for a fair statement of the financial position, results of operations and cash flows for the interim periods presented. Interim results are not necessarily indicative of results for a full year. The preparation of the Company’s consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimates in the Company’s consolidated financial statements relate to the fair value of equity awards and clinical trial expense accruals. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Organization	Organization Celladon was incorporated in California on December 21, 2000 (inception) and reincorporated in Delaware in April 2012. The Company is a biotechnology company that has been focused on the development of cardiovascular gene therapy. As a result of the negative results from the Phase 2b clinical trial of its lead product candidate, MYDICAR (AAV1/SERCA2a), the Company is evaluating its strategic opportunities to maximize shareholder value, including the possibility of seeking a merger, sale of the Company or all or some of its assets, and/or a liquidation, and has suspended further research and development activities to reduce operating expenses while it evaluates these opportunities. As of June 30, 2015, the Company has devoted substantially all of its efforts to product development, raising capital and building infrastructure and has not generated revenues from its planned principal operations.
Principles of Consolidation	Principles of Consolidation The financial statements of the Company’s former subsidiary Celladon Europe B.V. (Celladon Europe) were consolidated with those of the Company through Celladon Europe’s dissolution on December 30, 2014. All intercompany transactions and balances were eliminated in consolidation.
Investment Securities	Investment Securities Investment securities primarily consist of investment grade corporate debt securities. The Company classifies all investment securities as available-for-sale. Investments with maturity dates greater than 12 months from the end of each reporting period are classified as long-term. Investment securities are carried at fair value, with the unrealized gains and losses reported as a component of other comprehensive income (loss) in stockholders’ equity (deficit) until realized. Realized gains and losses from the sale of investment securities, if any, are determined on a specific identification basis. A decline in the market value of any investment security below cost that is determined to be other than temporary will result in an impairment charge to earnings and a new cost basis for the security is established. No such impairment charges were recorded for any period presented. As of June 30, 2015 and December 31, 2014, none of the investment securities have been in an unrealized loss position for more than 12 months. Premiums and discounts are amortized or accreted over the life of the related security as an adjustment to yield using the straight-line method and are included in interest income. Interest income is recognized when earned. The following table sets forth the composition of the Company’s investment securities (in thousands): Unrealized As of June 30, 2015 Maturity in Years Amortized Gains Losses Fair Corporate debt securities Less than 1 year $ 8,004 $ — $ — $ 8,004 Unrealized As of December 31, 2014 Maturity in Years Amortized Gains Losses Fair Corporate debt securities Less than 1 year $ 70,521 $ — $ (8 ) $ 70,513
Net Loss Per Share Attributable to Common Stockholders	Net Loss Per Share Attributable to Common Stockholders Basic and diluted net loss per common share is calculated by dividing net loss applicable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents. Potentially dilutive shares, which include convertible preferred stock and rights to acquire convertible preferred stock (non-controlling interest), warrants for the purchase of common stock and options outstanding under the Company’s equity incentive plans, are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive. Potentially dilutive securities not included in the calculation of diluted net loss per share attributable to common stockholders because to do so would be anti-dilutive are as follows (in common stock equivalent shares): Six Months Ended 2015 2014 Warrants for common stock 152,735 206,340 Common stock options and restricted stock units 2,544,854 2,510,828 2,697,589 2,717,168
Recent Accounting Pronouncements	Recent Accounting Pronouncements In April 2015, the FASB issued ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. The amendments in this ASU require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The amendments in this ASU are effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption of the amendments is permitted. The new guidance shall be applied on a retrospective basis, wherein the balance sheet of each individual period presented should be adjusted to reflect the period-specific effects of applying the new guidance. The Company is currently evaluating the impact of the adoption of this standard on its consolidated financial statements. In August 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2014-15, which defined management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related disclosure. ASU 2014-15 defined the term substantial doubt and requires an assessment for a period of one year after the date of the issuance of the financial statements. It requires certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans and requires an express statement and other disclosures when substantial doubt is not alleviated. The guidance becomes effective for reporting periods beginning after December 15, 2016, with early adoption permitted. The Company does not believe that the adoption of this guidance will have a material impact on its consolidated financial statements.

Basis of Presentation, Organi15

Basis of Presentation, Organization and Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Composition of Investment Securities	The following table sets forth the composition of the Company’s investment securities (in thousands): Unrealized As of June 30, 2015 Maturity in Years Amortized Gains Losses Fair Corporate debt securities Less than 1 year $ 8,004 $ — $ — $ 8,004 Unrealized As of December 31, 2014 Maturity in Years Amortized Gains Losses Fair Corporate debt securities Less than 1 year $ 70,521 $ — $ (8 ) $ 70,513
Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss Per Share Attributable to Common Stockholders	Potentially dilutive securities not included in the calculation of diluted net loss per share attributable to common stockholders because to do so would be anti-dilutive are as follows (in common stock equivalent shares): Six Months Ended 2015 2014 Warrants for common stock 152,735 206,340 Common stock options and restricted stock units 2,544,854 2,510,828 2,697,589 2,717,168

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Prepaid Expenses and Other Assets	Prepaid expenses and other assets consist of the following (in thousands): June 30, December 31, Prepaid expenses 874 756 Commercial manufacturing costs (1) — 1,751 Other receivables 185 628 Debt issue costs, current 106 — $ 1,165 $ 3,135 (1) The commercial manufacturing costs consisted mainly of design and engineering services for commercial drug manufacturing capabilities. The Company determined that it was probable that it would not complete the commercial manufacturing project in light of the CUPID 2 clinical data announced in April 2015 (see Note 7). The Company therefore recorded the costs accumulated as of December 31, 2014 and activity in the first half of 2015 as a period expense in the consolidated financial statements in the six month period ending June 30, 2015.
Summary of Property and Equipment	Property and equipment consist of the following (in thousands): June 30, December 31, Office furniture and other equipment (1) $ 520 $ 881 Leasehold improvements 246 246 Accumulated depreciation (1) (150 ) (364 ) $ 616 $ 763 (1) Equipment and related accumulated depreciation related to MYDICAR manufacturing assets were reduced by $0.5 and $0.3, respectively, for a net impairment of $0.2 million in the six months ended June 30, 2015 following the CUPID 2 trial results and suspension of further development of the MYDICAR program (see Note 7).
Summary of Accounts Payable and Accrued Expenses	Accounts payable and accrued expenses consist of the following (in thousands): June 30, December 31, Accounts payable $ 2,761 $ 3,293 Accrued compensation 268 1,909 Accrued other 406 596 Current portion of deferred rent 11 5 $ 3,446 $ 5,803

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Summary of Other Assets and Liabilities Measured at Fair Value	Cash equivalents measured at fair value as of June 30, 2015 and December 31, 2014 are all classified within Level 1. Below is a summary of other assets and liabilities measured at fair value (in thousands): Fair Value Measurements at As of Quoted Prices Significant Significant Assets: Corporate debt securities $ 8,004 $ — $ 8,004 $ — Fair Value Measurements at As of Quoted Prices (Level 1) Significant Significant Assets: Corporate debt securities $ 70,513 $ — $ 70,513 $ —

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Summary of Exercisable Warrants Outstanding for Purchase of Common Stock	The following table summarizes the fully exercisable warrants outstanding for the purchase of common stock as of June 30, 2015 and December 31, 2014: June 30, 2015 December 31, 2014 Exercise Price Expiration Date 152,735 206,340 $ 5.61 October 2018
Summary of Company's Stock Option and RSU Activity	A summary of the Company’s stock option and RSU activity is as follows: Options and RSUs Outstanding at December 31, 2014 2,408,634 Granted 1,342,750 Exercised (380,253 ) Cancelled (826,277 ) Outstanding at June 30, 2015 2,544,854
Schedule of Allocation of Stock-based Compensation for Equity Awards	The allocation of stock-based compensation for all equity awards is as follows (in thousands): Three Months Six Months 2015 2014 2015 2014 Research and development $ 681 $ 441 $ 1,591 $ 784 General and administrative 415 307 1,610 483 $ 1,096 $ 748 $ 3,201 $ 1,267

Long-Term Obligations (Tables)

Long-Term Obligations (Tables)	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Summary of Reconciliation of Future Contractual Principal and Final Fee Payments on Debt and Capital Lease Obligations	The following table provides a reconciliation of our future contractual principal and final fee payments on our debt and capital lease obligations to the reported carrying value (in thousands): June 30, December 31, Total loan debt and capital lease obligations $ 11,762 $ 11,762 Less: Debt discount (1,165 ) (1,659 ) Total carrying value: 10,597 10,103 Less: Carrying value of current portion of long-term obligations (10,587 ) (1 ) Carrying value of long-term obligations, less current portion $ 10 $ 10,102

Restructuring charges (Tables)

Restructuring charges (Tables)	6 Months Ended
	Jun. 30, 2015
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Charges	Restructuring charges for each period were as follows (in thousands): Three Months Six Months 2015 2014 2015 2014 Employee severance and related costs $ 2,868 $ — $ 2,868 $ — Asset impairments 213 — 213 — Total restructuring and asset impairment charges $ 3,081 $ — $ 3,081 $ —
Schedule of Accrued Restructuring Activity	The accrued restructuring activity during the six months ended June 30, 2015 was as follows: Employee Severance Accrued restructuring balance as of December 31, 2014 $ — Additional accruals 2,868 Cash payments (476 ) Accrued restructuring balance as of June 30, 2015 $ 2,392

Basis of Presentation, Organi21

Basis of Presentation, Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Impairment charges on investment securities	$ 0
Investment securities, unrealized loss position for more than 12 months	$ 0	$ 0

Basis of Presentation, Organi22

Basis of Presentation, Organization and Summary of Significant Accounting Policies - Composition of Investment Securities (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 8,004	$ 70,513
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity in Years	Less than 1 year	Less than 1 year
Amortized Cost	$ 8,004	$ 70,521
Unrealized Gains	0	0
Unrealized Losses		(8)
Fair Value	$ 8,004	$ 70,513

Basis of Presentation, Organi23

Basis of Presentation, Organization and Summary of Significant Accounting Policies - Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss Per Share Attributable to Common Stockholders (Detail) - shares	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	2,697,589	2,717,168
Warrants for Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	152,735	206,340
Common Stock Options and Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	2,544,854	2,510,828

Balance Sheet Details - Summary

Balance Sheet Details - Summary of Prepaid Expenses and Other Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid expenses	$ 874	$ 756
Commercial manufacturing costs		1,751
Other receivables	185	628
Debt issue costs, current	106
Prepaid expenses and other assets	$ 1,165	$ 3,135

Balance Sheet Details - Summa25

Balance Sheet Details - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, accumulated depreciation	$ (150)	$ (364)
Property and equipment, net	616	763
Office Furniture and Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	520	881
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 246	$ 246

Balance Sheet Details - Summa26

Balance Sheet Details - Summary of Property and Equipment (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Asset impairment, net	$ 213	$ 213
MYDICAR [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, accumulated depreciation		(500)
Accumulated depreciation related to manufacturing assets			$ (300)
Asset impairment, net		$ 213

Balance Sheet Details - Summa27

Balance Sheet Details - Summary of Accounts Payable and Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Accounts payable	$ 2,761	$ 3,293
Accrued compensation	268	1,909
Accrued other	406	596
Current portion of deferred rent	11	5
Accounts payable and accrued expenses	$ 3,446	$ 5,803

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value (Detail) - Corporate Debt Securities [Member] - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Assets:
Assets, Fair Value	$ 8,004	$ 70,513
Level 2 [Member]
Assets:
Assets, Fair Value	$ 8,004	$ 70,513

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	Jul. 18, 2014USD ($)	Mar. 31, 2015ft²	Jun. 30, 2012USD ($)	May. 31, 2009USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)
Other Commitments [Line Items]
Research and development expense					$ 9,501,000	$ 4,981,000	$ 21,019,000	$ 10,199,000
Rent expense					200,000	$ 21,000	300,000	42,000
Future minimum payments under long-term operating leases					2,800,000		$ 2,800,000
Lease Agreements One [Member]
Other Commitments [Line Items]
Long-term operating lease expiry period							2017-10
Lease Agreements Two [Member]
Other Commitments [Line Items]
Long-term operating lease expiry period							2021-09
Lease Agreements Three [Member]
Other Commitments [Line Items]
Long-term operating lease expiry period							2016-06
Area of office space | ft²		7,000
Lease Agreements Four [Member]
Other Commitments [Line Items]
Operating lease expiry year							2,015
Licensing Agreements [Member] | AmpliPhi Sublicense Transaction [Member]
Other Commitments [Line Items]
Sublicense initiation fee			$ 310,000
Aggregate potential milestone payments			850,000
Annual sublicense maintenance fee payable			$ 310,000
Notice period given by company for termination of license agreement							30 days
License agreement expiration year							2,019
Research and development expense							$ 300,000	300,000
Milestone obligations incurred							0
Licensing Agreements [Member] | AmpliPhi Amended Sublicense Transaction [Member]
Other Commitments [Line Items]
Milestone obligations incurred							$ 0
Licensing Agreements [Member] | Regents of University of Minnesota Patent Transaction [Member]
Other Commitments [Line Items]
Notice period given by company for termination of license agreement							90 days
Research and development expense							$ 100,000	100,000
Milestone obligations incurred							$ 0
Upfront payment				$ 120,000
Annual license fee				120,000
Estimated future annual license fee				$ 325,000
License agreement termination, description							The Company may unilaterally terminate the agreement upon 90 days’ written notice to UMinn. UMinn may terminate the agreement upon 10 days’ written notice to the Company upon the Company’s insolvency or for its breach of the agreement if such breach remains uncured for 90 days after the Company receives notice of such breach, or 30 days in the case of a non-payment breach. Absent early termination, the agreement will automatically terminate upon the expiration of all active claims in any licensed patent or patent application, which is expected to occur no earlier than January 2030.
Patent expiration period							2030-01
Licensing Agreements [Member] | Regents of University of Minnesota Patent Transaction [Member] | Insolvency [Member]
Other Commitments [Line Items]
Notice period given to company for termination of license agreement company							10 days
Licensing Agreements [Member] | Regents of University of Minnesota Patent Transaction [Member] | Breach of Agreement [Member]
Other Commitments [Line Items]
Notice period given to company for termination of license agreement company							90 days
Licensing Agreements [Member] | Regents of University of Minnesota Patent Transaction [Member] | Non-payment Breach [Member]
Other Commitments [Line Items]
Notice period given to company for termination of license agreement company							30 days
Licensing Agreements [Member] | Enterprise Transaction [Member]
Other Commitments [Line Items]
Notice period given by company for termination of license agreement							90 days
Upfront payment	$ 160,000
License agreement termination, description							Enterprise may terminate the agreement in the event of the Company's material breach of the Enterprise License Agreement if such breach remains uncured for 90 days following receipt of written notice of such breach.
Ownership interest, percentage	10.00%
Aggregate potential future milestone payments					1,000,000		$ 1,000,000
Royalty on net sales							2.00%
Licensing Agreements [Member] | Other Transaction [Member]
Other Commitments [Line Items]
Research and development expense							$ 100,000	$ 200,000
Aggregate potential future milestone payments					$ 900,000		900,000
Aggregate minimum annual payments to maintain cancelable licenses							$ 100,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Exercisable Warrants Outstanding for Purchase of Common Stock (Detail) - October 2018 [Member] - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Class of Warrant or Right [Line Items]
Warrants outstanding	152,735	206,340
Warrants outstanding, Exercise Price	$ 5.61	$ 5.61
Warrants outstanding, Expiration Date	2018-10	2018-10

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended		6 Months Ended
	Feb. 28, 2014	Jan. 31, 2014	Jun. 30, 2015
Class of Stock [Line Items]
Common stock reserved for issuance, description			The number of shares of common stock reserved for issuance will automatically increase on January 1 of each calendar year through January 1, 2023 by the least of (1) 1% of the total number of shares of the Company's common stock outstanding on December 31 of the preceding calendar year, (2) 384,307 shares, or (3) a number determined by the Company's board of directors that is less than (1) and (2).
Unrecognized compensation cost			$ 14.9
Unrecognized compensation cost expected to be recognized as expense period			3 years 2 months 12 days
Common Stock Options [Member] | Maximum [Member]
Class of Stock [Line Items]
Options, expiration period			10 years
Common Stock Options [Member] | Minimum [Member]
Class of Stock [Line Items]
Options, vesting period			4 years
Prior Plans [Member] | Common Stock Options [Member]
Class of Stock [Line Items]
Shares available for grant			0
2013 Equity Incentive Plan [Member]
Class of Stock [Line Items]
Percentage of common stock outstanding to increase shares reserved for issuance	5.00%
Common stock reserved for issuance, description			Additionally, the 2013 Equity Incentive Plan provides for the grant of performance cash awards. The number of shares of common stock reserved for issuance under the 2013 Equity Incentive Plan will automatically increase on January 1 of each year continuing through and including January 1, 2023 by 5% of the total number of shares of the Company's capital stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares determined by the Company's board of directors.
2013 Employee Stock Purchase Plan [Member]
Class of Stock [Line Items]
Percentage of common stock outstanding to increase shares reserved for issuance		1.00%
2013 Employee Stock Purchase Plan [Member] | Maximum [Member]
Class of Stock [Line Items]
Common stock authorized for issuance		384,307

Stockholders' Equity - Summar32

Stockholders' Equity - Summary of Company's Stock Option and RSU Activity (Detail)	6 Months Ended
	Jun. 30, 2015shares
Equity [Abstract]
Options and RSUs, Outstanding at beginning	2,408,634
Options and RSUs, Granted	1,342,750
Options and RSUs, Exercised	(380,253)
Options and RSUs, Cancelled	(826,277)
Options and RSUs, Outstanding at ending	2,544,854

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Allocation of Stock-based Compensation for Equity Awards (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 1,096	$ 748	$ 3,201	$ 1,267
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	681	441	1,591	784
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 415	$ 307	$ 1,610	$ 483

Long-Term Obligations - Additio

Long-Term Obligations - Additional Information (Detail)	Feb. 01, 2018USD ($)	Aug. 03, 2015USD ($)	Jun. 30, 2015USD ($)Payments	Aug. 01, 2014USD ($)	Jul. 31, 2014USD ($)
Debt Instrument [Line Items]
Loan agreement, milestone description			In April 2015, the Company's senior management and board of directors determined that the Company did not achieve the Milestone (see Note 7). Accordingly, the Company could not draw down the second tranche of $15.0 million.
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Capital lease, number of payments | Payments			60
Capital lease obligations			$ 600
Hercules Technology III L.P. and Hercules Technology Growth Capital, Inc. [Member]
Debt Instrument [Line Items]
Loan agreement, terms on interest rate calculation			The Loan accrued interest at a rate equal to the greater of either (i) 8.25% plus the prime rate as reported from time to time in The Wall Street Journal minus 5.25%, and (ii) 8.25%. Contractual payments under the Loan Agreement were interest only until August 1, 2015
Loan agreement, interest rate during the period			8.25%
Debt instrument prepayment date			Aug. 3, 2015
Hercules Technology III L.P. and Hercules Technology Growth Capital, Inc. [Member] | Prime Rate [Member]
Debt Instrument [Line Items]
Loan agreement, percentage to be reduced from interest rate under condition			(5.25%)
Hercules Technology III L.P. and Hercules Technology Growth Capital, Inc. [Member] | First Tranche [Member]
Debt Instrument [Line Items]
Loan agreement, maximum borrowing capacity					$ 25,000,000
Loan agreement, amount borrowed				$ 10,000,000
Hercules Technology III L.P. and Hercules Technology Growth Capital, Inc. [Member] | Second Tranche [Member]
Debt Instrument [Line Items]
Loan agreement, remaining amount available for borrowing			$ 15,000,000
Expiration date of tranche			Jun. 30, 2015
Hercules Technology III L.P. and Hercules Technology Growth Capital, Inc. [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Outstanding principal balance		$ 10,000,000
Accrued and unpaid interest		75,625
End of term charge		1,750,000
Total payment of debt		$ 11,825,625
Hercules Technology III L.P. and Hercules Technology Growth Capital, Inc. [Member] | Scenario, Forecast [Member]
Debt Instrument [Line Items]
Loan fees	$ 1,750,000

Long-Term Obligations - Summary

Long-Term Obligations - Summary of Reconciliation of Future Contractual Principal and Final Fee Payments on Debt and Capital Lease Obligations (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Debt Instruments [Abstract]
Total loan debt and capital lease obligations	$ 11,762	$ 11,762
Less: Debt discount	(1,165)	(1,659)
Total carrying value:	10,597	10,103
Current and long-term
Less: Carrying value of current portion of long-term obligations	(10,587)	(1)
Carrying value of long-term obligations, less current portion	10	10,102
Total carrying value:	$ 10,597	$ 10,103

Restructuring Charges - Additio

Restructuring Charges - Additional Information (Detail) $ in Thousands	Apr. 26, 2015Employees	Sep. 30, 2015Employees	Jun. 30, 2015USD ($)Employees	Jun. 30, 2015USD ($)Employees
Restructuring Cost and Reserve [Line Items]
Reduction of current peak employees percentage	70.00%
Current peak workforce | Employees	34
Reduction in force, description				In light of the CUPID 2 results and following analysis of the CUPID 2 data, the Company's board of directors, in two phases, approved an approximately 70% aggregate reduction of the Company's peak workforce of 34 employees to reduce operating expenses and conserve cash resources.
Employee severance and benefit arrangements				$ 2,400
Number of employees impacted | Employees			11	24
Retention payment accruals				$ 500
Restructuring accruals description				The accrued restructuring balance as of June 30, 2015, relates to employee severance and related costs which are expected to be paid within the next six months and was recorded as a current liability in the consolidated balance sheets.
Expected settled year of employee severance, retention and benefit arrangements				2,015
Aggregate charges related to employee severance, retention and benefit arrangements			$ 3,800	$ 3,800
Asset impairment, net			$ 213	213
MYDICAR [Member]
Restructuring Cost and Reserve [Line Items]
Asset impairment, net				$ 213
Scenario, Forecast [Member]
Restructuring Cost and Reserve [Line Items]
Employees expected to separate | Employees		13

Restructuring Charges - Schedul

Restructuring Charges - Schedule of Restructuring Charges (Detail) - Jun. 30, 2015 - USD ($) $ in Thousands	Total	Total
Restructuring and Related Activities [Abstract]
Employee severance and related costs	$ 2,868	$ 2,868
Asset impairments	213	213
Total restructuring and asset impairment charges	$ 3,081	$ 3,081

Restructuring Charges - Sched38

Restructuring Charges - Schedule of Accrued Restructuring Activity (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2015USD ($)
Restructuring Cost and Reserve [Line Items]
Ending balance	$ 2,392
Employee Severance and Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance	0
Additional accruals	2,868
Cash payments	(476)
Ending balance	$ 2,392

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail)	Jul. 31, 2015Complaints
Subsequent Event [Member]
Subsequent Event [Line Items]
Number of complaints filed	3