Tobira Therapeutics 10-K 12 Mar 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Mar. 10, 2014	Feb. 28, 2014
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'RGDO	'	'
Entity Registrant Name	'REGADO BIOSCIENCES INC	'	'
Entity Central Index Key	'0001311596	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Well-known Seasoned Issuer	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Filer Category	'Smaller Reporting Company	'	'
Entity Common Stock, Shares Outstanding	'	25,327,266	'
Entity Public Float	'	'	$90.50

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$30,688	$14,764
Restricted cash	82	82
Prepaid expenses	2,147	257
Other assets	6,211	4,580
Total current assets	39,128	19,683
Debt issuance costs, net	36	87
Property and equipment, net	108	66
Intangible assets, net	1,823	1,771
Other non-current assets	4,658	196
Total assets	45,753	21,803
Current liabilities:	'	'
Accounts payable	1,557	203
Accrued expenses	5,524	786
Warrant liability	19	'
Current portion of long-term debt	2,000	2,571
Total current liabilities	9,100	3,560
Long-term debt	2,452	1,929
Total liabilities	11,552	5,489
Commitments (Note 6)	'	'
Stockholders' equity:	'	'
Common stock, $0.001 par value; 500,000,000 shares authorized; 21,310,614 and 221,272 shares issued and outstanding at December 31, 2013 and December 31, 2012, respectively	21	'
Additional paid-in-capital	179,159	4,804
Deficit accumulated during the development stage	-144,979	-110,540
Total stockholders' equity	34,201	16,314
Total liabilities and stockholders' equity	45,753	21,803
Series A Convertible Preferred Stock [Member]	'	'
Stockholders' equity:	'	'
Convertible preferred stock	'	5,778
Series B Convertible Preferred Stock [Member]	'	'
Stockholders' equity:	'	'
Convertible preferred stock	'	19,888
Series C Convertible Preferred Stock [Member]	'	'
Stockholders' equity:	'	'
Convertible preferred stock	'	22,978
Series D Convertible Preferred Stock [Member]	'	'
Stockholders' equity:	'	'
Convertible preferred stock	'	51,237
Series E Convertible Preferred Stock [Member]	'	'
Stockholders' equity:	'	'
Convertible preferred stock	'	$22,169

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	21,310,614	221,272
Common stock, shares outstanding	21,310,614	221,272
Series A Convertible Preferred Stock [Member]	'	'
Convertible preferred stock, par value	$0.00	$0.00
Convertible preferred stock, shares designated	0	5,798,178
Convertible preferred stock, shares issued	0	5,798,178
Convertible preferred stock, shares outstanding	0	5,798,178
Convertible preferred stock, liquidation preference	'	$5,798
Series B Convertible Preferred Stock [Member]	'	'
Convertible preferred stock, par value	$0.00	$0.00
Convertible preferred stock, shares designated	0	16,666,665
Convertible preferred stock, shares issued	0	16,666,665
Convertible preferred stock, shares outstanding	0	16,666,665
Convertible preferred stock, liquidation preference	'	20,000
Series C Convertible Preferred Stock [Member]	'	'
Convertible preferred stock, par value	$0.00	$0.00
Convertible preferred stock, shares designated	0	17,037,037
Convertible preferred stock, shares issued	0	17,037,037
Convertible preferred stock, shares outstanding	0	17,037,037
Convertible preferred stock, liquidation preference	'	23,000
Series D Convertible Preferred Stock [Member]	'	'
Convertible preferred stock, par value	$0.00	$0.00
Convertible preferred stock, shares designated	0	71,666,667
Convertible preferred stock, shares issued	0	71,666,667
Convertible preferred stock, shares outstanding	0	71,666,667
Convertible preferred stock, liquidation preference	'	51,600
Series E Convertible Preferred Stock [Member]	'	'
Convertible preferred stock, par value	$0.00	$0.00
Convertible preferred stock, shares designated	0	31,437,442
Convertible preferred stock, shares issued	0	31,437,442
Convertible preferred stock, shares outstanding	0	31,437,442
Convertible preferred stock, liquidation preference	'	$22,635

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Loss (USD $)	12 Months Ended		145 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
Revenue:	'	'	'
Grant revenue	$0	$0	$832
Total revenue	'	'	832
Operating expenses:	'	'	'
Research and development	26,542	8,006	108,503
General and administrative	7,297	4,157	38,195
Total operating expenses	33,839	12,163	146,698
Loss from operations	-33,839	-12,163	-145,866
Other (expense) income:	'	'	'
Realized gain on investments	'	'	176
Interest income	80	5	2,878
Interest expense	-680	-904	-2,167
Total other (expense) income	-600	-899	887
Net loss	-34,439	-13,062	-144,979
Comprehensive loss	($34,439)	($13,062)	($144,979)
Loss per share - basic and diluted	($4.59)	($59.03)	($179.91)
Weighted-average common shares - basic and diluted	7,499,661	221,272	805,826

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Stockholders Equity (USD $)	Total	Common Stock [Member]	Additional Capital [Member]	Series A Convertible Preferred Stock [Member]	Series B Convertible Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]	Series D Convertible Preferred Stock [Member]	Series E Convertible Preferred Stock [Member]	Accumulated Deficit [Member]
In Thousands, except Share data
Beginning balance at Dec. 19, 2001	'	'	'	'	'	'	'	'	'
Beginning balance, shares at Dec. 19, 2001	'	'	'	'	'	'	'	'	'
Issuance of common stock, value	53	'	53	'	'	'	'	'	'
Issuance of common stock, shares	'	101	'	'	'	'	'	'	'
Issuance of preferred stock, value	99,897	'	'	5,778	19,888	22,978	51,253	'	'
Issuance of preferred stock, shares	'	'	'	5,798	16,667	17,037	71,667	'	'
Exercise of common stock options and stock warrants, value	205	'	205	'	'	'	'	'	'
Exercise of common stock options and stock warrants, shares	'	120	'	'	'	'	'	'	'
Stock compensation	3,908	'	3,908	'	'	'	'	'	'
Net loss	-97,478	'	'	'	'	'	'	'	-97,478
Ending balance at Dec. 31, 2011	6,585	'	4,166	5,778	19,888	22,978	51,253	'	-97,478
Ending balance, shares at Dec. 31, 2011	'	221	'	5,798	16,667	17,037	71,667	'	'
Issuance of preferred stock, value	-16	'	'	'	'	'	-16	'	'
Issuance of preferred stock, value	22,169	'	'	'	'	'	'	22,169	'
Issuance of preferred stock, shares	'	'	'	'	'	'	'	31,437	'
Stock compensation	703	'	703	'	'	'	'	'	'
Other	-65	'	-65	'	'	'	'	'	'
Net loss	-13,062	'	'	'	'	'	'	'	-13,062
Ending balance at Dec. 31, 2012	16,314	'	4,804	5,778	19,888	22,978	51,237	22,169	-110,540
Ending balance, shares at Dec. 31, 2012	'	221	'	5,798	16,667	17,037	71,667	31,437	'
Issuance of common stock, value	41,075	12	41,063	'	'	'	'	'	'
Issuance of common stock, shares	'	11,672	'	'	'	'	'	'	'
Issuance of preferred stock, value	10,163	'	'	'	'	'	'	10,163	'
Issuance of preferred stock, shares	'	'	'	'	'	'	'	14,320	'
Conversion of preferred stock to common stock upon initial public offering, value	'	9	132,204	-5,778	-19,888	-22,978	-51,237	-32,332	'
Conversion of preferred stock to common stock upon initial public offering, shares	'	9,397	'	-5,798	-16,667	-17,037	-71,667	-45,757	'
Issuance of common stock upon exercise of warrants, value	2	'	2	'	'	'	'	'	'
Issuance of common stock upon exercise of warrants, shares	'	13	'	'	'	'	'	'	'
Exercise of common stock options, value	33	'	33	'	'	'	'	'	'
Exercise of common stock options, shares	7,602	8	'	'	'	'	'	'	'
Stock compensation	988	'	988	'	'	'	'	'	'
Other	65	'	65	'	'	'	'	'	'
Net loss	-34,439	'	'	'	'	'	'	'	-34,439
Ending balance at Dec. 31, 2013	$34,201	$21	$179,159	$0	$0	$0	$0	$0	($144,979)
Ending balance, shares at Dec. 31, 2013	'	21,311	'	'	'	'	'	'	'

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Stockholders Equity (Parenthetical) (USD $)	120 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
	Series A, Series B, Series C, And Series D Preferred Stock [Member]	Common Stock [Member]	Series D Convertible Preferred Stock [Member]	Series E Convertible Preferred Stock [Member]	Series E Convertible Preferred Stock [Member]
Issuance costs	$501	$5,611	$16	$147	$466

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended		145 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
Cash flows used in operating activities:	'	'	'
Net loss	($34,439)	($13,062)	($144,979)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'	'
Depreciation	61	42	2,395
Amortization of patents and licenses	20	401	1,807
Impairment of patents	371	22	536
Accrued final bank fee	55	'	55
Amortization of debt discount	61	'	61
Amortization of debt issuance costs	108	34	156
Change in fair value of warrant liability	-60	'	-60
Stock-based compensation	988	703	5,599
Loss on disposal of property and equipment	2	2	30
Gain on sale of investments	'	'	-176
Other	65	-65	'
Changes in operating assets and liabilities:	'	'	'
Prepaid expenses	-1,890	-32	-2,147
Other assets	-1,708	-1,436	-6,211
Other non-current assets	-4,462	-196	-4,658
Accounts payable	1,354	-117	1,557
Accrued expenses	4,738	-525	5,863
Net cash used in operating activities	-34,736	-14,229	-140,172
Cash flows used in investing activities:	'	'	'
Change in restricted cash	'	'	-82
Purchase of property and equipment	-105	-17	-2,536
Proceeds received on disposal of property and equipment	'	'	5
Purchase of investments	'	'	-163,683
Proceeds from sales of investments	'	'	163,859
Patent and license acquisition costs	-543	-340	-4,266
Proceeds received from sale of patents	100	'	100
Net cash used in investing activities	-548	-357	-6,603
Cash flows from financing activities:	'	'	'
Proceeds from borrowing on convertible notes payable	'	6,781	15,079
Proceeds from borrowings on bank loan	4,500	'	10,500
Repayment of borrowings on bank loan	-4,500	-1,500	-6,000
Payment of bank origination fee	-85	'	-85
Payment of debt issuance costs	-57	-46	-152
Proceeds from issuance of common stock in IPO, net of underwriting discounts	43,418	'	43,418
Payment of IPO costs	-2,266	-77	-2,343
Proceeds from sale of preferred stock, net of issuance costs	10,163	14,957	116,795
Proceeds from issuance of common stock	33	'	224
Proceeds from exercise of warrants	2	'	27
Net cash provided by financing activities	51,208	20,115	177,463
Net increase in cash and cash equivalents	15,924	5,529	30,688
Cash and cash equivalents, beginning of period	14,764	9,235	'
Cash and cash equivalents, end of period	30,688	14,764	30,688
Supplemental disclosures of cash flow information:	'	'	'
Cash paid for interest	547	572	1,368
Supplemental disclosure of non-cash investing and financing activities:	'	'	'
Conversion of preferred stock into common stock	132,213	'	132,213
Conversion of note payable and interest into preferred stock	'	$7,120	$15,418

Organization_and_Description_o

Organization and Description of Business	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Organization and Description of Business	'
	1	Organization and Description of Business
	Regado Biosciences, Inc. (the “Company” or “we” or “our” or “us”) is a development stage enterprise incorporated in the State of Delaware on December 19, 2001 operating primarily in Basking Ridge, New Jersey and Durham, North Carolina. We are focused on the discovery and development of novel, first-in-class, actively controllable antithrombotic drug systems for acute and sub-acute cardiovascular indications. Each of our product candidates consists of a two-component system: an antithrombotic aptamer and its specific active control agent. Our lead product candidate, REG1, is a two-component system consisting of pegnivacogin, an anticoagulant aptamer specifically targeting coagulation Factor IXa, and its complementary oligonucleotide active control agent, anivamersen. REG1 is being developed for use in patients with a wide variety of acute coronary syndromes, or ACS, undergoing a percutaneous coronary intervention, or PCI, a hospital-based procedure used to mechanically open or widen obstructed coronary arteries. Our actively controllable product candidates have the potential to improve patient outcomes, enhance the patient experience and reduce overall treatment costs. In September 2013, we commenced our single, open-label, 13,200 subject Phase 3 trial of REG1 in patients undergoing PCI (excluding ST elevated myocardial infarction, or STEMI), or the REGULATE-PCI trial.
	In May 2013, our board of directors and our stockholders approved an amendment to the amended and restated certificate of incorporation to effect a one-for-16.7 reverse split of shares of common stock and to increase the number of authorized shares of common stock to 500,000,000, each of which was effected on May 21, 2013. All issued and outstanding common stock, options, warrants and per share amounts contained in these consolidated financial statements have been retroactively adjusted to reflect the reverse split for all periods presented.
	We completed our initial public offering (“IPO”) in August 2013. Inclusive of the underwriters’ exercise of the over-allotment option in connection with the IPO in September 2013, we issued 11,671,500 shares of common stock at a price of $4.00 per share, resulting in net proceeds of approximately $41.1 million, after deducting underwriting discounts of $3.3 million and offering costs of $2.3 million. Upon the closing of the IPO, all shares of convertible preferred stock then outstanding automatically converted into an aggregate of 9,396,767 shares of common stock.

Basis_of_Presentation_and_Summ

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Basis of Presentation and Summary of Significant Accounting Policies	'
	2	Basis of Presentation and Summary of Significant Accounting Policies
	Principles of Consolidation and Basis of Presentation
	In March 2013, we incorporated Regado Biosciences Europe Limited, a wholly owned subsidiary registered in England and Wales, in order to establish a legal presence in the European Union (EU) for the purpose of conducting clinical trials in the EU. Regado Biosciences Europe Limited had no operations during the year ended December 31, 2013.
	The accompanying consolidated financial statements include the accounts of Regado Biosciences, Inc. and its wholly owned subsidiary, Regado Biosciences Europe Limited. There were no significant intercompany accounts or transactions that needed to be eliminated in consolidation. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). All intercompany balances and transactions have been eliminated in consolidation.
	Going Concern Uncertainty
	Our financial statements have been prepared on a going-concern basis, which contemplates the realization of assets and settlement of liabilities and commitments in the normal course of business. Operations since inception have consisted primarily of developing and acquiring product technologies and securing financing.
	The accompanying financial statements have been prepared assuming that we will operate as a going concern. We have suffered negative cash flows from operating activities of $34.7 million during the year ended December 31, 2013 and a net accumulated deficit of $145.0 million since inception as of December 31, 2013. Prior to our IPO, we were funded primarily through the issuance of preferred stock and debt. We will require additional capital until such time that we can generate operating revenue in excess of operating expenditures. Our plans include continued product development and a move toward completion of clinical trials. We will continue to closely monitor and analyze expenses and make adjustments as necessary to prioritize business operations. We believe that the net proceeds from the IPO and from our 2014 Private Placement pursuant to which we sold $20 million of our common stock to new and existing investors (see Note 14 - Subsequent Events), will be sufficient for us to fund the REGULATE-PCI trial through the second interim analysis, which we expect will occur in the third quarter of 2014. We will need to raise additional financing in the first half of 2014 to fund projected operations through 2014 and we can provide no assurances that such additional financing will be available on favorable terms, or at all. Actual results may differ from estimates and the financial statements do not include any adjustments that might be necessary if we are unable to fund operations.
	Reclassifications
	We have reclassified supplies inventory, net to other current assets in the accompanying consolidated balance sheet at December 31, 2012. This reclassification did not have any impact on our loss from operations or net loss for the year ended December 31, 2012 or on total assets as of December 31, 2012.
	We have reclassified certain costs associated with research and development activities, including all laboratory and clinical indirect costs, laboratory and clinical personnel stock compensations costs, and patent and product license amortization and patent impairment costs for the year ended December 31, 2012, and for the period from inception through December 31, 2012, from general and administrative expense to research and development expense in the accompanying consolidated statements of comprehensive loss. These reclassifications did not have any impact on our loss from operations or net loss for the year ended December 31, 2012, or for the period from inception through December 31, 2012.
	Both of the aforementioned classifications were made to conform to the current year presentation.
	Use of Estimates
	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Fair Value of Financial Instruments
	The carrying amount of certain of our financial instruments, including cash and cash equivalents, prepaid expenses, and accounts payable approximate fair value due to the short maturities of those financial instruments. The carrying amount of our debt at December 31, 2013 and 2012 approximated fair value because the interest rates and terms of our debt approximate market terms. In conjunction with the refinancing of our long term debt in May 2013, we held a warrant liability at December 31, 2013 that is required to be measured at fair value on a recurring basis (see Note 3).
	Our valuation of financial instruments is based on a three-tiered approach, which requires that fair value measurements be classified and disclosed in one of three tiers. These tiers are: Level 1, defined as quoted prices in active markets for identical assets or liabilities; Level 2, defined as valuations based on observable inputs other than those included in Level 1, such as quoted prices for similar assets and liabilities in active markets, or other inputs that are observable or can be corroborated by observable input data; and Level 3, defined as valuations based on unobservable inputs reflecting our own assumptions, consistent with reasonably available assumptions made by other market participants.
	Cash and Cash Equivalents
	We consider all interest-bearing investments due on demand and all highly liquid debt instruments purchased with a maturity of three months or less to be cash equivalents. Cash and cash equivalents included cash of $363 and $235 at December 31, 2013 and 2012, respectively. Cash and cash equivalents at December 31, 2013 and 2012 also included investments of $30.3 million and $14.5 million, respectively, in money market funds invested in U.S. Treasury securities with original maturities of less than three months. Cash deposits are held in federally insured financial institutions in the United States of America. We maintain cash in accounts which are in excess of federally insured limits.
	Restricted Cash
	Restricted cash consists primarily of funds invested in two certificates of deposit. One certificate of deposit serves as collateral for a lease of laboratory space. The other certificate of deposit serves as collateral for the Company’s corporate credit card. These certificates of deposit mature every seven days and renew weekly.
	Credit Risk
	Financial instruments which potentially subject the Company to concentrations of credit risk consist principally of cash and equivalents. The Company’s cash and equivalents were primarily invested in money market funds invested exclusively in treasury securities. Total cash and equivalent balances exceed insured balances by the Federal Depository Insurance Company.
	Limited Suppliers
	We do not have a manufacturing infrastructure and do not intend to develop one for the foreseeable future. We have agreements with third-party contract manufacturing organizations (“CMOs”), to supply bulk drug substances for our product candidates and with third parties to formulate, package and distribute our drug product candidates. Our employees include professionals with expertise in pharmaceutical manufacturing development who oversee the manufacture and distribution of our drug product candidates by third-party companies. We may not currently have sufficient amounts of REG1 on hand to complete enrollment in the REGULATE-PCI trial, however the Company is currently contracted to produce sufficient amounts of REG1 in early 2014. The Company may not have enough bivalirudin to complete REGULATE-PCI and may need to secure additional quantities to complete the trial. All of the drug substances used in our product candidates are manufactured by single suppliers. While we have not experienced any supply disruptions, the number of oligonucleotide manufacturers is limited. In the event it is necessary or advisable to acquire supplies from an alternative supplier, we might not be able to obtain them on commercially reasonable terms, if at all. It could also require significant time and expense to redesign our manufacturing processes to work with another supplier. Formulation and distribution of our finished drug product candidates are also conducted by a single supplier but we believe that alternative sources for these services are readily available on commercially reasonable terms (see Note 6).
	Segment and Geographic Information
	Operating segments are defined as components of an enterprise engaging in business activities for which discrete financial information is available and regularly reviewed by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company operates and manages its business as one operating segment and all of the Company’s operations were in North America during 2013.
	Clinical Trial Supplies
	We capitalize materials that will be used in our REG I clinical trial that also have an alternative future use in either ongoing or future clinical research and development projects. Clinical trial supplies may comprise material used to manufacture active pharmaceutical ingredients (“API”) used to develop our product candidates, in-process or completed API, in-process or completed unlabeled finished drug product and labeled finished drug product. Clinical trial supplies are stated at cost, using the first-in, first-out method (“FIFO”), and are reported in the accompanying consolidated balance sheets in other current assets. Clinical trial supplies that are determined to be unsuitable for future use are immediately expensed; otherwise clinical trial supplies are expensed when shipped to clinical sites for use in clinical studies or when used in other research and development projects.
	We utilize CMOs to produce API and finished drug product for use in clinical trials. As we do not have facilities that meet the requisite regulatory requirements for storage of API or finished drug product produced, we use a third-party facility for storage. Upon release from the manufacturer, API is shipped to a third-party storage facility. For production of finished drug product, API is shipped from the storage facility to the finished drug product manufacturing site. Unlabelled finished drug product is either shipped from the manufacturer back to the third-party storage facility or directly to the third-party labeling site. Labeled finished drug product is held by the third-party labeling site until it is shipped to the clinical sites for trial use.
	We do not have multiple sources of supply for the components of our finished drug product. If we are unable to obtain the supplies needed at a reasonable price or on a timely basis, it could have a material adverse effect on our ability to complete the development of our finished drug product.
	As of December 31, 2013 clinical trial supplies included in other current assets were $4.6 million, of which $1.6 million and $3.0 million represented API held at the third-party storage facility and drug product located at depots, respectively. As of December 31, 2012, clinical trial supplies included in other current assets were $4.5 million which represented API held at the third-party storage facility.
	Clinical Agreements
	We enter into various clinical trial agreements with academic research organizations (“AROs”) and clinical research organizations (“CROs”) for the planning, management and execution of clinical trials. The financial terms of these agreements are subject to negotiation, vary from contract to contract, and may result in uneven payment flows. The majority of our service providers invoice us monthly in arrears for services performed or when contractual milestones are met. Costs for ARO and CRO contracts are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations, or information provided by vendors on their actual costs incurred; such costs are charged to research and development expense in the accompanying consolidated statements of comprehensive loss. There may be instances in which payments made to our vendors will exceed the level of services provided and result in a prepayment of the research and development expense. Upfront contract signing fees are amortized over the life of the respective contract; unamortized contract signing fees are included in other non-current assets.
	In the accompanying consolidated balance sheet as of December 31, 2013, prepaid expenses include $1.1 million related to clinical agreements, and other non-current assets include $4.5 million of upfront payments of which $2.8 million will be applied to final invoices as required under the respective contract, and $1.7 million will be amortized as contract signing costs over the remaining life of the respective contract, or approximately three years.
	In general, our ARO and CRO service agreements permit either party to terminate at will, although we would continue to be responsible for payment of all services completed (or pro-rata completed) at the time of notice of termination, plus any non-cancellable expenses that have been entered into by the ARO and CRO on the Company’s behalf. Accordingly, such expenses would be accrued at time of contract termination and any prepaid expenses and unamortized advance payments would be expensed, accordingly.
	Value Added Taxes
	We are charged value added taxes on purchases, made on the Company’s behalf by a CRO, of certain clinical supplies from manufacturers in foreign jurisdictions. As of December 31, 2013, the Company had recorded $1,206 as a VAT receivable and $708 as a VAT liability in the accompanying consolidated balance sheet within other current assets and accrued expenses, respectively. There was $0 impact on our loss from operations or net loss for the year ended December 31, 2013 related to VAT.
	Property and Equipment
	Property and equipment consists primarily of laboratory and computer equipment and furniture, which are recorded at cost and depreciated using the straight-line method over their estimated useful lives, ranging from two to five years. Amortization for leasehold improvements is computed using the straight-line method over the estimated useful lives of the assets or over the term of the related leases, whichever is shorter.
	Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts, and any resulting gain or loss is credited or charged to income. Repairs and maintenance costs are expensed as incurred.
	Intangible Assets
	The Company’s policy is to file patent application(s) to protect technology, inventions and improvements that are considered important to the development of its business. The patent positions of technology companies, including the Company, are uncertain and involve complex legal and factual questions for which important legal principles are largely unresolved. Upon receipt of a patent grant; respective costs are amortized over the remaining life of the patent.
	The Company amortizes license agreements over the stated contractual life.
	Impairment of Long-lived Assets
	The Company recognizes impairment of long-lived assets in the event the net book value of such assets exceeds the estimated future undiscounted cash flows attributable to such assets. Accordingly, when indicators of impairment are present, the Company evaluates the carrying value of these assets in relation to the operating performance of the assets and the future undiscounted cash flows expected to result from the use of these assets. No such impairments have been recognized for the years ended December 31, 2013 and 2012, and for the period from inception to December 31, 2013, respectively, except for expense recognized for expired and abandoned patents totaling $371,000, $22,000 and $536,000 for the years ended December 31, 2013 and 2012, and for the period from inception to December 31, 2013, respectively. Such expenses are included in research and development expenses in the accompanying statements of comprehensive loss.
	Grant Revenue
	We were awarded several grants under the Therapeutic Discovery Project Grant program during 2010, related to research amounts previously expensed and have historically received modest other grant funding. The total amount recognized within Grant Revenue in the consolidated statement of comprehensive loss was $0 for the years ended December 31, 2013 and 2012, and $832 for the period from inception to December 31, 2013.
	Research and Development
	Research and development (“R&D”) expenses include direct and indirect R&D costs. Direct R&D consists principally of external costs, such as fees paid to investigators, consultants, central laboratories and clinical research organizations, including costs incurred in connection with our clinical trials, and related clinical trial fees and all employee-related expenses for those employees working in research and development functions, including stock-based compensation for R&D personnel. Indirect R&D costs include overhead costs related to facilities, depreciation, insurance, and small supplies are that not allocated to specific product candidates or indications. R&D costs are expensed as incurred.
	Stock-based Compensation
	In accordance with FASB ASC Topic 718, Stock Compensation, as modified or supplemented, we measure compensation cost for share-based payment awards granted to employees and non-employee directors at fair value using the Black-Scholes option-pricing model. We recognize compensation expense on a straight-line basis over the service period for awards expected to vest. Share-based compensation cost related to share-based payment awards granted to non-employees is adjusted each reporting period for changes in the fair value of our common stock until the measurement date. The measurement date is generally considered to be the date when all services have been rendered or the date that options are fully vested.
	Net Loss Per Share
	Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by dividing the net loss by the weighted-average number of common stock equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, options outstanding under our stock option plan and warrants.
	Recent Accounting Pronouncements
	Section 107 of the Jumpstart our Business Startups Act of 2012, or the JOBS Act, provides that an “emerging growth company” can take advantage of the extended transition period provided in Section 7(a)(2)(B) of the Securities Act of 1933, as amended, for complying with new or revised accounting standards. In other words, an “emerging growth company” can delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. However, we are choosing to “opt out” of such extended transition period, and as a result, we will comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth companies. Section 107 of the JOBS Act provides that our decision to opt out of the extended transition period for complying with new or revised accounting standards is irrevocable.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	3	Fair Value of Financial Instruments
	The following table (in thousands) sets forth our assets and liabilities that were measured at fair value on a recurring basis at December 31, 2013 and 2012 by level within the fair value hierarchy. As required by ASC 820-10, assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability.
			As of December 31, 2013									As of December 31, 2012
	Assets and Liabilities		Quoted Prices			Significant		Significant		Balance as of		Quoted Prices		Significant		Significant		Balance at
			In Active			Other		Unobservable		December 31,		In Active		Other		Unobservable		December 31,
			Markets for			Observable		Inputs		2013		Markets for		Observable		Inputs		2012
			Identical			Inputs		(Level 3)				Identical		Inputs		(Level 3)
			Assets			(Level 2)						Assets		(Level 2)
			(Level 1)									(Level 1)
	Assets:
	Money market funds		$	30,325		$	—	$	—	$	30,325	$	14,529	$	—	$	—	$	14,529
	Total assets at fair value		$	30,325		$	—	$	—	$	30,325	$	14,529	$	—	$	—	$	14,529
	Liabilities:
	Warrant liability		$	—		$	—	$	19	$	19	$	—	$	—	$	—	$	—
	Total liabilities at fair value		$	—		$	—	$	19	$	19	$	—	$	—	$	—	$	—
	The change in the fair value measurement using significant unobservable inputs (Level 3) is summarized below (in thousands):
	Balance at December 31, 2012		$	—
	Allocation of long-term debt proceeds to warrant			79
	Change in fair value recorded as interest income			(69	)
	Change in fair value recorded as interest expense			9
	Balance at December 31, 2013		$	19
	The warrant liability represents our allocation of a portion of the proceeds from the May 2013 Comerica Loan (as defined in Note 8). The allocation of the proceeds from the Comerica Loan was based on the fair value of the warrant liability on the date of grant. We accounted for the warrant liability in accordance with ASC Topic 815, Derivatives and Hedging, which requires that equity contracts not indexed to the issuer’s own stock and not meeting the definition of a derivative should be reported as an asset or liability. We utilized the Binomial pricing model to determine the fair value of the warrant liability. We record changes in the fair value of the warrant liability as interest expense or interest income, as applicable.
	We used significant assumptions in estimating the fair value of the warrant liability including the estimated volatility, risk free interest rate, estimated fair value of the preferred shares, and the estimated life of the warrant. These assumptions were used to establish an expected set of cash flows which were probability-weighted and discounted to present value to determine a fair value.

Property_and_Equipment_Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2013
Property Plant And Equipment [Abstract]	'
Property and Equipment, Net	'
	4	Property and Equipment, net
	Property and equipment consist of the following (in thousands):
			As of December 31,
			2013			2012
	Leasehold improvements		$	333		$	325
	Computer equipment and software			184			145
	Laboratory equipment			1,775			1,775
	Furniture and equipment			27			27
	Less – Accumulated depreciation			(2,211	)		(2,207	)
	Property and equipment, net		$	108		$	66
	Depreciation expense for the years ended December 31, 2013 and 2012, and for the period from inception to December 31, 2013, was $61, $42, and $2,395, respectively.

Intangibles

Intangibles	12 Months Ended
	Dec. 31, 2013
Goodwill And Intangible Assets Disclosure [Abstract]	'
Intangibles	'
	5	Intangibles
	The following information details the carrying amounts and accumulated amortization of our intangible assets subject to amortization (in thousands):
			As of December 31, 2013									As of December 31, 2012
			Weighted		Gross		Accumulated			Net		Gross		Accumulated			Net
			Average		Carrying		Amortization			Carrying		Carrying		Amortization			Carrying
			Useful Life		Amount					Amount		Amount					Amount
			Remaining
	Identifiable intangible assets:
	Patents			8.0 years	$	1,518	$	(383	)	$	1,135	$	1,607	$	(349	)	$	1,258
	Product licenses			2.0 years		1,555		(1,424	)		131		1,547		(1,439	)		108
	Total			7.8 years	$	3,073	$	(1,807	)	$	1,266	$	3,154	$	(1,788	)	$	1,366
	Expected future amortization expenses for intangible assets as of December 31, 2013 are as follows:
	For the year ending December 31:		Amount
	2014		$	137
	2015			128
	2016			128
	2017			128
	2018			128
	Thereafter			617
			$	1,266
	We record amortization of patent and product license costs in research and development expense in the accompanying consolidated statements of comprehensive loss.
	Patents
	Patent costs consist of expenditures incurred for various patent applications. As of December 31, 2013 and 2012, we had $557,000 and $405,000, respectively, of costs related to patents not subject to amortization as they have yet to be granted.
	Product Licenses
	We have primary license agreements with Duke University, Archemix Corporation, and Nektar Therapeutics AL and all of the licenses are being amortized over the stated contractual life.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Commitments	'
	6	Commitments
	Supply and Manufacturing Agreements
	We have agreements with CMOs, to supply bulk drug substances for our product candidates and with third parties to formulate, package and distribute our drug product candidates (see Note 2—Limited Suppliers).
	In July 2006, we entered into a supply and service agreement with Agilent Technologies, Inc., which was amended in July 2011, for the manufacture of pegnivacogin and anivamersen bulk drug substance for use in the clinical development of REG1. Drug substances are manufactured pursuant to a Good Manufacturing Practices and a Quality Agreement entered into in May 2010. Manufacture of bulk drug substance lots is on a purchase order basis, with no minimum purchase obligation.
	In December 2006, we entered into a license, manufacturing and supply agreement with Nektar Therapeutics, or Nektar, for the supply of polyethylene glycol, or PEG, used in the manufacture of pegnivacogin. We must provide Nektar with a rolling forecast of our anticipated requirements for the succeeding six quarters, with respect to precommercial supply, or eight quarters, with respect to commercial supply, with a required lead time to commit to and guarantee availability of the reagent at an agreed upon pricing structure, which is subject to revision on an annual basis. In addition, we have agreed to pay Nektar specific development and commercial milestones and a specific royalty on product sales (see Milestone and Other Obligations below).
	In March 2012, we entered into a clinical supply agreement with Althea Technologies, Inc., for the formulation and primary packaging of pegnivacogin and anivamersen for use in our clinical trials. Drug products are manufactured and the packaging is conducted pursuant to a Good Manufacturing Practices and a Quality Agreement entered into in January 2012. Formulation and packaging services are provided on a purchase order basis, with no minimum purchase obligation.
	Clinical Agreements
	We have various clinical trial agreements with AROs and CROs for the planning, management and execution of clinical trials. The financial terms of these agreements are subject to negotiation, vary from contract to contract, and may result in uneven payment flows. These contracts generally provide for termination on notice (see Note 2—Clinical Agreements).
	Milestone and Other Obligations
	Upon the commencement of our REGULATE-PCI trial which occurred in September 2013, we were obligated to make milestone payments of $500,000 to Duke University (“Duke”), and $1.0 million to Archemix Corporation, (“Archemix”). We have paid $500,000 of such milestone obligations and the $1.0 million remaining balance is included in accrued expenses in the accompanying consolidated balance sheet as of December 31, 2013; accordingly, aggregate milestone obligations of $1.5 million are included in research and development expense in the accompanying statement of comprehensive loss for the year ended December 31, 2013. In addition, upon the filing of a new drug application, we are obligated to make additional milestone payments to Duke, Archemix and Nektar Therapeutics AL, Corporation. Given the uncertainty of the drug development process, we cannot be certain when, if ever, we will be required to make these milestone payments.
	As a condition of closing the Series E Preferred Stock financing in December 2012, we assigned all intellectual property (“IP”) rights and titles in Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine and Uzbekistan ( the “Covered Territory”) to Domain Russia Investments Limited (“DRI”). Additionally, we agreed to assist an affiliate of DRI with certain development support related to the development of the IP. Concurrently with the signing of this agreement, we agreed to make a payment to DRI up to a maximum amount of $1.2 million based on an independent appraiser’s valuation of the IP rights transferred. Such independent appraiser’s valuation was received during 2013, the result of which confirmed that we do not have any further obligation pursuant to this agreement.
	We may be required to pay to Nektar an aggregate of $7.75 million upon the achievement of specified development and regulatory approval milestones. Since December 2006, we made payments under this license agreement totaling $1.25 million which are included in research and development expense in the accompanying statement of comprehensive loss for the period from inception to December 31, 2013.
	We also are required to pay Nektar royalties based on a percentage of net sales of our REG1 product by us or our sublicensees. The percentage royalty rates are in the mid-single digits, and are subject to reduction with respect to sales in a country if none of the patents and patent applications that we license under the agreement cover REG1 or the PEG in such country. These royalties also may be reduced if we are required to pay royalties to a third party due to infringement relating to the PEG. The duration of our royalty obligation expires on a country-by-country basis on the later of ten years after first commercial sale of REG1 in a country and the expiration of the last-to-expire of the licensed patent rights in such country.
	License Agreements
	In December 2012, in connection with its Series E Preferred Stock financing, we entered into a Technology Transfer Agreement, (the “Tech Transfer Agreement”), with DRI. In accordance with the terms of the Tech Transfer Agreement, in May 2013 we entered into a Clinical Development and Collaboration Agreement with NovaMedica pursuant to which we agreed to assist NovaMedica in the development and commercialization of our product candidates in the Covered Territory, as defined. NovaMedica is required to reimburse us for any out-of-pocket expenses incurred by us in providing this assistance, including travel-related expenses.
	Operating Leases
	We maintain three separate office locations. On May 1, 2013, we entered into a lease agreement for 1,657 square feet of administrative office space located in Durham, North Carolina (the “Durham Office Lease”). The lease is for 36 months with annual lease obligations of $39,000, $40,000 and $41,000 for years one through three, respectively. We had rented an administrative office space in Cary, North Carolina under an operating lease agreement effective December 2012, with base monthly payments at $2,000 per month. The six month lease expired in May 2013 and was replaced with the Durham Office Lease. In April 2007, we entered into an operating lease for 8,495 square feet of laboratory space in Durham, North Carolina. The lease expired July 31, 2012 and subsequent thereto we were on a month-to-month basis with base rent of $11,000 per month. In December 2013 the Company signed a new one year lease for such space with base rent of approximately $13,000 per month. An initial letter of credit of $115,000 was given to the lessor for use of the facility, and the letter of credit was reduced to $46,000 on the fourth anniversary date of the lease. In November 2008, an operating lease was entered into for corporate headquarters in Basking Ridge, New Jersey. The lease expired on November 1, 2011 and is currently on a month-to-month basis. Monthly payments are fixed at $16,000 per month, with an additional $1,000 per month due for utilities.
	Rent expense related to operating leases was $464,000 and $498,000 for the years ended December 31, 2013 and 2012, respectively, and $2.9 million for the period from inception to December 31, 2013.
	Future minimum aggregate payments under non-cancelable lease obligations as of December 31, 2013 are as follows (in thousands):
	For the year ending December 31:		Amount
	2014		$	187
	2015			37
	2016			12
	Total minimum lease payments		$	236
	Severance
	Selected executive employees of ours have employment or severance agreements which provide for severance payments of up to two times base salary, bonuses and benefits upon termination, depending on the reasons for the termination. Certain other employees of ours have employment or severance agreements which generally provide for six months of severance, including base salary, bonuses and benefits upon termination, depending on the reasons for the termination. All employees would be required to execute a release and settlement agreement.
	Effective September 26, 2013, we reduced our workforce by eliminating 5 of our 32 full-time employees. The majority of the affected employees worked in drug discovery roles at our laboratory facility in North Carolina. The goal of our reduction in workforce was to enable us to focus management and financial resources on advancing our lead product candidate, REG1, in our REGULATE-PCI trial. In connection with the reduction in workforce, severance expense of approximately $250,000 was charged to research and development expense in the accompanying consolidated statement of comprehensive loss for the year ended December 31, 2013.
	In connection with the termination of an executive officer effective as of December 31, 2013, accrued severance expense of $417,000 was recorded and charged to general and administrative expense in the accompanying consolidated statement of comprehensive loss for the year ended December 31, 2013.

Accrued_Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2013
Payables And Accruals [Abstract]	'
Accrued Expenses	'
	7	Accrued Expenses
	The components of accrued expenses are as follows (in thousands):
			As of December 31,
			2013		2012
	Accrued license milestones		$	1,000	$	—
	Accrued obligations under clinical contracts			1,957		—
	Accrued legal and professional services			152		14
	Accrued VAT expenses			780		—
	Accrued interest			24		40
	Accrued compensation and benefits			1,225		478
	Accrued expenses, other			386		254
	Total accrued expenses		$	5,524	$	786

Longterm_Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Long-term Debt	'
	8	Long-term Debt
	In May 2011, we entered into a loan and security agreement with MidCap Financial SBIC, LP pursuant to which we borrowed a total of $6.0 million, at the stated rate of LIBOR, at a 2% rate floor, plus 8% spread per annum. The loan was payable in monthly installments beginning September 2012 through August 2014. Our assets (including intellectual property) were collateral for the borrowings, and we were required to pay a 3% final payment of $180,000 regardless of when the loan was paid in full.
	On May 13, 2013, we secured a venture debt loan with Comerica Bank (the “Comerica Loan”). We borrowed $4.5 million (“Tranche One”), and the proceeds of the loan were utilized to repay all amounts due to MidCap Financial SBIC, LP. The Comerica Loan bears interest at Comerica’s Prime Reference Rate (as defined in the Loan Agreement) subject to a floor of 30 day LIBOR plus 250 basis points plus 4.0%, or 7.25% as of December 31, 2013. The terms allow for an interest only period of 15 months, and the remaining principal and interest will be repaid starting September 2014 over a nine-month period (24 months in total). Maturities for 2014 and 2015 are $2.0 million and $2.5 million, respectively. Upon (i) Comerica’s receipt of evidence satisfactory to Comerica that the 1,000 patient interim analysis in the REGULATE-PCI study is successful and performed by April 30, 2014 and (ii) our completion of the IPO and receipt of net proceeds of at least $50.0 million prior to June 30, 2013, we had the option to borrow an additional $4.0 million in the second tranche, or (“Tranche Two”). Since the latter of the Tranche Two conditions was not satisfied, Tranche Two is solely at the discretion of Comerica.
	Interest expense recorded related to the Comerica Loan was $346,000 and $0 for the years ended December 31, 2013 and 2012, respectively, and $346,000 for the period from inception to December 31, 2013. Interest expense recorded related to the MidCap Loan was $325,000 and $559,000 for the years ended December 31, 2013 and 2012, respectively, and $1.1 million for the period from inception to December 31, 2013
	In connection with the funding of Tranche One, we issued to Comerica a warrant to purchase 156,250 shares of the Series E Preferred Stock at a price of $0.72 per share, or the Warrant Price, subject to adjustment for stock splits, combinations, reclassifications or exchanges and certain dilutive issuances. After giving effect to our IPO and reverse stock split, the warrant was adjusted to a warrant to purchase 9,356 shares of our common stock at a price of $12.02 per share (see Note 3).
	If we had borrowed the additional $4.0 million in Tranche Two, the warrant would have become exercisable for an additional number of shares of the Series E Preferred Stock equal to 100,000 divided by the Warrant Price, as defined, subject to adjustment for stock splits, combinations, reclassifications or exchanges and certain dilutive issuances. As previously noted, as we did not complete an IPO by the required milestone date, Tranche Two is solely at the discretion of Comerica.
	Scheduled maturities of long-term debt are as follows (in thousands):
			December 31,
			2013
	Year ending December 31:
	2014		$	2,000
	2015			2,500
	Total		$	4,500
	Less: unamortized discount			(103	)
	Less - current portion			(2,000	)
	Plus - fees due at closing(1)			55
	Long-term debt, net		$	2,452
	-1	On the date that all of the principal and interest of the Comerica Loan become due and payable, we must pay an end of term fee of $173,000 (the “Final Fee”). The Final Fee is being accreted to interest expense over the term of the Comerica Loan.
	Included in the consolidated balance sheets within long-term debt are $85,000 in loan origination costs that are being amortized to interest expense over the remaining life of the Comerica Loan using the effective interest rate method.
	In accounting for the Comerica Loan, the loan was separated into debt and warrant liability components. We utilized the Binomial pricing model to determine the fair value of the warrant liability component (see Note 3). The carrying amount of the debt component was determined by deducting the fair value of the warrant liability component from the par value of the Comerica Loan as a whole. The excess of the principal amount of the Comerica Loan component over its carrying amount, referred to as the debt discount, is amortized to interest expense over the term of the loan. The warrant liability component is re-measured at each reporting date and changes in the fair value of the warrant liability are recorded as interest expense or interest income, as applicable.
	In accounting for the transaction costs related to the issuance of the Comerica Loan, we allocated the total costs incurred to the debt and warrant liability components of the Comerica Loan based on their relative values. Transaction costs attributable to the debt component are amortized to interest expense over the term of the Comerica Loan, and transaction costs attributable to the warrant liability component were immediately expensed.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Stockholders' Equity	'
	9	Stockholders’ Equity (in thousands except share and per share amounts)
	IPO
	We completed our initial public offering (“IPO”) in August 2013. Inclusive of the underwriters’ exercise of the over-allotment option in connection with the IPO in September 2013, we issued 11,671,500 shares of common stock, at a price of $4.00 per share, resulting in net proceeds to us of approximately $41.1 million after deducting underwriting discounts of $3.3 million and offering costs of $2.3 million.
	Pre IPO Common and Preferred Stock Authorized Shares
	Prior to the IPO the Company was authorized to issue two (2) classes of shares to be designated, respectively, “Pre-IPO Common Stock” and “Pre-IPO Preferred Stock.” The total number of shares of capital stock that the Company was authorized to issue was 698,363,299 shares. The total number of shares of Pre-IPO Common Stock the Company was authorized to issue was 500,000,000 shares, $0.001 par value per share. The total number of shares of Preferred Stock the Company was authorized to issue was 198,363,299 shares, $0.001 par value per share, of which (a) 5,798,178 shares were to be designated Series A Preferred Stock (the “Series A Preferred Stock”); (b) 16,666,665, shares were to be designated Series B Preferred Stock (the “Series B Preferred Stock”); (c) 17,037,037 shares were to be designated Series C Preferred Stock (the “Series C Preferred Stock”), (d) 71,666,667 shares were to be designated Series D Preferred Stock (the “Series D Preferred Stock”), and (e) 87,194,752 shares were to be designated Series E Preferred Stock (the “Series E Preferred Stock,” and together with the Series A Preferred Stock, the Series B Preferred Stock, the Series C Preferred Stock, and the Series D Preferred Stock, the “Pre-IPO Preferred Stock”).
	During the period from inception to December 31, 2011, the Company issued an aggregate of 111,169 shares of Series A, B, C and D Preferred Stock for aggregate proceeds of $99,897, net of issuance costs of $501.
	On December 18, 2012, the first tranche of the Series E financing was completed with 31,437,442 preferred shares issued for $22.6 million. This included $15.5 million in cash plus $6.8 million in convertible loan principal and $339,000 in converted loan interest originally secured on May 3, 2012.
	Per the Series E Preferred Stock financing agreement executed on December 18, 2012, a second financing tranche of $10.3 million for 14,320,168 shares of Series E Preferred Stock took place on March 22, 2013. On March 22, 2013 a portion of the second tranche of the Series E financing was completed with 7,160,084 preferred shares issued for $5.2 million. The RMI Investments, S.a.r.l (“RMI”) portion of the second tranche totaling $5.2 million was delivered into an escrow account at the time of the second tranche, and the RMI funds and Series E shares relating to the RMI investment were released on April 26, 2013.
	The agreement also provided that a third financing tranche of $17.8 million for 24,770,476 shares of Series E preferred stock would take place on or before January 17, 2014. However, pursuant to the terms of a Termination Agreement entered into by the parties to the Series E Purchase Agreement, our obligation to sell additional shares of Series E Preferred Stock to the investors and the obligations of the investors to purchase additional shares of Series E Preferred Stock terminated immediately prior to the consummation of the IPO and no additional shares of Series E Preferred Stock will be sold pursuant thereto.
	Reverse Stock Split
	In May 2013, we executed an amendment to our Fifth Amended and Restated Certificate of Incorporation instituting a one–for-16.7 reverse split of common stock and an increase in the number of shares of common stock we are authorized to issue to 500,000,000.
	Post IPO Common and Preferred Stock Authorized Shares
	Pursuant to the IPO all shares of Series Preferred Stock then outstanding automatically converted into an aggregate of 9,396,767 shares of common stock.
	Effective with the IPO, pursuant to the Company’s Sixth Amended and Restated Certificate of Incorporation (the “Restated Certificate”) the Company is authorized to issue two (2) classes of shares to be designated, respectively, “Common Stock” and “Preferred Stock.” The total number of shares of capital stock that the Company is authorized to issue is 501,000,000 shares of capital stock, of which (i) 500,000,000 shares are designated as common stock, par value $0.001 per share (the “Common Stock”), and (ii) 1,000,000 shares are class designated as preferred stock, par value $0.001 per share. (the “Preferred Stock”).
	Each holder of record of Common Stock shall have one vote for each share of Common Stock which is outstanding in his, her or its name on the books of the Corporation on all matters on which stockholders are entitled to vote generally. Except as otherwise required by law, holders of Common Stock shall not be entitled to vote on any amendment to the Restated Certificate (including any certificate of designation relating to any series of Preferred Stock) that relates solely to the terms of one or more outstanding series of Preferred Stock if the holders of such affected series are entitled, either separately or together with the holders of one or more other such series, to vote thereon pursuant to the Restated Certificate (including any certificate of designation relating to any series of Preferred Stock) or pursuant to the General Corporation Law of the State of Delaware. Except as otherwise required by law, holders of any series of Preferred Stock shall be entitled to only such voting rights, if any, as shall expressly be granted thereto by the Restated Certificate (including any certificate of designation relating to such series of Preferred Stock).
	Subject to applicable law and the rights, if any, of the holders of any outstanding series of Preferred Stock or any class or series of stock having a preference over or the right to participate with the Common Stock with respect to the payment of dividends, dividends may be declared and paid or set apart for payment upon the Common Stock out of any assets or funds of the Corporation legally available for the payment of dividends, but only when and as declared by the Board of Directors or any authorized committee thereof.
	Upon the dissolution, liquidation or winding up of the Company, after payment or provision for payment of the debts and other liabilities of the Company and subject to the rights, if any, of the holders of any outstanding series of Preferred Stock or any class or series of stock having a preference over or the right to participate with the Common Stock with respect to the distribution of assets of the Company upon such dissolution, liquidation or winding up of the Company, the holders of Common Stock shall be entitled to receive the remaining assets of the Company available for distribution to its stockholders ratably in proportion to the number of shares held by them.
	The Board of Directors is authorized, by resolution or resolutions, to provide, out of the unissued shares of Preferred Stock, for one or more series of Preferred Stock and, with respect to each such series, to fix the number of shares constituting such series and the designation of such series, and the powers (including voting powers, if any), preferences and relative, participating, optional and other special rights, if any, and any qualifications, limitations or restrictions thereof, of the shares of such series of Preferred Stock. The powers, preferences and relative, participating, optional and other special rights of, and the qualifications, limitations or restrictions thereof, of each series of Preferred Stock, if any, may differ from those of any and all other series at any time outstanding.
	Warrants
	See Notes 3 and 8 regarding our issuance of a warrant for Series E Preferred Stock in connection with obtaining the Comerica Loan. As of December 31, 2013 and 2012, we had 16,332 and 20,449 warrants outstanding, respectively, that were exercisable into common shares at a weighted average price of $6.96 and $0.17 per share, respectively, at the option of the warrant holder. During the year ended December 31, 2013, a warrant for 13,473 shares of common stock was exercised at an exercise price of $0.17.

Stock_Based_Compensation

Stock Based Compensation	12 Months Ended
	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock Based Compensation	'
	10	Stock Based Compensation
	Equity Compensation Plans
	The 2013 Equity Compensation Plan (the “2013 Plan”) adopted by our Board of Directors in May 2013, became effective upon consummation of the IPO in August 2013. There are 3,342,839 common shares authorized for future issuance under the 2013 Plan of which 94,862 were available as of December 31, 2013. Upon effectiveness of the 2013 Plan, stock options outstanding under the 2004 Equity Compensation Plan (the “2004 Plan”) to acquire 1,406,910 shares of our common stock were assumed under the 2013 Plan, leaving stock options to acquire 34,342 shares of our common stock outstanding under the 2004 Plan. There will be no further awards made under the 2004 Plan.
	The 2013 Plan includes an “evergreen provision” that allows for an annual increase in the number of shares of common stock available for issuance under the 2013 Plan. The annual increase will be added on the first day of each fiscal year starting January 1, 2014, inclusive, and will be equal to five percent of the total number of shares of Common Stock outstanding on December 31st of the preceding calendar year as determined by the board of directors (the Board). The Board may act prior to the first day of any calendar year, to provide that there shall be no increase in the share reserve for such calendar year or that the increase in the share reserve for such calendar year shall be a lesser number of shares of Common Stock than would otherwise occur. On January 1, 2014 another 1,065,530 options became available for grant under this evergreen provision.
	Stock Options
	We use the Black-Scholes-Merton option pricing model to determine the fair value of our stock options. The determination of the fair value of stock-based payment awards on the date of grant using an option pricing model is affected by our stock price, as well as assumptions regarding a number of complex and subjective variables. These variables include our expected stock price volatility over the term of the awards, risk-free interest rate, actual employee exercise behaviors and expected dividends.
	The following table shows the weighted average assumptions used to value stock options on the date of grant, as follows:
			Year ended December 31,
			2013						2012						Period from Inception
															(December 19, 2001) to
															December 31, 2013
			Employee			Non-Employees			Employee			Non-Employees			Employee			Non-Employees
	Expected stock price volatility			46.9	%		45.3	%		44	%		44	%		44.08	%		41.13	%
	Risk-free interest rate			1.04	%		0.37	%		1.38	%		1.38	%		1.64	%		1.21	%
	Expected life of option (in years)			3.69			2			6.25			6.25			4.44			3.38
	Estimated dividend yield			0	%		0	%		0	%		0	%		0	%		0	%
	Weighted-average grant date fair value per share			1.91			1.49			1.67			1.67			2.32			1.99
	Expected stock price volatility was calculated based on the weighted-average of historical information of similar public entities. We will continue to use a weighted-average approach using other similar public entities’ volatility information until our historical volatility is relevant to measure expected volatility for future option grants. The risk-free rate was based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected life assumption. The average expected life was determined based on anticipated exercise strategy and cancellation behavior for employees and nonemployees, primarily non-employee directors. Effective in 2013, a forfeiture rate of 1% and 0% was used for employees and nonemployees, respectively. We have not paid and do not anticipate paying cash dividends; therefore, the expected dividend rate was assumed to be 0%.
	The following table summarizes our aggregate Equity Compensation Plan activity:
			Number of			Weighted Average			Weighted Average			Aggregate
			Options			Exercise Price			Contractual Term			Intrinsic Value(1)
									(in years)
	Outstanding – December 31, 2012			1,409,659
	Granted			1,965,696
	Exercised			(7,602	)
	Forfeited			(56,623	)
	Expired			(38,283	)
	Outstanding – December 31, 2013			3,272,847		$	5.38			7.87		$	2,420,963
	Exercisable – December 31, 2013			1,386,653		$	6.98			5.43		$	800,721
	Vested and expected to vest at December 31, 2013(2)			3,255,969		$	5.39			7.86		$	2,403,403
	-1	Intrinsic value is the excess of the fair value of the underlying common shares as of December 31, 2013 over the weighted-average exercise price.
	-2	The number of stock options expected to vest takes into account an estimate of expected forfeitures.
	The total intrinsic value of options exercised during 2013 and 2012, and for the period from inception to December 31, 2013, was $11,000, $0 and $82,000, respectively.
	The following table summarizes certain information about all options outstanding as of December 31, 2013:
			Options Outstanding						Options Exercisable
	Exercise Price		Options			Weighted Average			Options			Weighted Average
			Outstanding			Remaining			Exercisable			Remaining
						Contractual Life						Contractual Life
						(Years)						(Years)
	$1.67-$3.84			334,921			5.8			254,829			5
	$4.00			1,366,760			9.6			4,256			1
	$4.51-$4.81			951,961			7.8			626,455			6.7
	$4.87-$12.53			619,205			5.2			501,113			4.1
				3,272,847			7.9			1,386,653			5.4
	Stock-Based Compensation Expense
	Total stock-based compensation expense recognized based on the total grant date fair value of options vested and expected to vest was approximately $988,000 and $703,000 for the years ended December 31, 2013 and 2012, respectively, and $5.6 million for the period from inception to December 31, 2013. Due to the valuation allowance against our net deferred tax asset, we have never recognized a tax benefit for stock based compensation.
	All stock options issued to nonemployees have been recorded at fair value. Options issued to nonemployees in exchange for services have resulted in expenses of $59,000, $38,000, and $156,000 during the years ended December 31, 2013 and 2012 and for the period from inception to December 31, 2013, respectively.
	As of December 31, 2013, approximately $2.9 million of total unrecognized compensation cost related to unvested share options is expected to be recognized over a weighted-average period of 2.8 years.

Employee_Benefit_Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2013
Postemployment Benefits [Abstract]	'
Employee Benefit Plan	'
	11	Employee Benefit Plan
	In 2006, the Company adopted the Regado Biosciences 401k Plan (the Plan). The Plan allows eligible employees to defer up to 87% of their compensation, up to allowable Internal Revenue Service limits. Effective December 19, 2013 the Company elected to match participant elective deferrals in an amount equal to 50% of such elective deferrals up to 3% of each participant’s total compensation for the Plan Year. The Company also declared a retroactive match for the year ended December 31, 2013. The Company’s aggregate 401K match expense for the year ended December 31, 2013 was $87,813.
	The Company has a Special Incentive Plan that provides for retention bonuses to be granted to certain participants in the event of a change of control.
	Effective upon the consummation of the IPO, the Company adopted an Employee Stock Purchase Plan (the “ESPP”). Upon effectiveness, up to 96,360 shares of the Company’s common stock may be issued pursuant to the ESPP. There were no shares outstanding under this ESPP as of December 31, 2013.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	12	Income Taxes
	Significant components of the Company’s deferred income tax assets and liabilities at December 31, 2013 and 2012, consisted of the following (in thousands):
			2013			2012
	Deferred income tax assets:
	Net operating loss carryforwards		$	53,436		$	41,886
	Property and equipment			136			121
	Stock-based compensation expense			661			391
	Accruals			1,220			—
	Other			44			221
	Valuation allowance for deferred income tax assets			(54,999	)		(41,997	)
	Net deferred income tax assets			498			622
	Deferred income tax liabilities:
	Patent costs			(498	)		(622	)
	Net deferred income taxes		$	—		$	—
	At December 31, 2013 and 2012, the Company provided a full valuation allowance against its net deferred income tax assets, as management has assessed that the realization of these benefits is not more-likely-than-not. The change in the valuation allowance is primarily attributable to additional net operating loss carryforwards from current year activity.
	The differences between the statutory rate and the effective rate are due to the valuation allowance and other permanent differences, as shown in the table below (dollars in thousands):
			2013						2012
			Tax			Rate			Tax			Rate
	Rate Reconciliation
	Tax at statutory rate		$	(12,054	)		35	%	$	(4,572	)		35	%
	Incentive stock options			148			(0.4	)%		248			(1.9	)%
	State taxes			(1,378	)		4	%		(522	)		4	%
	Change in valuation allowance			13,002			(37.8	)%		4,846			(37.1	)%
	Other			282			(0.8	)%		—			0	%
	Income tax expense reported		$	—			0	%	$	—			0	%
	As of December 31, 2013, the Company had estimated federal and state operating loss carry forwards of $137.0 million. These federal and state operating loss carry forwards begin to expire in 2022 and 2017, respectively. The utilization of the federal net operating loss carry forwards may be subject to limitations under the rules regarding a change in stock ownership as determined by the Internal Revenue Code, and state laws. Section 382 of the Internal Revenue Code of 1986, as amended, imposes annual limitations on the utilization of net operating loss (“NOL”) carry forwards, other tax carry forwards, and certain built-in losses upon an ownership change as defined by that section. In general terms, an ownership change may result from transactions that increase the aggregate ownership of certain stockholders in the Company stock by more than 50 percentage points over a three year testing period (“Section 382 Ownership Change”). If the Company has undergone a Section 382 Ownership change, an annual limitation would be imposed on certain of the Company’s tax attributes, including NOL and capital loss carry forwards, and certain other losses, credits, deductions of tax basis. As of December 31, 2013, the Company has not performed a formal study to determine whether there are Section 382 limitations that apply.
	The Company recognizes the financial statement benefit of a tax position only after determining that the relevant tax authority would more-likely-than-not sustain the position following an audit. For tax positions meeting the more-likely-than-not threshold, the amount recognized in the financial statements is the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement with the relevant tax authority. As of the end of 2013 or 2012, the Company did not record a liability for uncertain tax positions because no material positions existed.
	The Company did not have any accrued interest or penalties associated with any unrecognized tax positions at December 31, 2013, and there were no such interest or penalties recognized during the period since inception through December 31, 2013.

Net_Loss_Per_Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Net Loss Per Share	'
	13	Net Loss Per Share
	The following table presents the computation of basic and diluted net loss per common share (in thousands, except share and per share data):
			Years ended December 31,
			2013			2012
	Net loss attributable to common shareholders		$	(34,439	)	$	(13,062	)
	Weighted average common shares outstanding, basic and diluted			7,499,661			221,272
	Net loss per share attributable to common shareholders, basic and diluted		$	(4.59	)	$	(59.03	)
	For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to our net loss position. Securities that may potentially dilute earnings per share in the future that have not been included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common equivalent shares):
			Years ended December 31,
			2013			2012
	Convertible preferred stock			—			8,539,257
	Common stock options			3,272,847			1,409,659
	Warrants			16,332			20,449
	Total			3,289,179			9,969,365
	In August 2013, all convertible preferred stock converted into common stock in conjunction with the consummation of our IPO. As of December 31, 2013 and 2012, we had 16,332 and 20,449 of warrants outstanding, respectively, that were exercisable into common shares at a weighted average price of $6.96 and $0.17 per share, respectively, at the option of the warrant holder.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	14	Subsequent Events
	2014 Private Placement
	In 2014, we sold 4,000,000 shares of our common stock at a purchase price of $5.00 per share to certain accredited and institutional investors (the “2014 Private Placement”). The net proceeds of approximately $ 18.7 million from this offering will be used for general corporate and working capital purposes, including the ongoing Phase 3 REGULATE-PCI clinical trial.
	Related Party Transactions
	Purchasers of securities pursuant to the 2014 Private Placement included Robert Kierlin and Biotechnology Value Fund, LP, or BVF, LP each a holder of more than 5% of our capital stock. Mr. Kierlin purchased 400,000 shares of our common stock for an aggregate purchase price of $2.0 million. BVF, LP, purchased 2,000,000 shares of our common stock for an aggregate purchase price of $10.0 million.

Basis_of_Presentation_and_Summ1

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Principles of Consolidation and Basis of Presentation	'
	Principles of Consolidation and Basis of Presentation
	In March 2013, we incorporated Regado Biosciences Europe Limited, a wholly owned subsidiary registered in England and Wales, in order to establish a legal presence in the European Union (EU) for the purpose of conducting clinical trials in the EU. Regado Biosciences Europe Limited had no operations during the year ended December 31, 2013.
	The accompanying consolidated financial statements include the accounts of Regado Biosciences, Inc. and its wholly owned subsidiary, Regado Biosciences Europe Limited. There were no significant intercompany accounts or transactions that needed to be eliminated in consolidation. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). All intercompany balances and transactions have been eliminated in consolidation.
Going Concern Uncertainty	'
	Going Concern Uncertainty
	Our financial statements have been prepared on a going-concern basis, which contemplates the realization of assets and settlement of liabilities and commitments in the normal course of business. Operations since inception have consisted primarily of developing and acquiring product technologies and securing financing.
	The accompanying financial statements have been prepared assuming that we will operate as a going concern. We have suffered negative cash flows from operating activities of $34.7 million during the year ended December 31, 2013 and a net accumulated deficit of $145.0 million since inception as of December 31, 2013. Prior to our IPO, we were funded primarily through the issuance of preferred stock and debt. We will require additional capital until such time that we can generate operating revenue in excess of operating expenditures. Our plans include continued product development and a move toward completion of clinical trials. We will continue to closely monitor and analyze expenses and make adjustments as necessary to prioritize business operations. We believe that the net proceeds from the IPO and from our 2014 Private Placement pursuant to which we sold $20 million of our common stock to new and existing investors (see Note 14 - Subsequent Events), will be sufficient for us to fund the REGULATE-PCI trial through the second interim analysis, which we expect will occur in the third quarter of 2014. We will need to raise additional financing in the first half of 2014 to fund projected operations through 2014 and we can provide no assurances that such additional financing will be available on favorable terms, or at all. Actual results may differ from estimates and the financial statements do not include any adjustments that might be necessary if we are unable to fund operations.
Reclassifications	'
	Reclassifications
	We have reclassified supplies inventory, net to other current assets in the accompanying consolidated balance sheet at December 31, 2012. This reclassification did not have any impact on our loss from operations or net loss for the year ended December 31, 2012 or on total assets as of December 31, 2012.
	We have reclassified certain costs associated with research and development activities including all laboratory and clinical indirect costs, laboratory and clinical personnel stock compensations costs, and patent and product license amortization and patent impairment costs for the year ended December 31, 2012, and for the period from inception through December 31, 2012, from general and administrative expense to research and development expense in the accompanying consolidated statements of comprehensive loss. These reclassifications did not have any impact on our loss from operations or net loss for the year ended December 31, 2012, or for the period from inception through December 31, 2012.
	Both of the aforementioned classifications were made to conform to the current year presentation.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	The carrying amount of certain of our financial instruments, including cash and cash equivalents, prepaid expenses, and accounts payable approximate fair value due to the short maturities of those financial instruments. The carrying amount of our debt at December 31, 2013 and 2012 approximated fair value because the interest rates and terms of our debt approximate market terms. In conjunction with the refinancing of our long term debt in May 2013, we held a warrant liability at December 31, 2013 that is required to be measured at fair value on a recurring basis (see Note 3).
	Our valuation of financial instruments is based on a three-tiered approach, which requires that fair value measurements be classified and disclosed in one of three tiers. These tiers are: Level 1, defined as quoted prices in active markets for identical assets or liabilities; Level 2, defined as valuations based on observable inputs other than those included in Level 1, such as quoted prices for similar assets and liabilities in active markets, or other inputs that are observable or can be corroborated by observable input data; and Level 3, defined as valuations based on unobservable inputs reflecting our own assumptions, consistent with reasonably available assumptions made by other market participants.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	We consider all interest-bearing investments due on demand and all highly liquid debt instruments purchased with a maturity of three months or less to be cash equivalents. Cash and cash equivalents included cash of $363 and $235 at December 31, 2013 and 2012, respectively. Cash and cash equivalents at December 31, 2013 and 2012 also included investments of $30.3 million and $14.5 million, respectively, in money market funds invested in U.S. Treasury securities with original maturities of less than three months. Cash deposits are held in federally insured financial institutions in the United States of America. We maintain cash in accounts which are in excess of federally insured limits.
Restricted Cash	'
	Restricted Cash
	Restricted cash consists primarily of funds invested in two certificates of deposit. One certificate of deposit serves as collateral for a lease of laboratory space. The other certificate of deposit serves as collateral for the Company’s corporate credit card. These certificates of deposit mature every seven days and renew weekly.
Credit Risk	'
	Credit Risk
	Financial instruments which potentially subject the Company to concentrations of credit risk consist principally of cash and equivalents. The Company’s cash and equivalents were primarily invested in money market funds invested exclusively in treasury securities. Total cash and equivalent balances exceed insured balances by the Federal Depository Insurance Company.
Limited Suppliers	'
	Limited Suppliers
	We do not have a manufacturing infrastructure and do not intend to develop one for the foreseeable future. We have agreements with third-party contract manufacturing organizations (“CMOs”), to supply bulk drug substances for our product candidates and with third parties to formulate, package and distribute our drug product candidates. Our employees include professionals with expertise in pharmaceutical manufacturing development who oversee the manufacture and distribution of our drug product candidates by third-party companies. We may not currently have sufficient amounts of REG1 on hand to complete enrollment in the REGULATE-PCI trial, however the Company is currently contracted to produce sufficient amounts of REG1 in early 2014. The Company may not have enough bivalirudin to complete REGULATE-PCI and may need to secure additional quantities to complete the trial. All of the drug substances used in our product candidates are manufactured by single suppliers. While we have not experienced any supply disruptions, the number of oligonucleotide manufacturers is limited. In the event it is necessary or advisable to acquire supplies from an alternative supplier, we might not be able to obtain them on commercially reasonable terms, if at all. It could also require significant time and expense to redesign our manufacturing processes to work with another supplier. Formulation and distribution of our finished drug product candidates are also conducted by a single supplier but we believe that alternative sources for these services are readily available on commercially reasonable terms (see Note 6).
Segment and Geographic Information	'
	Segment and Geographic Information
	Operating segments are defined as components of an enterprise engaging in business activities for which discrete financial information is available and regularly reviewed by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company operates and manages its business as one operating segment and all of the Company’s operations were in North America during 2013.
Clinical Trial Supplies	'
	Clinical Trial Supplies
	We capitalize materials that will be used in our REG I clinical trial that also have an alternative future use in either ongoing or future clinical research and development projects. Clinical trial supplies may comprise material used to manufacture active pharmaceutical ingredients (“API”) used to develop our product candidates, in-process or completed API, in-process or completed unlabeled finished drug product and labeled finished drug product. Clinical trial supplies are stated at cost, using the first-in, first-out method (“FIFO”), and are reported in the accompanying consolidated balance sheets in other current assets. Clinical trial supplies that are determined to be unsuitable for future use are immediately expensed; otherwise clinical trial supplies are expensed when shipped to clinical sites for use in clinical studies or when used in other research and development projects.
	We utilize CMOs to produce API and finished drug product for use in clinical trials. As we do not have facilities that meet the requisite regulatory requirements for storage of API or finished drug product produced, we use a third-party facility for storage. Upon release from the manufacturer, API is shipped to a third-party storage facility. For production of finished drug product, API is shipped from the storage facility to the finished drug product manufacturing site. Unlabelled finished drug product is either shipped from the manufacturer back to the third-party storage facility or directly to the third-party labeling site. Labeled finished drug product is held by the third-party labeling site until it is shipped to the clinical sites for trial use.
	We do not have multiple sources of supply for the components of our finished drug product. If we are unable to obtain the supplies needed at a reasonable price or on a timely basis, it could have a material adverse effect on our ability to complete the development of our finished drug product.
	As of December 31, 2013 clinical trial supplies included in other current assets were $4.6 million, of which $1.6 million and $3.0 million represented API held at the third-party storage facility and drug product located at depots, respectively. As of December 31, 2012, clinical trial supplies included in other current assets were $4.5 million which represented API held at the third-party storage facility.
Clinical Agreements	'
	Clinical Agreements
	We enter into various clinical trial agreements with academic research organizations (“AROs”) and clinical research organizations (“CROs”) for the planning, management and execution of clinical trials. The financial terms of these agreements are subject to negotiation, vary from contract to contract, and may result in uneven payment flows. The majority of our service providers invoice us monthly in arrears for services performed or when contractual milestones are met. Costs for ARO and CRO contracts are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations, or information provided by vendors on their actual costs incurred; such costs are charged to research and development expense in the accompanying consolidated statements of comprehensive loss. There may be instances in which payments made to our vendors will exceed the level of services provided and result in a prepayment of the research and development expense. Upfront contract signing fees are amortized over the life of the respective contract; unamortized contract signing fees are included in other non-current assets.
	In the accompanying consolidated balance sheet as of December 31, 2013, prepaid expenses include $1.1 million related to clinical agreements, and other non-current assets include $4.5 million of upfront payments of which $2.8 million will be applied to final invoices as required under the respective contract, and $1.7 million will be amortized as contract signing costs over the remaining life of the respective contract, or approximately three years.
	In general, our ARO and CRO service agreements permit either party to terminate at will, although we would continue to be responsible for payment of all services completed (or pro-rata completed) at the time of notice of termination, plus any non-cancellable expenses that have been entered into by the ARO and CRO on the Company’s behalf. Accordingly, such expenses would be accrued at time of contract termination and any prepaid expenses and unamortized advance payments would be expensed, accordingly.
Value Added Taxes	'
	Value Added Taxes
	We are charged value added taxes on purchases, made on the Company’s behalf by a CRO, of certain clinical supplies from manufacturers in foreign jurisdictions. As of December 31, 2013, the Company had recorded $1,206 as a VAT receivable and $708 as a VAT liability in the accompanying consolidated balance sheet within other current assets and accrued expenses, respectively. There was $0 impact on our loss from operations or net loss for the year ended December 31, 2013 related to VAT.
Property and Equipment	'
	Property and Equipment
	Property and equipment consists primarily of laboratory and computer equipment and furniture, which are recorded at cost and depreciated using the straight-line method over their estimated useful lives, ranging from two to five years. Amortization for leasehold improvements is computed using the straight-line method over the estimated useful lives of the assets or over the term of the related leases, whichever is shorter.
	Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts, and any resulting gain or loss is credited or charged to income. Repairs and maintenance costs are expensed as incurred.
Intangible Assets	'
	Intangible Assets
	The Company’s policy is to file patent application(s) to protect technology, inventions and improvements that are considered important to the development of its business. The patent positions of technology companies, including the Company, are uncertain and involve complex legal and factual questions for which important legal principles are largely unresolved. Upon receipt of a patent grant; respective costs are amortized over the remaining life of the patent.
	The Company amortizes license agreements over the stated contractual life.
Impairment of Long-lived Assets	'
	Impairment of Long-lived Assets
	The Company recognizes impairment of long-lived assets in the event the net book value of such assets exceeds the estimated future undiscounted cash flows attributable to such assets. Accordingly, when indicators of impairment are present, the Company evaluates the carrying value of these assets in relation to the operating performance of the assets and the future undiscounted cash flows expected to result from the use of these assets. No such impairments have been recognized for the years ended December 31, 2013 and 2012, and for the period from inception to December 31, 2013, respectively, except for expense recognized for expired and abandoned patents totaling $371,000, $22,000 and $536,000 for the years ended December 31, 2013 and 2012, and for the period from inception to December 31, 2013, respectively. Such expenses are included in research and development expenses in the accompanying statements of comprehensive loss.
Grant Revenue	'
	Grant Revenue
	We were awarded several grants under the Therapeutic Discovery Project Grant program during 2010, related to research amounts previously expensed and have historically received modest other grant funding. The total amount recognized within Grant Revenue in the consolidated statement of comprehensive loss was $0 for the years ended December 31, 2013 and 2012, and $832 for the period from inception to December 31, 2013.
Research and Development	'
	Research and Development
	Research and development (“R&D”) expenses include direct and indirect R&D costs. Direct R&D consists principally of external costs, such as fees paid to investigators, consultants, central laboratories and clinical research organizations, including costs incurred in connection with our clinical trials, and related clinical trial fees and all employee-related expenses for those employees working in research and development functions, including stock-based compensation for R&D personnel. Indirect R&D costs include overhead costs related to facilities, depreciation, insurance, and small supplies are that not allocated to specific product candidates or indications. R&D costs are expensed as incurred.
Stock-based Compensation	'
	Stock-based Compensation
	In accordance with FASB ASC Topic 718, Stock Compensation, as modified or supplemented, we measure compensation cost for share-based payment awards granted to employees and non-employee directors at fair value using the Black-Scholes option-pricing model. We recognize compensation expense on a straight-line basis over the service period for awards expected to vest. Share-based compensation cost related to share-based payment awards granted to non-employees is adjusted each reporting period for changes in the fair value of our common stock until the measurement date. The measurement date is generally considered to be the date when all services have been rendered or the date that options are fully vested.
Net Loss Per Share	'
	Net Loss Per Share
	Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by dividing the net loss by the weighted-average number of common stock equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, options outstanding under our stock option plan and warrants.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	Section 107 of the Jumpstart our Business Startups Act of 2012, or the JOBS Act, provides that an “emerging growth company” can take advantage of the extended transition period provided in Section 7(a)(2)(B) of the Securities Act of 1933, as amended, for complying with new or revised accounting standards. In other words, an “emerging growth company” can delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. However, we are choosing to “opt out” of such extended transition period, and as a result, we will comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth companies. Section 107 of the JOBS Act provides that our decision to opt out of the extended transition period for complying with new or revised accounting standards is irrevocable.

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'
	Our assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability.
		As of December 31, 2013									As of December 31, 2012
	Assets and Liabilities	Quoted Prices			Significant		Significant		Balance as of		Quoted Prices		Significant		Significant		Balance at
		In Active			Other		Unobservable		December 31,		In Active		Other		Unobservable		December 31,
		Markets for			Observable		Inputs		2013		Markets for		Observable		Inputs		2012
		Identical			Inputs		(Level 3)				Identical		Inputs		(Level 3)
		Assets			(Level 2)						Assets		(Level 2)
		(Level 1)									(Level 1)
	Assets:
	Money market funds	$	30,325		$	—	$	—	$	30,325	$	14,529	$	—	$	—	$	14,529
	Total assets at fair value	$	30,325		$	—	$	—	$	30,325	$	14,529	$	—	$	—	$	14,529
	Liabilities:
	Warrant liability	$	—		$	—	$	19	$	19	$	—	$	—	$	—	$	—
	Total liabilities at fair value	$	—		$	—	$	19	$	19	$	—	$	—	$	—	$	—
Change in Fair Value Measurement Using Significant Unobservable Inputs (Level 3)	'
	The change in the fair value measurement using significant unobservable inputs (Level 3) is summarized below (in thousands):
	Balance at December 31, 2012	$	—
	Allocation of long-term debt proceeds to warrant		79
	Change in fair value recorded as interest income		(69	)
	Change in fair value recorded as interest expense		9
	Balance at December 31, 2013	$	19

Property_and_Equipment_Net_Tab

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2013
Property Plant And Equipment [Abstract]	'
Schedule of Property and Equipment	'
	Property and equipment consist of the following (in thousands):
		As of December 31,
		2013			2012
	Leasehold improvements	$	333		$	325
	Computer equipment and software		184			145
	Laboratory equipment		1,775			1,775
	Furniture and equipment		27			27
	Less – Accumulated depreciation		(2,211	)		(2,207	)
	Property and equipment, net	$	108		$	66

Intangibles_Tables

Intangibles (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill And Intangible Assets Disclosure [Abstract]	'
Summary of Carrying Amounts and Accumulated Amortization of Intangible Assets Subject to Amortization	'
	The following information details the carrying amounts and accumulated amortization of our intangible assets subject to amortization (in thousands):
		As of December 31, 2013									As of December 31, 2012
		Weighted		Gross		Accumulated			Net		Gross		Accumulated			Net
		Average		Carrying		Amortization			Carrying		Carrying		Amortization			Carrying
		Useful Life		Amount					Amount		Amount					Amount
		Remaining
	Identifiable intangible assets:
	Patents		8.0 years	$	1,518	$	(383	)	$	1,135	$	1,607	$	(349	)	$	1,258
	Product licenses		2.0 years		1,555		(1,424	)		131		1,547		(1,439	)		108
	Total		7.8 years	$	3,073	$	(1,807	)	$	1,266	$	3,154	$	(1,788	)	$	1,366
Schedule of Expected Future Amortization Expenses for Intangible Assets	'
	Expected future amortization expenses for intangible assets as of December 31, 2013 are as follows:
	For the year ending December 31:	Amount
	2014	$	137
	2015		128
	2016		128
	2017		128
	2018		128
	Thereafter		617
		$	1,266

Commitments_Tables

Commitments (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Schedule of Future Minimum Aggregate Payments under Non-Cancelable Lease Obligations	'
	Future minimum aggregate payments under non-cancelable lease obligations as of December 31, 2013 are as follows (in thousands):
	For the year ending December 31:	Amount
	2014	$	187
	2015		37
	2016		12
	Total minimum lease payments	$	236

Accrued_Expenses_Tables

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2013
Payables And Accruals [Abstract]	'
Components of Accrued Expenses	'
	The components of accrued expenses are as follows (in thousands):
		As of December 31,
		2013		2012
	Accrued license milestones	$	1,000	$	—
	Accrued obligations under clinical contracts		1,957		—
	Accrued legal and professional services		152		14
	Accrued VAT expenses		780		—
	Accrued interest		24		40
	Accrued compensation and benefits		1,225		478
	Accrued expenses, other		386		254
	Total accrued expenses	$	5,524	$	786

Longterm_Debt_Tables

Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Schedule of Long-Term Debt Maturities	'
	Scheduled maturities of long-term debt are as follows (in thousands):
			December 31,
			2013
	Year ending December 31:
	2014		$	2,000
	2015			2,500
	Total		$	4,500
	Less: unamortized discount			(103	)
	Less - current portion			(2,000	)
	Plus - fees due at closing(1)			55
	Long-term debt, net		$	2,452
	-1	On the date that all of the principal and interest of the Comerica Loan become due and payable, we must pay an end of term fee of $173,000 (the “Final Fee”). The Final Fee is being accreted to interest expense over the term of the Comerica Loan.

Stock_Based_Compensation_Table

Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Summary of Weighted Average Assumptions Used to Value Stock Options on Date of Grant	'
	The following table shows the weighted average assumptions used to value stock options on the date of grant, as follows:
			Year ended December 31,
			2013						2012						Period from Inception
															(December 19, 2001) to
															December 31, 2013
			Employee			Non-Employees			Employee			Non-Employees			Employee			Non-Employees
	Expected stock price volatility			46.9	%		45.3	%		44	%		44	%		44.08	%		41.13	%
	Risk-free interest rate			1.04	%		0.37	%		1.38	%		1.38	%		1.64	%		1.21	%
	Expected life of option (in years)			3.69			2			6.25			6.25			4.44			3.38
	Estimated dividend yield			0	%		0	%		0	%		0	%		0	%		0	%
	Weighted-average grant date fair value per share			1.91			1.49			1.67			1.67			2.32			1.99
Summary of Aggregate Equity Compensation Plan Activity	'
	The following table summarizes our aggregate Equity Compensation Plan activity:
			Number of			Weighted Average			Weighted Average			Aggregate
			Options			Exercise Price			Contractual Term			Intrinsic Value(1)
									(in years)
	Outstanding – December 31, 2012			1,409,659
	Granted			1,965,696
	Exercised			(7,602	)
	Forfeited			(56,623	)
	Expired			(38,283	)
	Outstanding – December 31, 2013			3,272,847		$	5.38			7.87		$	2,420,963
	Exercisable – December 31, 2013			1,386,653		$	6.98			5.43		$	800,721
	Vested and expected to vest at December 31, 2013(2)			3,255,969		$	5.39			7.86		$	2,403,403
	-1	Intrinsic value is the excess of the fair value of the underlying common shares as of December 31, 2013 over the weighted-average exercise price.
	-2	The number of stock options expected to vest takes into account an estimate of expected forfeitures.
Summary of Information about Options Outstanding	'
	The following table summarizes certain information about all options outstanding as of December 31, 2013:
			Options Outstanding						Options Exercisable
	Exercise Price		Options			Weighted Average			Options			Weighted Average
			Outstanding			Remaining			Exercisable			Remaining
						Contractual Life						Contractual Life
						(Years)						(Years)
	$1.67-$3.84			334,921			5.8			254,829			5
	$4.00			1,366,760			9.6			4,256			1
	$4.51-$4.81			951,961			7.8			626,455			6.7
	$4.87-$12.53			619,205			5.2			501,113			4.1
				3,272,847			7.9			1,386,653			5.4

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Components of Company's Deferred Income Tax Assets and Liabilities	'
	Significant components of the Company’s deferred income tax assets and liabilities at December 31, 2013 and 2012, consisted of the following (in thousands):
		2013			2012
	Deferred income tax assets:
	Net operating loss carryforwards	$	53,436		$	41,886
	Property and equipment		136			121
	Stock-based compensation expense		661			391
	Accruals		1,220			—
	Other		44			221
	Valuation allowance for deferred income tax assets		(54,999	)		(41,997	)
	Net deferred income tax assets		498			622
	Deferred income tax liabilities:
	Patent costs		(498	)		(622	)
	Net deferred income taxes	$	—		$	—
Schedule of Effective Income Tax Rate Reconciliation	'
	The differences between the statutory rate and the effective rate are due to the valuation allowance and other permanent differences, as shown in the table below (dollars in thousands):
		2013						2012
		Tax			Rate			Tax			Rate
	Rate Reconciliation
	Tax at statutory rate	$	(12,054	)		35	%	$	(4,572	)		35	%
	Incentive stock options		148			(0.4	)%		248			(1.9	)%
	State taxes		(1,378	)		4	%		(522	)		4	%
	Change in valuation allowance		13,002			(37.8	)%		4,846			(37.1	)%
	Other		282			(0.8	)%		—			0	%
	Income tax expense reported	$	—			0	%	$	—			0	%

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Computation of Basic and Diluted Net Loss Per Common Share	'
	The following table presents the computation of basic and diluted net loss per common share (in thousands, except share and per share data):
		Years ended December 31,
		2013			2012
	Net loss attributable to common shareholders	$	(34,439	)	$	(13,062	)
	Weighted average common shares outstanding, basic and diluted		7,499,661			221,272
	Net loss per share attributable to common shareholders, basic and diluted	$	(4.59	)	$	(59.03	)
Schedule of Anti-Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share	'
	Securities that may potentially dilute earnings per share in the future that have not been included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common equivalent shares):
		Years ended December 31,
		2013			2012
	Convertible preferred stock		—			8,539,257
	Common stock options		3,272,847			1,409,659
	Warrants		16,332			20,449
	Total		3,289,179			9,969,365

Organization_and_Description_o1

Organization and Description of Business - Additional Information (Detail) (USD $)	1 Months Ended		12 Months Ended		145 Months Ended	1 Months Ended
	Sep. 30, 2013	31-May-13	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Sep. 30, 2013	Aug. 31, 2013
	Patient					IPO [Member]	IPO [Member]
Organization And Description Of Business [Line Items]	'	'	'	'	'	'	'
Number of subject in Phase 3 trial	13,200	'	'	'	'	'	'
Reverse stock split	'	'	'Stockholders approved an amendment to the amended and restated certificate of incorporation to effect a one-for-16.7 reverse split of shares of common stock and to increase the number of authorized shares of common stock to 500,000,000, each of which was effected on May 21, 2013.	'	'	'	'
Reverse stock split, conversion ratio	'	16.7	'	'	'	'	'
Common stock, shares authorized	'	500,000,000	500,000,000	500,000,000	500,000,000	'	'
Common stock, shares issued	'	'	21,310,614	221,272	21,310,614	11,671,500	'
Common stock, price per share	'	'	'	'	'	$4	$4
Proceeds from issuance of common stock	'	'	$21,000	'	$21,000	$41,100,000	'
Underwriting discounts	'	'	'	'	'	3,300,000	'
Offering costs	'	'	$2,266,000	$77,000	$2,343,000	$2,300,000	'
Conversion of preferred stock into common stock	'	'	'	'	'	9,396,767	'

Basis_of_Presentation_and_Summ2

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended		144 Months Ended	145 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013
	Segment		Certificates_of_Deposits	Certificates_of_Deposits
	Certificates_of_Deposits
Basis Of Presentation And Significant Accounting Policies [Line Items]	'	'	'	'
Cash flows from operating activities	($34,736,000)	($14,229,000)	'	($140,172,000)
Accumulated deficit, net	144,979,000	110,540,000	144,979,000	144,979,000
Highly liquid debt instruments, maturity period	'3 months	'	'	'
Cash	363	235	363	363
Investments	30,300,000	14,500,000	30,300,000	30,300,000
Number of certificates of deposits	2	'	2	2
Certificates of deposit mature and renewal description	'Certificates of deposit mature every seven days and renew weekly.	'	'	'
Number of operating segment	1	'	'	'
Clinical trial supplies included in other current assets	4,600,000	4,500,000	4,600,000	4,600,000
API held at third-party storage facility	1,600,000	'	1,600,000	1,600,000
Drug product located at depots	3,000,000	'	3,000,000	3,000,000
Prepaid expenses related to clinical agreements	1,100,000	'	1,100,000	1,100,000
Upfront payments	4,500,000	'	'	'
Prepaid costs applied to final invoices	2,800,000	'	2,800,000	2,800,000
VAT receivable, current	1,206	'	1,206	1,206
VAT liability	708	'	708	708
Impairments of long-lived assets	0	0	0	'
Grant revenue	0	0	832,000	832,000
Value Added Taxes [Member]	'	'	'	'
Basis Of Presentation And Significant Accounting Policies [Line Items]	'	'	'	'
Impact of VAT on net loss	0	'	0	0
Patents [Member] | Research and Development Expenses [Member]	'	'	'	'
Basis Of Presentation And Significant Accounting Policies [Line Items]	'	'	'	'
Impairments of long-lived assets	371,000	22,000	536,000	'
Upfront Contract [Member]	'	'	'	'
Basis Of Presentation And Significant Accounting Policies [Line Items]	'	'	'	'
Other non-current assets include upfront contract signing costs	1,700,000	'	1,700,000	1,700,000
Upfront contract signing costs amortized period	'3 years	'	'	'
Two Thousand and Fourteen Private Placement [Member]	'	'	'	'
Basis Of Presentation And Significant Accounting Policies [Line Items]	'	'	'	'
Sale of common stock in private placement	$20,000,000	'	'	'
Minimum [Member]	'	'	'	'
Basis Of Presentation And Significant Accounting Policies [Line Items]	'	'	'	'
Property, plant and equipment useful lives	'2 years	'	'	'
Maximum [Member]	'	'	'	'
Basis Of Presentation And Significant Accounting Policies [Line Items]	'	'	'	'
Property, plant and equipment useful lives	'5 years	'	'	'

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets:	'	'
Total assets at fair value	$30,325	$14,529
Liabilities:	'	'
Total liabilities at fair value	19	'
Warrant Liability [Member]	'	'
Liabilities:	'	'
Total liabilities at fair value	19	'
Money Market Funds [Member]	'	'
Assets:	'	'
Total assets at fair value	30,325	14,529
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	'	'
Assets:	'	'
Total assets at fair value	30,325	14,529
Liabilities:	'	'
Total liabilities at fair value	'	'
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Warrant Liability [Member]	'	'
Liabilities:	'	'
Total liabilities at fair value	'	'
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Money Market Funds [Member]	'	'
Assets:	'	'
Total assets at fair value	30,325	14,529
Significant Other Observable Inputs (Level 2) [Member]	'	'
Assets:	'	'
Total assets at fair value	'	'
Liabilities:	'	'
Total liabilities at fair value	'	'
Significant Other Observable Inputs (Level 2) [Member] | Warrant Liability [Member]	'	'
Liabilities:	'	'
Total liabilities at fair value	'	'
Significant Other Observable Inputs (Level 2) [Member] | Money Market Funds [Member]	'	'
Assets:	'	'
Total assets at fair value	'	'
Significant Unobservable Inputs (Level 3) [Member]	'	'
Assets:	'	'
Total assets at fair value	'	'
Liabilities:	'	'
Total liabilities at fair value	19	'
Significant Unobservable Inputs (Level 3) [Member] | Warrant Liability [Member]	'	'
Liabilities:	'	'
Total liabilities at fair value	19	'
Significant Unobservable Inputs (Level 3) [Member] | Money Market Funds [Member]	'	'
Assets:	'	'
Total assets at fair value	'	'

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Change in Fair Value Measurement Using Significant Unobservable Inputs (Level 3) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Beginning balance	'
Allocation of long-term debt proceeds to warrant	79
Change in fair value recorded as interest income	-69
Change in fair value recorded as interest expense	9
Ending balance	$19

Property_and_Equipment_Net_Sch

Property and Equipment, Net - Schedule of Property and Equipment (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Less - Accumulated depreciation	($2,211)	($2,207)
Property and equipment, net	108	66
Leasehold Improvements [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	333	325
Computer Equipment and Software [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	184	145
Laboratory Equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	1,775	1,775
Furniture and Equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	$27	$27

Property_and_Equipment_Net_Add

Property and Equipment, Net - Additional Information (Detail) (USD $)	12 Months Ended		145 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
Property Plant And Equipment [Abstract]	'	'	'
Depreciation expense	$61	$42	$2,395

Intangibles_Summary_of_Carryin

Intangibles - Summary of Carrying Amounts and Accumulated Amortization of Intangible Assets Subject to Amortization (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]	'	'
Weighted Average Useful Life Remaining	'7 years 9 months 18 days	'
Gross Carrying Amount	$3,073	$3,154
Accumulated Amortization	-1,807	-1,788
Net Carrying Amount	1,266	1,366
Patents [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Weighted Average Useful Life Remaining	'8 years	'
Gross Carrying Amount	1,518	1,607
Accumulated Amortization	-383	-349
Net Carrying Amount	1,135	1,258
Product Licenses [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Weighted Average Useful Life Remaining	'2 years	'
Gross Carrying Amount	1,555	1,547
Accumulated Amortization	-1,424	-1,439
Net Carrying Amount	$131	$108

Intangibles_Schedule_of_Expect

Intangibles - Schedule of Expected Future Amortization Expenses for Intangible Assets (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Goodwill And Intangible Assets Disclosure [Abstract]	'	'
2014	$137	'
2015	128	'
2016	128	'
2017	128	'
2018	128	'
Thereafter	617	'
Net Carrying Amount	$1,266	$1,366

Intangibles_Additional_Informa

Intangibles - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Goodwill And Intangible Assets Disclosure [Abstract]	'	'
Patent costs not yet granted	$557,000	$405,000

Commitments_Additional_Informa

Commitments - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended		145 Months Ended
	Sep. 26, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
	Method	Buildings		Buildings
		sqft		sqft
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'
Area of administrative office	'	1,657	'	1,657
Lease term, in months	'	'36 months	'	'
Annual lease obligations in first year	'	$187,000	'	$187,000
Annual lease obligations in second year	'	37,000	'	37,000
Annual lease obligations in third year	'	12,000	'	12,000
Number of office locations	'	3	'	3
Operating lease expire date	'	31-May-13	'	'
Rent expense, operating leases	'	464,000	498,000	2,900,000
Number of full-time employees	32	'	'	'
Number of eliminated employees	5	'	'	'
Severance cost charged to research and development expense	'	250,000	'	'
Accrued severance expense	'	417,000	'	417,000
Research and Development Expenses [Member]	'	'	'	'
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'
Milestone payments	'	1,500,000	'	'
Duke University [Member]	'	'	'	'
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'
Milestone payments	'	500,000	'	'
DRI [Member]	'	'	'	'
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'
Maximum amount of payment to DRI	'	1,200,000	'	'
Nektar [Member]	'	'	'	'
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'
Milestone payments	'	7,750,000	'	'
Payment for license agreement	'	1,250,000	'	'
Durham Office Lease [Member]	'	'	'	'
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'
Annual lease obligations in first year	'	39,000	'	39,000
Annual lease obligations in second year	'	40,000	'	40,000
Annual lease obligations in third year	'	41,000	'	41,000
Accrued Expenses [Member] | Archemix Corporation [Member]	'	'	'	'
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'
Milestone payments	'	1,000,000	'	'
Office Building [Member]	'	'	'	'
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'
Monthly operating lease payments	'	2,000	'	'
Corporate Headquarters [Member]	'	'	'	'
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'
Monthly operating lease payments	'	16,000	'	'
Operating lease expire date	'	1-Nov-11	'	'
Monthly lease payment due for utilities	'	1,000	'	'
Laboratory Space [Member]	'	'	'	'
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'
Monthly operating lease payments	'	11,000	'	'
Operating lease expire date	'	31-Jul-12	'	'
Operating lease monthly base rent	'	13,000	'	'
Operating lease period	'	'1 year	'	'
Initial letter of credit to lessor	'	115,000	'	115,000
Reduced letter of credit on fourth anniversary date of lease	'	$46,000	'	$46,000
Operating lease	'	8,495	'	8,495

Commitments_Schedule_of_Future

Commitments - Schedule of Future Minimum Aggregate Payments under Non-Cancelable Lease Obligations (Detail) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Operating Leases Future Minimum Payments Due [Abstract]	'
2014	$187
2015	37
2016	12
Total minimum lease payments	$236

Accrued_Expenses_Components_of

Accrued Expenses - Components of Accrued Expenses (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]	'	'
Accrued license milestones	$1,000	'
Accrued obligations under clinical contracts	1,957	'
Accrued legal and professional services	152	14
Accrued VAT expenses	780	'
Accrued interest	24	40
Accrued compensation and benefits	1,225	478
Accrued expenses, other	386	254
Total accrued expenses	$5,524	$786

LongTerm_Debt_Additional_Infor

Long-Term Debt - Additional Information (Detail) (USD $)

1 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

144 Months Ended

12 Months Ended

12 Months Ended

144 Months Ended

31-May-11

Dec. 31, 2013

13-May-13

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

MidCap Financial SBIC, LP [Member]

MidCap Financial SBIC, LP [Member]

Comerica Bank [Member]

Comerica Bank [Member]

Comerica Bank [Member]

Comerica Bank [Member]

Comerica Bank [Member]

Comerica Bank [Member]

Comerica Bank [Member]

MidCap Loan [Member]

MidCap Loan [Member]

MidCap Loan [Member]

Tranche Two [Member]

Series E Convertible Preferred Stock [Member]

Common Stock [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, borrowed amount

$6,000,000

'

$4,500,000

'

'

'

'

'

'

'

'

'

Loan and security agreement, floor interest rate

2.00%

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, interest rate spread

8.00%

'

'

4.00%

'

'

'

'

'

'

'

'

Loan and security agreement, variable interest rate basis

'

'LIBOR

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, interest rate description

'

'The stated rate of LIBOR, at a 2% rate floor, plus 8% spread per annum.

'

'

'

'

'

'

'

'

'

'

Final payment of loan and security agreement, percentage

3.00%

'

'

'

'

'

'

'

'

'

'

'

Final payment of loan and security agreement

180,000

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, repayment description

'

'The loan was payable in monthly installments beginning September 2012 through August 2014.

'

'The terms allow for an interest only period of 15 months, and the remaining principal and interest will be repaid starting September 2014 over a nine-month period (24 months in total).

'

'

'

'

'

'

'

'

Loan and security agreement, repayment start date

'2012-09

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, repayment end date

'2014-08

'

'

'

'

'

'

'

'

'

'

'

Venture debt loan, LIBOR period

'

'

'

'30 days

'

'

'

'

'

'

'

'

Venture debt loan, basis points

'

'

'

2.50%

'

2.50%

'

'

'

'

'

'

Debt instrument term

'

'

'24 months

'

'

'

'

'

'

'

'

'

Venture debt loan, interest period

'

'

'15 months

'

'

'

'

'

'

'

'

'

Venture debt loan, interest rate

'

'

'

7.25%

'

7.25%

'

'

'

'

'

'

Due period for repayment of principal and interest

'

'

'9 months

'

'

'

'

'

'

'

'

'

Debt instrument maturity amount in 2014

'

'

'

2,000,000

'

'

'

'

'

'

'

'

Debt instrument maturity amount in 2015

'

'

'

2,500,000

'

'

'

'

'

'

'

'

Venture debt loan, Description

'

'

'

'Upon (i) Comericabs receipt of evidence satisfactory to Comerica that the 1,000 patient interim analysis in the REGULATE-PCI study is successful and performed by April 30, 2014 and (ii) our completion of the IPO and receipt of net proceeds of at least $50.0 million prior to June 30, 2013, we had the option to borrow an additional $4.0 million in the second tranche, or (bTranche Twob). Since the latter of the Tranche Two conditions was not satisfied, Tranche Two is solely at the discretion of Comerica.

'

'

'

'

'

'

'

'

Debt security, option to borrow additional loans

'

'

'

'

'

'

4,000,000

'

'

'

'

'

Loan and security agreement, interest expense

'

'

'

346,000

0

346,000

'

'

'

325,000

559,000

1,100,000

Issuance of warrants to purchase of stock

'

'

'

'

'

'

'

156,250

9,356

'

'

'

Warrant price per share

'

'

'

'

'

'

'

0.72

12.02

'

'

'

Warrants exercise, Description

'

'

'

'

'

'

'

'If we had borrowed the additional $4.0 million in Tranche Two, the warrant would have become exercisable for an additional number of shares of the Series E Preferred Stock equal to 100,000 divided by the Warrant Price, as defined, subject to adjustment for stock splits, combinations, reclassifications or exchanges and certain dilutive issuances. As previously noted, as we did not complete an IPO by the required milestone date, Tranche Two is solely at the discretion of Comerica.

'

'

'

'

Deferred loan origination costs

'

'

'

$85,000

'

$85,000

'

'

'

'

'

'

LongTerm_Debt_Schedule_of_Long

Long-Term Debt - Schedule of Long-Term Debt Maturities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'	'
2014	$2,000	'
2015	2,500	'
Long-term debt, Total	4,500	'
Less: unamortized discount	-103	'
Less - current portion	-2,000	-2,571
Plus - fees due at closing	55	'
Long-term debt, net	$2,452	$1,929

LongTerm_Debt_Schedule_of_Long1

Long-Term Debt - Schedule of Long-Term Debt Maturities (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Debt instrument end of term fee	$173,000

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)

1 Months Ended

12 Months Ended

120 Months Ended

120 Months Ended

1 Months Ended

12 Months Ended

12 Months Ended

0 Months Ended

31-May-13

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Sep. 30, 2013

Aug. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 18, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 18, 2012

Apr. 26, 2013

Mar. 22, 2013

Series A Convertible Preferred Stock [Member]

Series A Convertible Preferred Stock [Member]

Series B Convertible Preferred Stock [Member]

Series B Convertible Preferred Stock [Member]

Series C Convertible Preferred Stock [Member]

Series C Convertible Preferred Stock [Member]

Series D Convertible Preferred Stock [Member]

Series D Convertible Preferred Stock [Member]

Series E Convertible Preferred Stock [Member]

Series E Convertible Preferred Stock [Member]

Series A, Series B, Series C, And Series D Preferred Stock [Member]

Common Stock [Member]

Common Stock [Member]

Preferred Stock [Member]

IPO [Member]

IPO [Member]

Pre IPO [Member]

Pre IPO [Member]

Pre IPO [Member]

Pre IPO [Member]

Pre IPO [Member]

Pre IPO [Member]

Pre IPO [Member]

Pre IPO [Member]

Post IPO [Member]

First Tranche [Member]

Third Tranche [Member]

Third Tranche [Member]

Second Tranche [Member]

Second Tranche [Member]

Second Tranche [Member]

Warrants [Member]

Pre-IPO Common Stock [Member]

Pre-IPO Preferred Stock [Member]

Pre-IPO Preferred Stock [Member]

Pre-IPO Preferred Stock [Member]

Pre-IPO Preferred Stock [Member]

Pre-IPO Preferred Stock [Member]

Pre-IPO Preferred Stock [Member]

Series E Convertible Preferred Stock [Member]

Series E Convertible Preferred Stock [Member]

Maximum [Member]

Series E Convertible Preferred Stock [Member]

Series E Convertible Preferred Stock [Member]

Series E Convertible Preferred Stock [Member]

Series A Convertible Preferred Stock [Member]

Series B Convertible Preferred Stock [Member]

Series C Convertible Preferred Stock [Member]

Series D Convertible Preferred Stock [Member]

Series E Convertible Preferred Stock [Member]

Series E Convertible Preferred Stock [Member]

Subsidiary, Sale of Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, shares issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11,671,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares issued, price per share

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$4

$4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from issuance of common stock

'

$21,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$41,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Underwriting discounts

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Offering costs

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Authorized shares

'

501,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

698,363,299

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, shares authorized

500,000,000

500,000,000

500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

500,000,000

'

'

'

'

'

500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, par value

'

$0.00

$0.00

'

'

'

'

'

'

'

'

'

'

'

'

$0.00

'

'

'

'

'

$0.00

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock, shares authorized

'

'

'

'

0

5,798,178

0

16,666,665

0

17,037,037

0

71,666,667

0

31,437,442

'

'

'

1,000,000

'

'

'

'

198,363,299

5,798,178

16,666,665

17,037,037

71,666,667

87,194,752

'

'

'

'

'

'

'

Preferred stock, par value

'

'

'

'

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00

'

'

'

$0.00

'

'

'

'

$0.00

'

'

'

'

'

'

'

'

'

'

'

'

Number of preferred shares issued

'

'

'

'

0

5,798,178

0

16,666,665

0

17,037,037

0

71,666,667

0

31,437,442

111,169

'

'

'

'

'

'

'

'

'

'

'

'

'

'

31,437,442

24,770,476

'

14,320,168

'

7,160,084

Proceeds from issuance of preferred shares

'

10,163,000

-16,000

99,897,000

'

'

'

'

'

'

'

'

'

'

99,897,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance costs

'

'

'

'

'

'

'

'

'

'

'

'

'

'

501,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Value of preferred shares issued

'

'

'

'

'

5,778,000

'

19,888,000

'

22,978,000

'

51,237,000

'

22,169,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

22,600,000

17,800,000

'

10,300,000

'

5,200,000

Preferred shares for cash

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,500,000

'

'

'

'

'

Convertible loan principal amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,800,000

'

'

'

'

'

Convertible loan interest

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

339,000

'

'

'

'

'

Preferred stock, financing tranche effective date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

17-Jan-14

22-Mar-13

'

'

Portion delivered into escrow account

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$5,200,000

'

Sale of additional preferred stock, shares

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Reverse stock split ratio

16.7

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion of preferred stock into common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9,396,767

'

'

'

'

'

'

'

'

'

9,396,767

'

'

'

'

'

'

Warrants outstanding

'

16,332

20,449

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants exercisable into common shares at a weighted average exercise price

'

$6.96

$0.17

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of warrant to purchase of common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13,473

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrant exercised for common stock at an exercise price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.17

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock_Based_Compensation_Addit

Stock Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended		145 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Remaining stock options outstanding to acquire common stock, assumed under the 2013 plan	3,272,847	1,409,659	3,272,847
Expected dividend rate	0.00%	'	'
Intrinsic value of options exercised	$11,000	$0	$82,000
Stock-based compensation	988,000	703,000	5,599,000
Expenses related to options issued to non-employee	59,000	38,000	156,000
Total unrecognized compensation related to unvested	$2,900,000	'	$2,900,000
Recognized over a weighted-average period	'2 years 9 months 18 days	'	'
2013 Plan [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Common shares authorized for future issuance	3,342,839	'	3,342,839
Common shares available for issuance	94,862	'	94,862
Remaining stock options outstanding to acquire common stock, assumed under the 2013 plan	1,406,910	'	1,406,910
2004 Plan [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock option to acquire common stock	34,342	'	34,342
Evergreen Provision [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Common shares available for issuance	1,065,530	'	1,065,530
Percentage of Common Stock outstanding	5.00%	'	'
Experience Group One [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Forfeiture rate	0.00%	'	'
Experience Group Two [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Forfeiture rate	1.00%	'	'

Stock_Based_Compensation_Summa

Stock Based Compensation - Summary of Weighted Average Assumptions Used to Value Stock Options on Date of Grant (Detail) (USD $)	12 Months Ended		145 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
Employee [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected stock price volatility	46.90%	44.00%	44.08%
Risk-free interest rate	1.04%	1.38%	1.64%
Expected life of option (in years)	'3 years 8 months 9 days	'6 years 3 months	'4 years 5 months 9 days
Estimated dividend yield	0.00%	0.00%	0.00%
Weighted-average grant date fair value per share	$1.91	$1.67	$2.32
Non-Employees [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected stock price volatility	45.30%	44.00%	41.13%
Risk-free interest rate	0.37%	1.38%	1.21%
Expected life of option (in years)	'2 years	'6 years 3 months	'3 years 4 months 17 days
Estimated dividend yield	0.00%	0.00%	0.00%
Weighted-average grant date fair value per share	$1.49	$1.67	$1.99

Stock_Based_Compensation_Summa1

Stock Based Compensation - Summary of Aggregate Equity Compensation Plan Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Number of Options, Outstanding, Beginning Balance	1,409,659
Number of Options, Granted	1,965,696
Number of Options, Exercised	-7,602
Number of Options, Forfeited	-56,623
Number of Options, Expired	-38,283
Number of Options, Outstanding, Ending Balance	3,272,847
Number of Options, Exercisable	1,386,653
Number of Options, Vested and expected to vest	3,255,969
Weighted Average Exercise Price, Outstanding	$5.38
Weighted Average Exercise Price, Outstanding, Exercisable	$6.98
Weighted Average Exercise Price, Outstanding, Vested and expected to vest	$5.39
Weighted Average Contractual Term, Outstanding	'7 years 10 months 13 days
Weighted Average Contractual Term, Exercisable	'5 years 5 months 5 days
Weighted Average Contractual Term, Vested and Expected to Vest	'7 years 10 months 10 days
Aggregate Intrinsic Value of Stock Options Outstanding	$2,420,963
Aggregate Intrinsic Value of Stock Options Exercisable	800,721
Aggregate Intrinsic Value of Stock Options Vested and Expected to Vest	$2,403,403

Stock_Based_Compensation_Summa2

Stock Based Compensation - Summary of Information about Options Outstanding (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Options Outstanding	3,272,847
Weighted Average Remaining Contractual Life(Years), Outstanding	'7 years 10 months 24 days
Options Exercisable	1,386,653
Weighted Average Remaining Contractual Life(Years), Exercisable	'5 years 4 months 24 days
Exercise Price Range One [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Options Outstanding	334,921
Weighted Average Remaining Contractual Life(Years), Outstanding	'5 years 9 months 18 days
Options Exercisable	254,829
Weighted Average Remaining Contractual Life(Years), Exercisable	'5 years
Exercise Price Range One [Member] | Minimum [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise Price	1.67
Exercise Price Range One [Member] | Maximum [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise Price	3.84
Exercise Price Range Two [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise Price	4
Options Outstanding	1,366,760
Weighted Average Remaining Contractual Life(Years), Outstanding	'9 years 7 months 6 days
Options Exercisable	4,256
Weighted Average Remaining Contractual Life(Years), Exercisable	'1 year
Exercise Price Range Three [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Options Outstanding	951,961
Weighted Average Remaining Contractual Life(Years), Outstanding	'7 years 9 months 18 days
Options Exercisable	626,455
Weighted Average Remaining Contractual Life(Years), Exercisable	'6 years 8 months 12 days
Exercise Price Range Three [Member] | Minimum [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise Price	4.51
Exercise Price Range Three [Member] | Maximum [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise Price	4.81
Exercise Price Range Four [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Options Outstanding	619,205
Weighted Average Remaining Contractual Life(Years), Outstanding	'5 years 2 months 12 days
Options Exercisable	501,113
Weighted Average Remaining Contractual Life(Years), Exercisable	'4 years 1 month 6 days
Exercise Price Range Four [Member] | Minimum [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise Price	4.87
Exercise Price Range Four [Member] | Maximum [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise Price	12.53

Employee_Benefit_Plan_Addition

Employee Benefit Plan - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
401k Plan [Member]	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'
Eligible percentage that employees can defer from their compensation	87.00%
Matching contributions made by company for elective deferrals	50.00%
Matching contribution made by company for each participant	3.00%
Aggregate matching contribution expense	$87,813
Employee Stock Purchase Plan [Member]	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'
Common stock may be issued pursuant to the ESPP	96,360
Shares outstanding	0

Income_Taxes_Components_of_Com

Income Taxes - Components of Company's Deferred Income Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Deferred income tax assets:	'	'
Net operating loss carryforwards	$53,436	$41,886
Property and equipment	136	121
Stock-based compensation expense	661	391
Accruals	1,220	'
Other	44	221
Valuation allowance for deferred income tax assets	-54,999	-41,997
Net deferred income tax assets	498	622
Deferred income tax liabilities:	'	'
Patent costs	-498	-622
Net deferred income taxes	'	'

Income_Taxes_Schedule_of_Effec

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Rate Reconciliation	'	'
Tax at statutory rate	($12,054)	($4,572)
Incentive stock options	148	248
State taxes	-1,378	-522
Change in valuation allowance	13,002	4,846
Other	282	'
Income tax expense reported	'	'
Rate Reconciliation	'	'
Tax at statutory rate	35.00%	35.00%
Incentive stock options	-0.40%	-1.90%
State taxes	4.00%	4.00%
Change in valuation allowance	-37.80%	-37.10%
Other	-0.80%	0.00%
Income tax expense reported	0.00%	0.00%

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Line Items]	'	'
Operating loss carry forwards	$137,000,000	'
Change in ownership percentage points	50.00%	'
Liability for uncertain tax positions	0	0
Accrued interest or penalties associated with any unrecognized tax positions	$0	'
Maximum [Member]	'	'
Income Taxes [Line Items]	'	'
Percentage likely of largest amount of tax benefit being realized upon ultimate settlement with tax authority	50.00%	'
Domestic Tax Authority [Member]	'	'
Income Taxes [Line Items]	'	'
Operating loss carry forwards expiration year	'2022	'
State and Local Jurisdiction [Member]	'	'
Income Taxes [Line Items]	'	'
Operating loss carry forwards expiration year	'2017	'

Net_Loss_Per_Share_Computation

Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Common Share (Detail) (USD $)	12 Months Ended		120 Months Ended	145 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net loss attributable to common shareholders	($34,439)	($13,062)	($97,478)	($144,979)
Weighted average common shares outstanding, basic and diluted	7,499,661	221,272	'	805,826
Net loss per share attributable to common shareholders, basic and diluted	($4.59)	($59.03)	'	($179.91)

Net_Loss_Per_Share_Schedule_of

Net Loss Per Share - Schedule of Anti-Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total	3,289,179	9,969,365
Convertible Preferred Stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total	'	8,539,257
Common Stock Options [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total	3,272,847	1,409,659
Warrants [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total	16,332	20,449

Net_Loss_Per_Share_Additional_

Net Loss Per Share - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]	'	'
Warrants outstanding	16,332	20,449
Warrants exercisable into common shares at a weighted average exercise price	$6.96	$0.17

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (USD $)	12 Months Ended	145 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Subsequent Event [Line Items]	'	'	'
Number of common stock sold	21,310,614	21,310,614	221,272
Net proceeds from issuance of common stock	$33,000	$224,000	'
Two Thousand and Fourteen Private Placement [Member]	'	'	'
Subsequent Event [Line Items]	'	'	'
Aggregate purchase price of common stock	20,000,000	'	'
Subsequent Event [Member] | Two Thousand and Fourteen Private Placement [Member]	'	'	'
Subsequent Event [Line Items]	'	'	'
Number of common stock sold	4,000,000	4,000,000	'
Common stock price per share	$5	$5	'
Net proceeds from issuance of common stock	18,700,000	'	'
Subsequent Event [Member] | Two Thousand and Fourteen Private Placement [Member] | Robert Kierlin [Member]	'	'	'
Subsequent Event [Line Items]	'	'	'
Number of common stock sold	400,000	400,000	'
Aggregate purchase price of common stock	2,000,000	'	'
Subsequent Event [Member] | Two Thousand and Fourteen Private Placement [Member] | BVF, LP [Member]	'	'	'
Subsequent Event [Line Items]	'	'	'
Number of common stock sold	2,000,000	2,000,000	'
Aggregate purchase price of common stock	$10,000,000	'	'
Subsequent Event [Member] | Two Thousand and Fourteen Private Placement [Member] | BVF, LP [Member] | Robert Kierlin [Member]	'	'	'
Subsequent Event [Line Items]	'	'	'
Percentage of capital stock	5.00%	'	'