Insmed (INSM) 10-Q 6 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Jul. 31, 2014
Document and Entity Information	'	'
Entity Registrant Name	'INSMED INC	'
Entity Central Index Key	'0001104506	'
Document Type	'10-Q	'
Document Period End Date	30-Jun-14	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	39,283,016
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$82,697	$113,894
Prepaid expenses and other current assets	4,015	2,269
Total current assets	86,712	116,163
In-process research and development	58,200	58,200
Fixed assets, net	4,778	1,812
Other assets	420	323
Total assets	150,110	176,498
Current liabilities:	'	'
Accounts payable	11,407	5,929
Accrued expenses	4,546	3,905
Accrued compensation	2,071	2,839
Accrued lease expense, current	314	307
Deferred rent	167	129
Capital lease obligations, current	32	64
Current portion of long term debt	3,281	3,283
Total current liabilities	21,818	16,456
Accrued lease expense, long-term	250	380
Debt, long-term	16,494	16,338
Total liabilities	38,562	33,174
Shareholders' equity:	'	'
Common stock, $0.01 par value; 500,000,000 authorized shares, 39,276,389 and 39,137,679 issued and outstanding shares at June 30, 2014 and December 31, 2013, respectively.	393	391
Additional paid-in capital	540,298	534,554
Accumulated deficit	-429,143	-391,621
Total shareholders' equity	111,548	143,324
Total liabilities and shareholders' equity	$150,110	$176,498

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Consolidated Balance Sheets	'	'
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, authorized shares	500,000,000	500,000,000
Common stock, issued shares	39,276,389	39,137,679
Common stock, outstanding shares	39,276,389	39,137,679

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Loss (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Consolidated Statements of Comprehensive Loss	'	'	'	'
Other revenue	'	$11,500	'	$11,500
Operating expenses:	'	'	'	'
Research and development	14,942	12,225	26,293	22,559
General and administrative	7,874	7,544	14,602	11,520
Total operating expenses	22,816	19,769	40,895	34,079
Operating loss	-22,816	-8,269	-40,895	-22,579
Investment income	12	50	29	101
Interest expense	-595	-635	-1,201	-1,277
Other income, net	175	'	156	2
Loss before income taxes	-23,224	-8,854	-41,911	-23,753
Benefit from income taxes	'	'	-4,389	-1,221
Net loss and comprehensive loss	($23,224)	($8,854)	($37,522)	($22,532)
Basic and diluted net loss per share (in dollars per share)	($0.59)	($0.28)	($0.96)	($0.71)
Weighted average basic and diluted common shares outstanding (in shares)	39,273	31,754	39,256	31,654

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Operating activities	'	'
Net loss	($37,522)	($22,532)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Depreciation and amortization	342	304
Stock based compensation expense	5,336	4,953
Gain on sale of asset, net	'	-2
Amortization of debt discount and debt issuance costs	192	236
Accrual of the end of term charge on the debt	62	97
Changes in operating assets and liabilities:	'	'
Prepaid expenses and other assets	-1,843	-1,186
Accounts payable	3,642	805
Accrued expenses and deferred rent	103	1,449
Accrued lease expenses	-123	-127
Accrued compensation	-768	-318
Net cash used in operating activities	-30,579	-16,321
Investing activities	'	'
Purchases of fixed assets	-895	-493
Proceeds from sale of asset	'	2
Net cash used in investing activities	-895	-491
Financing activities	'	'
Payments on capital lease obligations	-32	-59
Proceeds from exercise of stock options	409	677
Payment of debt issuance costs	-100	'
Net cash provided by financing activities	277	618
Decrease in cash and cash equivalents	-31,197	-16,194
Cash and cash equivalents at beginning of period	113,894	90,782
Cash and cash equivalents at end of period	82,697	74,588
Supplemental disclosures of cash flow information:	'	'
Cash paid for interest	930	944
Cash received for taxes	4,389	1,221
Supplemental disclosures of non-cash investing and financing activities:	'	'
Value of warrant exercised by converting the warrant into shares of common stock ("net issuance method")	'	$790

The_Company_and_Basis_of_Prese

The Company and Basis of Presentation	6 Months Ended
	Jun. 30, 2014
The Company and Basis of Presentation	'
The Company and Basis of Presentation	'
	1.                                    The Company and Basis of Presentation
	Insmed is a biopharmaceutical company currently focused on developing and commercializing inhaled therapies for patients battling serious lung diseases that are often life threatening.  The Company’s lead product candidate, ARIKAYCETM, or liposomal amikacin for inhalation, is an inhaled antibiotic treatment that delivers a proven and potent anti-infective directly to the site of serious lung infections. The Company was incorporated in the Commonwealth of Virginia on November 29, 1999.  On December 1, 2010, the Company completed a business combination with Transave, Inc. (Transave), a privately held, New Jersey-based pharmaceutical company focused on the development of differentiated and innovative inhaled pharmaceuticals for the treatment of serious lung infections (the “Merger”).  The Company’s continuing operations are based on the technology and products historically developed by Transave.  The Company’s principal executive offices are located in Bridgewater, New Jersey.
	The accompanying unaudited interim consolidated financial statements have been prepared pursuant to the rules and regulations for reporting on Form 10-Q. Accordingly, certain information and disclosures required by accounting principles generally accepted in the United States for complete consolidated financial statements have been condensed or are not included herein. The interim statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Form 10-K for the year ended December 31, 2013.
	The results of operations of any interim period are not necessarily indicative of the results of operations for the full year. The unaudited interim condensed consolidated financial information presented herein reflects all normal adjustments that are, in the opinion of management, necessary for a fair statement of the financial position, results of operations and cash flows for the periods presented. The Company is responsible for the unaudited interim consolidated financial statements included in this report.
	The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Transave, LLC, Insmed Pharmaceuticals, Incorporated, Insmed Limited, and Celtrix Pharmaceuticals, Incorporated.  All intercompany transactions and balances have been eliminated in consolidation.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2014
Summary of Significant Accounting Policies	'
Summary of Significant Accounting Policies	'
	2.                                      Summary of Significant Accounting Policies
	The following are interim updates to certain of the policies described in “Note 2”  to the Company’s audited consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013:
	Fair Value Measurements - The Company categorizes its financial assets and liabilities measured and reported at fair value in the financial statements on a recurring basis based upon the level of judgments associated with the inputs used to measure their fair value.  Hierarchical levels, which are directly related to the amount of subjectivity associated with the inputs used to determine the fair value of financial assets and liabilities, are as follows:
	·         Level 1 — Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.
	·         Level 2 — Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the assets or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.
	·         Level 3 — Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date.  Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.
	Each major category of financial assets and liabilities measured at fair value on a recurring basis are categorized in the tables below based upon the lowest level of significant input to the valuations.  The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value.  Financial instruments in Level 1 generally include US treasuries and mutual funds listed in active markets.
	The following table presents assets and liabilities measured at fair value as of June 30, 2014 and December 31, 2013 (in thousands):
		Fair Value Measurements at Reporting Date Using
					Quoted Prices in			Quoted Prices in
					Active Markets for			Inactive Markets for			Significant
					Identical Assets			Identical Assets			Unobservable Inputs
		Total			(Level 1)			(Level 2)			(Level 3)
	As of June 30, 2014:
	Assets:
	Cash and cash equivalents	$	82,697		$	82,697		$	—		$	—
		$	82,697		$	82,697		$	—		$	—
	As of December 31, 2013:
	Assets:
	Cash and cash equivalents	$	113,894		$	113,894		$	—		$	—
		$	113,894		$	113,894		$	—		$	—
	The Company’s cash and cash equivalents permit daily redemption and the fair values of these investments are based upon the quoted prices in active markets provided by the holding financial institutions.  Cash equivalents consist of liquid investments with a maturity of three months or less from the date of purchase.
	The Company recognizes transfers between levels within the fair value hierarchy, if any, at the end of each quarter.  There were no transfers in or out of Level 1, Level 2 or Level 3 during the three and six months ended June 30, 2014 and 2013, respectively.
	As of June 30, 2014 and December 31, 2013, the Company held no securities that were in an unrealized gain or loss position.  The Company reviews the status of each security quarterly to determine whether an other-than-temporary impairment has occurred.  In making its determination, the Company considers a number of factors, including: (1) the significance of the decline, (2) whether the securities were rated below investment grade, (3) how long the securities have been in an unrealized loss position, and (4) the Company’s ability and intent to retain the investment for a sufficient period of time for it to recover.
	Revenue Recognition — Other revenue during the three and six months ended June 30, 2013 solely consists of an $11.5 million payment the Company received from Premacure (now Shire plc) in exchange for the Company’s right to receive future royalties under its license agreement with Premacure. The Company recorded this as Other revenue during the three months ended June 30, 2013, since all four revenue recognition criteria were met at that time and the Company had no continuing performance obligations related to the payment received. Also see Note 11 of the Company’s audited consolidated financial statements on Form 10-K for the year ended December 31, 2013 for more information.
	Net Loss Per Common Share - Basic net loss per common share is computed by dividing net loss by the weighted average number of common shares outstanding during the period.  Diluted net loss per common share is computed by dividing net loss by the weighted average number of common shares and other dilutive securities outstanding during the period.  Potentially dilutive securities from stock options, restricted stock units and warrants to purchase common stock would be antidilutive as the Company incurred a net loss.  Potentially dilutive common shares resulting from the assumed exercise of outstanding stock options and warrants are determined based on the treasury stock method.
	The following table sets forth the reconciliation of the weighted average number of shares used to compute basic and diluted net loss per share for the three and six months ended June 30, 2014 and 2013:
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
		(In thousands, except per share amounts)
	Numerator:
	Net loss	$	(23,224	)	$	(8,854	)	$	(37,522	)	$	(22,532	)
	Denominator:
	Weighted average common shares used in calculation of basic net loss per share:	39,273			31,754			39,256			31,654
	Effect of dilutive securities:
	Common stock options	—			—			—			—
	Restricted stock and restricted stock units	—			—			—			—
	Common stock warrant	—			—			—			—
	Weighted average common shares outstanding used in calculation of diluted net loss per share	39,273			31,754			39,256			31,654
	Net loss per share:
	Basic and Diluted	$	(0.59	)	$	(0.28	)	$	(0.96	)	$	(0.71	)
	The following potentially dilutive securities have been excluded from the computations of diluted weighted-average common shares outstanding as of June 30, 2014 and 2013 as their effect would have been anti-dilutive (in thousands):
		2014		2013
	Stock options to purchase common stock	5,058		3,275
	Restricted stock and restricted stock units	21		111

Identifiable_Intangible_Assets

Identifiable Intangible Assets and Goodwill	6 Months Ended
	Jun. 30, 2014
Identifiable Intangible Assets and Goodwill	'
Identifiable Intangible Assets and Goodwill	'
	3.                                      Identifiable Intangible Assets and Goodwill
	The Company believes there are no indicators of impairment relating to its in-process research and development intangible assets as of June 30, 2014.

Accrued_Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2014
Accrued Expenses	'
Accrued Expenses	'
	4.                                      Accrued Expenses
	Accrued expenses consist of the following:
		As of June 30,		As of December 31,
		2014		2013
		(in thousands)
	Accrued clinical trial expenses	$	2,882	$	2,484
	Accrued technical operation expenses	516		1,220
	Accrued professional fees	669		24
	Accrued interest payable	155		159
	Other accrued expenses	324		18
		$	4,546	$	3,905

Debt

Debt	6 Months Ended
	Jun. 30, 2014
Debt	'
Debt	'
	5.                                    Debt
	On June 29, 2012, the Company and its domestic subsidiaries, as co-borrowers, entered into a Loan and Security Agreement with Hercules Technology Growth Capital, Inc. (“Hercules”) that allowed the Company to borrow up $20.0 million in $10.0 million increments (“Loan Agreement”).  The Company borrowed the first and second $10.0 million increments by signing two Secured Promissory Notes (“Note A” and “Note B” and collectively, the “Notes”) on June 29, 2012 and December 27, 2012, respectively.  Notes A and B bear interest at 9.25%.  Note A was originally scheduled to be repaid over a 42-month period with the first twelve monthly payments representing interest only followed by thirty monthly equal payments of principal and interest.  Note B was originally scheduled to be repaid over a 36-month period with the first six monthly payments representing interest only followed by thirty monthly equal payments of principal and interest.  The Loan Agreement provided that in certain circumstances the Company could delay the first principal payment by five months.  In July 2013, subsequent to the completion of certain ARIKAYCE-related development milestones, the Company elected to extend the interest only period under the Notes from July 31, 2013 to December 31, 2013 and delay the first monthly principal repayments for Notes A and B from August 1, 2013 to January 1, 2014.  On November 25, 2013, the Company and Hercules entered into an amendment (the “Amendment”) of the Loan Agreement. The Amendment initially extended the interest-only period through June 30, 2014 and called for the first monthly principal payment on July 1, 2014.  The Amendment also allowed the Company to further extend the interest-only period through December 31, 2014 and delay the first payment of principal until January 1, 2015, so long as the Company paid a $100,000 fee and obtained positive data from its phase 2 clinical trial of ARIKAYCE in patients who have lung infections caused by nontuberculous mycobacteria (NTM).  In June 2014, the Company paid the $100,000 fee and exercised its option to extend the interest-only period and delay the first payment of principal to January 1, 2015. The election and amendment did not change the maturity date for Notes A and B, which is January 1, 2016.
	In connection with the Loan Agreement, the Company granted the lender a first position lien on all of the Company’s assets, excluding intellectual property.  Prepayment of the loans made pursuant to the Loan Agreement is subject to penalty and the Company is required to pay an “end of term” charge of $390,000, which is being charged to interest expense (and accreted to the debt) using the effective interest method over the life of the Loan Agreement.  Debt issuance fees paid to the lender were recorded as a discount on the debt and are being amortized to interest expense using the effective interest method over the life of the Loan Agreement.  Debt issuance fees paid to third parties were capitalized and are being amortized to interest expense using the effective interest method over the life of the Loan Agreement.
	The Loan Agreement also contains representations and warranties by the Company and the lender and indemnification provisions in favor of the lender and customary covenants (including limitations on other indebtedness, liens, acquisitions, investments and dividends, but no financial covenants), and events of default (including payment defaults, breaches of covenants following any applicable cure period, a material impairment in the perfection or priority of the lender’s security interest or in the collateral, and events relating to bankruptcy or insolvency).  Upon the occurrence of an event of default, a default interest rate of an additional 5% may be applied to the outstanding loan balances, and the lender may terminate its lending commitment, declare all outstanding obligations immediately due and payable, and take such other actions as set forth in the Loan Agreement.  In addition, pursuant to the Loan Agreement, the lender has the right to participate, in an amount of up to $1.0 million, in certain future private equity financing(s) by the Company.
	In conjunction with entering into the Loan Agreement, the Company granted a warrant to the lender to purchase shares of the Company’s common stock.  Since the warrant was granted in conjunction with entering into the Loan Agreement, the relative fair value of the warrant was recorded as equity and debt discount.  The debt discount is being amortized to interest expense over the term of the related debt using the effective interest method.
	The following table presents the components of the Company’s debt balance as of June 30, 2014 (in thousands):
	Debt:
	Notes payable	$	20,000
	Accretion of end of term charge	266
	Issuance fees paid to lender	(247		)
	Discount from warrant	(244		)
	Current portion of long-term debt	(3,281		)
	Long-term debt	$	16,494
	As of June 30, 2014, future principal repayments of the two Notes for the period July 1, 2014 to December 31, 2014 and in each of the years ending December 31, 2015 and 2016 were as follows (in thousands):
	Year Ending in December 31:
	2014	$	—
	2015	7,430
	2016	12,570
		$	20,000
	The estimated fair value of the debt (categorized as a Level 2 liability for fair value measurement purposes) is determined using current market factors and the ability of the Company to obtain debt at comparable terms to those that are currently in place.  The Company believes the estimated fair value at June 30, 2014 approximates the carrying amount.

Stockholders_Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2014
Stockholders' Equity	'
Stockholders' Equity	'
	6.                                      Stockholders’ Equity
	Common Stock — As of June 30, 2014, the Company had 500,000,000 shares of common stock authorized with a par value of $0.01 and 39,276,389 shares of common stock issued and outstanding.  In addition, as of June 30, 2014, the Company had reserved 5,058,459 shares of common stock for issuance upon the exercise of outstanding common stock options and 20,960 for issuance upon the vesting of restricted stock units.
	On July 22, 2013, the Company completed an underwritten public offering of 6,900,000 shares of the Company’s common stock, which included the underwriter’s exercise in full of its over-allotment option of 900,000 shares, at a price to the public of $10.40 per share.  The Company’s net proceeds from the sale of the shares, after deducting the underwriter’s discount and offering expenses of $4.7 million, were $67.0 million.
	Warrant - In conjunction with entering into the Loan Agreement (See Note 5 — Debt), the Company granted a warrant to the lender to purchase 329,932 shares of the Company’s common stock at an exercise price of $2.94 per share.  The fair value of the warrant of $0.8 million was calculated using the Black-Scholes warrant-pricing methodology at the date of issuance and was recorded as equity and as a discount to the debt and is being amortized to interest expense over the term of the related debt using the effective interest method.  On April 30, 2013, the lender exercised the warrant in full via the “net issuance” method specified in the warrant agreement.  In accordance with such provisions, the Company issued and delivered 223,431 shares of common shares to the lender on May 1, 2013.  As a result of the exercise, the warrant is no longer outstanding and there are no additional shares issuable under this instrument.

StockBased_Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2014
Stock-Based Compensation	'
Stock-Based Compensation	'
	7.                                      Stock-Based Compensation
	The Company currently has one equity compensation plan, the 2013 Incentive Plan, which was approved by shareholders at the Company’s Annual Meeting of Shareholders on May 23, 2013 (the “2013 Incentive Plan”).  The 2013 Incentive Plan is administered by the Compensation Committee and the Board of Directors of the Company.  Under the terms of the 2013 Incentive Plan, the Company is authorized to grant a variety of incentive awards based on its common stock, including stock options (both incentive stock options and non-qualified stock options), performance shares and other stock awards, as well as the payment of incentive bonuses to all employees and non-employee directors.  As of June 30, 2014, 323,222 shares of the Company’s common stock were reserved for future grants (or issuances) of restricted stock, restricted stock units, stock options, and stock warrants under the 2013 Incentive Plan.  The 2013 Incentive Plan will terminate on April 16, 2023 unless it is extended or terminated earlier pursuant to its terms.
	During the first quarter of 2013, the Company completed a review of equity compensation awards granted under its previous equity compensation plan and determined that it had inadvertently exceeded the annual per-person sub-limits involving certain awards previously made to certain of its current and past officers and directors (the “excess awards”).  The aggregate amount of common stock represented by these excess awards, which consisted of Restricted Stock Units (“RSUs”) and stock options, was approximately 1.4 million shares.  These awards were deemed to be granted outside of the plan and as such the Company applied liability accounting to these awards.  On May 23, 2013 (the date of the Company’s 2013 Annual Meeting of Stockholders), the Company’s shareholders approved the grants associated with the excess awards, which as of that date, allowed the excess awards to be deemed granted under the previous equity compensation plan.  As a result, the excess awards were remeasured at fair value on May 23, 2013 and the liability was reclassified to additional paid-in capital.  The unrecognized fair value calculated for the excess awards as of May 23, 2013 is recognized as compensation expense ratably over the remaining requisite service period for each award.
	Stock Options - The Company calculates the fair value of stock options granted using the Black-Scholes valuation model.
	The following table summarizes the Company’s grant date fair value and assumptions used in determining the fair value of stock options granted under its’ equity compensation plans:
		Three Months Ended June 30,				Six Months Ended June 30,
		2014		2013		2014		2013
	Volatility	83.1%-85.0%		90.2%-96.0%		83.1%-85.5%		90.2%-96.0%
	Risk-free interest rate	1.52%-1.76%		0.65%-1.13%		1.46%-1.76%		0.65%-1.13%
	Dividend yield	0.00%		0.00%		0.00%		0.00%
	Expected option term (in years)	6.25		6.25		6.25		6.25
	Weighted-average fair value of stock options granted	$9.61		$8.10		$11.83		$7.14
	For all periods presented, the volatility factor was based on the Company’s historical volatility since the closing of the Company’s merger with Transave on December 1, 2010.  The expected life was determined using the simplified method as described in ASC Topic 718, “Accounting for Stock Compensation”, which is the midpoint between the vesting date and the end of the contractual term.  The risk-free interest rate is based on the US Treasury yield in effect at the date of grant.  Forfeitures are based on actual percentage of option forfeitures since the closing of the Company’s merger with Transave on December 1, 2010, and this is the basis for future forfeiture expectations.
	The following table summarizes the Company’s stock option activity for the six months ended June 30, 2014:
		Number of		Weighted			Weighted		Aggregate
		Shares		Average			Average		Intrinsic
				Exercise			Remaining		Value (in
				Price			Contractual		thousands)
							Life in Years
	Options outstanding at December 31, 2013	3,632,996		$	7.94
	Granted	1,517,350		$	16.22
	Exercised	(59,788	)	$	6.86
	Forfeited or expired	(32,099	)	$	11.27
	Options outstanding at June 30, 2014	5,058,459		$	10.42		8.92		$	48,601
	Vested and expected to vest at June 30, 2014	4,732,947		$	10.29		8.9		$	46,057
	Exercisable at June 30, 2014	827,113		$	5.37		8.07		$	12,083
	The total intrinsic value of stock options exercised during the three months ended June 30, 2014 and 2013 was $0.0 million and $1.0 million and during the six months ended June 30, 2014 and 2013 was $0.6 million and $1.1 million, respectively.
	As of June 30, 2014, there was $35.4 million of unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted average period of 2.8 years.  The following table summarizes the range of exercise prices and the number of stock options outstanding and exercisable:
	Outstanding as of June 30, 2014									Exercisable as of June 30, 2014
						Weighted
						Average
						Remaining		Weighted
	Range of Exercise			Number of		Contractual		Average		Number of		Weighted Average
	Prices			Options		Term (in years)		Exercise Price		Options		Exercise Price
	3.03	3.29		272,100		7.39		3.04		167,455		3.04
	3.4	3.4		708,314		8.2		3.4		265,619		3.4
	3.48	6.9		793,153		8.36		6.19		207,660		5.83
	6.96	10.35		535,200		8.73		7.59		99,125		7.36
	11.14	11.46		257,000		9.09		11.22		—		—
	12.44	12.44		543,642		8.87		12.44		78,024		12.44
	12.58	12.58		626,050		9.92		12.58		—		—
	12.7	15.61		521,950		9.42		14.19		9,230		13.05
	15.63	20.49		786,050		9.62		19.38		—		—
	21.54	21.54		15,000		9.56		21.54		—		—
	Restricted Stock and Restricted Stock Units — The Company may grant Restricted Stock (“RS”) and RSUs to eligible employees, including its executives, and non-employee directors.  Each RS and RSU represents a right to receive one share of the Company’s common stock upon the completion of a specific period of continued service or achievement of a certain milestone.  RS and RSU awards granted are generally valued at the market price of the Company’s common stock on the date of grant.  RSUs granted in excess of certain plan sub-limits were considered to be granted outside the previous equity compensation plan and were classified as a liability and remeasured at fair value at the end of each reporting period and changes in fair value are included in compensation expense in the Consolidated Statements of Comprehensive Loss (see additional disclosures related to certain RSUs granted outside the previous equity compensation plan at the end of this note).  The Company recognizes noncash compensation expense for the fair values of these RS and RSUs on a straight-line basis over the requisite service period of these awards.
	The following table summarizes the Company’s RSU award activity during the six months ended June 30, 2014:
				Weighted
		Number of		Average
		RSUs		Grant Price
	Outstanding at December 31, 2013	92,641		$	6.27
	Granted	20,258		19.53
	Released	(91,939	)	6.21
	Outstanding at June 30, 2014	20,960		$	19.35
	Expected to vest	20,960		$	19.35
	Awards Granted outside of the previous equity compensation plan — As described above, during the first quarter of 2013, the Company completed a review of equity compensation awards granted under its previous equity compensation plan and determined that it had inadvertently exceeded the annual per-person sub-limits involving certain awards previously made to certain of its current and past officers and directors.  The aggregate amount of common stock represented by these excess awards, which consisted of RSUs and stock options, was approximately 1.4 million shares.  These awards were deemed to be granted outside of the plan and as such the Company applied liability accounting to these awards.  On May 23, 2013 (the date of the Company’s 2013 Annual Meeting of Stockholders), the Company’s shareholders approved the grants associated with the excess awards, which as of that date, allowed the excess awards to be deemed granted under the previous equity compensation plan.  As a result, the excess awards were remeasured at fair value on May 23, 2013 and the liability was reclassified to additional paid-in capital.  The unrecognized fair value calculated for the excess awards as of May 23, 2013 is recognized as compensation expense ratably over the remaining requisite service period for each award.
	The following table summarizes the aggregate stock-based compensation recorded in the Consolidated Statements of Comprehensive Loss related to stock options and RSUs during the three and six months ended June 30, 2014 and 2013:
		Three months ended June 30,						Six months ended June 30,
		2014			2013			2014			2013
		(in millions)						(in millions)
	Research and development expenses	$	1.4		$	1		$	2.3		$	1.3
	General and administrative expenses	1.6			3			3.1			3.7
	Total	$	3		$	4		$	5.4		$	5

Income_Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2014
Income Taxes	'
Income Taxes	'
	8.                                      Income Taxes
	The benefit for income taxes was $4.4 million and $1.2 million for the six months ended June 30, 2014 and 2013, respectively.  The benefit for income taxes recorded for the six months ended June 30, 2014 and 2013 solely reflect the reversal of a valuation allowance previously recorded against the Company’s New Jersey State net operating losses (“NOL”) that resulted from the Company’s sale of a portion of its New Jersey State NOLs under the State of New Jersey’s Technology Business Tax Certificate Transfer Program (the “Program”) for cash of $4.4 million and $1.2 million, respectively and net of commissions.  The Program allows qualified technology and biotechnology businesses in New Jersey to sell unused amounts of NOLs and defined research and development tax credits for cash.
	The Company is subject to US federal and state income taxes.  The Company has never been audited and the statute of limitations for tax audit is generally open for the years 2010 and later.  The Company has incurred net operating losses since inception, except in 2009.  Such loss carryforwards would be subject to audit in any tax year in which those losses are utilized, notwithstanding the year of origin.  The Company’s policy is to recognize interest accrued related to unrecognized tax benefits and penalties in income tax expense.  The Company has recorded no such expense.  As of June 30, 2014 and December 31, 2013, the Company has recorded no reserves for unrecognized income tax benefits, nor has it recorded any accrued interest or penalties related to uncertain tax positions.  The Company does not anticipate any material changes in the amount of unrecognized tax positions over the next twelve months.  Due to the Company’s history of operating losses, the Company recorded a full valuation allowance on its net deferred tax assets as it is more likely than not that such tax benefits will not be realized.
	At December 31, 2013, the Company had federal net operating loss carryforwards for income tax purposes of approximately $398.7 million available to offset future taxable income, if any.  The NOL carryovers and general business tax credits expire in various years beginning in 2018.
	Utilization of the Company’s NOL and general business tax credit carryforwards generated in prior years through September 2012 (the “September 2012 and prior NOLs”) are likely subject to substantial limitations under Section 382 of the Internal Revenue Code (“Section 382”) due to ownership changes that occurred at various points during years prior to 2012 and during September 2012.  In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain shareholders or public groups in the stock of a corporation by more than 50 percentage points over a three-year period.  Since the Company’s formation, it has raised capital through the issuance of common stock on several occasions which, combined with the purchasing shareholders’ subsequent disposition of those shares, likely resulted in multiple changes in ownership, as defined by Section 382 since the Company’s formation in 1999.  The substantial limitations on the use of the September 2012 and prior NOLs are likely to result in expiration of a substantial portion of these NOL or general business tax credit carryforwards before utilization which would substantially reduce the Company’s gross deferred tax assets.  The Company is currently in the process of completing a Section 382 analysis regarding the limitation of its NOL and general business tax credit carryforwards and intends to disclose the results of this analysis when it is completed.

Collaboration_Agreements

Collaboration Agreements	6 Months Ended
	Jun. 30, 2014
Collaboration Agreements	'
Collaboration Agreements	'
	9.                                      Collaboration Agreements
	Therapure Biopharma Inc. — In February 2014, the Company entered into a Contract Manufacturing Agreement (the “Agreement”) with Therapure Biopharma Inc. (“Therapure”) for the manufacture of the Company’s product ARIKAYCE. Pursuant to the Agreement, the Company and Therapure are collaborating to construct a production area for the manufacture of ARIKAYCE in Therapure’s existing manufacturing facility in Mississauga, Ontario, Canada. Therapure will manufacture ARIKAYCE for the Company on a non-exclusive basis. The Agreement has an initial term of five years from the first date on which Therapure delivers ARIKAYCE to Insmed after Insmed obtains permits related to the manufacture of ARIKAYCE, and will renew automatically for successive periods of two years each, unless terminated by either party by providing the required two years’ prior written notice to the other party.  Notwithstanding the foregoing, the parties have rights and obligations under the Agreement prior to the commencement of the initial term. The Agreement allows for termination by either party upon the occurrence of certain events, including (i) the material breach by the other party of any provision of the Agreement or the quality agreement expected to be entered into between the parties, or (ii) the default or bankruptcy of the other party. In addition, the Company may terminate the Agreement for any reason upon no fewer than one hundred eighty days’ advance notice.  Costs incurred under this agreement will be recorded as a component of research and development expense until such time as the Company receives US Food and Drug Administration approval for ARIKAYCE.
	PARI Pharma GmbH— In July 2014, the Company entered into a Commercialization Agreement (the “PARI Agreement”) with PARI Pharma GmbH (“PARI”) for the manufacture and supply of eFlow nebulizer systems and related accessories (the “Device”) as optimized for use with the Company’s proprietary liposomal amikacin for inhalation. The PARI Agreement has an initial term of fifteen years from the first commercial sale of the Device (the “Initial Term”). The term of the PARI Agreement may be extended by the Company for an additional five years by providing written notice to PARI at the least one year prior to the expiration of the Initial Term. Notwithstanding the foregoing, the parties have certain rights and obligations under the PARI Agreement prior to the commencement of the Initial Term. The PARI Agreement allows for termination by either party upon the occurrence of certain events, including (i) the material breach by the other party of any provision of the PARI Agreement, (ii) the default or bankruptcy of the other party, or (iii) upon termination by the Company of the License Agreement between the parties.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies	'
Commitments and Contingencies	'
	10.                               Commitments and Contingencies
	Commitments
	The Company has two operating leases for office and laboratory space located in Monmouth Junction, New Jersey through December 31, 2014.  Future minimum rental payments under these two leases as of June 30, 2014 total approximately $0.4 million.  The Company also has an operating lease for office and laboratory space located in Bridgewater, New Jersey that terminates in November 2019.  Future minimum rental payments under this lease as of June 30, 2014 total approximately $3.6 million.  The Company also leases office space in Richmond, Virginia, where the Company’s corporate headquarters were once located, through October 2016.  Future minimum rental payments under this lease as of June 30, 2014 total approximately $1.2 million.
	Rent expense charged to operations was $0.3 million and $0.2 million for the three months ended June 30, 2014 and 2013 and $0.6 million and $0.6 million for the six months ended June 30, 2014 and 2013, respectively.  Future minimum rental payments required under the Company’s operating leases for the period from July 1, 2014 to December 31, 2014 and for each of the next five years are as follows (in thousands):
	2014 (remaining)	$	680
	2015	1,106
	2016	1,144
	2017	741
	2018	762
	2019	718
		$	5,151
	Legal Proceedings
	Pilkiewicz v. Transave LLC
	On March 28, 2011, Frank G. Pilkiewicz and other former stockholders of Transave (collectively, the “Petitioners”) filed an appraisal action against the Company’s subsidiary Transave, LLC in the Delaware Court of Chancery captioned Frank G. Pilkiewicz, et al. v. Transave, LLC, C.A. No. 6319-CS.  On December 13, 2011, following the mailing of the revised notice of appraisal rights in accordance with the settlement terms of Mackinson et al. v. Insmed, an Amended Petition for Appraisal of Stock was filed by the Petitioners.
	The Petitioners sought appraisal under Delaware law of their total combined common stock holdings representing total dissenting shares of approximately 7.77 million shares of Transave common stock (the “Transave Stock”).  The Petitioners were challenging the value of the consideration that they would have been entitled to receive for their Transave Stock under the terms of the Company’s merger with Transave.
	Under the terms of the Merger Agreement, certain of the former stockholders of Transave (the “Transave Stockholders”) were obligated to indemnify the Company for certain liabilities in connection with the appraisal action.  The Company notified the Transave Stockholders in May 2012 that the Company was seeking indemnification in accordance with the Merger Agreement and that it would continue to retain the aggregate amount of the holdback shares totaling 1,765,271 shares, as security for any indemnification payments due under the Merger Agreement.  Discovery was completed and a trial was scheduled.  Prior to commencement of the trial, in May 2014, the parties entered into a settlement, dismissal and release agreement.  The Company was indemnified in full for the settlement and related costs incurred in defending the appraisal action.
	From time to time, the Company is a party to various other lawsuits, claims and other legal proceedings that arise in the ordinary course of our business.  While the outcomes of these matters are uncertain, management does not expect that the ultimate costs to resolve these matters will have a material adverse effect on the Company’s consolidated financial position, results of operations or cash flows.

Retirement_Plan

Retirement Plan	6 Months Ended
	Jun. 30, 2014
Retirement Plan	'
Retirement Plan	'
	11.                               Retirement Plan
	The Company has a 401(k) defined contribution plan for the benefit for all employees and permits voluntary contributions by employees subject to IRS-imposed limitations.  There were no employer contributions in the three and six months ended June 30, 2014 and 2013.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2014
Summary of Significant Accounting Policies	'
Fair Value Measurements	'
	Fair Value Measurements - The Company categorizes its financial assets and liabilities measured and reported at fair value in the financial statements on a recurring basis based upon the level of judgments associated with the inputs used to measure their fair value.  Hierarchical levels, which are directly related to the amount of subjectivity associated with the inputs used to determine the fair value of financial assets and liabilities, are as follows:
	·         Level 1 — Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.
	·         Level 2 — Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the assets or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.
	·         Level 3 — Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date.  Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.
	Each major category of financial assets and liabilities measured at fair value on a recurring basis are categorized in the tables below based upon the lowest level of significant input to the valuations.  The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value.  Financial instruments in Level 1 generally include US treasuries and mutual funds listed in active markets.
	The following table presents assets and liabilities measured at fair value as of June 30, 2014 and December 31, 2013 (in thousands):
		Fair Value Measurements at Reporting Date Using
					Quoted Prices in			Quoted Prices in
					Active Markets for			Inactive Markets for			Significant
					Identical Assets			Identical Assets			Unobservable Inputs
		Total			(Level 1)			(Level 2)			(Level 3)
	As of June 30, 2014:
	Assets:
	Cash and cash equivalents	$	82,697		$	82,697		$	—		$	—
		$	82,697		$	82,697		$	—		$	—
	As of December 31, 2013:
	Assets:
	Cash and cash equivalents	$	113,894		$	113,894		$	—		$	—
		$	113,894		$	113,894		$	—		$	—
	The Company’s cash and cash equivalents permit daily redemption and the fair values of these investments are based upon the quoted prices in active markets provided by the holding financial institutions.  Cash equivalents consist of liquid investments with a maturity of three months or less from the date of purchase.
	The Company recognizes transfers between levels within the fair value hierarchy, if any, at the end of each quarter.  There were no transfers in or out of Level 1, Level 2 or Level 3 during the three and six months ended June 30, 2014 and 2013, respectively.
	As of June 30, 2014 and December 31, 2013, the Company held no securities that were in an unrealized gain or loss position.  The Company reviews the status of each security quarterly to determine whether an other-than-temporary impairment has occurred.  In making its determination, the Company considers a number of factors, including: (1) the significance of the decline, (2) whether the securities were rated below investment grade, (3) how long the securities have been in an unrealized loss position, and (4) the Company’s ability and intent to retain the investment for a sufficient period of time for it to recover.
Revenue Recognition	'
	Revenue Recognition — Other revenue during the three and six months ended June 30, 2013 solely consists of an $11.5 million payment the Company received from Premacure (now Shire plc) in exchange for the Company’s right to receive future royalties under its license agreement with Premacure. The Company recorded this as Other revenue during the three months ended June 30, 2013, since all four revenue recognition criteria were met at that time and the Company had no continuing performance obligations related to the payment received. Also see Note 11 of the Company’s audited consolidated financial statements on Form 10-K for the year ended December 31, 2013 for more information.
Net Loss Per Common Share	'
	Net Loss Per Common Share - Basic net loss per common share is computed by dividing net loss by the weighted average number of common shares outstanding during the period.  Diluted net loss per common share is computed by dividing net loss by the weighted average number of common shares and other dilutive securities outstanding during the period.  Potentially dilutive securities from stock options, restricted stock units and warrants to purchase common stock would be antidilutive as the Company incurred a net loss.  Potentially dilutive common shares resulting from the assumed exercise of outstanding stock options and warrants are determined based on the treasury stock method.
	The following table sets forth the reconciliation of the weighted average number of shares used to compute basic and diluted net loss per share for the three and six months ended June 30, 2014 and 2013:
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
		(In thousands, except per share amounts)
	Numerator:
	Net loss	$	(23,224	)	$	(8,854	)	$	(37,522	)	$	(22,532	)
	Denominator:
	Weighted average common shares used in calculation of basic net loss per share:	39,273			31,754			39,256			31,654
	Effect of dilutive securities:
	Common stock options	—			—			—			—
	Restricted stock and restricted stock units	—			—			—			—
	Common stock warrant	—			—			—			—
	Weighted average common shares outstanding used in calculation of diluted net loss per share	39,273			31,754			39,256			31,654
	Net loss per share:
	Basic and Diluted	$	(0.59	)	$	(0.28	)	$	(0.96	)	$	(0.71	)
	The following potentially dilutive securities have been excluded from the computations of diluted weighted-average common shares outstanding as of June 30, 2014 and 2013 as their effect would have been anti-dilutive (in thousands):
		2014		2013
	Stock options to purchase common stock	5,058		3,275
	Restricted stock and restricted stock units	21		111

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2014
Summary of Significant Accounting Policies	'
Assets and liabilities measured on recurring basis	'
	The following table presents assets and liabilities measured at fair value as of June 30, 2014 and December 31, 2013 (in thousands):
		Fair Value Measurements at Reporting Date Using
					Quoted Prices in			Quoted Prices in
					Active Markets for			Inactive Markets for			Significant
					Identical Assets			Identical Assets			Unobservable Inputs
		Total			(Level 1)			(Level 2)			(Level 3)
	As of June 30, 2014:
	Assets:
	Cash and cash equivalents	$	82,697		$	82,697		$	—		$	—
		$	82,697		$	82,697		$	—		$	—
	As of December 31, 2013:
	Assets:
	Cash and cash equivalents	$	113,894		$	113,894		$	—		$	—
		$	113,894		$	113,894		$	—		$	—
Reconciliation of the weighted average number of shares used to compute basic and diluted net loss per share	'
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
		(In thousands, except per share amounts)
	Numerator:
	Net loss	$	(23,224	)	$	(8,854	)	$	(37,522	)	$	(22,532	)
	Denominator:
	Weighted average common shares used in calculation of basic net loss per share:	39,273			31,754			39,256			31,654
	Effect of dilutive securities:
	Common stock options	—			—			—			—
	Restricted stock and restricted stock units	—			—			—			—
	Common stock warrant	—			—			—			—
	Weighted average common shares outstanding used in calculation of diluted net loss per share	39,273			31,754			39,256			31,654
	Net loss per share:
	Basic and Diluted	$	(0.59	)	$	(0.28	)	$	(0.96	)	$	(0.71	)
Potentially dilutive securities excluded from computations of diluted weighted-average shares outstanding	'
	The following potentially dilutive securities have been excluded from the computations of diluted weighted-average common shares outstanding as of June 30, 2014 and 2013 as their effect would have been anti-dilutive (in thousands):
		2014		2013
	Stock options to purchase common stock	5,058		3,275
	Restricted stock and restricted stock units	21		111

Accrued_Expenses_Tables

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2014
Accrued Expenses	'
Accrued Expenses	'
		As of June 30,		As of December 31,
		2014		2013
		(in thousands)
	Accrued clinical trial expenses	$	2,882	$	2,484
	Accrued technical operation expenses	516		1,220
	Accrued professional fees	669		24
	Accrued interest payable	155		159
	Other accrued expenses	324		18
		$	4,546	$	3,905

Debt_Tables

Debt (Tables)	6 Months Ended
	Jun. 30, 2014
Debt	'
Components of the Company's debt balances	'
	The following table presents the components of the Company’s debt balance as of June 30, 2014 (in thousands):
	Debt:
	Notes payable	$	20,000
	Accretion of end of term charge	266
	Issuance fees paid to lender	(247		)
	Discount from warrant	(244		)
	Current portion of long-term debt	(3,281		)
	Long-term debt	$	16,494
Future principal repayments of the Notes	'
	As of June 30, 2014, future principal repayments of the two Notes for the period July 1, 2014 to December 31, 2014 and in each of the years ending December 31, 2015 and 2016 were as follows (in thousands):
	Year Ending in December 31:
	2014	$	—
	2015	7,430
	2016	12,570
		$	20,000

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2014
Stock-Based Compensation	'
Summary of Company's grant date fair value and assumptions used in determining fair value of stock options	'
		Three Months Ended June 30,				Six Months Ended June 30,
		2014		2013		2014		2013
	Volatility	83.1%-85.0%		90.2%-96.0%		83.1%-85.5%		90.2%-96.0%
	Risk-free interest rate	1.52%-1.76%		0.65%-1.13%		1.46%-1.76%		0.65%-1.13%
	Dividend yield	0.00%		0.00%		0.00%		0.00%
	Expected option term (in years)	6.25		6.25		6.25		6.25
	Weighted-average fair value of stock options granted	$9.61		$8.10		$11.83		$7.14
Summary of Company's stock option activity	'
		Number of		Weighted			Weighted		Aggregate
		Shares		Average			Average		Intrinsic
				Exercise			Remaining		Value (in
				Price			Contractual		thousands)
							Life in Years
	Options outstanding at December 31, 2013	3,632,996		$	7.94
	Granted	1,517,350		$	16.22
	Exercised	(59,788	)	$	6.86
	Forfeited or expired	(32,099	)	$	11.27
	Options outstanding at June 30, 2014	5,058,459		$	10.42		8.92		$	48,601
	Vested and expected to vest at June 30, 2014	4,732,947		$	10.29		8.9		$	46,057
	Exercisable at June 30, 2014	827,113		$	5.37		8.07		$	12,083
Summary of range of exercise prices and the number of stock options outstanding and exercisable	'
	Outstanding as of June 30, 2014									Exercisable as of June 30, 2014
						Weighted
						Average
						Remaining		Weighted
	Range of Exercise			Number of		Contractual		Average		Number of		Weighted Average
	Prices			Options		Term (in years)		Exercise Price		Options		Exercise Price
	3.03	3.29		272,100		7.39		3.04		167,455		3.04
	3.4	3.4		708,314		8.2		3.4		265,619		3.4
	3.48	6.9		793,153		8.36		6.19		207,660		5.83
	6.96	10.35		535,200		8.73		7.59		99,125		7.36
	11.14	11.46		257,000		9.09		11.22		—		—
	12.44	12.44		543,642		8.87		12.44		78,024		12.44
	12.58	12.58		626,050		9.92		12.58		—		—
	12.7	15.61		521,950		9.42		14.19		9,230		13.05
	15.63	20.49		786,050		9.62		19.38		—		—
	21.54	21.54		15,000		9.56		21.54		—		—
Summary of Company's RSU activity	'
				Weighted
		Number of		Average
		RSUs		Grant Price
	Outstanding at December 31, 2013	92,641		$	6.27
	Granted	20,258		19.53
	Released	(91,939	)	6.21
	Outstanding at June 30, 2014	20,960		$	19.35
	Expected to vest	20,960		$	19.35
Summary of the aggregate stock-based compensation recorded in the Consolidated Statements of Comprehensive Loss	'
		Three months ended June 30,						Six months ended June 30,
		2014			2013			2014			2013
		(in millions)						(in millions)
	Research and development expenses	$	1.4		$	1		$	2.3		$	1.3
	General and administrative expenses	1.6			3			3.1			3.7
	Total	$	3		$	4		$	5.4		$	5

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies	'
Future minimum rental payments required under operating leases	'
	Future minimum rental payments required under the Company’s operating leases for the period from July 1, 2014 to December 31, 2014 and for each of the next five years are as follows (in thousands):
	2014 (remaining)	$	680
	2015	1,106
	2016	1,144
	2017	741
	2018	762
	2019	718
		$	5,151

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Assets measured at fair value	'	'
Securities that were in an unrealized loss or gain position	$0	$0
Recurring basis	'	'
Assets measured at fair value	'	'
Cash and cash equivalents	82,697,000	113,894,000
Total assets measured at fair value	82,697,000	113,894,000
Recurring basis | Level 1	'	'
Assets measured at fair value	'	'
Cash and cash equivalents	82,697,000	113,894,000
Total assets measured at fair value	$82,697,000	$113,894,000

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Details 2) (Premacure License Agreement, USD $)	3 Months Ended	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2013
Premacure License Agreement	'	'
License and Collaborative Agreements	'	'
License revenues	$11.50	$11.50

Summary_of_Significant_Account5

Summary of Significant Accounting Policies (Details 3) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Numerator:	'	'	'	'
Net loss	($23,224)	($8,854)	($37,522)	($22,532)
Denominator:	'	'	'	'
Weighted average common shares used in calculation of basic net loss per share:	39,273	31,754	39,256	31,654
Weighted average common shares outstanding used in calculation of diluted net loss per share	39,273	31,754	39,256	31,654
Net loss per share:	'	'	'	'
Basic and Diluted (in dollars per share)	($0.59)	($0.28)	($0.96)	($0.71)

Summary_of_Significant_Account6

Summary of Significant Accounting Policies (Details 4)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Stock options to purchase common stock	'	'
Anti-dilutive securities excluded from computations of diluted weighted-average common shares outstanding	'	'
Potentially dilutive securities excluded from computations of diluted weighted-average shares outstanding (in shares)	5,058	3,275
Restricted stock units	'	'
Anti-dilutive securities excluded from computations of diluted weighted-average common shares outstanding	'	'
Potentially dilutive securities excluded from computations of diluted weighted-average shares outstanding (in shares)	21	111

Accrued_Expenses_Details

Accrued Expenses (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accrued Expenses	'	'
Accrued clinical trial expenses	$2,882	$2,484
Accrued technical operation expenses	516	1,220
Accrued professional fees	669	24
Accrued interest payable	155	159
Other accrued expenses	324	18
Total accrued expenses	$4,546	$3,905

Debt_Details

Debt (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Jun. 29, 2012	Jun. 30, 2014	Jun. 30, 2014	Jun. 29, 2012	Dec. 27, 2012
			Loan and Security Agreement	Loan and Security Agreement	Notes	Note A	Note B
			item
Debt	'	'	'	'	'	'	'
Maximum borrowing capacity of term loan	'	'	$20,000,000	'	'	'	'
Incremental amount of term loan	'	'	'	'	'	10,000,000	10,000,000
Number of Secured Promissory Notes	'	'	2	'	'	'	'
Interest rate (as a percent)	'	'	'	'	9.25%	'	'
Period over which note is to be repaid	'	'	'	'	'	'42 months	'36 months
Payment periods representing interest only	'	'	'	'	'	'12 months	'6 months
Periods of equal payment of principal and interest	'	'	'	'	'	'30 months	'30 months
Period over which principal payment could be delayed	'	'	'	'5 months	'	'	'
Fee paid to extend the interest-only period	'	'	'	100,000	'	'	'
"End of term" charge	'	'	390,000	'	'	'	'
Additional interest rate in event of default (as a percent)	'	'	'	5.00%	'	'	'
Limit on lender's participation rights in certain future private equity financings	'	'	'	1,000,000	'	'	'
Debt:	'	'	'	'	'	'	'
Notes payable	20,000,000	'	'	'	'	'	'
Accretion of end of term charge	266,000	'	'	'	'	'	'
Issuance fees paid to lender	-247,000	'	'	'	'	'	'
Discount from warrant	-244,000	'	'	'	'	'	'
Current portion of long-term debt	-3,281,000	'	'	'	'	'	'
Long-term debt	16,494,000	16,338,000	'	'	'	'	'
Future principal repayments of the Notes	'	'	'	'	'	'	'
2015	7,430,000	'	'	'	'	'	'
2016	12,570,000	'	'	'	'	'	'
Total	$20,000,000	'	'	'	'	'	'

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	0 Months Ended			0 Months Ended
In Millions, except Share data, unless otherwise specified	Jul. 22, 2013	Jun. 30, 2014	Dec. 31, 2013	1-May-13	Jun. 30, 2014	Jun. 29, 2012	Jun. 30, 2014	Jun. 30, 2014
				Warrant	Warrant	Warrant	Stock options	Restricted stock units
Stockholders' Equity	'	'	'	'	'	'	'	'
Common stock, authorized shares	'	500,000,000	500,000,000	'	'	'	'	'
Common stock, par value (in dollars per share)	'	$0.01	$0.01	'	'	'	'	'
Common stock, issued shares	'	39,276,389	39,137,679	'	'	'	'	'
Common stock, outstanding shares	'	39,276,389	39,137,679	'	'	'	'	'
Common stock disclosures	'	'	'	'	'	'	'	'
Common stock shares reserved for issuance	'	323,222	'	'	'	'	5,058,459	20,960
Number of shares issued under underwritten public offering	6,900,000	'	'	'	'	'	'	'
Number of share's exercise in full of over-allotment option by underwriter	900,000	'	'	'	'	'	'	'
Shares price (in dollars per share)	$10.40	'	'	'	'	'	'	'
Net proceeds from the sale of shares	$67	'	'	'	'	'	'	'
Underwriter's discount and offering expenses	4.7	'	'	'	'	'	'	'
Warrant disclosures	'	'	'	'	'	'	'	'
Warrant to purchase common stock, number of shares	'	'	'	'	0	329,932	'	'
Exercise price of warrants (in dollars per share)	'	'	'	'	'	$2.94	'	'
Fair value of warrant	'	'	'	$0.80	'	'	'	'
Warrant Shares issued and delivered	'	'	'	223,431	'	'	'	'
Warrant Shares outstanding	'	'	'	'	0	'	'	'

StockBased_Compensation_Detail

Stock-Based Compensation (Details)	Jun. 30, 2014	Dec. 31, 2013	Mar. 31, 2013
		item	Previous equity compensation plan
Stock Based Compensation disclosures	'	'	'
Number of equity compensation plans	'	1	'
Common stock shares reserved for issuance	323,222	'	'
RSUs and stock options in excess of the per person annual sub-limits	'	'	1,400,000

StockBased_Compensation_Detail1

Stock-Based Compensation (Details 2) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Number of Shares	'	'	'	'
Options outstanding (in shares)	'	'	3,632,996	'
Granted (in shares)	'	'	1,517,350	'
Exercised (in shares)	'	'	-59,788	'
Forfeited or expired (in shares)	'	'	-32,099	'
Options outstanding (in shares)	5,058,459	'	5,058,459	'
Vested and expected to vest (in shares)	4,732,947	'	4,732,947	'
Exercisable (in shares)	827,113	'	827,113	'
Weighted Average Exercise Price	'	'	'	'
Options outstanding (in dollars per share)	'	'	$7.94	'
Granted (in dollars per share)	'	'	$16.22	'
Exercised (in dollars per share)	'	'	$6.86	'
Forfeited and expired (in dollars per share)	'	'	$11.27	'
Options outstanding (in dollars per share)	$10.42	'	$10.42	'
Vested and expected to vest (in dollars per share)	$10.29	'	$10.29	'
Exercisable (in dollars per share)	$5.37	'	$5.37	'
Weighted Average Remaining Contractual Life	'	'	'	'
Options outstanding	'	'	'8 years 11 months 1 day	'
Vested and expected to vest	'	'	'8 years 10 months 24 days	'
Exercisable	'	'	'8 years 25 days	'
Aggregate Intrinsic Value	'	'	'	'
Options outstanding (in dollars)	$48,601	'	$48,601	'
Vested and expected to vest (in dollars)	46,057	'	46,057	'
Exercisable (in dollars)	$12,083	'	$12,083	'
Stock options	'	'	'	'
Fair value and assumptions used in determining fair value of stock options	'	'	'	'
Dividend yield (as a percent)	0.00%	0.00%	0.00%	0.00%
Expected option term	'6 years 3 months	'6 years 3 months	'6 years 3 months	'6 years 3 months
Weighted-average fair value of stock options granted (in dollars per share)	$9.61	$8.10	$11.83	$7.14
Stock options | Minimum	'	'	'	'
Fair value and assumptions used in determining fair value of stock options	'	'	'	'
Volatility (as a percent)	83.10%	90.20%	83.10%	90.20%
Risk-free interest rate (as a percent)	1.52%	0.65%	1.46%	0.65%
Stock options | Maximum	'	'	'	'
Fair value and assumptions used in determining fair value of stock options	'	'	'	'
Volatility (as a percent)	85.00%	96.00%	85.50%	96.00%
Risk-free interest rate (as a percent)	1.76%	1.13%	1.76%	1.13%

StockBased_Compensation_Detail2

Stock-Based Compensation (Details 3) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Stock options	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Total intrinsic value of stock options exercised during the period	$0	$1	$0.60	$1.10
Unrecognized compensation expense related to unvested stock options	$35.40	'	$35.40	'
Expected weighted average period for recognizing unrecognized compensation expense	'	'	'2 years 9 months 18 days	'
$3.03 to $3.29	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Range of Exercise Prices lower range limit (in dollars per share)	'	'	$3.03	'
Range of Exercise Prices upper range limit (in dollars per share)	'	'	$3.29	'
Number of Options outstanding (in shares)	272,100	'	272,100	'
Weighted Average Remaining Contractual Term	'	'	'7 years 4 months 20 days	'
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$3.04	'	$3.04	'
Number of Options exercisable (in shares)	167,455	'	167,455	'
Exercisable Options, Weighted Average Exercise Price (in dollars per share)	$3.04	'	$3.04	'
$3.40 to $3.40	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Range of Exercise Prices lower range limit (in dollars per share)	'	'	$3.40	'
Range of Exercise Prices upper range limit (in dollars per share)	'	'	$3.40	'
Number of Options outstanding (in shares)	708,314	'	708,314	'
Weighted Average Remaining Contractual Term	'	'	'8 years 2 months 12 days	'
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$3.40	'	$3.40	'
Number of Options exercisable (in shares)	265,619	'	265,619	'
Exercisable Options, Weighted Average Exercise Price (in dollars per share)	$3.40	'	$3.40	'
$3.48 to $6.90	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Range of Exercise Prices lower range limit (in dollars per share)	'	'	$3.48	'
Range of Exercise Prices upper range limit (in dollars per share)	'	'	$6.90	'
Number of Options outstanding (in shares)	793,153	'	793,153	'
Weighted Average Remaining Contractual Term	'	'	'8 years 4 months 10 days	'
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$6.19	'	$6.19	'
Number of Options exercisable (in shares)	207,660	'	207,660	'
Exercisable Options, Weighted Average Exercise Price (in dollars per share)	$5.83	'	$5.83	'
$6.96 to $10.35	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Range of Exercise Prices lower range limit (in dollars per share)	'	'	$6.96	'
Range of Exercise Prices upper range limit (in dollars per share)	'	'	$10.35	'
Number of Options outstanding (in shares)	535,200	'	535,200	'
Weighted Average Remaining Contractual Term	'	'	'8 years 8 months 23 days	'
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$7.59	'	$7.59	'
Number of Options exercisable (in shares)	99,125	'	99,125	'
Exercisable Options, Weighted Average Exercise Price (in dollars per share)	$7.36	'	$7.36	'
$11.14 to $11.46	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Range of Exercise Prices lower range limit (in dollars per share)	'	'	$11.14	'
Range of Exercise Prices upper range limit (in dollars per share)	'	'	$11.46	'
Number of Options outstanding (in shares)	257,000	'	257,000	'
Weighted Average Remaining Contractual Term	'	'	'9 years 1 month 2 days	'
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$11.22	'	$11.22	'
$12.44 to $12.44	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Range of Exercise Prices lower range limit (in dollars per share)	'	'	$12.44	'
Range of Exercise Prices upper range limit (in dollars per share)	'	'	$12.44	'
Number of Options outstanding (in shares)	543,642	'	543,642	'
Weighted Average Remaining Contractual Term	'	'	'8 years 10 months 13 days	'
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$12.44	'	$12.44	'
Number of Options exercisable (in shares)	78,024	'	78,024	'
Exercisable Options, Weighted Average Exercise Price (in dollars per share)	$12.44	'	$12.44	'
$12.58 to $12.58	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Range of Exercise Prices lower range limit (in dollars per share)	'	'	$12.58	'
Range of Exercise Prices upper range limit (in dollars per share)	'	'	$12.58	'
Number of Options outstanding (in shares)	626,050	'	626,050	'
Weighted Average Remaining Contractual Term	'	'	'9 years 11 months 1 day	'
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$12.58	'	$12.58	'
$12.70 to $15.61	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Range of Exercise Prices lower range limit (in dollars per share)	'	'	$12.70	'
Range of Exercise Prices upper range limit (in dollars per share)	'	'	$15.61	'
Number of Options outstanding (in shares)	521,950	'	521,950	'
Weighted Average Remaining Contractual Term	'	'	'9 years 5 months 1 day	'
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$14.19	'	$14.19	'
Number of Options exercisable (in shares)	9,230	'	9,230	'
Exercisable Options, Weighted Average Exercise Price (in dollars per share)	$13.05	'	$13.05	'
$15.63 to $20.49	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Range of Exercise Prices lower range limit (in dollars per share)	'	'	$15.63	'
Range of Exercise Prices upper range limit (in dollars per share)	'	'	$20.49	'
Number of Options outstanding (in shares)	786,050	'	786,050	'
Weighted Average Remaining Contractual Term	'	'	'9 years 7 months 13 days	'
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$19.38	'	$19.38	'
$21.54 to $21.54	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range	'	'	'	'
Range of Exercise Prices lower range limit (in dollars per share)	'	'	$21.54	'
Range of Exercise Prices upper range limit (in dollars per share)	'	'	$21.54	'
Number of Options outstanding (in shares)	15,000	'	15,000	'
Weighted Average Remaining Contractual Term	'	'	'9 years 6 months 22 days	'
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$21.54	'	$21.54	'

StockBased_Compensation_Detail3

Stock-Based Compensation (Details 4) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Stock options and RSUs	'	'	'	'
Weighted Average Grant Price	'	'	'	'
Allocated share-based compensation expense	$3	$4	$5.40	$5
Stock options and RSUs | Research and development expenses	'	'	'	'
Weighted Average Grant Price	'	'	'	'
Allocated share-based compensation expense	1.4	1	2.3	1.3
Stock options and RSUs | General and administrative expenses	'	'	'	'
Weighted Average Grant Price	'	'	'	'
Allocated share-based compensation expense	$1.60	$3	$3.10	$3.70
Restricted stock units	'	'	'	'
Number of RSUs	'	'	'	'
Outstanding, beginning balance (in shares)	'	'	92,641	'
Granted (in shares)	'	'	20,258	'
Released (in shares)	'	'	-91,939	'
Outstanding, ending balance (in shares)	20,960	'	20,960	'
Expected to Vest (in shares)	20,960	'	20,960	'
Weighted Average Grant Price	'	'	'	'
Outstanding weighted average grant price (in dollars per share)	'	'	$6.27	'
Granted (in dollars per share)	'	'	$19.53	'
Released (in dollars per share)	'	'	$6.21	'
Outstanding weighted average grant price (in dollars per share)	$19.35	'	$19.35	'
Expected to Vest (in dollars per share)	$19.35	'	$19.35	'
Restricted Stock and Restricted Stock Units	'	'	'	'
Stock Based Compensation disclosures	'	'	'	'
Number of common shares each award holder is entitled to receive	'	'	1	'

Income_Taxes_Details

Income Taxes (Details) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Income Taxes	'	'	'
Benefit from income taxes	$4,389,000	$1,221,000	'
Unrecognized tax benefits disclosures	'	'	'
Unrecognized tax benefits, interest and penalties accrued	0	'	0
Unrecognized tax benefits, reserves	0	'	0
IRS	'	'	'
NOL carryforwards	'	'	'
Net operating loss carryforwards for income tax purposes	'	'	398,700,000
Ownership change, as defined in Section 382, which could limit utilization of NOLs (as a percent)	50.00%	'	'
Period of time for measuring ownership changes under Section 382	'3 years	'	'
New Jersey	'	'	'
NOL carryforwards	'	'	'
Cash proceeds from sale of NOLs, net of commissions	$4,400,000	$1,200,000	'

Collaboration_Agreements_Detai

Collaboration Agreements (Details)	1 Months Ended
	Feb. 28, 2014	Feb. 28, 2014	Jul. 31, 2014
	Therapure	Therapure	PARI Agreement
		Minimum	Subsequent events
License and Collaborative Agreements	'	'	'
Initial term of contract manufacturing agreement	'5 years	'	'15 years
Period of each automatic renewal of contract manufacturing agreement	'2 years	'	'
Additional term of contract manufacturing agreement	'	'	'5 years
Written notice period required for termination of contract manufacturing agreement	'2 years	'	'1 year
Advance notice period for termination of contract manufacturing agreement by the entity	'	'180 days	'

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Commitments	'	'	'	'
Future minimum rental payments under leases	$5,151,000	'	$5,151,000	'
Rent expense charged to operations	300,000	200,000	600,000	600,000
Future minimum rental payments under operating leases	'	'	'	'
2014 (remaining)	680,000	'	680,000	'
2015	1,106,000	'	1,106,000	'
2016	1,144,000	'	1,144,000	'
2017	741,000	'	741,000	'
2018	762,000	'	762,000	'
2019	718,000	'	718,000	'
Total	5,151,000	'	5,151,000	'
Monmouth Junction New Jersey Facility	'	'	'	'
Commitments	'	'	'	'
Number of Leases	2	'	2	'
Future minimum rental payments under leases	400,000	'	400,000	'
Future minimum rental payments under operating leases	'	'	'	'
Total	400,000	'	400,000	'
Bridgewater New Jersey Facility	'	'	'	'
Commitments	'	'	'	'
Future minimum rental payments under leases	3,600,000	'	3,600,000	'
Future minimum rental payments under operating leases	'	'	'	'
Total	3,600,000	'	3,600,000	'
Richmond facility	'	'	'	'
Commitments	'	'	'	'
Future minimum rental payments under leases	1,200,000	'	1,200,000	'
Future minimum rental payments under operating leases	'	'	'	'
Total	$1,200,000	'	$1,200,000	'

Commitments_and_Contingencies_2

Commitments and Contingencies (Details 2) (Pilkiewicz v. Transave LLC)	6 Months Ended
	Jun. 30, 2014
Pilkiewicz v. Transave LLC	'
Legal Proceedings	'
Number of dissenting shares to Transave Merger represented in appraisal action	7,770,000
Total holdback shares as securities for indemnification payments due under merger agreement	1,765,271

Retirement_Plan_Details

Retirement Plan (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Retirement Plan	'	'	'	'
Employer contribution to retirement plan	$0	$0	$0	$0