Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2015	Mar. 10, 2016	Jun. 30, 2015
Document and Entity Information
Entity Registrant Name	Bellerophon Therapeutics, Inc.
Entity Central Index Key	0001600132
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		13,477,296
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Public Float			$ 39.1

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 6,260	$ 16,815
Restricted cash	0	9,264
Marketable securities	17,807	0
Prepaid expenses and other current assets	5,385	1,602
Total current assets	29,452	27,681
Restricted cash, non-current	457	1,548
Deferred transaction costs	0	2,466
Other non-current assets	6,701	0
Property and equipment, net	1,799	1,696
Total assets	38,409	33,391
Current liabilities:
Accounts payable	1,613	376
Accrued research and development	2,825	6,666
Accrued expenses	3,487	2,751
Due to Ikaria, Inc.	148	661
Total current liabilities	8,073	10,454
Total liabilities	$ 8,073	$ 10,454
Commitments and contingencies
Stockholders' / members’ equity:
Common stock, $0.01 par value per share; 125,000,000 shares authorized, 13,130,800 shares issued and outstanding at December 31, 2015	$ 131
Preferred Stock, Value, Issued	0
Additional paid-in capital	130,902
Accumulated other comprehensive loss	(19)
Membership units, no par value per unit; 94,273,819 voting units authorized, 7,524,196 voting units issued and outstanding at December 31, 2014; 19,416,481 non-voting units authorized, 381,129 non-voting units issued and outstanding at December 31, 2014		$ 77,156
Accumulated deficit	(100,678)	(54,219)
Total stockholders' / members’ equity	30,336	22,937
Total liabilities and stockholders' / members' equity	$ 38,409	$ 33,391

Consolidated Balance Sheets (Parenthetical)	Dec. 31, 2015 $ / shares shares	Dec. 31, 2014 shares
Common stock, par value \| $ / shares	$ 0.0001
Membership units, par value \| $ / shares	0
Preferred Stock, Shares Authorized	5,000,000
Preferred Stock, Shares Issued	0
Preferred Stock, Shares Outstanding	0
Voting
Common stock, shares authorized (in shares)	125,000,000
Common stock, shares issued (in shares)	13,130,800
Common stock, shares outstanding (in shares)	13,130,800
Membership units, units authorized (in shares)		94,273,819
Membership units, units issued (in shares)		7,524,196
Membership units, units outstanding (in shares)		7,524,196
Non-voting
Membership units, units authorized (in shares)		19,416,481
Membership units, units issued (in shares)		381,129
Membership units, units outstanding (in shares)		381,129

Consolidated Statements of Operations - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								11 Months Ended	12 Months Ended
	Feb. 11, 2014	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating expenses:
Research and development		$ 8,329	$ 7,090	$ 8,426	$ 9,520	$ 9,610	$ 11,559	$ 12,769	$ 12,040		$ 33,365	$ 45,978	$ 52,985
General and administrative		2,533	4,329	3,435	4,573	3,177	3,934	4,194	2,470		14,870	13,775	9,013
Total operating expenses		10,862	11,419	11,861	14,093	12,787	15,493	16,963	14,510		48,235	59,753	61,998
Other operating income		0	250	251	1,166	0	0	0	0		1,667	0	0
Loss from operations		(10,862)	(11,169)	(11,610)	(12,927)	(12,787)	(15,493)	(16,963)	(14,510)		(46,568)	(59,753)	(61,998)
Interest income		36	27	27	19	18	13	48	0		109	79	0
Pre-tax loss		(10,826)	(11,142)	(11,583)	(12,908)	(12,769)	(15,480)	(16,915)	(14,510)		(46,459)	(59,674)	(61,998)
Income tax benefit (expense)		0	0	0	0	0	0	0	0		0	0	0
Net loss	$ (5,455)	$ (10,826)	$ (11,142)	$ (11,583)	$ (12,908)	$ (12,769)	$ (15,480)	$ (16,915)	$ (14,510)	$ (54,219)	$ (46,459)	$ (59,674)	$ (61,998)
Weighted average shares/units outstanding:
Basic and diluted (in shares)		13,026,816	12,911,905	12,910,975	10,152,487	7,898,922	7,897,143	7,898,301	7,899,251		12,267,693	7,898,289
Net loss per share/unit:
Basic and diluted (in dollars per share)		$ (0.83)	$ (0.86)	$ (0.90)	$ (1.27)	$ (1.62)	$ (1.96)	$ (2.14)	$ (1.84)		$ (3.79)	$ (7.56)

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net loss	$ (46,459)	$ (59,674)	$ (61,998)
Other comprehensive loss
Unrealized losses on available-for-sale marketable securities	(19)	0	0
Total other comprehensive loss	(19)	0	0
Net loss and comprehensive loss	$ (46,478)	$ (59,674)	$ (61,998)

Consolidated Statements of Changes in Stockholders'/Members Equity - USD ($) $ in Thousands	Total	Membership Units	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Loss	Accumulated Net Investment Gain (Loss) Attributable to Parent	Accumulated Deficit
Balance at beginning of period at Dec. 31, 2013	$ (15,737)					$ 160,778	$ (176,515)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(5,455)						(5,455)
Investment by Ikaria, Inc., net prior to Spin-Out	7,547					7,547
Additional investment by Ikaria, Inc. for settlement of liabilities prior to Spin-Out	9,196					9,196
Balance at end of period at Feb. 11, 2014	(4,449)					177,521	(181,970)
Balance at beginning of period at Dec. 31, 2013	(15,737)					160,778	(176,515)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(59,674)
Balance at end of period (in shares) at Dec. 31, 2014		7,905,325
Balance at end of period at Dec. 31, 2014	22,937	$ 77,156					(54,219)
Balance at beginning of period at Feb. 11, 2014	(4,449)					177,521	(181,970)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(54,219)						(54,219)
Spinoff transaction	80,000	$ 75,551				$ (177,521)	181,970
Spinoff transaction (in shares)		7,899,251
Stock-based compensation	1,568	$ 1,568
Exercise of options (in shares)		8,182
Exercise of options	66	$ 66
Stock repurchased during period, shares (in shares)		(2,108)
Stock repurchased during period, value	(29)	$ (29)
Balance at end of period (in shares) at Dec. 31, 2014		7,905,325
Balance at end of period at Dec. 31, 2014	22,937	$ 77,156					(54,219)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(46,459)
Stock-based compensation	1,751		$ 1	$ 1,750
Exercise of options (in shares)			126,499
Exercise of options	186		$ 1	185
Other comprehensive income	(19)				$ (19)
Sale of membership units	1	$ 1
Sale of membership units (in units)		67
Conversion of membership units into common stock in connection with conversion of LLC into a C-Corp. (in shares)		(7,905,392)	7,905,392
Conversion of membership units into common stock in connection with conversion of LLC into a C-Corp.		$ (77,157)	$ 79	77,078
Sale of common stock in initial public offering ($12.00 per share), net of underwriting discounts and commissions and offering expenses of $8,085) (in shares)			5,000,000
Sale of common stock in initial public offering ($12.00 per share), net of underwriting discounts and commissions and offering expenses of $8,085)	51,915		$ 50	51,865
Stock issued during period, shares, issued for services			8,000
Stock issued during period, value, issued for services	24		$ 0	24
Stock-based compensation (in shares)			90,909
Balance at end of period (in shares) at Dec. 31, 2015			13,130,800
Balance at end of period at Dec. 31, 2015	$ 30,336		$ 131	$ 130,902	$ (19)		$ (100,678)

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net loss	$ (46,459)	$ (59,674)	$ (61,998)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	(377)	(388)	(429)
Stock-based compensation	1,751	1,839	1,721
Other items	45	0	149
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(3,783)	(50)	94
Restricted cash held for Ikaria, Inc.	10,812	(10,812)	0
Restricted cash held as security deposit	457	0	0
Other non-current assets	6,701	0	0
Accounts payable, accrued research and development, accrued expenses and other liabilities	(1,336)	(2,914)	2,374
Amounts due to Ikaria, Inc.	513	(661)	0
Net cash used in operating activities	(46,264)	(70,562)	(57,231)
Cash flows from investing activities:
Capital expenditures	(458)	0	(727)
Purchase of marketable securities	(22,757)	0	0
Proceeds from sale of marketable securities	4,910	0	0
Net cash used in investing activities	(18,305)	0	(727)
Cash flows from financing activities:
Contribution from Ikaria, Inc. in connection with Spin-Out	0	80,000	0
Contributions from Ikaria, Inc., net	0	9,252	57,958
Transaction costs paid	0	(1,912)	0
Proceeds from sale of membership units	1	0	0
Proceeds received from exercise of options	186	66	0
Repurchase of units	0	(29)	0
Cash proceeds from issuance of common stock from initial public offering, net of issuance costs	53,827	0	0
Net cash provided by financing activities	54,014	87,377	57,958
Net change in cash and cash equivalents	(10,555)	16,815	0
Cash and cash equivalents at beginning of year	16,815	0	0
Cash and cash equivalents at end of year	6,260	16,815	0
Non-cash investing activities:
Change in unrealized holding losses on marketable securities, net	(19)	0	0
Contribution of property, plant and equipment from Ikaria, Inc.	0	0	83
Non-cash financing activities:
Investment by Ikaria, Inc., net	$ 0	$ 7,491	$ (581)

Organization and Nature of the Business

12 Months Ended

Dec. 31, 2015

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Nature of the Business

Bellerophon Therapeutics, Inc., or the Company, is a clinical-stage therapeutics company focused on developing innovative products at the intersection of drugs and devices that address significant unmet medical needs in the treatment of cardiopulmonary diseases. The focus of the Company’s clinical program is the continued development of its nitric oxide therapy for patients with pulmonary hypertension, or PH, using its proprietary delivery system, INOpulse, with pulmonary arterial hypertension, or PAH, representing the lead indication.

The Company’s business is subject to significant risks and uncertainties, including but not limited to:


•	The risk that the Company will not achieve success in its research and development efforts, including clinical trials conducted by it or its potential collaborative partners.


•	The expectation that the Company will experience operating losses for the next several years.


•	Decisions by regulatory authorities regarding whether and when to approve the Company’s regulatory applications as well as their decisions regarding labeling and other matters which could affect the commercial potential of the Company’s products or product candidates.


•	The risk that the Company will fail to obtain adequate financing to meet its future operational and capital needs.


•	The risk that key personnel will leave the Company and/or that the Company will be unable to recruit and retain senior level officers to manage its business.

The Company was formerly the research and development operating segment of Ikaria, Inc. (a subsidiary of Mallinckrodt plc), or Ikaria. During the third quarter of 2013 in conjunction with Ikaria’s financing activities, Ikaria began reporting financial information for two operating segments: its research and development business and its commercial business. During the fourth quarter of 2013, Ikaria completed an internal reorganization of the assets and subsidiaries of its two operating segments. In connection with the internal reorganization, Ikaria formed Bellerophon Therapeutics LLC as a new wholly-owned subsidiary and transferred the research and development-related assets related to INOpulse for PAH and INOpulse for PH-COPD to the Company and/or its subsidiaries.

On December 24, 2013, Ikaria and Madison Dearborn Partners, or MDP, entered into an agreement and plan of merger, under which MDP would acquire a majority ownership position in Ikaria and existing shareholders retained a minority ownership position in Ikaria through certain merger transactions, or the Merger.

On February 12, 2014, prior to the Merger, Ikaria distributed all of the Company’s outstanding units to Ikaria’s stockholders in a pro rata distribution through a special dividend, which is referred to as the Spin-Out.

In the Spin-Out, each holder of Ikaria common stock received one voting limited liability company interest in the Company for each share of Ikaria common stock held.

On February 2, 2015, the Company effected a reverse unit split of its outstanding units at a ratio of one unit for every 12.5257 units previously held. All unit and per unit data included in these consolidated financial statements reflect the reverse unit split.

In February 2015, the Company converted from a limited liability company to a C-corporation. For periods prior to February 2015, references to the Company refer to Bellerophon Therapeutics, LLC.

In connection with the Spin-Out, $80.0 million of cash was distributed to the Company. At the time of the Spin-Out, $18.5 million of the $80.0 million cash held by the Company was deposited in escrow to guarantee payment of the monthly services fees payable by the Company to Ikaria in exchange for the services to be provided by Ikaria pursuant to the Company’s transition services agreement with Ikaria, or the TSA, during the 24 months following the Spin-Out. See Note 8- Related-Party Transactions. On July 9, 2015, the Company entered into an amendment to the TSA advancing the termination date from February 9, 2016 to September 30, 2015. Pursuant to this amendment, during October 2015, the Company received from escrow $3.3 million, which is equal to the amount it deposited to pay amounts owed to Ikaria under the TSA for the remainder of the original period.

On February 19, 2015, the Company completed the sale of 5,000,000 shares of common stock, or the IPO, at a price to the public of $12.00 per share, resulting in net proceeds to the Company of $51.9 million after deducting underwriting discounts and commissions of $4.2 million and offering costs of $3.9 million. The Company’s common stock began trading on the NASDAQ Global Market under the symbol “BLPH” on February 13, 2015.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Summary of Significant Accounting Policies


(a)	Basis of Presentation

The financial statements have been prepared in accordance with U.S. generally accepted accounting principles or GAAP. Intercompany balances and transactions have been eliminated. For periods prior to the Spin-Out, the financial statements were carved out of the consolidated financial statements of Ikaria. Although the financial statements prior to the Spin-Out were prepared on a combined carve-out basis, the financial statements for all periods presented have been labeled “consolidated” financial statements for ease of reference since the most recent balance sheet at December 31, 2015 and 2014 are consolidated balance sheets. At the date of the Spin-Out, the historical accumulated deficit of approximately $182.0 million based on the carve-out financial statements through February 11, 2014 was eliminated in the transfer of net assets to the Company. The net loss for the period February 12, 2014 through December 31, 2014 of $54.2 million has been reflected as the accumulated deficit on the December 31, 2014 consolidated balance sheet, representing the net loss since the date of the Spin-Out. Net assets contributed to the Company in the Spin-Out were $75.6 million, including cash of $80.0 million. The results of operations and cash flows for the year ended December 31, 2015 and from February 12, 2014 through December 31, 2014 and the balance sheet as of December 31, 2015 and 2014 represent actual results and the financial position of the Company on a stand-alone basis. The Company operates in one reportable segment and solely within the United States. Accordingly, no segment or geographic information has been presented.

The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of costs and expenses during the reporting period, including accrued research and development expenses, stock-based compensation, income taxes and valuation of long-lived assets. Actual results could differ from those estimates.

For periods prior to the Spin-Out, the financial statements were carved out of the consolidated financial statements of Ikaria. Management believes that the statements of operations for the periods prior to the Spin-Out (which include a period of forty-two days prior to the Spin-Out in the year ended December 31, 2014) include reasonable allocations of costs and expenses incurred by Ikaria which benefited the Company. However, such amounts may not be indicative of the actual level of costs and expenses that would have been incurred by the Company if it had operated as an independent stand-alone company or of the costs and expenses expected to be incurred in the future. As such, the financial information for the years ended December 31, 2014 and 2013 may not necessarily reflect the results of operations and cash flows of the Company had it been an independent stand-alone company for the period, or the results of operations and cash flows expected in the future.

Direct and indirect costs related to the Company for INOpulse for PAH, INOpulse for PH-COPD and BCM clinical programs have been allocated to the Company for periods prior to February 12, 2014. These allocations were based on either a specific identification basis or, when specific identification was not practicable, proportional cost allocation methods, such as time and wage studies, depending on the nature of the expense. All allocations were based on actual costs incurred. For purposes of allocating non-project specific expenses, each departmental head provided information as to the percentage of employee time incurred on behalf of the Company.

Allocations of general and administrative expenses by Ikaria to the Company for periods prior to February 12, 2014 include allocations of corporate management, finance, information technology, legal, human resources and other overhead expenses, based on an approximate pro-rata headcount of employees.


(b)	Cash and Cash Equivalents

The Company considers all highly liquid investments with an original maturity date of three months or less to be cash equivalents. All investments with maturities of greater than three months from date of purchase are classified as available-for-sale marketable securities.


(c)	Restricted Cash

Restricted cash as of December 31, 2014 represents amounts previously held on deposit with a bank in relation to the TSA. The funds related to the TSA were held in an account to settle the required payment to Ikaria for services to be provided in connection with the TSA. Restricted cash as of December 31, 2015 represents amounts held on deposit with a bank as a security deposit for the lease of office space. The required deposits to be maintained in excess of one year from the balance sheet date are classified as long-term restricted cash.


(d)	Property and Equipment

Property and equipment are recorded at acquisition cost, which for internally developed assets include labor, materials and overhead. Additions and improvements that increase the value or extend the life of an asset are capitalized. Repairs and maintenance costs are expensed as incurred.

Property and equipment are depreciated on a straight-line basis over the estimated useful lives (3-15 years) of the respective assets.

Leasehold improvements are capitalized and amortized over the lesser of the remaining life of the lease or the estimated useful life of the asset.


(e)	Impairment of Long-Lived Assets

Long-lived assets, such as property, plant and equipment, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted expected future cash flows. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be sold are no longer depreciated and are reclassified outside of property, plant and equipment at the lower of the carrying amount or fair value less costs to sell.


(f)	Stock-Based Compensation

The Company accounts for its stock-based compensation in accordance with Accounting Standards Codification, or ASC, 718 Compensation- Stock Compensation, which establishes accounting for share-based awards, including stock options and restricted stock, exchanged for services and requires companies to expense the estimated fair value of these awards over the requisite service period. The Company recognizes stock-based compensation expense in operations based on the fair value of the award on the date of the grant. The resulting compensation expense is recognized on a straight-line basis over the requisite service period or sooner if the awards immediately vest. The Company determines the fair value of stock options issued using a Black-Scholes-Merton option pricing model. Certain assumptions used in the model include expected volatility, dividend yield, risk-free interest rate, and expected term. For restricted stock, the fair value is the closing market price per share on the grant date. See Note 7 - Stock-Based Compensation for a description of these assumptions.

Prior to the date of the Spin-Out, stock-based compensation expense for the Company represented an allocation of Ikaria’s stock-based compensation expense based on the allocation percentages of the Company’s cost centers, which were determined based on specific identification or the proportionate percentage of employee time or headcount to the respective total Ikaria employee time or headcount.


(g)	Deferred Transaction Costs

Deferred transaction costs represent IPO-related costs primarily associated with third-party professional legal, accounting and printing fees associated with the IPO of the Company’s shares. These IPO-related costs were deferred and charged against the gross proceeds of the offering when the public offering of equity securities was complete as a reduction of additional paid-in capital. As of December 31, 2015, the Company charged all deferred transaction costs against the gross proceeds of the offering.


(h)	Income Taxes

Prior to its conversion to a Delaware corporation in February 2015, the Company was a Delaware limited liability company, or LLC, that passed through income and losses to its members for U.S. federal and state income tax purposes. As a result of its conversion to a Delaware corporation, the Company recognized deferred income taxes through income tax expense related to temporary differences that existed as of the date of its tax status change. The Company uses the asset and liability approach to account for income taxes as required by ASC 740, Income Taxes, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Valuation allowances are provided when necessary to reduce deferred tax assets to the amount expected to be realized, on a more likely than not basis. The Company recognizes the benefit of an uncertain tax position that it has taken or expects to take on income tax returns it files if such tax position is more likely than not to be sustained on examination by the taxing authorities, based on the technical merits of the position. These tax benefits are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate resolution.

As of the date of the conversion to a taxable corporation, the Company recognized approximately $17.9 million of deferred tax assets which consisted principally of excess tax-over-book basis in intangible assets and property, plant and equipment and certain accruals that were transferred from the limited liability company to the corporation. The Company also recognized a full valuation allowance since it had a cumulative loss position and no positive evidence of taxable income to support recovery of the deferred tax assets. The Company incurred transaction costs of approximately $8.1 million in connection with the IPO which were recorded as a reduction of equity. These costs are nondeductible until and if the Company liquidates or terminates, which is not expected in the foreseeable future. Therefore, the Company did not recognize a deferred tax asset for such costs.


(i)	Marketable Securities

The Company’s marketable securities consist of federally insured certificates of deposit classified as available-for-sale that are recorded at amortized cost, which approximates fair value, and corporate or agency bonds classified as available-for-sale that are recorded at fair value. Unrealized gains and losses are reported as accumulated other comprehensive (loss) income, except for losses from impairments which are determined to be other-than-temporary. Realized gains and losses, and declines in value judged to be other-than-temporary on available-for-sale securities are included in the determination of net loss and are included in interest income, at which time the average cost basis of these securities are adjusted to fair value. Fair values are based on quoted market prices at the reporting date. Interest on available-for-sale securities are included in interest income.


(j)	Research and Development Expense

Research and development costs are expensed as incurred. These expenses include the costs of the Company’s proprietary research and development efforts, as well as costs incurred in connection with certain licensing arrangements. Upfront and milestone payments made to third parties in connection with research and development collaborations are expensed as incurred up to the point of regulatory approval. Payments made to third parties upon or subsequent to regulatory approval are capitalized and amortized over the remaining useful life of the related product. The Company also expenses the cost of purchased technology and equipment in the period of purchase if it believes that the technology or equipment has not demonstrated technological feasibility and it does not have an alternative future use. Nonrefundable advance payments for goods or services that will be used or rendered for future research and development activities are deferred and are recognized as research and development expense as the related goods are delivered or the related services are performed.

(k) Financial Instruments

The carrying amounts of cash and cash equivalents, restricted cash, prepaid expenses and other current assets and current liabilities approximate fair value due to the short-term maturity of these instruments.

(l) Reclassification

Certain prior period balances have been reclassified to conform to the current period presentation.

(m) New Accounting Pronouncements

In August 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2014-15, “Presentation of Financial Statements - Going Concern: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern”. This guidance clarifies that an entity’s management should evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued. The amendments in this update are effective for annual reporting periods ending after December 15, 2016, and annual and interim periods thereafter, and early application is permitted. The Company is assessing ASU 2014-15’s impact and will adopt it when effective.

On May 28, 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers”, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for the Company on January 1, 2018. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is assessing ASU 2014-09’s impact and will adopt it when effective.

In February 2016, the FASB issued ASU 2016-02, "Leases", which is intended to improve financial reporting about leasing transactions. This standard requires a lessee to record on the balance sheet the assets and liabilities for the rights and obligations created by lease terms of more than 12 months. This standard will be effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is currently evaluating the impact the adoption of ASU 2016-02 will have on the consolidated financial position, results of operations or cash flows.

Liquidity	12 Months Ended
Liquidity	Dec. 31, 2015
Liquidity
Liquidity	Liquidity In the course of its development activities, the Company has sustained operating losses and expects such losses to continue over the next several years. The Company had cash and cash equivalents of $6.3 million and marketable securities of $17.8 million as of December 31, 2015. The Company received net proceeds of $51.9 million in February 2015 as a result of the IPO, after deducting underwriting discounts and commissions of $4.2 million and offering costs of $3.9 million. The Company expects to continue to incur significant expenses and operating losses for the foreseeable future as it continues the development and clinical trials of, and seek regulatory approval for, its product candidates. The Company's primary uses of capital are, and it expects will continue to be, compensation and related expenses, third-party clinical research and development services, contract manufacturing services, laboratory and related supplies, clinical costs, legal and other regulatory expenses and general overhead costs. The Company's existing cash and cash equivalents and marketable securities as of December 31, 2015 will be used primarily to fund the first of two INOpulse for PAH Phase 3 trials, in which the Company expects to enroll the first patient in the first half of 2016. In addition, as of December 31, 2015, the Company had $11.3 million prepayments of research and development expenses related to its amended drug supply agreement with Ikaria and the clinical research organization it has partnered with for the first of the two Phase 3 clinical trials for INOpulse for PAH. The Company believes, as of December 31, 2015, it has sufficient funds to satisfy its operating cash needs for at least the next 12 months due in part to the Restructuring and other cost saving initiatives. The Company expects these funds, combined with additional funding anticipated from Global Corporate Finance, or GCF, will be sufficient to complete the first of two PAH Phase 3 trials. During December 2015, the Company entered into a letter agreement with GCF. In accordance with the terms of the letter agreement, the Company has agreed to place with GCF up to $20 million of its common stock subject to the execution of a definitive share purchase agreement and registration rights agreement. The Company may not draw down amounts that would result in GCF owning more than 19.9% of our outstanding shares. The first two draw downs under this letter agreement may not exceed $2 million. Thereafter, the draw down amounts will depend on the average daily trading volume of the Company's shares. The Company’s estimates and assumptions may prove to be wrong, and the Company may exhaust its capital resources sooner than expected. The process of testing product candidates in clinical trials is costly, and the timing of progress in clinical trials is uncertain. Because the Company’s product candidates are in clinical development and the outcome of these efforts is uncertain, the Company cannot estimate the actual amounts that will be necessary to successfully complete the development and commercialization, if approved, of its product candidates or whether, or when, the Company may achieve profitability. Until such time, if ever, as the Company can generate substantial product revenues, its expects to finance its cash needs through a combination of equity and debt offerings, existing working capital and funding from potential future collaboration arrangements. To the extent that the Company raises additional capital through the future sale of equity or debt, the ownership interest of its existing stockholders will be diluted, and the terms of such securities may include liquidation or other preferences or rights such as anti-dilution rights that adversely affect the rights of our existing stockholders. If the Company raises additional funds through strategic partnerships in the future, it may have to relinquish valuable rights to its technologies, future revenue streams or product candidates or grant licenses on terms that may not be favorable to it. If the Company is unable to raise additional funds through equity or debt financings when needed, it may be required to delay, limit, reduce or terminate its product development or future commercialization efforts or grant rights to develop and market product candidates that it would otherwise prefer to develop and market itself.

Restructuring Charges

12 Months Ended

Dec. 31, 2015

Restructuring and Related Activities [Abstract]

Restructuring Charges

On July 27, 2015, the Company announced that its PRESERVATION I clinical trial for its BCM product candidate did not meet its primary or secondary endpoints. Following these results, on September 11, 2015, the Board of Directors of the Company approved a staff reduction plan in order to reduce operating expenses and conserve cash resources, or the Restructuring. The Restructuring included a workforce reduction of approximately 20 people and was completed by the end of 2015.

The Company has offered severance benefits to the affected employees, including cash severance payments. Each affected employee’s eligibility for the severance benefits is contingent upon such employee’s execution (and non-revocation) of a separation agreement, which includes a general release of claims against the Company.

The following table summarizes restructuring activities for the year ended December 31, 2015:



	Amounts
	(in thousands)
Accrual balance at December 31, 2014	$	—
Charged to research and development expense	321
Charged to general and administrative expense	1,053
Cash payments	(405		)
Accrual balance at December 31, 2015⁽¹⁾	$	969

(1) Included under Accrued expenses

There were no restructuring activities in the years ended December 31, 2014 and 2013.

Property and Equipment

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Property and Equipment

At the date of the Spin-Out, Ikaria transferred specifically identified assets to the Company at the carrying amount of the assets as of February 12, 2014. Prior to the date of the Spin-Out, property, plant and equipment and accumulated depreciation were either specifically identified or allocated to the Company by Ikaria. Property and equipment as of December 31, 2015 and December 31, 2014 consist of the following (in thousands):



	December 31, 2015			December 31, 2014
Machinery and equipment	$	2,943		$	2,943
Leasehold improvements	204			—
Furniture and fixtures	276			—
Less accumulated depreciation	(1,624		)	(1,247		)
	$	1,799		$	1,696

Income Taxes

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Income Taxes

The Company’s tax rate for 2015 is zero because the Company expects to generate additional losses and currently has a full valuation allowance. The Company was an LLC as of December 31, 2014 and until February 12, 2015 when it converted to a C corporation. Although, the Company was not subject to income taxes in any jurisdiction while it was an LLC, one of the Company’s subsidiaries was a C-corporation and subject to state and federal income taxes. This subsidiary generated an immaterial operating loss in 2014 and the short year ended February 12, 2015. Accordingly, no provision or benefit for income taxes is reflected in the Company’s 2014 or 2015 consolidated financial statements. Prior to the date of the Spin-Out, the Company did not file a separate tax return as the Company was included in the tax groupings of other Ikaria entities within the respective entity’s tax jurisdiction. As such, the income tax provision for 2013 was calculated using the separate return method, as if the Company filed a separate tax return in each of its respective tax jurisdictions. The income tax provisions for 2013 included in these carve out financial statements reflects Ikaria’s status as a C-corporation.

A reconciliation of the statutory federal income tax rate to the Company’s effective tax rate for the years ended December 31, 2015 and 2013 is as follows:



	Year Ended December 31, 2015		Year Ended December 31, 2013
U.S. federal statutory rate	34.0	%	35.0	%
State and local taxes, net of federal tax effect	5.8	%	5.3	%
Research tax credits	15.8	%	5.0	%
Valuation allowance	(55.1	)%	(44.4	)%
Incentive stock options	(0.5	)%	(0.1	)%
Other	—	%	(0.8	)%
	0.0	%	0.0	%

Deferred taxes as of December 31, 2015 reflect the tax effects of the differences between the amounts recorded as assets and liabilities for financial reporting purposes and the comparable amounts recorded for income tax purposes. Significant components of the deferred tax assets (liabilities) at December 31, 2015 are as follows:



	December 31, 2015
	Assets			(Liabilities)
Net operating loss carryforwards	$	15,459		$	—
Research tax credit carryforwards	9,753			—
Property and equipment	—			(130		)
Stock based compensation	359			—
Intangible assets	12,371			—
Accrued expenses	2,521			—
Subtotal	40,463			(130		)
Valuation allowance	(40,333		)	—
Total deferred tax assets (liabilities)	$	130		$	(130	)
Net deferred tax assets	$	—

There were no deferred taxes as of December 31, 2014. The increase in deferred tax assets after the corporate conversion is principally due to the year-to-date loss, adjusted for nondeductible items, including stock compensation expense related to the Company’s equity incentive plan, the nondeductible portion of the orphan drug costs, and the orphan drug credits partially offset by a reduction in accrued expenses.

A valuation allowance is provided when it is more likely than not that some portion or all of the deferred tax assets will not be realized. As of December 31, 2015, management believed that it was more likely than not that the deferred tax assets would not be realized, based on future operations, consideration of tax strategies and the reversal of deferred tax liabilities. The valuation allowance is required until the Company has sufficient positive evidence of taxable income necessary to support realization of its deferred tax assets. A valuation allowance release is recognized as an income tax benefit.

Deferred taxes arising from the loss in the Company’s C-corporation subsidiary as of December 31, 2014 were immaterial. No other deferred taxes existed at December 31, 2014 due to the Company’s limited liability company structure.

As of December 31, 2015 and 2014, the Company had no material uncertain tax positions.

Stock-Based Compensation

12 Months Ended

Dec. 31, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

Determining the appropriate fair value of stock-based awards requires the input of subjective assumptions, including the fair value of the Company’s units (prior to the IPO date) and for options, the expected term of the option and expected volatility. The Company uses the Black-Scholes-Merton option pricing model to value its stock option awards. The assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment. As a result, if factors change and management uses different assumptions, stock-based compensation expense could be materially different for future awards. The expected term of stock options is estimated using the “simplified method,” as the Company has no historical information to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for its stock options grants. The simplified method is based on the average of the vesting tranches and the contractual life of each grant. For volatility, the Company uses comparable public companies as a basis for its expected volatility to calculate the fair value of option grants due to its limited history as a public company. The risk-free interest rate is based on U.S. Treasury notes with a term approximating the expected term of the option. For restricted stock, the fair value is the closing market price per share on the grant date. The estimation of the number of stock awards that will ultimately vest requires judgment, and to the extent actual results or revised estimates differ from the Company’s current estimates, such amounts will be recorded as an adjustment in the period in which estimates are revised.

Bellerophon 2015 Equity Incentive Plan

During the year ended December 31, 2015, the Company adopted the 2015 Equity Incentive Plan, or the 2015 Plan, which provides for the grant of options, restricted stock and other forms of equity compensation. As of December 31, 2015, the Company is authorized to issue equity compensation under the 2015 Plan in an amount up to an aggregate of 500,162 shares to eligible employees, directors and consultants.

As of December 31, 2015, there was approximately $3.5 million of total unrecognized compensation expense related to unvested stock awards. This expense is expected to be recognized over a weighted-average period of 2.5 years.

No tax benefit was recognized during the year end December 31, 2015 related to stock-based compensation expense since the Company incurred operating losses and has established a full valuation allowance to offset all the potential tax benefits associated with its deferred tax assets.

Options

Compensation expense is measured based on the fair value of the option on the grant date and is recognized on a straight-line basis over the requisite service period, or sooner if vesting occurs sooner than on a straight-line basis. Options are forfeited if the employee ceases to be employed by the Company prior to vesting.

During the year ended December 31, 2014, the Company adopted the 2014 Equity Incentive Plan, or the 2014 Plan, which provides for the grant of options. Following the effectiveness of the Company’s registration statement filed in connection with its IPO, no options may be granted under the 2014 Plan. The awards granted under the 2014 Plan generally have a vesting period of four years, of which 25% of the awards vest on the second anniversary of grant date, 25% vest on the third anniversary and the remaining 50% vest on the fourth anniversary of the grant date. The awards granted under the 2015 Plan have a vesting period of either three or four years, of which equal annual installments vest over the vesting period either beginning on the date of grant or on the one year anniversary of the date of grant.

The weighted average grant-date fair value of options issued during the year ended December 31, 2015 and 2014 was $6.55 and $9.98, respectively. The following are the weighted average assumptions used in estimating the fair value of options issued during the years ended December 31, 2015 and 2014.



	Year Ended December 31, 2015		Year Ended December 31, 2014
Valuation assumptions:
Risk-free interest rate	1.60	%	1.71	%
Expected volatility	79.18	%	90.00	%
Expected term (in years)	6.1		6.1
Dividend yield	—	%	—	%

A summary of option activity under the 2015 and 2014 Plan for the year ended December 31, 2014 and 2015 is presented below:



	Bellerophon 2015 and 2014 Equity Incentive Plans
	Shares		Exercise Price				Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)
Options outstanding as of February 12, 2014	—		—				—
Granted	514,266		$	13.28			$	13.28
Exercised	—
Forfeited	(5,986	)	$	13.28			$	13.28
Options outstanding as of December 31, 2014	508,280		$	13.28			$	13.28	9.5
Granted	443,607		4.12		-	12.00	9.53
Exercised	—
Forfeited	(246,707	)	8.23		-	13.28	9.95
Options outstanding as of December 31, 2015	705,180		$	4.12	-	13.28	$	12.08	8.7
Options vested and exercisable as of December 31, 2015	210,723		$	10.22	-	13.28	$	12.97	8.6

Restricted Stock

All restricted stock awards granted under the 2015 Plan to date were in relation to 2015 incentives for employees and vest in full one year from the grant date.

A summary of restricted stock activity under the 2015 Plan for the year ended December 31, 2015 is presented below:



	Bellerophon 2015 Equity Incentive Plan
	Shares		Weighted Average Fair Value			Aggregate Grant Date Fair Value(in millions)			Weighted Average Remaining Contractual Life (in years)
Restricted stock outstanding as of December 31, 2014	—		$	—		$	—		—
Granted	90,909		3.86			0.4
Vested	(13,116	)	(3.08		)	(0.1		)
Forfeited	—
Restricted stock outstanding as of December 31, 2015	77,793		$	3.99		$	0.3		0.7

Ikaria Equity Incentive Plans for Periods Prior to February 12, 2014

Options

In February 2014, prior to the Spin-Out, each Ikaria stock option, other than options held by non-accredited investors who were also not employees of Ikaria, was adjusted such that it became an option to acquire the same number of shares of Ikaria non-voting common stock as were subject to the Ikaria stock option, or an Adjusted Ikaria Option, and an option to acquire the same number of non-voting limited liability company units of the Company as the number of shares of Ikaria non-voting common stock that were subject to the Ikaria stock option, or a Bellerophon Option. There were 618,212 Bellerophon Options issued as a result of the adjustment of Ikaria stock options. The vesting of each Adjusted Ikaria Option and Bellerophon Option was fully accelerated on the date of the Spin-Out and all related compensation expense was recognized as an expense by Ikaria.

Prior to and in connection with the Spin-Out, the exercise price of each Adjusted Ikaria Option and Bellerophon Option was adjusted by allocating the relative post Spin-Out estimated fair values of Ikaria and the Company in a ratio of 85% and 15%, respectively, to the original Ikaria option exercise price. The expiration date of the options was not modified. The Company’s allocable portion of Ikaria’s stock-based compensation expense related to options for the period from January 1, 2014 through February 11, 2014 was approximately $0.1 million.

A summary of option activity under the assumed Ikaria 2007 stock option plan and the assumed Ikaria 2010 long term incentive plan for the year ended December 31, 2015 is presented below:



	Ikaria Equity Incentive Plans for Periods Prior to February 12, 2014
	Shares		Range of Exercise Price				Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)
Options issued and vested at date of Spin-Out as of February 12, 2014	618,212		$	0.26	-	17.92	$	7.24
Exercised	(8,182	)	7.77		-	8.77	7.99
Forfeited	(32,055	)	7.77		-	14.91	9.39
Options outstanding, vested and exercisable as of December 31, 2014	577,975		$	0.26	-	17.92	$	7.11	4.5
Exercised	(126,499	)	1.13		-	7.77	1.47
Forfeited	(337,767	)	7.77		-	17.92	8.61
Options outstanding, vested and exercisable as of December 31, 2015	113,709		$	0.26	-	17.92	$	8.93	5.2

The intrinsic value of options exercised during the year ended December 31, 2015 and 2014 was $0.4 million and de minimis, respectively. The intrinsic value of options outstanding, vested and exercisable as of December 31, 2015 was de minimis.

Restricted Stock Units

In February 2014, prior to the Spin-Out, each Ikaria restricted stock unit, or RSU, was adjusted such that it became an RSU with respect to the same number of shares of Ikaria non-voting common stock as were subject to the Ikaria RSU, or an Adjusted Ikaria RSU, and an RSU with respect to the same number of non-voting limited liability company units of the Company as were subject to the Ikaria RSU, or a Bellerophon RSU. In connection with the Merger and the Spin-Out, the vesting of each Adjusted Ikaria RSU and Bellerophon RSU was fully accelerated. The compensation expense incurred upon the acceleration of the RSUs was recognized by Ikaria. Fully vested Bellerophon RSUs of 372,947 became Bellerophon non-voting units as of the date of the Spin-Out.

Ikaria had granted RSUs to employees that generally vested over four years. RSUs granted prior to January 1, 2011 vested 25% annually. RSUs granted on and after January 1, 2011 vested 25% on the second and third anniversary of the date of grant and 50% on the fourth anniversary of the date of grant. Shares of Ikaria non-voting common stock were delivered to the employee upon vesting, subject to payment of applicable withholding taxes, which were paid in cash or an equivalent amount of shares withheld. Compensation expense for all RSUs was based on the grant date fair value of the RSU issued, which was based on the fair value of common stock of Ikaria. Compensation expense for RSUs was recognized by Ikaria on a straight-line basis over the requisite service period. The RSU expense allocated from Ikaria totaled $0.2 million for the period from January 1, 2014 through February 11, 2014.

Stock-Based Compensation Expense, Net of Estimated Forfeitures

The following table summarizes the stock-based compensation expense for the years ended December 31, 2015, 2014 and 2013. The following disclosures include stock-based compensation expense recognized under the 2015 Plan and the 2014 Plan and expenses for dates prior to the Spin-Out that were allocated to the Company related to Ikaria share-based awards.



	Year Ended December 31,
(in thousands)	2015		2014		2013
Research and development	$	364	$	271	$	1,120
General and administrative	1,387		1,568		601
Total expense	$	1,751	$	1,839	$	1,721

Related-Party Transactions

12 Months Ended

Dec. 31, 2015

Related-Party Transactions

During the years ended December 31, 2013 and 2014, Ikaria was a related party of the Company. Included below and elsewhere in the financial statements are transactions and balances that relate to agreements entered into while Ikaria was a related party of the Company. Amendments to those agreements entered into during the year ended December 31, 2015 were entered into while the Company was no longer a related party.

Separation and Distribution Agreement

In connection with the Spin-Out, in February 2014, the Company and Ikaria entered into a separation and distribution agreement which sets forth provisions relating to the separation of the Company’s business from Ikaria’s other businesses. The separation and distribution agreement described the assets and liabilities that remained with or were transferred to the Company and those that remained with or were transferred to Ikaria. The separation and distribution agreement provides for a full and complete release and discharge of all liabilities between Ikaria and the Company, except as expressly set forth in the agreement. The Company and Ikaria each agreed to indemnify, defend and hold harmless the other party and its subsidiaries, and each of their respective past and present directors, officers and employees, and each of their respective permitted successors and assigns, from any and all damages relating to, arising out of or resulting from, among other things, the Company’s business and certain additional specified liabilities or Ikaria’s business and certain additional specified liabilities, as applicable.

License Agreement

In February 2014, the Company entered into a cross-license, technology transfer and regulatory matters agreement with a subsidiary of Ikaria. Pursuant to the terms of the license agreement, Ikaria granted to the Company a fully paid-up, non-royalty-bearing, exclusive license under specified intellectual property rights controlled by Ikaria to engage in the development, manufacture and commercialization of nitric oxide, devices to deliver nitric oxide and related services for or in connection with out-patient, chronic treatment of patients who have PAH, PH-COPD or PH associated with idiopathic pulmonary fibrosis, or PH-IPF. Pursuant to the terms of the license agreement, the Company granted Ikaria a fully paid-up, non-royalty-bearing, exclusive license under specified intellectual property rights that the Company controls to engage in the development, manufacture and commercialization of products and services for or used in connection with the diagnosis, prevention or treatment, whether in- or out-patient, of certain conditions and diseases other than PAH, PH-COPD or PH-IPF and for the use of nitric oxide to treat or prevent conditions that are primarily managed in the hospital. The Company agreed that, during the term of the license agreement, it will not, without the prior written consent of Ikaria, grant a sublicense under any of the intellectual property licensed to the Company under the license agreement to any of its affiliates or any third party, in either case, that directly or indirectly competes with Ikaria’s nitric oxide business.

On July 27, 2015, the Company entered into an amendment to the license agreement to expand the scope of the Company’s license to allow the Company to develop its INOpulse program for the treatment of three additional indications: chronic thromboembolic PH, or CTEPH, PH associated with sarcoidosis and PH associated with pulmonary edema from high altitude sickness. Subject to the terms set forth therein, the amendment to the license agreement also provides that the Company will pay Ikaria a royalty equal to 5% of net sales of any commercialized products for the three additional indications.

In November 2015, the Company entered into an amendment to its exclusive cross-license, technology transfer and regulatory matters agreement with Ikaria that included a royalty equal to 3% of net sales of any commercial products for PAH.

Agreements Not to Compete

In September 2013, October 2013 and February 2014, the Company and each of its subsidiaries entered into an agreement not to compete with a subsidiary of Ikaria, each of which was amended in July 2015, or, collectively, the agreements not to compete. Pursuant to the agreements not to compete, as amended, the Company and each of its subsidiaries agreed not to engage, anywhere in the world, in any manner, directly or indirectly, until the earlier of five years after the effective date of such agreement not to compete amendments or the date on which Ikaria and all of its subsidiaries are no longer engaged in such business as specified in the agreements.

Transition Services Agreement

In February 2014, the Company and Ikaria entered into the TSA, pursuant to which Ikaria agreed to use commercially reasonable efforts to provide certain transition services to the Company, which services include management/executive, human resources, real estate, information technology, accounting, financial planning and analysis, legal, quality and regulatory support. Ikaria also agreed to use reasonable efforts to provide the Company with the use of office space at Ikaria’s headquarters in Hampton, New Jersey pursuant to the terms of the TSA. In July 2015, the Company entered into an amendment to the TSA advancing the termination date from February 9, 2016 to September 30, 2015. Concurrently, the Company also entered into a new lease agreement for its office space - see Note 9. In exchange for the services, beginning in February 2014, the Company was obligated to pay Ikaria monthly services fees in the amount of $772,000 plus out of pocket expenses and certain other expenses. At December 31, 2015, the Company had no accrued expenses due to Ikaria in connection with the TSA. At December 31, 2014, related accrued expenses due to Ikaria amounted to $0.5 million.

At the time of the Spin-Out, the Company deposited the sum of $18.5 million, representing the aggregate of the $772,000 monthly service fees payable by the Company under the TSA, in escrow to guarantee payment of the monthly services fees by the Company. The escrowed cash is classified as restricted cash as of December 31, 2014. Pursuant to the July 2015 amendment, during October 2015, the Company received from escrow $3.3 million, which is equal to the amount it deposited to pay amounts owed to Ikaria under the TSA for the remainder of the original term.

Effective as of January 1, 2015, the Company entered into a services agreement with Ikaria, or the 2015 Services Agreement, pursuant to which the Company had agreed to use commercially reasonable efforts to provide certain services to Ikaria, including services related to regulatory matters, drug and device safety, clinical operations, biometrics and scientific affairs. In connection with the execution of the 2015 Services Agreement, Ikaria paid the Company a one-time service fee in the amount of $916,666 and was obligated to pay the Company a service fee in the amount of $83,333 per month, subject to performance of the services. The Company has no receivable due from Ikaria in connection with this agreement as of December 31, 2015. In July 2015, the Company entered into an amendment to the 2015 Services Agreement advancing the termination date from February 8, 2016 to September 30, 2015. In addition, pursuant to the 2015 Services Agreement, Ikaria had agreed to use commercially reasonable efforts to provide services to the Company, including information technology and servicing and upgrades of devices.

The following table summarizes the amounts recorded under the TSA and the 2015 Services Agreement for the years ended December 31, 2015 and 2014:



	Year Ended December 31,

(in millions)	2015		2014
Expense in connection with the TSA	7.0		8.2
Other operating income in connection with the 2015 Services Agreement	(1.7	)	—
Expense in connection with the 2015 Services Agreement	0.2		—

Supply Agreements

In February 2014, the Company entered into drug supply and device supply agreements with a subsidiary of Ikaria. Under these agreements, Ikaria agreed to use commercially reasonable efforts to supply inhaled nitric oxide and nitric oxide delivery devices for use in the Company’s clinical trials, and in the case of the drug supply agreement, the Company has agreed to purchase its clinical supply of inhaled nitric oxide from Ikaria. The Company also granted Ikaria a right of first negotiation in the event that the Company desires to enter into a commercial supply agreement with a third party for supply of nitric oxide for inhalation. The device supply agreement expired on February 9, 2015 and no amounts were due to Ikaria under that agreement as of December 31, 2015 or 2014.

In November 2015, the Company amended its drug supply agreement with Ikaria to secure future supply and pricing for cartridges and nitric oxide. Under the amended supply agreement, the Company paid Ikaria $6.6 million, $0.6 million of which was applied to outstanding amounts owed to Ikaria under the drug supply agreement. The remaining $6.0 million resulted in a prepayment to Ikaria in exchange for defined levels of cartridges and nitric oxide. The amendment to the agreement also fixes pricing for any additional cartridges or nitric oxide beyond the defined levels. Additionally, the amendment requires the Company to pay to Ikaria an additional $1.75 million upon successful completion of the initial PAH phase 3 clinical trial and a perpetual royalty calculated as 3% of PAH sales on a quarterly basis. As of December 31, 2015, no amount was due to Ikaria under the drug supply agreement.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References + Details

Commitments and Contingencies

12 Months Ended

Dec. 31, 2015

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Legal Proceedings

The Company periodically becomes subject to legal proceedings and claims arising in connection with its business.

BioLineRx Ltd., or BioLine, previously indicated to the Company that it believed that the Company had breached the license agreement in several ways, including, but not limited to, failure to use commercially reasonable efforts to develop bioabsorbable cardiac matrix, or BCM, failure to provide BioLine with material information concerning the development and commercialization plans for BCM and failure to notify BioLine in advance of material public disclosures regarding BCM. The Company and BioLine also previously disagreed about the timing of a certain milestone payment that the Company would owe BioLine based upon progress in the Company’s BCM clinical development program. The Company believed it had complied with its obligations under the license agreement to use commercially reasonable efforts to develop BCM and was not in breach of its other obligations under the license agreement. No amounts were previously accrued for this matter since no loss was probable as of December 31, 2014. On January 8, 2015, the Company and BioLine agreed to amend the license agreement, which resolved the prior disputes and provided for a release of claims by BioLine. The amendment also changed certain milestones and related payments, but the total potential milestone payments to be paid to BioLine under the license agreement remained the same. No additional milestones have been met as of December 31, 2015.

As of the date of this report, the Company is not aware of any proceeding, claim or litigation, pending or threatened, that could, individually or in the aggregate, have a material adverse effect on the Company’s business, operating results, financial condition and/or liquidity.

Operating Leases

The following is a summary of the Company’s long-term contractual cash obligations as of December 31, 2015 (in thousands).



	Operating Lease(1)
2016	$	413
2017	631
2018	641
2019	653
2020	663
Thereafter	1,532
Total	$	4,533

(1) Operating lease obligations include the lease agreement the Company entered into on August 6, 2015 for office space in Warren, New Jersey and the Company’s lease of an operating facility located in North Brunswick, New Jersey.

Rent expense, including direct and allocated expenses for year prior to 2015, is calculated on the straight-line basis and amounted to approximately $0.4 million for the year ended December 31, 2015 and $0.5 million for each of the years ended December 31, 2014 and 2013.

Royalty payments and success-based milestones associated with the Company’s license and supply agreements with Ikaria have not been included in the above table of contractual obligations as the Company cannot reasonably estimate if or when they will occur.

In the course of its normal business operations, the Company also enters into agreements with contract service providers and others to assist in the performance of its research and development and manufacturing activities. The Company can elect to discontinue the work under these contracts and purchase orders at any time with notice, and such contracts and purchase orders do not contain minimum purchase obligations.

BioLineRx Ltd.

In August 2009, the Company entered into a license agreement with BioLineRx Ltd. and BioLine Innovations Jerusalem L.P., which are referred to collectively as BioLine, under which the Company obtained an exclusive worldwide license to BCM.

The Company does not intend to proceed with further clinical development of BCM until and unless it can determine an alternative path forward. Consequently, any future milestone and royalty payments to BioLine would depend on finding a path forward for future clinical development. Under the terms of the license agreement, the Company is obligated to use commercially reasonable efforts to develop and commercialize at least one product containing BCM. Under the terms of the license agreement, if the Company achieves certain clinical and regulatory events specified in the license agreement, the Company will be obligated to pay milestone payments to BioLine that could total, in the aggregate, up to $115.5 million, and if the Company achieves certain commercialization targets specified in the license agreement, the Company will be obligated to pay additional milestone payments to BioLine that could total, in the aggregate, up to $150.0 million. In addition, the Company is obligated to pay BioLine a specified percentage of any upfront consideration it receives for sublicensing BCM, as well as royalties on net sales, if any, at a percentage ranging from 11% to 15%, depending on net sales level, of any approved product containing BCM, subject to offsets for specified payments to third parties made in connection with BCM. The Company has reimbursed BioLine for certain legal fees in the amount of $250,000 following completion of its IPO.

Net Loss Per Share/Unit	12 Months Ended
Net Loss Per Share/Unit	Dec. 31, 2015
Earnings Per Share [Abstract]
Net Loss Per Share/Unit	Net Loss Per Share/Unit Basic net loss per share/unit is calculated by dividing net loss by the weighted average number of shares or units outstanding during the period, as applicable. Diluted net loss per share/unit is calculated by dividing net loss by the weighted average number of shares/units outstanding, adjusted to reflect potentially dilutive securities (options) using the treasury stock method, except when the effect would be anti-dilutive. No net loss per unit information is presented for periods prior to the Spin-Out. The Company is reporting a net loss for the years ended December 31, 2015 and 2014, therefore diluted net loss per share/unit is the same as the basic net loss per share/unit. As of December 31, 2015, the Company had 818,899 options to purchase units and 77,793 restricted stock awards outstanding that have been excluded from the computation of diluted weighted average units outstanding, because such securities had an antidilutive impact due to the loss reported.

Fair Value Measurements

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Fair Value Measurements

Assets and liabilities recorded at fair value on the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure the fair value. Level inputs are as follows:


•	Level 1 - Values are based on unadjusted quoted prices for identical assets or liabilities in an active market which the company has the ability to access at the measurement date.


•	Level 2 - Values are based on quoted market prices in markets where trading occurs infrequently or whose values are based on quoted prices of instruments with similar attributes in active markets.


•	Level 3 - Values are based on prices or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement. These inputs reflect management’s own assumptions about the assumptions a market participant would use in pricing the asset.

The following table summarizes fair value measurements by level at December 31, 2015 for financial instruments measured at fair value on a recurring basis:



(Dollar amounts in thousands)	Level 1		Level 2		Level 3		Total
Marketable securities	$	—	$	17,807	$	—	$	17,807

There were no marketable securities at December 31, 2014.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Marketable Securities

12 Months Ended

Dec. 31, 2015

Marketable Securities [Abstract]

Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]

Marketable Securities

The Company considers all of its current investments to be available-for-sale. Marketable securities as of December 31, 2015 consist of the following (in thousands):



	Amortized Cost	Gross Unrealized Gains	Gross Unrealized Losses		Fair Value
Certificates of deposit	10,140	—	—		10,140
Corporate bonds	4,938	—	(11	)	4,927
Agency bonds	2,748	—	(8	)	2,740
Total	17,826	—	(19	)	17,807

Maturities of marketable securities classified as available-for-sale were as follows at December 31, 2015 (in thousands):



	Fair Value
Due within one year	10,230
Due after one year through two years	7,577
	17,807

There were no marketable securities as of December 31, 2014.

- Definition

The entire disclosure for investments in certain debt and equity securities.

+ References + Details

Quarterly Financial Data (unaudited)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information

Quarterly Financial Data (unaudited)



	Three Months Ended December 31,						Three Months Ended September 30,						Three Months Ended June 30,						Three Months Ended March 31,
(in thousands, except share/unit and per share/per unit data)	2015			2014			2015			2014			2015			2014			2015			2014

Operating expenses:
Research and development	$	8,329		$	9,610		$	7,090		$	11,559		$	8,426		$	12,769		$	9,520		$	12,040
General and administrative	2,533			3,177			4,329			3,934			3,435			4,194			4,573			2,470
Total operating expenses	10,862			12,787			11,419			15,493			11,861			16,963			14,093			14,510
Other operating income	—			—			250			—			251			—			1,166			—
Loss from operations	(10,862		)	(12,787		)	(11,169		)	(15,493		)	(11,610		)	(16,963		)	(12,927		)	(14,510		)
Interest income	36			18			27			13			27			48			19			—
Pre-tax loss	(10,826		)	(12,769		)	(11,142		)	(15,480		)	(11,583		)	(16,915		)	(12,908		)	(14,510		)
Income tax benefit (expense)	—			—			—			—			—			—			—			—
Net loss and comprehensive loss	$	(10,826	)	$	(12,769	)	$	(11,142	)	$	(15,480	)	$	(11,583	)	$	(16,915	)	$	(12,908	)	$	(14,510	)
Weighted average units outstanding:
Basic and diluted	13,026,816			7,898,922			12,911,905			7,897,143			12,910,975			7,898,301			10,152,487			7,899,251
Net loss per unit:
Basic and diluted	$	(0.83	)	$	(1.62	)	$	(0.86	)	$	(1.96	)	$	(0.90	)	$	(2.14	)	$	(1.27	)	$	(1.84	)

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The financial statements have been prepared in accordance with U.S. generally accepted accounting principles or GAAP. Intercompany balances and transactions have been eliminated. For periods prior to the Spin-Out, the financial statements were carved out of the consolidated financial statements of Ikaria. Although the financial statements prior to the Spin-Out were prepared on a combined carve-out basis, the financial statements for all periods presented have been labeled “consolidated” financial statements for ease of reference since the most recent balance sheet at December 31, 2015 and 2014 are consolidated balance sheets. At the date of the Spin-Out, the historical accumulated deficit of approximately $182.0 million based on the carve-out financial statements through February 11, 2014 was eliminated in the transfer of net assets to the Company. The net loss for the period February 12, 2014 through December 31, 2014 of $54.2 million has been reflected as the accumulated deficit on the December 31, 2014 consolidated balance sheet, representing the net loss since the date of the Spin-Out. Net assets contributed to the Company in the Spin-Out were $75.6 million, including cash of $80.0 million. The results of operations and cash flows for the year ended December 31, 2015 and from February 12, 2014 through December 31, 2014 and the balance sheet as of December 31, 2015 and 2014 represent actual results and the financial position of the Company on a stand-alone basis. The Company operates in one reportable segment and solely within the United States. Accordingly, no segment or geographic information has been presented. The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of costs and expenses during the reporting period, including accrued research and development expenses, stock-based compensation, income taxes and valuation of long-lived assets. Actual results could differ from those estimates. For periods prior to the Spin-Out, the financial statements were carved out of the consolidated financial statements of Ikaria. Management believes that the statements of operations for the periods prior to the Spin-Out (which include a period of forty-two days prior to the Spin-Out in the year ended December 31, 2014) include reasonable allocations of costs and expenses incurred by Ikaria which benefited the Company. However, such amounts may not be indicative of the actual level of costs and expenses that would have been incurred by the Company if it had operated as an independent stand-alone company or of the costs and expenses expected to be incurred in the future. As such, the financial information for the years ended December 31, 2014 and 2013 may not necessarily reflect the results of operations and cash flows of the Company had it been an independent stand-alone company for the period, or the results of operations and cash flows expected in the future. Direct and indirect costs related to the Company for INOpulse for PAH, INOpulse for PH-COPD and BCM clinical programs have been allocated to the Company for periods prior to February 12, 2014. These allocations were based on either a specific identification basis or, when specific identification was not practicable, proportional cost allocation methods, such as time and wage studies, depending on the nature of the expense. All allocations were based on actual costs incurred. For purposes of allocating non-project specific expenses, each departmental head provided information as to the percentage of employee time incurred on behalf of the Company. Allocations of general and administrative expenses by Ikaria to the Company for periods prior to February 12, 2014 include allocations of corporate management, finance, information technology, legal, human resources and other overhead expenses, based on an approximate pro-rata headcount of employees.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity date of three months or less to be cash equivalents. All investments with maturities of greater than three months from date of purchase are classified as available-for-sale marketable securities.
Restricted Cash	Restricted Cash Restricted cash as of December 31, 2014 represents amounts previously held on deposit with a bank in relation to the TSA. The funds related to the TSA were held in an account to settle the required payment to Ikaria for services to be provided in connection with the TSA. Restricted cash as of December 31, 2015 represents amounts held on deposit with a bank as a security deposit for the lease of office space. The required deposits to be maintained in excess of one year from the balance sheet date are classified as long-term restricted cash.
Property and Equipment	Property and Equipment Property and equipment are recorded at acquisition cost, which for internally developed assets include labor, materials and overhead. Additions and improvements that increase the value or extend the life of an asset are capitalized. Repairs and maintenance costs are expensed as incurred. Property and equipment are depreciated on a straight-line basis over the estimated useful lives (3-15 years) of the respective assets. Leasehold improvements are capitalized and amortized over the lesser of the remaining life of the lease or the estimated useful life of the asset.
Impairment or Disposal of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets, such as property, plant and equipment, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted expected future cash flows. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be sold are no longer depreciated and are reclassified outside of property, plant and equipment at the lower of the carrying amount or fair value less costs to sell.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for its stock-based compensation in accordance with Accounting Standards Codification, or ASC, 718 Compensation- Stock Compensation, which establishes accounting for share-based awards, including stock options and restricted stock, exchanged for services and requires companies to expense the estimated fair value of these awards over the requisite service period. The Company recognizes stock-based compensation expense in operations based on the fair value of the award on the date of the grant. The resulting compensation expense is recognized on a straight-line basis over the requisite service period or sooner if the awards immediately vest. The Company determines the fair value of stock options issued using a Black-Scholes-Merton option pricing model. Certain assumptions used in the model include expected volatility, dividend yield, risk-free interest rate, and expected term. For restricted stock, the fair value is the closing market price per share on the grant date. See Note 7 - Stock-Based Compensation for a description of these assumptions. Prior to the date of the Spin-Out, stock-based compensation expense for the Company represented an allocation of Ikaria’s stock-based compensation expense based on the allocation percentages of the Company’s cost centers, which were determined based on specific identification or the proportionate percentage of employee time or headcount to the respective total Ikaria employee time or headcount.
Deferred Transaction Costs	Deferred Transaction Costs Deferred transaction costs represent IPO-related costs primarily associated with third-party professional legal, accounting and printing fees associated with the IPO of the Company’s shares. These IPO-related costs were deferred and charged against the gross proceeds of the offering when the public offering of equity securities was complete as a reduction of additional paid-in capital. As of December 31, 2015, the Company charged all deferred transaction costs against the gross proceeds of the offering.
Income Taxes	Income Taxes Prior to its conversion to a Delaware corporation in February 2015, the Company was a Delaware limited liability company, or LLC, that passed through income and losses to its members for U.S. federal and state income tax purposes. As a result of its conversion to a Delaware corporation, the Company recognized deferred income taxes through income tax expense related to temporary differences that existed as of the date of its tax status change. The Company uses the asset and liability approach to account for income taxes as required by ASC 740, Income Taxes, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Valuation allowances are provided when necessary to reduce deferred tax assets to the amount expected to be realized, on a more likely than not basis. The Company recognizes the benefit of an uncertain tax position that it has taken or expects to take on income tax returns it files if such tax position is more likely than not to be sustained on examination by the taxing authorities, based on the technical merits of the position. These tax benefits are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate resolution. As of the date of the conversion to a taxable corporation, the Company recognized approximately $17.9 million of deferred tax assets which consisted principally of excess tax-over-book basis in intangible assets and property, plant and equipment and certain accruals that were transferred from the limited liability company to the corporation. The Company also recognized a full valuation allowance since it had a cumulative loss position and no positive evidence of taxable income to support recovery of the deferred tax assets. The Company incurred transaction costs of approximately $8.1 million in connection with the IPO which were recorded as a reduction of equity. These costs are nondeductible until and if the Company liquidates or terminates, which is not expected in the foreseeable future. Therefore, the Company did not recognize a deferred tax asset for such costs.
Marketable Securities	Marketable Securities The Company’s marketable securities consist of federally insured certificates of deposit classified as available-for-sale that are recorded at amortized cost, which approximates fair value, and corporate or agency bonds classified as available-for-sale that are recorded at fair value. Unrealized gains and losses are reported as accumulated other comprehensive (loss) income, except for losses from impairments which are determined to be other-than-temporary. Realized gains and losses, and declines in value judged to be other-than-temporary on available-for-sale securities are included in the determination of net loss and are included in interest income, at which time the average cost basis of these securities are adjusted to fair value. Fair values are based on quoted market prices at the reporting date. Interest on available-for-sale securities are included in interest income.
Research and Development Expense	Research and Development Expense Research and development costs are expensed as incurred. These expenses include the costs of the Company’s proprietary research and development efforts, as well as costs incurred in connection with certain licensing arrangements. Upfront and milestone payments made to third parties in connection with research and development collaborations are expensed as incurred up to the point of regulatory approval. Payments made to third parties upon or subsequent to regulatory approval are capitalized and amortized over the remaining useful life of the related product. The Company also expenses the cost of purchased technology and equipment in the period of purchase if it believes that the technology or equipment has not demonstrated technological feasibility and it does not have an alternative future use. Nonrefundable advance payments for goods or services that will be used or rendered for future research and development activities are deferred and are recognized as research and development expense as the related goods are delivered or the related services are performed.
Financial Instruments	Financial Instruments The carrying amounts of cash and cash equivalents, restricted cash, prepaid expenses and other current assets and current liabilities approximate fair value due to the short-term maturity of these instruments.
Reclassification	Reclassification Certain prior period balances have been reclassified to conform to the current period presentation.
New Accounting Pronouncements	New Accounting Pronouncements In August 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2014-15, “Presentation of Financial Statements - Going Concern: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern”. This guidance clarifies that an entity’s management should evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued. The amendments in this update are effective for annual reporting periods ending after December 15, 2016, and annual and interim periods thereafter, and early application is permitted. The Company is assessing ASU 2014-15’s impact and will adopt it when effective. On May 28, 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers”, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for the Company on January 1, 2018. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is assessing ASU 2014-09’s impact and will adopt it when effective. In February 2016, the FASB issued ASU 2016-02, "Leases", which is intended to improve financial reporting about leasing transactions. This standard requires a lessee to record on the balance sheet the assets and liabilities for the rights and obligations created by lease terms of more than 12 months. This standard will be effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is currently evaluating the impact the adoption of ASU 2016-02 will have on the consolidated financial position, results of operations or cash flows.

Restructuring Charges (Tables)

12 Months Ended

Dec. 31, 2015

Restructuring and Related Activities [Abstract]

Summary of restructuring activities

The following table summarizes restructuring activities for the year ended December 31, 2015:



	Amounts
	(in thousands)
Accrual balance at December 31, 2014	$	—
Charged to research and development expense	321
Charged to general and administrative expense	1,053
Cash payments	(405		)
Accrual balance at December 31, 2015⁽¹⁾	$	969

(1) Included under Accrued expenses

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Schedule of property, plant and equipment

Property and equipment as of December 31, 2015 and December 31, 2014 consist of the following (in thousands):



	December 31, 2015			December 31, 2014
Machinery and equipment	$	2,943		$	2,943
Leasehold improvements	204			—
Furniture and fixtures	276			—
Less accumulated depreciation	(1,624		)	(1,247		)
	$	1,799		$	1,696

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Schedule of effective income tax rate reconciliation

A reconciliation of the statutory federal income tax rate to the Company’s effective tax rate for the years ended December 31, 2015 and 2013 is as follows:



	Year Ended December 31, 2015		Year Ended December 31, 2013
U.S. federal statutory rate	34.0	%	35.0	%
State and local taxes, net of federal tax effect	5.8	%	5.3	%
Research tax credits	15.8	%	5.0	%
Valuation allowance	(55.1	)%	(44.4	)%
Incentive stock options	(0.5	)%	(0.1	)%
Other	—	%	(0.8	)%
	0.0	%	0.0	%

Summary of deferred tax assets and liabilities

Significant components of the deferred tax assets (liabilities) at December 31, 2015 are as follows:



	December 31, 2015
	Assets			(Liabilities)
Net operating loss carryforwards	$	15,459		$	—
Research tax credit carryforwards	9,753			—
Property and equipment	—			(130		)
Stock based compensation	359			—
Intangible assets	12,371			—
Accrued expenses	2,521			—
Subtotal	40,463			(130		)
Valuation allowance	(40,333		)	—
Total deferred tax assets (liabilities)	$	130		$	(130	)
Net deferred tax assets	$	—

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Stock-Based Compensation

Assumptions used in estimating the fair value of options issued

The following are the weighted average assumptions used in estimating the fair value of options issued during the years ended December 31, 2015 and 2014.



	Year Ended December 31, 2015		Year Ended December 31, 2014
Valuation assumptions:
Risk-free interest rate	1.60	%	1.71	%
Expected volatility	79.18	%	90.00	%
Expected term (in years)	6.1		6.1
Dividend yield	—	%	—	%

Summary of restricted stock activity

A summary of restricted stock activity under the 2015 Plan for the year ended December 31, 2015 is presented below:



	Bellerophon 2015 Equity Incentive Plan
	Shares		Weighted Average Fair Value			Aggregate Grant Date Fair Value(in millions)			Weighted Average Remaining Contractual Life (in years)
Restricted stock outstanding as of December 31, 2014	—		$	—		$	—		—
Granted	90,909		3.86			0.4
Vested	(13,116	)	(3.08		)	(0.1		)
Forfeited	—
Restricted stock outstanding as of December 31, 2015	77,793		$	3.99		$	0.3		0.7

Bellerophon 2015 And 2014 Equity Incentive Plan

Stock-Based Compensation

Summary of option activity

A summary of option activity under the 2015 and 2014 Plan for the year ended December 31, 2014 and 2015 is presented below:



	Bellerophon 2015 and 2014 Equity Incentive Plans
	Shares		Exercise Price				Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)
Options outstanding as of February 12, 2014	—		—				—
Granted	514,266		$	13.28			$	13.28
Exercised	—
Forfeited	(5,986	)	$	13.28			$	13.28
Options outstanding as of December 31, 2014	508,280		$	13.28			$	13.28	9.5
Granted	443,607		4.12		-	12.00	9.53
Exercised	—
Forfeited	(246,707	)	8.23		-	13.28	9.95
Options outstanding as of December 31, 2015	705,180		$	4.12	-	13.28	$	12.08	8.7
Options vested and exercisable as of December 31, 2015	210,723		$	10.22	-	13.28	$	12.97	8.6

Ikaria Equity Incentive Plans prior to February 12, 2014

Stock-Based Compensation

Summary of option activity



	Year Ended December 31,
(in thousands)	2015		2014		2013
Research and development	$	364	$	271	$	1,120
General and administrative	1,387		1,568		601
Total expense	$	1,751	$	1,839	$	1,721

Summary of stock-based compensation expense by the condensed consolidated statement of operations line item

A summary of option activity under the assumed Ikaria 2007 stock option plan and the assumed Ikaria 2010 long term incentive plan for the year ended December 31, 2015 is presented below:



	Ikaria Equity Incentive Plans for Periods Prior to February 12, 2014
	Shares		Range of Exercise Price				Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)
Options issued and vested at date of Spin-Out as of February 12, 2014	618,212		$	0.26	-	17.92	$	7.24
Exercised	(8,182	)	7.77		-	8.77	7.99
Forfeited	(32,055	)	7.77		-	14.91	9.39
Options outstanding, vested and exercisable as of December 31, 2014	577,975		$	0.26	-	17.92	$	7.11	4.5
Exercised	(126,499	)	1.13		-	7.77	1.47
Forfeited	(337,767	)	7.77		-	17.92	8.61
Options outstanding, vested and exercisable as of December 31, 2015	113,709		$	0.26	-	17.92	$	8.93	5.2

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2015

Commitments and Contingencies Disclosure [Abstract]

Future minimum payments for operating leases

The following is a summary of the Company’s long-term contractual cash obligations as of December 31, 2015 (in thousands).



	Operating Lease(1)
2016	$	413
2017	631
2018	641
2019	653
2020	663
Thereafter	1,532
Total	$	4,533

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Summary of fair value measurements by level

The following table summarizes fair value measurements by level at December 31, 2015 for financial instruments measured at fair value on a recurring basis:



(Dollar amounts in thousands)	Level 1		Level 2		Level 3		Total
Marketable securities	$	—	$	17,807	$	—	$	17,807

Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2015

Marketable Securities [Abstract]

Schedule of Available-for-sale Securities Reconciliation

The Company considers all of its current investments to be available-for-sale. Marketable securities as of December 31, 2015 consist of the following (in thousands):



	Amortized Cost	Gross Unrealized Gains	Gross Unrealized Losses		Fair Value
Certificates of deposit	10,140	—	—		10,140
Corporate bonds	4,938	—	(11	)	4,927
Agency bonds	2,748	—	(8	)	2,740
Total	17,826	—	(19	)	17,807

Available-for-sale Securities

Maturities of marketable securities classified as available-for-sale were as follows at December 31, 2015 (in thousands):



	Fair Value
Due within one year	10,230
Due after one year through two years	7,577
	17,807

- Definition

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

+ References + Details

Quarterly Financial Data (unaudited) (Tables)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Schedule of quarterly financial information

Quarterly Financial Data (unaudited)



	Three Months Ended December 31,						Three Months Ended September 30,						Three Months Ended June 30,						Three Months Ended March 31,
(in thousands, except share/unit and per share/per unit data)	2015			2014			2015			2014			2015			2014			2015			2014

Operating expenses:
Research and development	$	8,329		$	9,610		$	7,090		$	11,559		$	8,426		$	12,769		$	9,520		$	12,040
General and administrative	2,533			3,177			4,329			3,934			3,435			4,194			4,573			2,470
Total operating expenses	10,862			12,787			11,419			15,493			11,861			16,963			14,093			14,510
Other operating income	—			—			250			—			251			—			1,166			—
Loss from operations	(10,862		)	(12,787		)	(11,169		)	(15,493		)	(11,610		)	(16,963		)	(12,927		)	(14,510		)
Interest income	36			18			27			13			27			48			19			—
Pre-tax loss	(10,826		)	(12,769		)	(11,142		)	(15,480		)	(11,583		)	(16,915		)	(12,908		)	(14,510		)
Income tax benefit (expense)	—			—			—			—			—			—			—			—
Net loss and comprehensive loss	$	(10,826	)	$	(12,769	)	$	(11,142	)	$	(15,480	)	$	(11,583	)	$	(16,915	)	$	(12,908	)	$	(14,510	)
Weighted average units outstanding:
Basic and diluted	13,026,816			7,898,922			12,911,905			7,897,143			12,910,975			7,898,301			10,152,487			7,899,251
Net loss per unit:
Basic and diluted	$	(0.83	)	$	(1.62	)	$	(0.86	)	$	(1.96	)	$	(0.90	)	$	(2.14	)	$	(1.27	)	$	(1.84	)

Organization and Nature of the Business (Details) $ / shares in Units, $ in Millions				1 Months Ended		3 Months Ended
	Feb. 19, 2015 USD ($) $ / shares shares	Feb. 02, 2015	Feb. 12, 2014 USD ($) shares	Oct. 31, 2015 USD ($)	Feb. 28, 2015 USD ($)	Dec. 31, 2013 integer	Sep. 30, 2013 integer
Organization and Nature of the Business
Reverse stock split		0.079836
Amount deposited in escrow			$ 18.5
Cash on hand			80.0
Escrow deposit received after termination of agreement				$ 3.3
Price to the public (in dollars per share) \| $ / shares	$ 12.00
Net proceeds to the company					$ 51.9
Underwriting discounts and commissions deducted					4.2
Offering costs deducted					$ 3.9
IPO
Organization and Nature of the Business
Completed sale (in shares) \| shares	5,000,000
Price to the public (in dollars per share) \| $ / shares	$ 12.00
Net proceeds to the company	$ 51.9
Underwriting discounts and commissions deducted	4.2
Offering costs deducted	$ 3.9
Ikaria \| Transition services agreement (TSA)
Organization and Nature of the Business
Amount deposited in escrow			$ 18.5
Length of agreement			24 months
Escrow deposit received after termination of agreement				$ 3.3
Spin-Out of Company from Ikaria
Organization and Nature of the Business
Number of voting limited liability company interests in the Company for each share of Ikaria common stock held (in shares) \| shares			1
Spin-Out of Company from Ikaria \| Ikaria
Organization and Nature of the Business
Cash distributed to the company			$ 80.0
Cash on hand			$ 80.0
Ikaria
Organization and Nature of the Business
Number of operating segments (in segments) \| integer						2	2

Summary of Significant Accounting Policies (Details) $ in Thousands		12 Months Ended
	Feb. 19, 2015 USD ($)	Dec. 31, 2015 USD ($) integer	Dec. 31, 2014 USD ($)	Feb. 12, 2014 USD ($)	Feb. 11, 2014 USD ($)
Retained Earnings Adjustments [Line Items]
Accumulated deficit		$ 100,678	$ 54,219
Net assets				$ 75,600
Cash				$ 80,000
Number of reportable segments \| integer		1
Number of days carved out of financial statements of former parent that are presented with the reporting entity			42 days
Deferred tax assets before valuation allowance	$ 17,900	$ 40,463
Underwriting discounts and commissions and offering expenses	$ 8,100	$ 8,085
Predecessor
Retained Earnings Adjustments [Line Items]
Accumulated deficit					$ (182,000)

Summary of Significant Accounting Policies (Details 2)	12 Months Ended
Summary of Significant Accounting Policies (Details 2)	Dec. 31, 2015
Minimum
Property, Plant and Equipment [Line Items]
Useful life of property, plant and equipment	3 years
Maximum
Property, Plant and Equipment [Line Items]
Useful life of property, plant and equipment	15 years

Liquidity (Details) - USD ($) $ in Thousands	1 Months Ended
Liquidity (Details) - USD ($) $ in Thousands	Feb. 28, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Liquidity [Line Items]
Cash and cash equivalents		$ 6,260	$ 16,815	$ 0	$ 0
Marketable securities		17,807	$ 0
Net proceeds to the company	$ 51,900
Underwriting discounts and commissions deducted	4,200
Offering costs deducted	$ 3,900
Drug supply agreement \| Affiliated Entity
Liquidity [Line Items]
Prepaid research and development		11,300
Committed Equity Funding
Liquidity [Line Items]
Common stock, value, subscriptions		$ 20,000
Commitment letter maximum ownership percentage (more than)		19.90%
Committed Equity Funding First Two Draw Downs [Member]
Liquidity [Line Items]
Common stock, value, subscriptions		$ 2,000

Restructuring Charges (Details) $ in Thousands	12 Months Ended
Restructuring Charges (Details) $ in Thousands	Dec. 31, 2015 USD ($) person
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 0
Cash payments	(405)
Restructuring reserve, ending balance	969
General and administrative
Restructuring Reserve [Roll Forward]
Restructuring charge	1,053
Research and development
Restructuring Reserve [Roll Forward]
Restructuring charge	$ 321
Employee Severance
Restructuring and Related Cost, Positions Eliminated [Abstract]
Number of positions to be eliminated \| person	20

Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property and equipment
Less accumulated depreciation	$ (1,624)	$ (1,247)
Property and equipment, net	1,799	1,696
Machinery, equipment and furniture
Property and equipment
Gross	2,943	2,943
Leasehold Improvements
Property and equipment
Gross	204	0
Furniture and Fixtures
Property and equipment
Gross	$ 276	$ 0

Income Taxes (Reconciliation of Effective Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
U.S. federal statutory rate	34.00%	35.00%
State and local taxes, net of federal tax effect	5.80%	5.30%
Research tax credits	15.80%	5.00%
Valuation allowance	(55.10%)	(44.40%)
Incentive stock options	(0.50%)	(0.10%)
Other	0.00%	(0.80%)
Total	0.00%	0.00%

Income Taxes (Significant Components of Deferred Tax Assets & Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Feb. 19, 2015
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 15,459
Research tax credit carryforwards	9,753
Property and equipment	(130)
Stock based compensation	359
Intangible assets	12,371
Accrued expenses	2,521
Deferred tax assets before valuation allowance	40,463	$ 17,900
Deferred tax liabilities	130
Valuation allowance	(40,333)
Total deferred tax assets	130
Net deferred tax assets	$ 0

Stock-Based Compensation (Details Textual) - USD ($)		1 Months Ended		11 Months Ended	12 Months Ended
Stock-Based Compensation (Details Textual) - USD ($)	Feb. 12, 2014	Feb. 28, 2014	Feb. 11, 2014	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock-Based Compensation
Weighted-average period unrecognized compensation expense is to be recognized					2 years 6 months
Tax benefit recognized related to stock-based compensation expense					$ 0
Weighted average grant date fair value					$ 6.55	$ 9.98
Stock-based compensation expense					$ 1,751,000	$ 1,839,000	$ 1,721,000
Bellerophon Equity Incentive Plans
Stock-Based Compensation
Unrecognized compensation expense					$ 3,500,000
Number of options granted (in shares)				514,266	443,607
Exercise price of options granted				$ 13.28	$ 9.53
Ikaria Equity Incentive Plans prior to February 12, 2014
Stock-Based Compensation
Number of options granted (in shares)		618,212
Former parent fair value post spin out allocated to original exercise price (as a percent)	85.00%
Allocation percentage of post Spin-Out estimated fair value of the Company to original option exercise price (as a percent)	15.00%
Intrinsic value of options outstanding, vested and exercisable					$ 400,000
Ikaria Equity Incentive Plans prior to February 12, 2014 \| Stock Options
Stock-Based Compensation
Stock-based compensation expense			$ 100,000
Ikaria Equity Incentive Plans prior to February 12, 2014 \| Restricted Stock Units
Stock-Based Compensation
Stock-based compensation expense			$ 200,000
Number of awards converted upon plan modification (in shares)	372,947
2015 Equity Incentive Plan
Stock-Based Compensation
Number of shares authorized (in shares)					500,162
2015 Equity Incentive Plan \| First tranche
Stock-Based Compensation
Vesting period					3 years
2015 Equity Incentive Plan \| Second tranche
Stock-Based Compensation
Vesting period					4 years
2015 Equity Incentive Plan \| Restricted Stock
Stock-Based Compensation
Vesting period					1 year
2014 Equity Incentive Plan
Stock-Based Compensation
Vesting period					4 years
2014 Equity Incentive Plan \| Second anniversary
Stock-Based Compensation
Vesting percentage					25.00%
2014 Equity Incentive Plan \| Third anniversary
Stock-Based Compensation
Vesting percentage					25.00%
2014 Equity Incentive Plan \| Fourth anniversary
Stock-Based Compensation
Vesting percentage					50.00%
Ikaria \| Ikaria Equity Incentive Plans prior to February 12, 2014 \| Restricted Stock Units
Stock-Based Compensation
Vesting period	4 years
Ikaria \| Ikaria Equity Incentive Plans prior to February 12, 2014 \| Restricted Stock Units \| Prior to January 1, 2011
Stock-Based Compensation
Vesting percentage each anniversary	25.00%
Ikaria \| Ikaria Equity Incentive Plans prior to February 12, 2014 \| Restricted Stock Units \| Second anniversary \| On and after January 1, 2011
Stock-Based Compensation
Vesting percentage					25.00%
Ikaria \| Ikaria Equity Incentive Plans prior to February 12, 2014 \| Restricted Stock Units \| Third anniversary \| On and after January 1, 2011
Stock-Based Compensation
Vesting percentage	25.00%
Ikaria \| Ikaria Equity Incentive Plans prior to February 12, 2014 \| Restricted Stock Units \| Fourth anniversary \| On and after January 1, 2011
Stock-Based Compensation
Vesting percentage					50.00%

Stock-Based Compensation (Summary of Fair Value of Options Issued) (Details) - Bellerophon Equity Incentive Plans	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Assumptions used in estimating the fair value of awards issued
Risk-free rate (as a percent)	1.60%	1.71%
Expected volatility (as a percent)	79.18%	90.00%
Expected term (years)	6 years 1 month 6 days	6 years 1 month 6 days
Dividend yield (as a percent)	0.00%	0.00%

Stock-Based Compensation (Summary of Option Activity) (Details) - $ / shares	1 Months Ended	11 Months Ended	12 Months Ended
	Feb. 28, 2014	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Feb. 11, 2014
Minimum
Exercise Price
Options exercised, Exercise Price (in dollars per share)			$ 1.13
Maximum
Exercise Price
Options exercised, Exercise Price (in dollars per share)			$ 7.77
Bellerophon Equity Incentive Plans
Shares
Options outstanding as of beginning of period (in shares)		0	508,280
Granted (in shares)		514,266	443,607
Exercise of options (in shares)		0	0
Forfeited (in shares)		(5,986)	(246,707)
Options outstanding as of end of period (in shares)		508,280	705,180	508,280
Options vested and exercisable (in shares)		210,723		210,723
Exercise Price
Options outstanding, Exercise Price (in dollars per share)		13.28		13.28	0.00
Options granted, Exercise Price (in dollars per share)		$ 13.28
Options forfeited, Exercise Price (in dollars per share)		13.28
Weighted Average Price
Options outstanding as of beginning of period, Weighted Average Price (in dollars per share)		0.00	$ 13.28
Options granted, Weighted Average Price (in dollars per share)		13.28	$ 9.53
Options exercised, Weighted Average Price (in dollars per share)
Options forfeited, Weighted Average Price (in dollars per share)		13.28	$ 9.95
Options outstanding as of end of period, Weighted Average Price (in dollars per share)		13.28	$ 12.08	$ 13.28
Options vested and exercisable, Weighed Average Price (in dollars per share)		12.97		$ 12.97
Weighted Average Remaining Contractual Life (in years)
Options outstanding, Weighted Average Remaining Contractual Life (in years)			8 years 8 months 12 days	9 years 6 months
Options vested and exercisable, Weighted Average Remaining Contractual Life (in years)			8 years 7 months 6 days
Bellerophon Equity Incentive Plans \| Minimum
Exercise Price
Options outstanding, Exercise Price (in dollars per share)			4.12
Options granted, Exercise Price (in dollars per share)			$ 4.12
Options forfeited, Exercise Price (in dollars per share)			$ 8.23
Options vested and exercisable, Exercise Price (in dollars per share)		10.22		$ 10.22
Bellerophon Equity Incentive Plans \| Maximum
Exercise Price
Options outstanding, Exercise Price (in dollars per share)			13.28
Options granted, Exercise Price (in dollars per share)			$ 12.00
Options forfeited, Exercise Price (in dollars per share)			$ 13.28
Options vested and exercisable, Exercise Price (in dollars per share)		$ 13.28		$ 13.28
Ikaria Equity Incentive Plans prior to February 12, 2014
Shares
Options outstanding as of beginning of period (in shares)		618,212
Granted (in shares)	618,212
Exercise of options (in shares)		(8,182)	(126,499)
Forfeited (in shares)		(32,055)	(337,767)
Options vested and exercisable (in shares)		577,975	113,709	577,975
Weighted Average Price
Options outstanding as of beginning of period, Weighted Average Price (in dollars per share)		$ 7.24
Options exercised, Weighted Average Price (in dollars per share)		7.99	$ 1.47
Options forfeited, Weighted Average Price (in dollars per share)		9.39	8.61
Options vested and exercisable, Weighed Average Price (in dollars per share)		7.11	$ 8.93	$ 7.11
Weighted Average Remaining Contractual Life (in years)
Options vested and exercisable, Weighted Average Remaining Contractual Life (in years)			5 years 2 months 12 days	4 years 6 months
Ikaria Equity Incentive Plans prior to February 12, 2014 \| Minimum
Exercise Price
Options exercised, Exercise Price (in dollars per share)		7.77
Options forfeited, Exercise Price (in dollars per share)		7.77	$ 7.77
Options vested and exercisable, Exercise Price (in dollars per share)		0.26	0.26	$ 0.26	$ 0.26
Ikaria Equity Incentive Plans prior to February 12, 2014 \| Maximum
Exercise Price
Options exercised, Exercise Price (in dollars per share)		8.77
Options forfeited, Exercise Price (in dollars per share)		14.91	17.92
Options vested and exercisable, Exercise Price (in dollars per share)		$ 17.92	$ 17.92	$ 17.92	$ 17.92

Stock-Based Compensation (Summary of Restricted Stock Activity) (Details) - 2015 Equity Incentive Plan $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Restricted stock
Restricted stock outstanding, beginning of period (in shares)	0
Restricted stock granted (in shares)	90,909,000
Restricted stock vested and exercisable (in shares)	(13,116,000)
Restricted stock forfeited (in shares)	0
Restricted stock outstanding, end of period (in shares)	77,793
Restricted stock weighted average fair value per share
Restricted stock beginning of period, weighted average fair value (per share) \| $ / shares	$ 0.00
Restricted stock granted, weighted average fair value (per share) \| $ / shares	3,860.00
Restricted stock vested, weighted average fair value (per share) \| $ / shares	3,080.00
Restricted stock end of period, weighted average fair value (per share) \| $ / shares	$ 3,990.00
Restricted stock aggregate grant date fair value
Restricted stock beginning of period, aggregate grant date fair value \| $	$ 0.0
Restricted stock granted, aggregate grant date fair value \| $	0.4
Restricted stock vested, aggregate grant date fair value \| $	0.1
Restricted stock end of period, aggregate grant date fair value \| $	$ 0.3
Weighted average remaining contractual life (in years)
Restricted stock, weighted average remaining contractual life (in years)	8 months 12 days

Stock-Based Compensation (Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock-based compensation expense by condensed consolidated statement of operations and comprehensive loss line item
Total expense	$ 1,751	$ 1,839	$ 1,721
Research and development
Stock-based compensation expense by condensed consolidated statement of operations and comprehensive loss line item
Total expense	364	271	1,120
General and administrative
Stock-based compensation expense by condensed consolidated statement of operations and comprehensive loss line item
Total expense	$ 1,387	$ 1,568	$ 601

Related-Party Transactions (Details) - USD ($)			1 Months Ended				12 Months Ended
Related-Party Transactions (Details) - USD ($)	Jul. 27, 2015	Feb. 12, 2014	Nov. 30, 2015	Oct. 31, 2015	Jul. 31, 2015	Feb. 28, 2014	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Accrued expenses and amounts due							$ 148,000	$ 661,000
Amount deposited in escrow		$ 18,500,000
Escrow deposit received after termination of agreement				$ 3,300,000
Ikaria \| License Agreement
Related Party Transaction [Line Items]
Royalty to related party (as a percent)	5.00%
Ikaria \| Agreements Not to Compete
Related Party Transaction [Line Items]
Term of agreement					5 years
Ikaria \| Transition services agreement (TSA)
Related Party Transaction [Line Items]
Term of agreement		24 months
Monthly service fee						$ 772,000
Accrued expenses and amounts due							0	500,000
Amount deposited in escrow		$ 18,500,000
Escrow deposit received after termination of agreement				3,300,000
Ikaria \| Services agreement entered into January 2015
Related Party Transaction [Line Items]
Service fee							916,666
Monthly additional service fee							83,333
Ikaria \| Device supply agreement
Related Party Transaction [Line Items]
Accrued expenses and amounts due								$ 0
Affiliated Entity \| License Agreement
Related Party Transaction [Line Items]
Perpetual royalty (as a percent)			3.00%
Affiliated Entity \| Device supply agreement
Related Party Transaction [Line Items]
Accrued expenses and amounts due							0
Affiliated Entity \| Drug supply agreement
Related Party Transaction [Line Items]
Perpetual royalty (as a percent)			3.00%
Accrued expenses and amounts due				$ 600,000			$ 0
Payment to Related Party, Current			$ 6,600,000
Prepayment to Ikaria			6,000,000
Amount to be incurred for certain services provided by Ikaria			$ 1,750,000

Related-Party Transactions (Details 2) - Ikaria - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Transition services agreement (TSA)
Related Party Transaction [Line Items]
Expenses in connection with the agreement	$ 7,000	$ 8,200
Services agreement entered into January 2015
Related Party Transaction [Line Items]
Service fee	(916,666)
Related party operating expenses	200	0
Other Operating Income \| Services agreement entered into January 2015
Related Party Transaction [Line Items]
Service fee	$ (1,700)	$ 0

Commitments and Contingencies (Details)	12 Months Ended
Commitments and Contingencies (Details)	Dec. 31, 2015 USD ($) milestone	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Legal Proceedings
Rent expense	$ 400,000	$ 500,000	$ 500,000
License agreement to develop BCM
Legal Proceedings
Number of additional milestones met \| milestone	0
Bioline \| License agreement to develop BCM
Legal Proceedings
Losses accrued		0
Estimate of probable losses		$ 0
Bioline
Legal Proceedings
Legal fees	$ 250,000
Bioline \| Minimum
Legal Proceedings
Sublicensing payments, percentage	11.00%
Bioline \| Maximum
Legal Proceedings
Sublicensing payments, percentage	15.00%
License Agreement, Achievement of Clinical and Regulatory Events \| Bioline
Legal Proceedings
Estimate of probable losses	$ 115,500,000
License Agreement, Achievement of Commercialization Target \| Bioline
Legal Proceedings
Estimate of probable losses	$ 150,000,000

Commitments and Contingencies - Summary of Operating Lease Obligations (Details) $ in Thousands	Dec. 31, 2015 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Operating lease, due in less than 1 year	$ 413
Operating lease, due in second year	631
Operating lease, due in third year	641
Operating lease, due in fourth year	653
Operating lease, due in fifth year	663
Operating lease, due after fifth year	1,532
Operating lease, total	$ 4,533

Net Loss Per Share/Unit (Details) - shares	12 Months Ended
Net Loss Per Share/Unit (Details) - shares	Dec. 31, 2015	Dec. 31, 2014
Options to purchase units outstanding
Net Loss Per Share
Antidilutive securities excluded from computation of weighted average units outstanding		818,899
Restricted stock outstanding
Net Loss Per Share
Antidilutive securities excluded from computation of weighted average units outstanding	77,793

Fair Value Measurements (Details) - Recurring - Marketable Securities $ in Thousands	Dec. 31, 2015 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	$ 17,807
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	17,807
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	$ 0

Marketable Securities (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 17,826,000
Gross Unrealized Gains	0
Gross Unrealized Losses	(19,000)
Fair Value	17,807,000	$ 0
Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,140,000
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	10,140,000
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,938,000
Gross Unrealized Gains	0
Gross Unrealized Losses	(11,000)
Fair Value	4,927,000
Agency bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,748,000
Gross Unrealized Gains	0
Gross Unrealized Losses	(8,000)
Fair Value	$ 2,740,000

Marketable Securities (Details 2) $ in Thousands	Dec. 31, 2015 USD ($)
Marketable Securities [Abstract]
Due within one year	$ 10,230
Due after one year through two years	7,577
Available-for-sale securities, total	$ 17,807

Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended								11 Months Ended	12 Months Ended
	Feb. 11, 2014	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating expenses:
Research and development		$ 8,329	$ 7,090	$ 8,426	$ 9,520	$ 9,610	$ 11,559	$ 12,769	$ 12,040		$ 33,365	$ 45,978	$ 52,985
General and administrative		2,533	4,329	3,435	4,573	3,177	3,934	4,194	2,470		14,870	13,775	9,013
Total operating expenses		10,862	11,419	11,861	14,093	12,787	15,493	16,963	14,510		48,235	59,753	61,998
Other operating income		0	250	251	1,166	0	0	0	0		1,667	0	0
Loss from operations		(10,862)	(11,169)	(11,610)	(12,927)	(12,787)	(15,493)	(16,963)	(14,510)		(46,568)	(59,753)	(61,998)
Interest income		36	27	27	19	18	13	48	0		109	79	0
Pre-tax loss		(10,826)	(11,142)	(11,583)	(12,908)	(12,769)	(15,480)	(16,915)	(14,510)		(46,459)	(59,674)	(61,998)
Income tax benefit (expense)		0	0	0	0	0	0	0	0		0	0	0
Net loss	$ (5,455)	(10,826)	(11,142)	(11,583)	(12,908)	(12,769)	(15,480)	(16,915)	(14,510)	$ (54,219)	(46,459)	(59,674)	(61,998)
Comprehensive loss		$ (10,826)	$ (11,142)	$ (11,583)	$ (12,908)	$ (12,769)	$ (15,480)	$ (16,915)	$ (14,510)		$ (46,478)	$ (59,674)	$ (61,998)
Weighted average units outstanding:
Basic and diluted (in shares)		13,026,816	12,911,905	12,910,975	10,152,487	7,898,922	7,897,143	7,898,301	7,899,251		12,267,693	7,898,289
Net loss per share/unit:
Basic and diluted (in dollars per share)		$ (0.83)	$ (0.86)	$ (0.90)	$ (1.27)	$ (1.62)	$ (1.96)	$ (2.14)	$ (1.84)		$ (3.79)	$ (7.56)

Condensed Consolidated Statements of Changes in Stockholders'/Members Equity (Parenthetical) - USD ($) $ in Thousands		12 Months Ended
	Feb. 19, 2015	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Share price of initial public offering (in dollars per share)	$ 12.00
Underwriting discounts and commissions and offering expenses	$ 8,100	$ 8,085

Income Taxes (Details Textual)	12 Months Ended
Income Taxes (Details Textual)	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
U.S. effective rate	0.00%	0.00%

Marketable Securities - Narrative (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Marketable Securities [Abstract]
Marketable securities	$ 17,807,000	$ 0