Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2016	May. 05, 2016
Document and Entity Information
Entity Registrant Name	AGILE THERAPEUTICS INC
Entity Central Index Key	0001261249
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		28,742,719
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q1

Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 65,495	$ 34,395
Prepaid expenses	3,034	3,690
Total current assets	68,529	38,085
Property and equipment, net	12,316	12,318
Other assets	18	18
Total assets	80,863	50,421
Current liabilities:
Accounts payable	2,873	2,387
Accrued expenses	1,394	2,653
Loan payable, current portion	3,929	2,336
Warrant liability	213	406
Total current liabilities	8,409	7,782
Loan payable, long-term	$ 11,475	$ 12,896
Commitments and contingencies
Stockholders' equity:
Common stock, $.0001 par value, authorized 150,000,000 shares; 28,738,050 shares issued and outstanding as of March 31, 2016 and 22,315,612 shares issued and outstanding as of December 31, 2015;	$ 3	$ 2
Additional paid-in capital	233,021	194,468
Accumulated deficit	(172,045)	(164,727)
Total stockholders' equity	60,979	29,743
Total liabilities and stockholders' equity	$ 80,863	$ 50,421

Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2016	Dec. 31, 2015
Balance Sheets
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	150,000,000	150,000,000
Common stock, issued (in shares)	28,738,050	22,315,612
Common stock, outstanding (in shares)	28,738,050	22,315,612

Statements of Operations - USD ($) $ in Thousands	3 Months Ended
Statements of Operations - USD ($) $ in Thousands	Mar. 31, 2016	Mar. 31, 2015
Operating expenses:
Research and development	$ 4,927	$ 5,378
General and administrative	2,053	1,599
Total operating expenses	6,980	6,977
Loss from operations	(6,980)	(6,977)
Other income (expense)
Interest expense	(548)	(425)
Interest income	17	1
Change in fair value of warrants	193	(101)
Loss on extinguishment of debt		(1,036)
Loss before benefit from income taxes	(7,318)	(8,538)
Net loss	$ (7,318)	$ (8,538)
Net loss per share - basic and diluted (in dollars per share)	$ (0.27)	$ (0.40)
Weighted-average shares outstanding - basic and diluted (in shares)	26,826,223	21,282,692

Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
Statements of Cash Flows - USD ($) $ in Thousands	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities
Net loss	$ (7,318)	$ (8,538)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	4	5
Noncash stock based compensation	711	645
Noncash interest	172	73
Loss on extinguishment of debt		1,036
Change in fair value of warrants	(193)	101
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	656	308
Accounts payable and accrued expenses	(771)	724
Net cash used in operating activities	(6,739)	(5,646)
Cash flows from investing activities
Acquisition of property and equipment	(2)	(189)
Net cash used in investing activities	(2)	(189)
Cash flows from financing activities
Proceeds from issuance of long-term debt		16,265
Repayment of term loan		(15,784)
Cash paid for debt financing costs		(423)
Proceeds from the issuance of common stock, net	37,547	19,330
Proceeds from exercise of stock options	294	130
Net cash provided by financing activities	37,841	19,518
Net increase in cash and cash equivalents	31,100	13,683
Cash and cash equivalents, beginning of period	34,395	40,182
Cash and cash equivalents, end of period	65,495	53,865
Supplemental disclosure of noncash financing activities
Fair value of common stock warrants issued		1,184
Supplemental cash flow information
Interest paid	$ 375	$ 339

Organization and Description of Business	3 Months Ended
Organization and Description of Business	Mar. 31, 2016
Organization and Description of Business
Organization and Description of Business	1. Organization and Description of Business Nature of Operations Agile Therapeutics, Inc. (the “Company”) was incorporated in Delaware on December 22, 1997. The Company is engaged in research and development of transdermal patch technology for use in contraception. The Company’s activities since inception have consisted principally of raising capital and performing research and development. The Company is headquartered in Princeton, New Jersey. The Company is devoting substantially all of its efforts toward research and development of its transdermal patch for use in contraception, and raising capital. The Company has not generated product revenue to date and is subject to a number of risks similar to those of other early stage companies, including dependence on key individuals, the difficulties inherent in the development of commercially usable products, the potential need to obtain additional capital necessary to fund the development of its products, and competition from larger companies. The Company has incurred losses each year since inception. As of March 31, 2016, the Company had an accumulated deficit of approximately $172.0 million. The Company has financed its operations to date primarily through the issuance and sale of its common stock in both public and private offerings (see Note 7), private placements of its convertible preferred stock, venture loans, and non-dilutive grant funding. The Company expects to continue to incur net losses into the foreseeable future. As of March 31, 2016, the Company had cash and cash equivalents of $65.5 million. Although the Company has incurred recurring losses in each year since inception, the Company expects its cash and cash equivalents will be sufficient to fund operations for at least the next twelve months. Basis of Presentation The accompanying unaudited interim condensed financial statements have been prepared by the Company, without audit, in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim information and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for reporting on Form 10-Q. Accordingly, certain information and footnote disclosure normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These interim condensed financial statements should be read in conjunction with the audited financial statements and related notes included in the Company’s annual report on Form 10-K for the year ended December 31, 2015 filed with the SEC. In the opinion of management, the unaudited interim condensed financial statements reflects all adjustments, which are normal recurring adjustments, necessary for the fair presentation of the financial information for the interim periods have been made. The results of operations for the three months ended March 31, 2016 are not necessarily indicative of the operating results for the full fiscal year or any future period.

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2016

Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

The Company’s complete listing of significant accounting policies are described in Note 2 to the Company’s audited financial statements as of December 31, 2015 included in its annual report on Form 10-K filed with the SEC.

2. Summary of Significant Accounting Policies (Continued)

Use of Estimates

The preparation of the Company’s financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company bases its estimates and judgments on historical experience and various other assumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company’s balance sheets and the amounts of expenses reported for each of the periods presented are affected by estimates and assumptions, which are used for, but not limited to, the accounting for common stock warrants, stock-based compensation, income taxes, and accounting for research and development costs. Actual results could differ from those estimates.

Fair Value of Financial Instruments

In accordance with ASC 825, Financial Instruments, disclosures of fair value information about financial instruments are required, whether or not recognized in the balance sheet, for which it is practicable to estimate that value. Cash and cash equivalents are carried at fair value (see Note 3).

Financial instruments, including accounts payable and accrued liabilities, are carried at cost, which approximates fair value given their short-term nature.

Warrants

The Company accounts for its warrants to purchase redeemable convertible stock in accordance with ASC 480, Distinguishing Liabilities from Equity. ASC 480 requires that a financial instrument, other than outstanding share, that, at inception, is indexed to an obligation to repurchase the issuer’s equity shares, regardless of the timing or the probability of the redemption feature, and may require the issuer to settle the obligation by transferring assets be classified as a liability. The Company measures the fair value of its warrant liability using an option pricing model with changes in fair value recognized as increases or reductions to other income (expense) in the statement of operations.

In connection with the completion of the Company’s initial public offering in May 2014, the warrants to purchase shares of Series A-1 and Series A-2 preferred stock expired unexercised and the warrants to purchase shares of Series C preferred stock automatically converted into warrants to purchase shares of common stock. Warrants with non-standard anti-dilution provisions (referred to as down round protection) are classified as liabilities and re-measured each reporting period. As of March 31, 2016, there were outstanding 62,505 warrants to purchase common stock at $6.00 per share. These warrants expire on December 14, 2019.

The warrants issued in connection with the Company’s debt financing completed in February 2015 (see Note 6) are classified as a component of stockholders’ equity. The value of such warrants was determined using the Black-Scholes option-pricing model.

Stock-Based Compensation

The Company accounts for stock-based compensation in accordance with ASC 718, Compensation-Stock Compensation. The Company grants stock options for a fixed number of shares to employees and non-employees with an exercise price equal to the fair value of the shares at grant date. Compensation cost is recognized for all share-based payments granted and is based on the grant-date fair value estimated using the weighted-average assumption of the Black-Scholes option pricing model based on key assumptions such as stock price, expected volatility and expected term. The equity instrument is not considered to be issued until the instrument vests. As a result, compensation cost is recognized over the requisite service period with an offsetting credit to additional paid-in capital.

The Company also awards restricted stock units (RSUs) to employees. RSUs are generally subject to forfeiture if employment terminates prior to the completion of the vesting restrictions. The Company expenses the cost of the RSUs, which is determined to be the fair market value of the shares of common stock underlying the RSUs at the date of grant, ratably over the period during which the vesting restrictions lapse.

Awards for consultants are accounted for under ASC 505-50, Equity Based Payments to Non-Employees. Any compensation expense related to consultants is marked-to-market over the applicable vesting period as they vest.

Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding plus the effect of dilutive potential common shares outstanding during the period determined using the treasury-stock and if-converted methods. For purposes of diluted net loss per share calculation, common stock warrants, unvested RSUs and stock options are considered to be potentially dilutive securities but are excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive and therefore, basic and diluted net loss per share were the same for all periods presented.

Potentially dilutive securities that have been excluded from the calculation of diluted net loss per share for the three months ended March 31, 2016 and 2015 because to do so would be anti-dilutive are as follows (in common equivalent shares):

	March 31
	2016	2015
Common stock warrants	242,779	242,779
Common stock options	2,640,810	2,234,191
Unvested restricted stock units	33,334	—

Total	2,916,923	2,476,970

Recent Accounting Pronouncements

In August 2014, the Financial Accounting Standards Board (FASB) issued ASU 2014-15, Presentation of Financial Statements — Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which defines management’s responsibility to assess an entity’s ability to continue as a going concern, and to provide related footnote disclosures if there is substantial doubt about its ability to continue as a going concern. The new standard is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early application is permitted. The Company does not expect the adoption of ASU 2014-15 to have a material impact on its financial statements.

In April 2015, the FASB issued an amendment to U.S. GAAP to simplify the balance sheet presentation of the costs for issuing debt. The changes were adopted in Accounting Standards Update (ASU) No. 2015-03, Interest – Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issue Costs, or ASU 2015-03. ASU 2015-03 amends current presentation guidance by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. Prior to the issuance of ASU 2015-03, debt issuance costs were required to be presented as an asset in the balance sheet. The Company adopted the provisions of ASU 2015-03 on January 1, 2016 and prior period balances have been reclassified to conform to the current period presentation. As of December 31, 2015, $152 of debt issuance costs were reclassified in the balance sheet from “deferred financing costs, net” to “loan payable, current portion” and $139 was reclassified from “deferred financing costs, net” to “loan payable, long-term”. The adoption of ASU 2015-03 did not have an impact on the Company’s operations or cash flows.

In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases. The new standard establishes a right-of-use (ROU) model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the statement of operations. The new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. A modified retrospective transition approach is required for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The Company will be evaluating the impact of the pending adoption of the new standard on the Company’s financial statements.

In March 2016, the FASB issued guidance on employee share-based payment accounting requiring all tax effects related to share-based payments at settlement or expiration to be recorded through the statement of operations and be reported as operating activities on the statement of cash flows. Further, under the new guidance, entities are permitted to make an accounting policy election for the impact of forfeitures on the recognition of expense for share-based payment awards; whereas forfeitures can be estimated, as required today, or recognized when they occur. The guidance is effective for public business entities for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The Company is currently evaluating the impact this guidance will have on financial statements.

Fair Value Measurements

3 Months Ended

Mar. 31, 2016

Fair Value Measurements

Fair Value Measurements

3. Fair Value Measurements

ASC 820, Fair Value Measurements and Disclosures, describes the fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value.

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Assets and liabilities that are measured at fair value are reported using a three-level fair value hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable inputs and minimizes the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows:

Level 1 — Quotes prices in active markets for identical assets and liabilities. The Company’s Level 1 assets and liabilities consist of cash and cash equivalents.

Level 2 — Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted market prices for similar assets or liabilities in active markets or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets and liabilities. The Company has no Level 2 assets or liabilities.

Level 3 — Unobservable inputs that are supported by little or no market data and which require internal development of assumptions about how market participant price the fair value of the assets or liabilities. The Company’s Level 3 liabilities consist of the warrant liability.

The Company is required to mark the value of its warrant liability to market and recognize the change in valuation in its statements of operations each reporting period.

The following table sets forth the Company’s financial instruments measured at fair value by level within the fair value hierarchy as of March 31, 2016 and December 31, 2015.

	Level 1		Level 2		Level 3
March 31, 2016
Assets:
Cash equivalents	$	65,396	$	—	$	—

Total assets at fair value	$	65,396	$	—	$	—

Liabilities:
Common stock warrants	—		—		213

Total liabilities at fair value	$	—	$	—	$	213

The significant assumptions used in preparing the option pricing model for valuing the Company’s warrants as of March 31, 2016 include (i) volatility (75.0%), (ii) risk free interest rate of 1.04% (estimated using treasury bonds with a 3.75 year life), (iii) strike price ($6.00) for the common stock warrants, (iv) fair value of common stock ($6.21) and (v) expected life (3.75 years).

The following is a rollforward of the fair value of Level 3 warrants:

Beginning balance at December 31, 2015	$	406
Change in fair value	(193		)

Ending balance at March 31, 2016	$	213

	Level 1		Level 2		Level 3
December 31, 2015
Assets:
Cash equivalents	$	34,324	$	—	$	—

Total assets at fair value	$	34,324	$	—	$	—

Liabilities:
Common stock warrants	—		—		406

Total liabilities at fair value	$	—	$	—	$	406

The significant assumptions used in preparing the option pricing model for valuing the Company’s warrants as of December 31, 2015 include (i) volatility (75.0%), (ii) risk free interest rate of 1.54% (estimated using treasury bonds with a 4 year life), (iii) strike price ($6.00) for the common stock warrants, (iv) fair value of common stock ($9.76) and (v) expected life (four years).

There were no transfers between Level 1, 2 or 3 during 2016 or 2015. If the Company’s estimates regarding the fair value of its warrants are inaccurate, a future adjustment to these estimated fair values may be required. Additionally, these estimated fair values could change significantly.

- 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

Prepaid Expenses

3 Months Ended

Mar. 31, 2016

Prepaid Expenses

Prepaid Expenses

4. Prepaid Expenses

Prepaid expenses consist of the following:

	March 31 2016		December 31 2015
Prepaid clinical trial expense	$	2,449	$	2,803
Prepaid insurance	487		780
Other	98		107

Total prepaid expenses	$	3,034	$	3,690

Accrued Liabilities

3 Months Ended

Mar. 31, 2016

Accrued Liabilities

Accrued Liabilities

5. Accrued Liabilities

Accrued liabilities consist of the following:

	March 31 2016		December 31 2015
Employee bonuses	$	245	$	938
Accrued clinical trial costs	907		1,507
Other	242		208

Total accrued liabilities	$	1,394	$	2,653

Loan and Security Agreements	3 Months Ended
Loan and Security Agreements	Mar. 31, 2016
Loan and Security Agreements
Loan and Security Agreements	6. Loan and Security Agreements Oxford Finance LLC In December 2012, the Company entered into a Loan and Security Agreement (the “Oxford Loan”) with Oxford Finance LLC (“Oxford”) pursuant to which the Company borrowed a total of $15.0 million from Oxford. The Oxford Loan accrued interest at a fixed annual rate equal to 9.20% (Three-month U.S. Libor rate of 0.47% plus 8.73%). Interest on the Oxford Loan was payable monthly and principal was due in 30 equal consecutive monthly installments beginning on February 1, 2015 and ending on July 1, 2017. In addition, the Company was required to make a final payment of $675,000 on the maturity date of the Oxford Loan (July 1, 2017). In connection with the Oxford Loan, the Company issued Oxford warrants to purchase 62,505 shares of common stock at $6.00 per share. These warrants expire on December 14, 2019. In February 2015, the Company terminated and repaid all amounts outstanding under the Oxford Loan and recorded a loss on the extinguishment of the Oxford Loan (see further discussion below). Hercules Capital, Inc. In February 2015, the Company entered into a loan and security agreement (the “Hercules Loan”) with Hercules Capital, Inc. (“Hercules”) for a term loan of up to $25.0 million. A first tranche of $16.5 million was funded upon execution of the Hercules Loan, approximately $15.5 million of which was used to repay the Company’s existing term loan with Oxford. The Company is scheduled to make interest-only payments on the loan until July 1, 2016, which period may be extended under certain circumstances. Under the terms of the Hercules Loan, the Company may, but is not obligated to, draw an additional tranche of up to $8.5 million prior to July 1, 2016, subject to the achievement of certain clinical milestones, which may be extended to December 31, 2016 under certain circumstances. The Hercules Loan accrues interest at a rate of the greater of 9.0% or 9.0% plus Prime minus 4.25% and is payable monthly. Principal is due in 30 equal consecutive monthly installments beginning on July 1, 2016 and ending on December 1, 2018. In addition, the Company is required to make a final payment of $610,500 on the maturity date of the Hercules Loan (December 1, 2018). The Company may prepay all, but not less than all, of the Hercules Loan subject to a prepayment premium of 2.0% of the outstanding principal if prepaid during the second year (through February 24, 2017) and 1.0% of the outstanding principal if prepaid after February 24, 2017. The obligations of the Company under the Hercules Loan are secured by a perfected first position lien on all of the assets of the Company, excluding intellectual property assets. In connection with the Hercules Loan, the Company issued Hercules a warrant to purchase 180,274 shares of the Company’s common stock at an exercise price of $5.89 per share which expires on February 24, 2020 and granted Hercules the right to participate in future equity financings in an amount up to $2.0 million while the loan and warrant are outstanding. The Company allocated the proceeds of $16.5 million in accordance with ASC 470 based on the relative fair values. The relative fair value of the warrants of approximately $1.2 million at the time of issuance, which was determined using the Black-Scholes option-pricing model, was recorded as additional paid-in capital and reduced the carrying value of the debt. The significant assumptions used in preparing the option pricing model for valuing the Company’s warrant issued to Hercules include (i) volatility (75.0%), (ii) risk free interest rate of 1.22% (estimated using treasury bonds with a 4 year life), (iii) strike price ($5.89) for the common stock warrant, (iv) fair value of common stock ($9.82) and (v) expected life (four years). The discount on the debt is being amortized to interest expense over the term of the debt. As a result of the repayment of the Oxford Loan, the Company recorded a loss on the extinguishment of debt of approximately $1.0 million on the Company’s statement of operations for the three months ended March 31, 2015, representing a prepayment premium, the unamortized discount of the Oxford Loan and the write off of deferred financing costs.

Stockholders' Equity

3 Months Ended

Mar. 31, 2016

Stockholders' Equity

Stockholders' Equity

7. Stockholders’ Equity

2015 Private Placement of Common Stock

In January 2015, the Company completed a private placement of 3,418,804 shares of common stock at $5.85 per share. Proceeds from the Company’s private placement, net of commissions and other offering costs, were approximately $19.3 million. Two of the Company’s stockholders, who are also affiliated with members of the Company’s Board of Directors, purchased a total of 1,623,932 shares of common stock for approximately $9.5 million in the private placement.

Shelf Registration Statement

On June 19, 2015, the Company filed a universal shelf registration statement with the SEC for the issuance of common stock, preferred stock, warrants, rights, debt securities and units up to an aggregate amount of $150.0 million (the “2015 Shelf Registration Statement”). On July 1, 2015, the 2015 Shelf Registration Statement was declared effective by the SEC. The Company completed an offering of common stock in February 2016 utilizing the 2015 Shelf Registration Statement (see below). In the future, the Company may also periodically offer one or more of these securities in amounts, prices and terms to be announced when and if the securities are offered. At the time any of the securities covered by the 2015 Shelf Registration Statement are offered for sale, a prospectus supplement will be prepared and filed with the SEC containing specific information about the terms of any such offering.

2016 Public Offering of Common Stock

In January 2016, the Company completed an underwritten public offering of 5,511,812 shares of its common stock at a public offering price of $6.35 per share. In February 2016, the underwriters of the public offering of common stock exercised in full their option to purchase an additional 826,771 shares of common stock at the public offering price of $6.35 per share, less underwriting discounts and commissions. A total of 6,338,583 shares of common stock were sold in the public offering resulting in total net proceeds of approximately $37.5 million. One of the Company’s stockholders, who is also affiliated with a member of the Board of Directors, purchased 393,700 shares of common stock for approximately $2.5 million in the public offering.

Stock-Based Compensation Expense

Stock-based compensation expense was allocated as follows:

	Three Months Ended March 31
	2016		2015

Research and development	$	139	$	316
General and administrative	572		329

Total stock-based compensation expense	$	711	$	645

Related Party Transactions	3 Months Ended
Related Party Transactions	Mar. 31, 2016
Related Party Transactions
Related Party Transactions	8. Related Party Transactions Effective March 17, 2014, one of the Managing Partners of SmartPharma LLC, or SmartPharma, an entity which provides commercial and business development consulting services to the Company, was appointed Chief Commercial Officer. In connection with the appointment of this individual as Chief Commercial Officer, the Company amended its consulting agreement with SmartPharma to remove this individual from the list of persons providing service under the consulting agreement. SmartPharma invoiced the Company $2 and $26 of fees for the three months ended March 31, 2016 and 2015, respectively.

- 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

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2016

Summary of Significant Accounting Policies

Use of Estimates

Fair Value of Financial Instruments

Financial instruments, including accounts payable and accrued liabilities, are carried at cost, which approximates fair value given their short-term nature.

Warrants

Stock-Based Compensation

Net Loss Per Share

	March 31
	2016	2015
Common stock warrants	242,779	242,779
Common stock options	2,640,810	2,234,191
Unvested restricted stock units	33,334	—

Total	2,916,923	2,476,970

Recent Accounting Pronouncements

Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2016

Summary of Significant Accounting Policies

Schedule of potentially dilutive securities excluded from calculation of diluted net loss per share

	March 31
	2016	2015
Common stock warrants	242,779	242,779
Common stock options	2,640,810	2,234,191
Unvested restricted stock units	33,334	—

Total	2,916,923	2,476,970

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2016

Fair Value Measurements

Schedule of financial instruments measured at fair value by level within fair value hierarchy

	Level 1		Level 2		Level 3
March 31, 2016
Assets:
Cash equivalents	$	65,396	$	—	$	—

Total assets at fair value	$	65,396	$	—	$	—

Liabilities:
Common stock warrants	—		—		213

Total liabilities at fair value	$	—	$	—	$	213

	Level 1		Level 2		Level 3
December 31, 2015
Assets:
Cash equivalents	$	34,324	$	—	$	—

Total assets at fair value	$	34,324	$	—	$	—

Liabilities:
Common stock warrants	—		—		406

Total liabilities at fair value	$	—	$	—	$	406

Rollforward of fair value of Level 3 warrants

Beginning balance at December 31, 2015	$	406
Change in fair value	(193		)

Ending balance at March 31, 2016	$	213

Prepaid Expenses (Tables)

3 Months Ended

Mar. 31, 2016

Prepaid Expenses

Schedule of components of prepaid expenses

	March 31 2016		December 31 2015
Prepaid clinical trial expense	$	2,449	$	2,803
Prepaid insurance	487		780
Other	98		107

Total prepaid expenses	$	3,034	$	3,690

Accrued Liabilities (Tables)

3 Months Ended

Mar. 31, 2016

Accrued Liabilities

Schedule of components of accrued liabilities

	March 31 2016		December 31 2015
Employee bonuses	$	245	$	938
Accrued clinical trial costs	907		1,507
Other	242		208

Total accrued liabilities	$	1,394	$	2,653

Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2016

Stockholders' Equity

Schedule of allocation of stock-based compensation expense

	Three Months Ended March 31
	2016		2015

Research and development	$	139	$	316
General and administrative	572		329

Total stock-based compensation expense	$	711	$	645

Organization and Description of Business (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Organization and Description of Business
Product revenue	$ 0
Accumulated deficit	(172,045)	$ (164,727)
Cash and cash equivalents
Cash and cash equivalents	$ 65,495	$ 34,395	$ 53,865	$ 40,182

Summary of Significant Accounting Policies - Outstanding Potentially Dilutive Securities that are Anti-Dilutive (Details) - shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Anti-dilutive securities
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares)	2,916,923	2,476,970
Common stock warrants
Anti-dilutive securities
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares)	242,779	242,779
Stock options
Anti-dilutive securities
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares)	2,640,810	2,234,191
Restricted stock units
Anti-dilutive securities
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares)	33,334

Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Recent Accounting Pronouncements
Loan payable, current portion	$ 3,929	$ 2,336
Loan payable, long-term	$ 11,475	12,896
ASU 2015-03, Simplifying the Presentation of Debt Issue Costs \| Adjustment
Recent Accounting Pronouncements
Deferred financing costs, net, reclassified to loan payable, current portion		(152)
Deferred financing costs, net, reclassified to loan payable, long-term		(139)
Loan payable, current portion		(152)
Loan payable, long-term		$ (139)

Fair Value Measurements - Financial Instruments Measured at Fair Value by Hierarchy Level and Significant Assumptions Used for Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Liabilities:
Common stock warrants	$ 213	$ 406
Recurring \| Level 1
Assets:
Total assets at fair value	65,396	34,324
Recurring \| Level 1 \| Cash equivalents
Assets:
Cash and cash equivalents	65,396	34,324
Recurring \| Level 3
Liabilities:
Total liabilities at fair value	213	406
Recurring \| Level 3 \| Warrants \| Common stock warrants
Liabilities:
Common stock warrants	$ 213	$ 406
Recurring \| Level 3 \| Warrants \| Common stock warrants \| Option pricing model
Significant assumptions used in preparing the option pricing model for valuing the Company's warrants
Volatility (as a percent)	75.00%	75.00%
Risk free interest rate (as a percent)	1.04%	1.54%
Life of treasury bonds	3 years 9 months	4 years
Strike price (in dollars per share)	$ 6.00	$ 6.00
Fair value of stock (in dollars per share)	$ 6.21	$ 9.76
Expected life	3 years 9 months	4 years

Fair Value Measurements - Rollforward of Fair Value of Level 3 Warrants and Transfers Between Levels (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Fair value measurements
Asset transfers out of Level 1 into Level 2	$ 0	$ 0
Asset transfers out of Level 2 into Level 1	0	0
Asset transfers into (out of) Level 3	0	0
Liability transfers out of Level 1 into Level 2	0	0
Liability transfers out of Level 2 into Level 1	0	0
Liability transfers into (out of) Level 3	0	0
Liabilities \| Warrants
Rollforward of the fair value of Level 3 warrants
Beginning balance	406,000
Change in fair value	(193,000)
Ending balance	$ 213,000	$ 406,000

Prepaid Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Prepaid Expenses
Prepaid clinical trial expense	$ 2,449	$ 2,803
Prepaid insurance	487	780
Other	98	107
Total prepaid expenses	$ 3,034	$ 3,690

Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accrued Liabilities
Employee bonuses	$ 245	$ 938
Accrued clinical trial costs	907	1,507
Other	242	208
Total accrued liabilities	$ 1,394	$ 2,653

Loan and Security Agreements - Oxford Loan and Hercules Loan (Details)	1 Months Ended		3 Months Ended		12 Months Ended
	Feb. 28, 2015 USD ($) $ / shares shares	Dec. 31, 2012 USD ($) $ / shares shares	Mar. 31, 2016 USD ($) installment	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) installment
Significant assumptions used in preparing the option pricing model for valuing the Company's warrants
Loss on extinguishment of debt				$ 1,036,000
Warrants \| Common stock warrants
Loan and Security Agreements
Common stock that can be purchased with warrants (in shares) \| shares	180,274
Exercise price of warrants (in dollars per share) \| $ / shares	$ 5.89
Significant assumptions used in preparing the option pricing model for valuing the Company's warrants
Volatility (as a percent)	75.00%
Risk free interest rate (as a percent)	1.22%
Life of treasury bonds	4 years
Strike price (in dollars per share) \| $ / shares	$ 5.89
Fair value of stock (in dollars per share) \| $ / shares	$ 9.82
Expected life	4 years
Additional Paid-in Capital
Loan and Security Agreements
Fair value of common stock warrant issued with debt financing	$ 1,200,000
Warrants \| Common stock warrants
Loan and Security Agreements
Common stock that can be purchased with warrants (in shares) \| shares		62,505
Exercise price of warrants (in dollars per share) \| $ / shares		$ 6.00
Secured debt \| Oxford Loan
Loan and Security Agreements
Amount borrowed		$ 15,000,000
Repayment of existing debt	15,500,000
Number of consecutive monthly principal installments \| installment					30
Final payment					$ 675,000
Secured debt \| Hercules Loan
Loan and Security Agreements
Maximum borrowing capacity	25,000,000
Amount borrowed	16,500,000
Additional amount available			$ 8,500,000
Interest rate (as a percent)			9.00%
Number of consecutive monthly principal installments \| installment			30
Final payment			$ 610,500
Discount on debt	1,200,000
Secured debt \| LIBOR \| Oxford Loan
Loan and Security Agreements
Interest rate (as a percent)					9.20%
Variable rate basis					Three-month U.S. Libor rate
Variable rate base (as a percent)					0.47%
Variable interest rate margin (as a percent)					8.73%
Secured debt \| Prime \| Hercules Loan
Loan and Security Agreements
Variable rate basis			Prime minus 4.25%
Variable interest rate margin (as a percent)			9.00%
Variable rate adjustment (as a percent)			4.25%
Secured debt \| Second year (through February 24, 2017) \| Hercules Loan
Loan and Security Agreements
Prepayment premium as percentage of outstanding principal			2.00%
Secured debt \| After February 24, 2017 \| Hercules Loan
Loan and Security Agreements
Prepayment premium as percentage of outstanding principal			1.00%
Equity financings \| Right to participate in future equity financings \| Secured debt \| Hercules Loan \| Hercules \| Maximum
Loan and Security Agreements
Equity financings amount	$ 2,000,000
Secured debt \| Oxford Loan
Significant assumptions used in preparing the option pricing model for valuing the Company's warrants
Loss on extinguishment of debt				$ 1,000,000

Stockholders' Equity - Private Placement (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Jan. 31, 2015 USD ($) shareholder $ / shares shares	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)
Sale of stock
Proceeds from the issuance of common stock, net		$ 37,547	$ 19,330
Private Placement
Sale of stock
Proceeds from the issuance of common stock, net	$ 19,300
Private Placement \| Stockholders affiliated with members of Board of Directors
Sale of stock
Number of stockholders affiliated with members of Board of Directors who purchased shares \| shareholder	2
Proceeds from the issuance of common stock, net	$ 9,500
Private Placement \| Common stock
Sale of stock
Common stock issued (in shares) \| shares	3,418,804
Share price (in dollars per share) \| $ / shares	$ 5.85
Private Placement \| Common stock \| Stockholders affiliated with members of Board of Directors
Sale of stock
Common stock issued (in shares) \| shares	1,623,932

Stockholders' Equity - 2016 Public Offering of Common Stock (Details) $ / shares in Units, $ in Thousands	1 Months Ended		2 Months Ended	3 Months Ended
	Feb. 29, 2016 $ / shares shares	Jan. 31, 2016 USD ($) shareholder $ / shares shares	Feb. 29, 2016 USD ($) $ / shares shares	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)
Sale of stock
Proceeds from the issuance of common stock, net \| $				$ 37,547	$ 19,330
Underwritten public offering
Sale of stock
Proceeds from the issuance of common stock, net \| $			$ 37,500
Underwritten public offering \| Stockholders affiliated with members of Board of Directors
Sale of stock
Number of stockholders affiliated with members of Board of Directors who purchased shares \| shareholder		1
Proceeds from the issuance of common stock, net \| $		$ 2,500
Underwritten public offering \| Common stock
Sale of stock
Common stock issued (in shares) \| shares		5,511,812	6,338,583
Share price (in dollars per share) \| $ / shares		$ 6.35
Underwritten public offering \| Common stock \| Stockholders affiliated with members of Board of Directors
Sale of stock
Common stock issued (in shares) \| shares		393,700
Underwriter purchase option \| Common stock
Sale of stock
Common stock issued (in shares) \| shares	826,771
Share price (in dollars per share) \| $ / shares	$ 6.35		$ 6.35

Related Party Transactions (Details) - SmartPharma $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Mar. 17, 2014 person
Related party transactions
Number of Managing Partners appointed to Chief Commercial Officer \| person			1
Commercial and business development consulting services
Related party transactions
Fees invoiced by the related party \| $	$ 2	$ 26

Stockholders' Equity - Shelf Registration Statement (Details)	Jun. 19, 2015 USD ($)
2015 Shelf Registration
Sale of stock
Aggregate amount of securities issuable	$ 150,000,000