Daré Bioscience (DARE) 10-Q 6 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 31, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Trading Symbol	CERU
Entity Registrant Name	CERULEAN PHARMA INC.
Entity Central Index Key	1,401,914
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		27,303,452

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 85,476	$ 51,174
Accounts receivable, prepaid expenses, and other current assets	1,609	1,662
Total current assets	87,085	52,836
Property and equipment — Net	366	342
Other assets	653	215
Total	88,104	53,393
Current liabilities:
Current portion of loan payable	2,654	3,124
Accounts payable	1,808	1,255
Accrued expenses	3,356	3,648
Other liabilities	27	34
Total current liabilities	7,845	8,061
Long-term liabilities:
Loan payable — net of current portion	11,833
Non-current accrued interest	224
Other		7
Total long-term liabilities	$ 12,057	$ 7
Commitments
Stockholders’ equity:
Preferred stock, $0.01 par value; 5,000,000 shares authorized, no shares issued or outstanding
Common stock, $0.0001 par value; 120,000,000 shares authorized, 27,300,105 and 20,125,049 shares issued and outstanding at June 30, 2015 and December 31, 2014, respectively	$ 3	$ 2
Additional paid-in capital	208,315	167,104
Accumulated deficit	(140,116)	(121,781)
Total stockholders’ equity	68,202	45,325
Total	$ 88,104	$ 53,393

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	27,300,105	20,125,049
Common stock, shares outstanding	27,300,105	20,125,049

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Revenue		$ 33		$ 80
Operating expenses:
Research and development	$ 6,678	2,648	$ 11,699	4,143
General and administrative	2,717	2,029	5,398	3,539
Total operating expenses	9,395	4,677	17,097	7,682
Other income (expense):
Interest income	1	2	4	3
Interest expense	(513)	(268)	(1,242)	(729)
Loss on extinguishment of debt		(2,493)		(2,493)
Decrease in value of preferred stock warrant liability				504
Total other (expense) income — net	(512)	(2,759)	(1,238)	(2,715)
Net loss attributable to common stockholders	$ (9,907)	$ (7,403)	$ (18,335)	$ (10,317)
Net loss per share attributable to common stockholders:
Basic and diluted	$ (0.37)	$ (0.44)	$ (0.78)	$ (1.17)
Weighted-average common shares outstanding:
Basic and diluted	26,690,673	16,883,716	23,504,303	8,835,351

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net loss	$ (18,335)	$ (10,317)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	896	343
Noncash rent expense	(13)	2
Change in carrying value of preferred stock warrant liability		(504)
Depreciation and amortization	83	63
Gain on disposal of property and equipment		(30)
Loss on extinguishment of debt		2,493
Noncash interest expense	791	229
Changes in operating assets and liabilities:
Accounts receivable, prepaid expenses and other current assets	532	(174)
Accounts payable	503	(335)
Accrued expenses	(195)	335
Net cash used in operating activities	(15,738)	(7,895)
Cash flows from investing activities:
Purchases of property and equipment	(107)	(38)
Proceeds from sale of property and equipment		40
Increase in restricted cash	(230)
Net cash (used in) provided by investing activities	(337)	2
Cash flows from financing activities:
Proceeds from sale of common stock	2,472	133
Proceeds from issuance of loans payable	15,000
Proceeds from issuance of convertible promissory notes		8,500
Payments on loans payable	(3,921)	(1,640)
Cash paid for debt issuance costs	(359)	(179)
Proceeds from public stock offering, net of issuance costs	37,185	59,862
Net cash provided by financing activities	50,377	66,676
Net increase in cash and cash equivalents	34,302	58,783
Cash and cash equivalents — Beginning of period	51,174	5,488
Cash and cash equivalents — End of period	85,476	64,271
Supplemental disclosures of noncash investing and financing activities:
Conversion of redeemable convertible preferred stock into common stock		81,525
Conversion of convertible notes and accrued interest into common stock, net		20,138
Reclassification of warrants to additional paid in capital		424
Supplemental cash flow information — Interest paid	$ 443	$ 234

Nature of Business and Operatio

Nature of Business and Operations	6 Months Ended
	Jun. 30, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business and Operations	1. NATURE OF BUSINESS AND OPERATIONS Nature of Business — Cerulean Pharma Inc. (the “Company”) was incorporated on November 28, 2005 as a Delaware corporation and is located in Cambridge, Massachusetts. The Company was formed to develop novel, nanotechnology-based therapeutics in the areas of oncology and other diseases. Basis of Presentation — The consolidated financial statements include the accounts of the Company and its subsidiary, Cerulean Pharma Australia Pty Ltd, a wholly owned Australian-based proprietary limited company. All intercompany accounts and transactions have been eliminated. The consolidated interim financial statements of the Company included herein have been prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted from this report, as is permitted by such rules and regulations. Accordingly, these condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements as of and for the year ended December 31, 2014 and notes thereto, included in the Company’s Annual Report on Form 10-K, which was filed with the Securities and Exchange Commission on March 19, 2015 (the “2015 10-K”). The unaudited condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements. In the opinion of the Company’s management, the accompanying unaudited interim consolidated financial statements contain all adjustments that are necessary to present fairly the Company’s financial position as of June 30, 2015, the results of its operations for the three and six months ended June 30, 2015 and 2014 and cash flows for the six months ended June 30, 2015 and 2014. Such adjustments are of a normal and recurring nature. The results for the three and six months ended June 30, 2015 are not indicative of the results for the year ending December 31, 2015, or for any future period. On April 10, 2015, the Company completed the issuance and sale of 6,716,000 shares of common stock in an underwritten public offering at a price to the public of $6.00 per share. The sale of shares of common stock included 876,000 shares sold pursuant to the full exercise of the underwriters’ option to purchase additional shares of common stock. The net proceeds to the Company from this offering were $37.2 million after deducting underwriting discounts and commissions and offering expenses payable by the Company. On April 15, 2014, the Company completed the issuance and sale of 8,500,000 shares of its common stock in its initial public offering (the “IPO”), at a price to the public of $7.00 per share. On May 7, 2014, the Company completed the sale of an additional 1,069,715 shares of common stock at a price to the public of $7.00 per share under a partial exercise by the underwriters of their option to purchase additional shares of common stock. The sale of the shares to the public resulted in net proceeds to the Company of $59.9 million after deducting underwriting discounts and commissions and offering expenses payable by the Company. In connection with the closing of the IPO, all of the Company’s outstanding redeemable convertible preferred stock and convertible notes automatically converted into shares of common stock as of April 15, 2014, resulting in the issuance by the Company of an additional 9,728,237 shares of common stock. The significant increases in shares outstanding in April 2015 and April 2014 impacts the year-over-year comparability of the Company’s net loss per share calculations. In connection with the completion of the IPO on April 15, 2014, the Company’s outstanding warrants to purchase 1,857,226 shares of the Company’s preferred stock automatically converted into warrants to purchase an aggregate of 128,663 shares of the Company’s common stock and, as a result, the Company reclassified the warrant liability to additional paid-in capital.

Significant Accounting Policies

Significant Accounting Policies	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Significant Accounting Policies	2. SIGNIFICANT ACCOUNTING POLICIES There have been no material changes to the significant accounting policies previously disclosed in the 2015 10-K. Recent Accounting Pronouncements – In April 2015, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2015-03, “Interest – Imputation of Interest” (“ASU 2015-03”). To simplify presentation of debt issuance costs, ASU 2015-03 requires 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. ASU 2015-03 is effective for annual and interim reporting periods beginning January 1, 2016 and is not expected to have a material impact on the Company’s consolidated financial statements.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Stockholders	3. NET LOSS PER SHARE ATTRIBUTABLE TO COMMON STOCKHOLDERS The Company computes diluted loss per common share after giving effect to the dilutive effect of stock options, warrants and shares of unvested restricted stock that are outstanding during the period, except where the inclusion of such securities would be antidilutive. The Company has reported a net loss for all periods presented and, therefore, diluted net loss per common share is the same as basic net loss per common share. The following potentially dilutive securities that were outstanding prior to the use of the treasury stock method have been excluded from the computation of diluted weighted-average shares outstanding, because the inclusion of such securities would have an antidilutive impact due to the losses reported (in common stock equivalent shares): As of June 30, 2015 2014 Options to purchase common stock 2,989,627 1,755,786 Warrants to purchase common stock 300,564 128,663

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2015
Payables And Accruals [Abstract]
Accrued Expenses	4. ACCRUED EXPENSES Accrued expenses consist of the following (in thousands): As of June 30, 2015 As of December 31, 2014 Accrued expenses $ 538 $ 663 Accrued clinical trial costs 1,396 848 Accrued contract manufacturing expenses 392 580 Accrued compensation and benefits 939 983 Accrued interest 91 574 Total accrued expenses $ 3,356 $ 3,648

Convertible Notes Payable to Sh

Convertible Notes Payable to Shareholders	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Convertible Notes Payable to Shareholders	5. CONVERTIBLE NOTES PAYABLE TO SHAREHOLDERS In February and March 2014, the Company issued convertible promissory notes in the original principal amount of $6.0 million to existing investors and a convertible promissory note in the original principal amount of $2.5 million to a new investor. All of the notes had a stated interest rate of 7.0%. Outstanding principal and unpaid accrued interest due under the notes were automatically converted into shares of the Company’s common stock upon the closing of the IPO at a conversion price equal to 77.5% of the IPO price. The Company recorded a loss on the extinguishment of the notes of $2.5 million in April 2014, equal to the difference between the fair value of the shares into which the notes converted and the carrying amount of the notes upon the closing of the IPO.

Loan Agreements

Loan Agreements	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Loan Agreements	6. LOAN AGREEMENTS On January 8, 2015 (the “Closing Date”), the Company entered into a term loan facility of up to $26.0 million (the “Term Loan”) with Hercules Technology Growth Capital, Inc. (“Hercules”). The proceeds were used to repay the Company’s existing term loan facility with Lighthouse Capital Partners VI, L.P. (“Lighthouse Capital”) and for general corporate and working capital purposes. The Term Loan is governed by a loan and security agreement, dated January 8, 2015, between the Company and Hercules (the “Hercules Loan Agreement”). The Hercules Loan Agreement provides for up to three separate borrowings, the first of which was funded in the amount of $15.0 million on the Closing Date. The second borrowing of up to $5.0 million may be drawn by the Company, subject to the satisfaction of customary funding conditions, on or prior to December 15, 2015, provided that the Company meets certain clinical milestones. The third borrowing of up to $6.0 million (the “Term C Loan Advance”) may be drawn, at no less than $3.0 million per draw and subject to the satisfaction of customary funding conditions, on or after September 30, 2015 but before December 15, 2015, provided that between the Closing Date and December 15, 2015, the Company has received net cash proceeds of at least $40.0 million from the issuance and sale by the Company of its equity securities and/or upfront cash payments from one or more strategic corporate partnerships. The Term Loan will mature on July 1, 2018. Each advance under the Term Loan accrues interest at a floating per annum rate equal to the greater of (i) 7.30% or (ii) the sum of 7.30% plus the prime rate minus 5.75%. The Term Loan provides for interest-only payments on a monthly basis until December 31, 2015. The interest only period may be extended at the Company’s option for a three month period if the Company attains certain clinical milestones, and for an additional three month period if the Company attains certain clinical milestones and receives net cash proceeds of at least $30.0 million from the issuance and sale by the Company of its equity securities and/or upfront cash payments from one or more strategic corporate partnerships. Thereafter, payments will be payable monthly in equal installments of principal and interest to fully amortize the outstanding principal over the remaining term of the loan, subject to recalculation upon a change in the prime rate. The Company may prepay the Term Loan in whole or in part upon seven business days’ prior written notice to Hercules. Any such prepayment of the Term Loan is subject to a prepayment charge of (i) 3.0% if such prepayment occurs within twelve months of the Closing Date, (ii) 2.0% if such prepayment occurs after twelve months following the Closing Date but on or prior to twenty-four months following the Closing Date, and (iii) 1.0% thereafter. Amounts outstanding during an event of default are payable upon Hercules’ demand and shall accrue interest at an additional rate of 5.0% per annum of the past due amount outstanding. At the end of the loan term (whether at maturity, by prepayment in full or otherwise), the Company shall pay a final end of term charge to Hercules in the amount of 6.7% of the aggregate original principal amount advanced by Hercules. The amount of the end of term charge is being accrued over the loan term as interest expense. In connection with the Hercules Loan Agreement, the Company issued to Hercules a warrant to purchase shares of the common stock of the Company at an exercise price of $6.05 per share. The warrant is initially exercisable for 137,521 shares of common stock. On such date (if any) as a Term C Loan Advance is made to the Company, the warrant shall automatically become exercisable for an additional 34,380 shares of common stock. The warrant is exercisable until January 8, 2020. The Company estimated the fair value of the warrant for shares exercisable on the issue date in January 2015 to be $659,000. The value of the warrant was recorded as a discount to the loan and will be amortized to interest expense using the effective interest method over the term of the loan. The fair value of the warrant was estimated on the date of issue for the exercisable shares at that date using the Black-Scholes option-pricing model. The following table shows the Black-Scholes assumptions used to value the warrant: January 8, 2015 Contractual life 5 years Volatility rate 61 % Risk-free interest rate 1.50 % Expected dividends — In connection with the Hercules Loan Agreement, the Company entered into a stock purchase agreement with Hercules, whereby Hercules purchased 135,501 shares of common stock from the Company at a price per share of $7.38, which was equal to the closing price of the common stock on The NASDAQ Global Market on January 7, 2015, for an aggregate purchase price of approximately $1.0 million. In December 2011, the Company entered into a loan and security agreement with Lighthouse Capital to borrow up to $10.0 million in one or more advances by December 31, 2012. In both March 2012 and August 2012, the Company borrowed $5.0 million under the loan and security agreement, for a total of $10.0 million. This amount was being repaid over 36 months beginning on December 1, 2012, at an interest rate of 8.25%. In addition, the Company was required to make an additional payment in the amount of $600,000 at the end of the loan term. The amount was accrued over the loan term as interest expense. The amount accrued as of December 31, 2014 was $574,000, and it was included in accrued expense in the Company’s consolidated balance sheet. In January 2015, the Company repaid in full the amount outstanding under the Lighthouse Capital loan, or $3.6 million, with the proceeds from the Hercules Loan Agreement. In connection with the loan and security agreement with Lighthouse Capital, the Company issued Lighthouse Capital a warrant to purchase a maximum of 66,436 shares of the Company’s Series D Preferred Stock, at an exercise price of $12.04 per share and with an expiration date 10 years from the date of issue (December 2021). The Company determined the fair value of the warrant at the end of each reporting period using the Black-Scholes option pricing model until the warrant converted to a warrant to purchase 66,436 shares of common stock upon the completion of the IPO. The value of the warrant was recorded as a discount to the loan and was being amortized as interest expense using the effective interest method over the 36-month repayment term. The unamortized discount relating to the warrants, or $0.2 million, was expensed as interest expense upon repayment of the loan in January 2015.

Stock Option Plan

Stock Option Plan	6 Months Ended
	Jun. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Option Plan	7 . STOCK OPTION PLAN A summary of stock option activity for employee, director and nonemployee awards under all stock option plans during the six months ended June 30, 2015 is presented below (Aggregate Intrinsic Value in thousands): Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Outstanding — January 1, 2015 2,126,176 $ 4.97 6.7 $ 2,701 Granted 1,194,062 7.81 Exercised (323,555 ) 4.55 Forfeited (7,056 ) 5.36 Outstanding — June 30, 2015 2,989,627 $ 6.21 7.5 $ 687 Options expected to vest — June 30, 2015 2,198,792 $ 6.50 7.6 $ 273 Options exercisable — June 30, 2015 679,738 $ 5.22 7.0 $ 399 The weighted-average per share grant date fair value of options granted during the six months ended June 30, 2015 and 2014 was $7.81 and $3.82, respectively. The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model based on the assumptions noted in the table below. Expected volatility for the Company’s common stock was determined based on an average of the historical volatility of a peer-group of similar public companies. The Company has limited option exercise information, and as such, the expected term of the options granted was calculated using the simplified method that represents the average of the contractual term of the option and the weighted-average vesting period of the option. The assumed dividend yield is based upon the Company’s expectation of not paying dividends in the foreseeable future. The risk-free rate for periods within the contractual life of the option is based upon the U.S. Treasury yield curve in effect at the time of grant. The Company has recorded stock-based compensation expense related to the issuance of stock option awards to employees of $403,000 and $196,000, for the three months ended June 30, 2015 and 2014, respectively, and $823,000 and $343,000 for the six months ended June 30, 2015 and 2014, respectively. The assumptions used in the Black-Scholes option-pricing model for stock options granted to employees and to directors in respect of board services during the three and six months ended June 30, 2015 and 2014 are as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Expected life 5.4-6.1 years 6 years 5.4-6.1 years 6 years Risk-free interest rate 1.8%-2.0% 1.9%-2.0% 1.5%-2.0% 1.8%-2.0% Expected volatility 61 % 59 % 61%-63% 59%-60% Expected dividend rate —% —% —% —% During the six months ended June 30, 2015, the Company granted nonemployee stock options to purchase 180,000 shares of the Company’s common stock. The weighted-average exercise price and the weighted-average grant date fair value of nonemployee stock options granted for the six months ended June 30, 2015 was $5.30 per share and $3.07 per share, respectively. The fair value of the grants is being expensed over the vesting period of the options on a straight-line basis as the services are being provided. The Company did not grant any nonemployee stock option grants for the six months ended June 30, 2014. The Company recorded stock-based compensation expense related to nonemployee awards of $53,000 and $12,000 for the three months ended June 30, 2015 and 2014, respectively, and $73,000 and $24,000 for the six months ended June 30, 2015 and 2014, respectively. The compensation expense related to nonemployee awards is included in the total stock-based compensation each year and is subject to re-measurement until the options vest. The Black-Scholes assumptions used to estimate fair value for the three and six months ended June 30, 2015 and 2014 were as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Expected life 10 years 7 years 10 years 7 years Risk-free interest rate 2.2%-2.3% 2.0%-2.5% 2.2%-2.3% 2.0%-2.5% Expected volatility 59 % 55%-59% 59 % 55%-59% Expected dividend rate —% —% —% —%

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	8 . FAIR VALUE MEASUREMENTS The Company’s financial instruments consist of cash equivalents, accounts payable, accrued expenses, and debt obligations. The carrying amount of accounts payable and accrued expenses are considered a reasonable estimate of their fair value, due to the short-term maturity of these instruments. The carrying amount of debt is also considered to be a reasonable estimate of the fair value based on the short term nature of the debt and because the debt bears interest at the prevailing market rate for instruments with similar characteristics. 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 on the measurement date. Valuation techniques used to measure fair value are performed in a manner to maximize the use of observable inputs and minimize the use of unobservable inputs. The accounting standard describes a 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, which are the following: Level 1 — Quoted prices in active markets that are accessible at the market date for identical unrestricted assets or liabilities. Level 2 — Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs for which all significant inputs are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. A summary of the financial assets and liabilities that are measured on a recurring basis at fair value as of June 30, 2015 and December 31, 2014, is as follows (in thousands): Fair Value Measurements Using Carrying Quoted Prices Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Value (Level 1) (Level 2) (Level 3) June 30, 2015 Money market funds $ 85,520 $ — $ 85,520 $ — December 31, 2014 Money market funds $ 50,541 $ — $ 50,541 $ — The Company’s debt obligations are Level 2 measurements in the fair value hierarchy. The Company’s money market funds have been valued on the basis of valuations provided by third-party pricing services, as derived from such services’ pricing models. Inputs to the models may include, but are not limited to, reported trades, executable bid and asked prices, broker/dealer quotations, prices or yields of securities with similar characteristics, benchmark curves or information pertaining to the issuer, as well as industry and economic events. The pricing services may use a matrix approach, which considers information regarding securities with similar characteristics to determine the valuation for a security. The Company is ultimately responsible for the consolidated financial statements and underlying estimates. Accordingly, the Company assesses the reasonableness of the valuations provided by the third-party pricing services by reviewing actual trade data, broker/dealer quotes and other similar data, which are obtained from quoted market prices or other sources. No transfers between levels occurred during the periods presented.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2015
Subsequent Events [Abstract]
Subsequent Event	9 . SUBSEQUENT EVENT On July 9, 2015, the Company entered into a lease agreement (the “Lease”) with AstraZeneca Pharmaceuticals Limited Partnership, a Delaware limited partnership (the “Landlord”), for approximately 22,992 square feet of laboratory and office space in Waltham, Massachusetts. The term of the Lease commences on December 28, 2015 and expires on February 28, 2021, subject to a three-year extension option. During each of the first two years of the term, the Company’s annual base rent will be $689,760. Thereafter, the annual base rent will increase annually for the remainder of the term. In addition to the base rent, the Company is also responsible for its share of the operating expenses, utility costs and real estate taxes, in accordance with the terms of the Lease. Pursuant to the terms of the Lease, the Company provided a security deposit in the form of a letter of credit in the amount of $229,920.

Significant Accounting Polici15

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements – In April 2015, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2015-03, “Interest – Imputation of Interest” (“ASU 2015-03”). To simplify presentation of debt issuance costs, ASU 2015-03 requires 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. ASU 2015-03 is effective for annual and interim reporting periods beginning January 1, 2016 and is not expected to have a material impact on the Company’s consolidated financial statements.

Net Loss Per Share Attributab16

Net Loss Per Share Attributable to Common Stockholders (Tables)	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Potentially Dilutive Securities Excluded from Computation of Diluted Weighted-Average Shares Outstanding	The following potentially dilutive securities that were outstanding prior to the use of the treasury stock method have been excluded from the computation of diluted weighted-average shares outstanding, because the inclusion of such securities would have an antidilutive impact due to the losses reported (in common stock equivalent shares): As of June 30, 2015 2014 Options to purchase common stock 2,989,627 1,755,786 Warrants to purchase common stock 300,564 128,663

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2015
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following (in thousands): As of June 30, 2015 As of December 31, 2014 Accrued expenses $ 538 $ 663 Accrued clinical trial costs 1,396 848 Accrued contract manufacturing expenses 392 580 Accrued compensation and benefits 939 983 Accrued interest 91 574 Total accrued expenses $ 3,356 $ 3,648

Loan Agreements (Tables)

Loan Agreements (Tables)	6 Months Ended
	Jun. 30, 2015
Hercules Loan Agreement [Member] | Common Stock Warrants [Member]
Debt Instrument [Line Items]
Fair Value of Stock Warrants Calculated using Black-Scholes Assumptions	The following table shows the Black-Scholes assumptions used to value the warrant: January 8, 2015 Contractual life 5 years Volatility rate 61 % Risk-free interest rate 1.50 % Expected dividends —

Stock Option Plan (Tables)

Stock Option Plan (Tables)	6 Months Ended
	Jun. 30, 2015
Summary of Stock Option Activity for Employee, Director and Nonemployee Awards	A summary of stock option activity for employee, director and nonemployee awards under all stock option plans during the six months ended June 30, 2015 is presented below (Aggregate Intrinsic Value in thousands): Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Outstanding — January 1, 2015 2,126,176 $ 4.97 6.7 $ 2,701 Granted 1,194,062 7.81 Exercised (323,555 ) 4.55 Forfeited (7,056 ) 5.36 Outstanding — June 30, 2015 2,989,627 $ 6.21 7.5 $ 687 Options expected to vest — June 30, 2015 2,198,792 $ 6.50 7.6 $ 273 Options exercisable — June 30, 2015 679,738 $ 5.22 7.0 $ 399
Summary of Assumptions Used in Black-Scholes Option-Pricing Model for Stock Options Granted to Employees, Directors and Non Employees	The assumptions used in the Black-Scholes option-pricing model for stock options granted to employees and to directors in respect of board services during the three and six months ended June 30, 2015 and 2014 are as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Expected life 5.4-6.1 years 6 years 5.4-6.1 years 6 years Risk-free interest rate 1.8%-2.0% 1.9%-2.0% 1.5%-2.0% 1.8%-2.0% Expected volatility 61 % 59 % 61%-63% 59%-60% Expected dividend rate —% —% —% —%
Non Employee Awards [Member]
Summary of Assumptions Used in Black-Scholes Option-Pricing Model for Stock Options Granted to Employees, Directors and Non Employees	The Black-Scholes assumptions used to estimate fair value for the three and six months ended June 30, 2015 and 2014 were as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Expected life 10 years 7 years 10 years 7 years Risk-free interest rate 2.2%-2.3% 2.0%-2.5% 2.2%-2.3% 2.0%-2.5% Expected volatility 59 % 55%-59% 59 % 55%-59% Expected dividend rate —% —% —% —%

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Summary of Financial Assets and Liabilities Measured on Recurring Basis at Fair Value	A summary of the financial assets and liabilities that are measured on a recurring basis at fair value as of June 30, 2015 and December 31, 2014, is as follows (in thousands): Fair Value Measurements Using Carrying Quoted Prices Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Value (Level 1) (Level 2) (Level 3) June 30, 2015 Money market funds $ 85,520 $ — $ 85,520 $ — December 31, 2014 Money market funds $ 50,541 $ — $ 50,541 $ —

Nature of Business and Operat21

Nature of Business and Operations - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Apr. 10, 2015	May. 07, 2014	Apr. 15, 2014	Jun. 30, 2015	Jun. 30, 2014
Nature Of Business And Operations [Line Items]
Date of Company's incorporation				Nov. 28, 2005
Common stock issuance date				Apr. 10, 2015
Issuance and sale of common stock, Shares	6,716,000
Common share offering price, per share	$ 6
Proceeds from sale of common stock	$ 37,200			$ 2,472	$ 133
Option Exercised by Underwriter [Member]
Nature Of Business And Operations [Line Items]
Issuance and sale of common stock, Shares	876,000
IPO [Member]
Nature Of Business And Operations [Line Items]
Common stock issuance date				Apr. 15, 2014
Issuance and sale of common stock, Shares		1,069,715	8,500,000
Issuance/sale of stock, price per share		$ 7	$ 7
Proceeds from initial public offering, net		$ 59,900
Convertible preferred stock, shares issued upon conversion			9,728,237
Preferred stock conversion basis				In connection with the closing of the IPO, all of the Company’s outstanding redeemable convertible preferred stock and convertible notes automatically converted into shares of common stock as of April 15, 2014.
IPO [Member] | Warrants To Purchase Preferred Stock Converted Into Warrants To Purchase Common Stock [Member] | Preferred Stock Warrants [Member]
Nature Of Business And Operations [Line Items]
Warrant to purchase stock, number of securities called by warrants or rights			1,857,226
IPO [Member] | Warrants To Purchase Preferred Stock Converted Into Warrants To Purchase Common Stock [Member] | Common Stock Warrants [Member]
Nature Of Business And Operations [Line Items]
Warrant to purchase stock, number of securities called by warrants or rights			128,663

Net Loss Per Share Attributab22

Net Loss Per Share Attributable to Common Stockholders - Potentially Dilutive Securities Excluded from Computation of Diluted Weighted-Average Shares Outstanding (Detail) - shares	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted-average shares outstanding	2,989,627	1,755,786
Warrants [Member] | Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted-average shares outstanding	300,564	128,663

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Accrued expenses	$ 538	$ 663
Accrued clinical trial costs	1,396	848
Accrued contract manufacturing expenses	392	580
Accrued compensation and benefits	939	983
Accrued interest	91	574
Total accrued expenses	$ 3,356	$ 3,648

Convertible Notes Payable to 24

Convertible Notes Payable to Shareholders - Additional Information (Detail)	1 Months Ended	3 Months Ended	6 Months Ended
	Apr. 30, 2014USD ($)	Jun. 30, 2014USD ($)	Jun. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Loss on extinguishment of debt		$ (2,493,000)	$ (2,493,000)
Convertible Notes Payable [Member]
Debt Instrument [Line Items]
Debt instrument stated interest rate				7.00%
Debt instrument, Conversion Ratio	0.775
Loss on extinguishment of debt	$ (2,500,000)
Convertible Notes Payable [Member] | Existing Investors [Member]
Debt Instrument [Line Items]
Debt instrument, Original principal amount				$ 6,000,000
Convertible Notes Payable [Member] | New Investor [Member]
Debt Instrument [Line Items]
Debt instrument, Original principal amount				$ 2,500,000

Loan Agreements - Additional In

Loan Agreements - Additional Information (Detail)	Apr. 10, 2015USD ($)	Jan. 08, 2015USD ($)Tranches$ / sharesshares	Jan. 31, 2015USD ($)	Aug. 31, 2012USD ($)	Mar. 31, 2012USD ($)	Dec. 31, 2011USD ($)$ / sharesshares	Jun. 30, 2015USD ($)shares	Jun. 30, 2014USD ($)	Aug. 31, 2012USD ($)	Dec. 31, 2014USD ($)shares	Apr. 30, 2014shares
Debt Instrument [Line Items]
Common stock, shares issued | shares							27,300,105			20,125,049
Proceeds from sale of common stock	$ 37,200,000						$ 2,472,000	$ 133,000
Proceeds from loan payable							15,000,000
Accrued interest							91,000			$ 574,000
Loan and Security Agreement with Lighthouse Capital Partners VI, L.P. [Member]
Debt Instrument [Line Items]
Loan and security agreement, maximum borrowing capacity						$ 10,000,000
Loan and security agreement, borrowings repayment period						36 months
Proceeds from loan payable				$ 5,000,000	$ 5,000,000				$ 10,000,000
Debt instrument stated interest rate						8.25%
Loan and security agreement, borrowings repayment start date						Dec. 1, 2012
Line of credit facility, additional interest payment							$ 600,000
Proceeds from repayments of notes payable			$ 3,600,000
Unamortized discount relating to warrants			200,000
Loan and Security Agreement with Lighthouse Capital Partners VI, L.P. [Member] | Series D Convertible Preferred Stock [Member]
Debt Instrument [Line Items]
Exercise price of warrant | $ / shares						$ 12.04
Warrant expiration date						2021-12
Warrant expiration period						10 years
Loan and Security Agreement with Lighthouse Capital Partners VI, L.P. [Member] | Common Stock [Member]
Debt Instrument [Line Items]
Warrant to purchase stock, number of securities called by warrants or rights | shares											66,436
Maximum [Member] | Loan and Security Agreement with Lighthouse Capital Partners VI, L.P. [Member] | Series D Convertible Preferred Stock [Member]
Debt Instrument [Line Items]
Warrant to purchase stock, number of securities called by warrants or rights | shares						66,436
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member]
Debt Instrument [Line Items]
Loan and security agreement, maximum borrowing capacity		$ 26,000,000
Customary funding conditions minimum net cash proceeds required from issuance and sale of equity securities		$ 40,000,000
Term loan facility, maturity date		Jul. 1, 2018
Term loan facility, interest rate terms							The Term Loan will mature on July 1, 2018. Each advance under the Term Loan accrues interest at a floating per annum rate equal to the greater of (i) 7.30% or (ii) the sum of 7.30% plus the prime rate minus 5.75%. The Term Loan provides for interest-only payments on a monthly basis until December 31, 2015.
Interest only period extension requirement, minimum net cash proceeds required from issuance and sale of equity securities		$ 30,000,000
Additional interest rate during an event of default		5.00%
Final payment as percentage of aggregate original principal amount		6.70%
Term loan facility, interest rate		7.30%
Class of additional warrant or right number of securities called by warrants or rights | shares		34,380
Class of warrant or right, date until which warrants exercisable		Jan. 8, 2020
Estimated fair value of warrant			$ 659,000
Loan and security agreement, borrowings repayment period		30 months
Common stock, shares issued | shares		135,501
Issuance/sale of stock, price per share | $ / shares		$ 7.38
Proceeds from sale of common stock		$ 1,000,000
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member] | Common Stock [Member]
Debt Instrument [Line Items]
Exercise price of warrant | $ / shares		$ 6.05
Warrant to purchase stock, number of securities called by warrants or rights | shares		137,521
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member] | If Payment Occurs Within Twelve Months Of Closing Date [Member]
Debt Instrument [Line Items]
Debt prepayment charge		3.00%
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member] | If Payment Occurs After Twelve Months But on or Prior to Twenty Four Months Following Closing Date [Member]
Debt Instrument [Line Items]
Debt prepayment charge		2.00%
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member] | If Payment Occurs on or After Twenty Four Months Following Closing Date [Member[
Debt Instrument [Line Items]
Debt prepayment charge		1.00%
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member] | Prime Rate [Member]
Debt Instrument [Line Items]
Term loan facility, interest rate spread		5.75%
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member] | Borrowing One [Member]
Debt Instrument [Line Items]
Loan and security agreement, maximum borrowing capacity		$ 15,000,000
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member] | Borrowing Two [Member]
Debt Instrument [Line Items]
Loan and security agreement, maximum borrowing capacity		5,000,000
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member] | Borrowing Three [Member]
Debt Instrument [Line Items]
Loan and security agreement, maximum borrowing capacity		$ 6,000,000
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member] | Maximum [Member]
Debt Instrument [Line Items]
Number of tranches | Tranches		3
Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member] | Minimum [Member]
Debt Instrument [Line Items]
Amount of term loan facility required to be drawn		$ 3,000,000

Loan Agreements - Fair Value of

Loan Agreements - Fair Value of Preferred Stock Warrants Calculated using Black-Scholes Assumptions (Detail) - Jan. 08, 2015 - Loan and Security Agreement with Hercules Technology Growth Capital, Inc. [Member]	Total
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Contractual life	5 years
Volatility rate	61.00%
Risk-free interest rate	1.50%

Stock Option Plan -Summary of S

Stock Option Plan -Summary of Stock Option Activity for Employee, Director and Nonemployee Awards (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Number of shares
Number of Shares, Outstanding	2,126,176
Number of Shares, Granted	1,194,062
Number of Shares, Exercised	(323,555)
Number of Shares, Forfeited	(7,056)
Number of Shares, Outstanding	2,989,627	2,126,176
Number of Shares, Options expected to vest	2,198,792
Number of Shares, Options exercisable	679,738
Weighted-Average Exercise Price
Weighted-Average Exercise Price, Outstanding	$ 4.97
Weighted-Average Exercise Price, Granted	7.81
Weighted-Average Exercise Price, Exercised	4.55
Weighted-Average Exercise Price, Forfeited	5.36
Weighted-Average Exercise Price, Outstanding	6.21	$ 4.97
Weighted-Average Exercise Price, Options expected to vest	6.50
Weighted-Average Exercise Price, Options exercisable	$ 5.22
Weighted-Average Remaining Contractual Life (Years)
Weighted-Average Remaining Contractual Life (Years)	7 years 6 months	6 years 8 months 12 days
Weighted-Average Remaining Contractual Life (Years), Options expected to vest - December 31, 2014	7 years 7 months 6 days
Weighted-Average Remaining Contractual Life (Years), Options exercisable - December 31, 2014	7 years
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding	$ 687	$ 2,701
Aggregate Intrinsic Value, Options expected to vest	273
Aggregate Intrinsic Value, Options exercisable	$ 399

Stock Option Plan - Additional

Stock Option Plan - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average per share grant date fair value of options granted			$ 7.81	$ 3.82
Number of Shares, Granted			1,194,062
Weighted-Average Exercise Price, Options exercisable	$ 5.22		$ 5.22
Employee Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 403,000	$ 196,000	$ 823,000	$ 343,000
Non Employee Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 53,000	$ 12,000	$ 73,000	$ 24,000
Number of Shares, Granted			180,000	0
Weighted-Average Exercise Price, Options exercisable	$ 5.30		$ 5.30
Weighted-average grant date fair value			$ 3.07

Stock Option Plan - Summary of

Stock Option Plan - Summary of Assumptions Used in Black-Scholes Option-Pricing Model for Stock Options Granted to Employees, Directors and Non Employees (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life		6 years		6 years
Expected life, minimum	5 years 4 months 24 days		5 years 4 months 24 days
Expected life, maximum	6 years 1 month 6 days		6 years 1 month 6 days
Risk-free interest rate, minimum	1.80%	1.90%	1.50%	1.80%
Risk-free interest rate, maximum	2.00%	2.00%	2.00%	2.00%
Expected volatility	61.00%	59.00%
Expected volatility, minimum			61.00%	59.00%
Expected volatility, maximum			63.00%	60.00%
Non Employee Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	10 years	7 years	10 years	7 years
Risk-free interest rate, minimum	2.20%	2.00%	2.20%	2.00%
Risk-free interest rate, maximum	2.30%	2.50%	2.30%	2.50%
Expected volatility	59.00%		59.00%
Expected volatility, minimum		55.00%		55.00%
Expected volatility, maximum		59.00%		59.00%

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets and Liabilities Measured on Recurring Basis at Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	$ 85,520	$ 50,541
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	$ 85,520	$ 50,541

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - Jul. 09, 2015 - AstraZeneca Pharmaceuticals Limited Partnership [Member] - Subsequent Events [Member]	USD ($)ft²
Subsequent Event [Line Items]
Laboratory and office space square feet lease premises | ft²	22,992
Lease commenced date	Dec. 28, 2015
Lease expiration date	Feb. 28, 2021
Lease extension term	3 years
Annual base rent in year one	$ 689,760
Annual base rent in year two	689,760
Letter of Credit [Member]
Subsequent Event [Line Items]
Security deposit	$ 229,920