Larimar Therapeutics (LRMR) 10-Q 14 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Aug. 11, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Entity Registrant Name	'Zafgen, Inc.	'
Entity Central Index Key	'0001374690	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	22,707,012

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$134,233	$35,517
Prepaid expenses and other current assets	1,367	224
Tax incentive receivable	1,222	1,617
Total current assets	136,822	37,358
Property and equipment, net	42	37
Other assets	104	743
Total assets	136,968	38,138
Current liabilities:	'	'
Accounts payable	2,057	2,015
Accrued expenses	2,045	900
Total current liabilities	4,102	2,915
Notes payable, net of discount, long-term	7,447	'
Total liabilities	11,549	2,915
Commitments and contingencies (Note 7)	'	'
Redeemable convertible preferred stock (Series A, B, C, D and E), $0.001 par value; No shares and 99,292,610 shares authorized at June 30, 2014 and December 31, 2013, respectively; no shares and 94,483,404 shares issued and outstanding at June 30, 2014 and December 31, 2013, respectively; aggregate liquidation preference of $104,588 at December 31, 2013	'	103,797
Stockholders' equity (deficit):	'	'
Preferred stock; $0.001 par value; 5,000,000 and no shares authorized at June 30, 2014 and December 31, 2013, respectively; no shares issued and outstanding at June, 30, 2014 and December 31, 2013	'	'
Common stock, $0.001 par value; 115,000,000 shares authorized at June 30, 2014 and December 31, 2013; 22,707,012 and 729,391 shares issued and outstanding at June 30, 2014 and December 31, 2013, respectively	23	1
Additional paid-in capital	205,161	332
Accumulated deficit	-79,765	-68,907
Total stockholders' equity (deficit)	125,419	-68,574
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)	$136,968	$38,138

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Statement Of Financial Position [Abstract]	'	'
Redeemable convertible preferred stock (Series A, B, C, D and E), par value	$0.00	$0.00
Redeemable convertible preferred stock (Series A, B, C, D and E), shares authorized	0	99,292,610
Redeemable convertible preferred stock (Series A, B, C, D and E), shares issued	0	94,483,404
Redeemable convertible preferred stock (Series A, B, C, D and E), shares outstanding	0	94,483,404
Redeemable convertible preferred stock (Series A, B, C, D and E), aggregate liquidation preference value	'	$104,588
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	5,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	115,000,000	115,000,000
Common stock, shares issued	22,707,012	729,391
Common stock, shares outstanding	22,707,012	729,391

Consolidated_Statements_of_Ope

Consolidated Statements of Operations and Comprehensive Loss (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]	'	'	'	'
Revenue	'	'	'	'
Operating expenses:	'	'	'	'
Research and development	4,695	1,961	7,970	4,594
General and administrative	1,291	1,014	2,537	1,901
Total operating expenses	5,986	2,975	10,507	6,495
Loss from operations	-5,986	-2,975	-10,507	-6,495
Other income (expense):	'	'	'	'
Interest income	1	'	1	'
Interest expense	-443	'	-445	'
Foreign currency transaction gains (losses), net	28	-161	93	-182
Total other income (expense), net	-414	-161	-351	-182
Net loss and comprehensive loss	-6,400	-3,136	-10,858	-6,677
Accretion of redeemable convertible preferred stock to redemption value	-43	-54	-92	-107
Net loss attributable to common stockholders	($6,443)	($3,190)	($10,950)	($6,784)
Net loss per share attributable to common stockholders, basic and diluted	($2.96)	($4.37)	($7.51)	($9.31)
Weighted average common shares outstanding, basic and diluted	2,178,465	729,391	1,457,931	728,587

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:	'	'
Net loss	($10,858)	($6,677)
Adjustments to reconcile net loss to net cash used in operating activities	'	'
Stock-based compensation expense	444	153
Non-cash interest expense	19	'
Depreciation expense	6	6
Unrealized foreign currency transaction losses (gains)	-64	205
Changes in operating assets and liabilities:	'	'
Prepaid expenses and other current assets	-1,143	85
Tax incentive receivable	459	-1,198
Accounts payable	97	-515
Accrued expenses	791	513
Net cash used in operating activities	-10,249	-7,428
Cash flows from investing activities:	'	'
Purchases of property and equipment	-11	-8
Deposits for leased property	-57	'
Net cash used in investing activities	-68	-8
Cash flows from financing activities:	'	'
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs	442	5,955
Proceeds from issuance of notes payable, net of issuance costs	7,386	'
Payments of debt offering costs	-49	'
Proceeds from initial public offering, net of commissions and underwriting discounts	102,672	'
Payments of initial public offering costs	-1,418	'
Net cash provided by financing activities	109,033	5,955
Net increase (decrease) in cash and cash equivalents	98,716	-1,481
Cash and cash equivalents at beginning of period	35,517	9,935
Cash and cash equivalents at end of period	134,233	8,454
Supplemental disclosure of non-cash investing and financing activities:	'	'
Accretion of redeemable convertible preferred stock to redemption values	92	107
Deferred offering costs included in accounts payable and accrued expenses	894	23
Conversion of redeemable preferred stock to common stock	104,331	'
Supplemental disclosure of cash flow information:	'	'
Cash paid for interest	$103	'

Nature_of_the_Business_and_Bas

Nature of the Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Nature of the Business and Basis of Presentation	'
	1. Nature of the Business and Basis of Presentation
	Zafgen, Inc. (the “Company”) was incorporated on November 22, 2005 under the laws of the State of Delaware. The Company is a biopharmaceutical company dedicated to significantly improving the health and well-being of patients affected by obesity. Beloranib, the Company’s lead product candidate, is a novel, first-in-class, twice-weekly subcutaneous injection being developed for the treatment of multiple indications, including obesity and hyperphagia in Prader-Willi syndrome patients, hypothalamic injury-associated obesity including craniopharyngioma-associated obesity, and severe obesity in the general population. Since its inception, the Company has devoted substantially all of its efforts to research and development, recruiting management, acquiring operating assets and raising capital.
	The Company was previously classified as a “development stage entity” in the Accounting Standards Codification and, as such, was required to present inception-to-date information in the Company’s consolidated statements of operations and comprehensive loss, redeemable convertible preferred stock and stockholders’ deficit, and cash flows. In June 2014, the Financial Accounting Standards Board (“FASB”) issued an accounting standards update that eliminates the concept of a development stage entity from U.S. generally accepted accounting principles and removes the related incremental reporting requirements. See Note 2 below for additional information on this new standard. The Company elected to early adopt the new standard. Accordingly, in contrast to the Company’s consolidated financial statements and the notes thereto for the year ended December 31, 2013 included in Company’s Registration Statement on Form S-1 on file with the Securities and Exchange Commission (“SEC”), the consolidated financial statements contained in this report do not include inception-to-date information.
	The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing. Product candidates currently under development will require significant additional research and development efforts, including extensive pre-clinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure, and extensive compliance-reporting capabilities.
	The Company’s product candidates are all in the development stage. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees and consultants.
	The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries Zafgen Securities Corporation, Zafgen Australia Pty Limited, and Zafgen Animal Health, LLC. All significant intercompany balances and transactions have been eliminated.
	The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”).
	On June 24, 2014 the Company completed an initial public offering (“IPO”) of its common stock, which resulted in the sale of 6,900,000 shares at a price of $16.00 per share. The Company received net proceeds from the IPO of approximately $102,672 based upon the price of $16.00 per share and after deducting underwriting discounts and commissions paid by the Company. The Company also incurred offering costs of $2,508 related to the IPO.
	Unaudited Interim Financial Information
	The consolidated balance sheet at December 31, 2013 was derived from audited financial statements, but does not include all disclosures required by GAAP. The accompanying unaudited consolidated financial statements as of June 30, 2014 and for the three months and six months ended June 30, 2014 and 2013 have been prepared by the Company, pursuant to the rules and regulations of the SEC for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2013 included in the Company’s Registration Statement on Form S-1, File Number 333-195391 on file with the SEC. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s consolidated financial position as of June 30, 2014 and consolidated results of operations for the three and six months ended June 30, 2014 and 2013 and consolidated cash flows for the six months ended June 30, 2014 and 2013 have been made. The results of operations for the three and six months ended June 30, 2014 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2014.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	2. Summary of Significant Accounting Policies
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the accrual of research and development expenses and the valuation of common stock prior to the IPO and stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.
	Cash Equivalents
	The Company considers all short-term, highly liquid investments with original maturities of ninety days or less at acquisition date to be cash equivalents. Cash equivalents, which consist of money market accounts, are stated at fair value.
	Concentration of Credit Risk and of Significant Suppliers
	Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company has all cash and cash equivalents balances at one accredited financial institution, in amounts that exceed federally insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships.
	The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs.
	Fair Value Measurements
	Certain assets and liabilities are carried at fair value under GAAP. 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 must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:
		•		Level 1—Quoted prices in active markets for identical assets or liabilities.
		•		Level 2—Observable inputs (other than Level 1 quoted prices) such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.
		•		Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques.
	The Company’s cash equivalents of $120,000 and $26,501 as of June 30, 2014 and December 31, 2013, respectively, were carried at fair value based on quoted prices in active markets, a Level 1 measurement. The carrying values of accounts payable and accrued expenses approximate their fair value due to the short-term nature of these liabilities. The Company’s carrying value of outstanding debt issued in the first quarter of 2014 approximates fair value based on the recent execution date of the credit facility agreement, and is considered a Level 2 measurement.
	Deferred Offering Costs
	The Company capitalizes certain legal, accounting and other third-party fees that are directly associated with in-process equity financings as other assets until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ equity (deficit) as a reduction of additional paid-in capital generated as a result of the offering or as a reduction to the carrying value of preferred stock issued. As of December 31, 2013, the Company had recorded $743 of deferred offering costs, included in other assets in the accompanying consolidated balance sheet in contemplation of the Company’s IPO of its common stock which closed in June 2014. The Company has no deferred offering costs as of June 30, 2014.
	Property and Equipment
	Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over a five-year estimated useful life for both furniture and fixtures and office equipment. Expenditures for repairs and maintenance of assets are charged to expense as incurred. Upon retirement or sale, the cost and related accumulated depreciation of assets disposed of are removed from the accounts and any resulting gain or loss is included in loss from operations.
	Impairment of Long-Lived Assets
	Long-lived assets consist of property and equipment. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of an asset are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset over its fair value, determined based on discounted cash flows. To date, the Company has not recorded any impairment losses on long-lived assets.
	Research and Development Costs
	Research and development costs are expensed as incurred. Included in research and development expenses are wages, stock-based compensation and benefits of employees, third-party license fees and other operational costs related to the Company’s research and development activities, including facility-related expenses and external costs of outside vendors engaged to conduct both pre-clinical studies and clinical trials. The Company records research and development expenses net of any research and development tax incentives the Company is entitled to receive from government authorities.
	Research Contract Costs and Accruals
	The Company has entered into various research and development contracts with research institutions and other companies both inside and outside of the United States. These agreements are generally cancelable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs.
	Patent Costs
	All patent-related costs incurred in connection with filing and prosecuting patent applications are recorded as general and administrative expenses as incurred, as recoverability of such expenditures is uncertain.
	Accounting for Stock-Based Compensation
	The Company measures all stock options and other stock-based awards granted to employees and directors at the fair value on the date of the grant using the Black-Scholes option-pricing model. The fair value of the awards is recognized as expense, net of estimated forfeitures, over the requisite service period, which is generally the vesting period of the respective award. The straight-line method of expense recognition is applied to all awards with service-only conditions.
	For stock-based awards granted to consultants and nonemployees, compensation expense is recognized over the period during which services are rendered by such consultants and nonemployees until completed. At the end of each financial reporting period prior to completion of the service, the fair value of these awards is re-measured using the then-current fair value of the Company’s common stock and updated assumption inputs in the Black-Scholes option-pricing model.
	The Company classifies stock-based compensation expense in its consolidated statement of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified or in which the award recipients’ service payments are classified.
	The Company recognizes compensation expense for only the portion of awards that are expected to vest. In developing a forfeiture rate estimate, the Company has considered its historical experience to estimate pre-vesting forfeitures for service-based awards. The impact of a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual forfeiture rate is materially different from the Company’s estimate, the Company may be required to record adjustments to stock-based compensation expense in future periods.
	Income Taxes
	The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in the Company’s tax returns. Deferred taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies.
	The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
	Segment Data
	The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is on advancing novel therapeutics for patients suffering from severe obesity and obesity-related disorders. No revenue has been generated since inception, and all tangible assets are held in the United States.
	Comprehensive Loss
	Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. For the three and six months ended June 30, 2014 and 2013, there was no difference between net loss and comprehensive loss.
	Net Income (Loss) Per Share
	Upon the closing of the Company’s IPO in June 2014, all of the Company’s outstanding redeemable convertible preferred shares were converted into shares of common stock. Prior to this conversion, the Company followed the two-class method when computing net income (loss) per share as the Company had issued shares that meet the definition of participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common shareholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. The Company’s redeemable convertible preferred shares contractually entitled the holders of such shares to participate in dividends, but did not contractually require the holders of such shares to participate in losses of the Company. Accordingly, the two-class method did not apply for periods in which the Company reported a net loss or a net loss attributable to common shareholders resulting from dividends or accretion related to its redeemable convertible preferred shares.
	Basic net income (loss) per share attributable to common shareholders is computed by dividing the net income (loss) attributable to common shareholders by the weighted average number of common shares outstanding for the period. Diluted net income (loss) per share attributable to common shareholders is computed by dividing the diluted net income (loss) attributable to common shareholders by the weighted average number of common shares, including potential dilutive common shares assuming the dilutive effect of outstanding stock options and unvested restricted common shares, as determined using the treasury stock method. For periods in which the Company has reported net losses, diluted net loss per common share attributable to common shareholders is the same as basic net loss per common share attributable to common shareholders, since dilutive common shares are not assumed to have been issued if their effect is antidilutive.
	The Company reported a net loss attributable to common stockholders for the three and six months ended June 30, 2014 and 2013.
	The following common stock equivalents outstanding as of June 30, 2014 and 2013, were excluded from the computation of diluted net loss per share for the three and six months ended June 30, 2014 and 2013, because they had an anti-dilutive impact:
			As of June 30,
			2014		2013
	Options to purchase common stock			1,839,895		1,283,264
	Redeemable convertible preferred stock			—		78,372,931
	Total options and redeemable convertible preferred stock exercisable or convertible into common stock			1,839,895		79,656,195
	Recently Issued and Adopted Accounting Pronouncements
	In June 2014, the FASB issued Accounting Standards Update No. 2014-10, Development Stage Entities (Topic 915): Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation. The amendments in this guidance remove all incremental financial reporting requirements for development stage entities. Among other changes, this guidance will no longer require development stage entities to present inception-to-date information about income statement line items, cash flows, and equity transactions. This guidance is effective for public companies in the first annual period beginning after December 15, 2014. Early application is permitted for interim and annual periods for which financial statements have not yet been issued. The Company elected to apply this disclosure guidance to its consolidated financial statements for the three months ended June 30, 2014 and as a result, no longer discloses inception-to-date information in its Consolidated Statements of Operations and Comprehensive Loss, Cash Flows and Stockholders’ Deficit and the related notes thereto.

Accrued_Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2014
Payables And Accruals [Abstract]	'
Accrued Expenses	'
	3. Accrued Expenses
	Accrued expenses consisted of the following:
		June 30,		December 31,
		2014		2013
	Accrued payroll and related expenses	$	465	$	49
	Accrued research and development expenses		592		616
	Accrued professional fees		657		196
	Accrued interest expense		266		—
	Accrued other		65		39
		$	2,045	$	900

Notes_Payable

Notes Payable	6 Months Ended
	Jun. 30, 2014
Debt Disclosure [Abstract]	'
Notes Payable	'
	4. Notes Payable
	On March 31, 2014, the Company entered into a loan and security agreement with Oxford Finance LLC and Midcap Financial (the “Credit Facility”). The Credit Facility provides for initial borrowings of $7,500 under a term loan (“Term Loan A”) and additional borrowings of up to $12,500 under other term loans, for a maximum of $20,000. On March 31, 2014, the Company received proceeds of $7,500 from the issuance of promissory notes under the Term Loan A. Of the additional $12,500 amount that is available, $7,500 (“Term Loan B”) is available to be drawn down until September 30, 2014 and $5,000 (“Term Loan C”) was available to be drawn down for a 30-day period upon the completion of the Company’s IPO that occurred in June 2014. The Company elected not to draw down Term Loan C and this amount is no longer available to the Company. All promissory notes issued under the Credit Facility are collateralized by substantially all of the Company’s personal property, other than its intellectual property.
	Upon entering into this Credit Facility, the Company was obligated to make monthly, interest-only payments on any term loans funded under the Credit Facility until December 1, 2014 and, thereafter, to pay 36 consecutive, equal monthly installments of principal and interest from January 1, 2015 through December 1, 2017. As per the terms of the agreement, in June 2014, upon the completion of the Company’s IPO, the term of monthly, interest-only payments has been extended until June 1, 2015. Outstanding term loans under the Credit Facility bear interest at an annual rate of 8.1%. In addition, a final payment equal to 6.0% of any amounts drawn under the Credit Facility is due upon the earlier of the maturity date, acceleration of the term loans or prepayment of all or part of the term loans. The Company accrues the amount due relating to Term Loan A of $450, to outstanding debt by charges to interest expense using the effective-interest method from the date of issuance through the maturity date.
	Term Loan A was recorded in the balance sheet net of debt discount of $114 that was related to fees assessed by the lender at the time of borrowing. The debt discount is being accreted to the principal amount of the debt. In addition, deferred financing costs of $49 are being amortized to interest expense using the effective-interest method over the same term. For both the three and six months ended June 30, 2014, the Company recorded additional interest expense of $19 related the accretion of the debt discount and amortization of deferred financing costs.
	The Company is obligated to pay a separate fee upon any IPO; a sale of substantially all of the Company’s assets; or a merger, reorganization or sale of the Company’s voting equity securities where existing voting stockholders hold less than 50% of voting equity securities after such transaction. As of June 30, 2014, the Company recorded additional interest expense of $225 relating to the accrual of the fee payable upon the Company’s IPO.
	There are no financial covenants associated with the debt facility; however, there are negative covenants restricting the Company’s activities, including limitations on dispositions, mergers or acquisitions; encumbering or granting a security interest in its intellectual property; incurring indebtedness or liens; paying dividends; making certain investments; and certain other business transactions.
	The Credit Facility also includes events of default, the occurrence and continuation of any of which provides the lenders the right to exercise remedies against the Company and the collateral securing the loans under the Credit Facility, including cash. These events of default include, among other things, failure to pay any amounts due under the Credit Facility, insolvency, the occurrence of a material adverse event, the occurrence of any default under certain other indebtedness and a final judgment against the Company in an amount greater than $250.
	Estimated future principal payments due under the Term Loan A are as follows:
	Years Ending December 31,
	2014	$	—
	2015		1,381
	2016		2,936
	2017		3,183
	Total	$	7,500
	During the three and six months ended June 30, 2014, the Company recognized $443 and $445, respectively, of interest expense related to the Credit Facility.
	The Company had no debt outstanding as of December 31, 2013.

Stockholders_Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2014
Equity [Abstract]	'
Stockholders' Equity	'
	5. Stockholders’ Equity
	On June 5, 2014, the Company effected a 1-for-6.28 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each series of redeemable convertible preferred stock. Accordingly, all share and per share amounts for all periods presented in these consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect this reverse stock split and adjustment of the redeemable convertible preferred stock conversion ratios.
	On June 24, 2014 the Company completed an IPO of its common stock, which resulted in the sale of 6,900,000 shares at a price of $16.00 per share. The Company received net proceeds from the IPO of approximately $102,672 based upon the price of $16.00 per share and after deducting underwriting discounts and commissions paid by the Company. The Company also incurred offering costs of $2,508 related to the IPO.
	Upon closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock were converted into 15,077,621 shares of common stock.
	As of June 30, 2014 the Company’s Certificate of Incorporation, as amended and restated, authorizes the Company to issue 5,000,000 shares of $0.001 par value preferred stock.
	As of June 30, 2014 and December 31, 2013, the Company’s Certificate of Incorporation, as amended and restated, authorizes the Company to issue 115,000,000 shares of $0.001 par value common stock.
	During the six months ended June 30, 2013, the Company reacquired and retired 6,635 shares of restricted common stock, at cost, that were forfeited by a former employee.

StockBased_Awards

Stock-Based Awards	6 Months Ended
	Jun. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock-Based Awards	'
	6. Stock-Based Awards
	Stock Option Plans
	The Company’s Amended and Restated 2006 Stock Option Plan (the “2006 Plan”) provided for the Company to sell or issue common stock or restricted common stock, or to grant incentive stock options or nonqualified stock options for the purchase of common stock, to employees, members of the board of directors and consultants of the Company. The 2006 Plan is administered by the board of directors, or at the discretion of the board of directors, by a committee of the board. The exercise prices, vesting and other restrictions are determined at the discretion of the board of directors, or their committee if so delegated, except that the exercise price per share of stock options may not be less than 100% of the fair market value of the share of common stock on the date of grant and the term of stock option may not be greater than ten years. The total number of shares of common stock that could be issued under the 2006 Plan was 1,889,150 shares. Upon closing of the Company’s IPO, 168,221 shares reserved and not then subject to outstanding options were transferred to the 2014 Stock Option and Incentive Plan, and no further awards will be made under the 2006 Plan.
	On June 5, 2014, the Company’s stockholders approved the 2014 Stock Option and Incentive Plan (the “2014 Stock Option Plan”), which became effective upon the completion of the IPO of the Company’s shares of common stock in June 2014. The 2014 Stock Option Plan provides for the grant of stock options, stock appreciation rights, restricted stock, restricted stock units, unrestricted stock, performance-share awards and cash-based awards. The number of shares initially reserved for issuance under the 2014 Stock Option Plan is 2,168,221 shares of common stock and may be increased by the number of shares under the 2006 Plan that are not needed to fulfill the Company’s obligations for awards issued under the 2006 Plan as a result of forfeiture, expiration, cancellation, termination or net issuances of awards thereunder. The number of shares of common stock that may be issued under the plan is also subject to increase on the first day of each fiscal year by the lesser of (i) 4% of the Company’s outstanding shares of common stock as of that date, or (ii) an amount determined by the board of directors.
	The Company generally grants stock-based awards with service conditions only (“service-based” awards).
	As required by the 2006 Plan and 2014 Stock Option Plan, the exercise price for stock options granted is not to be less than the fair value of common shares as of the date of grant. Prior to the IPO, the value of common stock was determined by the board of directors by taking into consideration its most recently available valuation of common shares performed by management and the board of directors as well as additional factors which might have changed since the date of the most recent contemporaneous valuation through the date of grant.
	For the three months ended June 30, 2014, the Company granted 326,542 stock options, 324,950 stock options to employees and 1,592 stock options to a consultant.
	2014 Employee Stock Purchase Plan
	On June 5, 2014, the Company’s stockholders approved the 2014 Employee Stock Purchase Plan. A total of 265,000 shares of common stock were reserved for issuance under this plan. The 2014 Employee Stock Purchase Plan became effective upon the completion of the IPO of the Company’s shares of common stock. No offering periods have commenced as of June 30, 2014.
	Stock Option Valuation
	The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The Company historically has been a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The expected term of stock options granted to nonemployees is equal to the contractual term of the option award. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. The assumptions that the Company used to determine the fair value of the stock options granted to employees and directors are as follows, presented on a weighted average basis:
	As of June 30, 2014, there were outstanding unvested service-based stock options held by nonemployees for the purchase of 17,513 shares of common stock. Additionally as of June 30, 2014, there were outstanding unvested performance-based stock options held by nonemployees for the purchase of 796 shares of common stock.
	Stock-based Compensation
	The Company recorded stock-based compensation expense related to stock options and restricted common stock in the following expense categories of its statements of operations:
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2014		2013		2014		2013
	Research and development	$	99	$	43	$	168	$	69
	General and administrative		169		60		276		84
		$	268	$	103	$	444	$	153
	As of June 30, 2014, the Company had an aggregate of $2,798 of unrecognized stock-based compensation cost, which is expected to be recognized over a weighted average period of 3.6 years.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	7. Commitments and Contingencies
	Leases
	The Company leases its office space under an operating lease agreement that initially expired on July 31, 2013, but was amended to extend the lease through July 31, 2014.
	On May 15, 2014, the Company entered into new lease of office space in Boston, Massachusetts, effective as of July 28, 2014, with a term expiring July 31, 2017 and an option to extend the lease for three additional years.
	Future minimum lease payments for its operating leases as of June 30, 2014, are as follows:
	Year Ending December 31,
	2014	$	106
	2015		229
	2016		235
	2017		139
	Total	$	709
	During the three months ended June 30, 2014 and 2013, the Company recognized $27 and $32, respectively, of rental expense related to office space. During the six months ended June 30, 2014 and 2013, the Company recognized $52 and $64, respectively, of rental expense related to office space.
	Intellectual Property Licenses
	The Company has acquired exclusive rights to develop patented compounds and related know-how for beloranib under two licensing agreements with two third parties in the course of its research and development activities. The licensing rights obligate the Company to make payments to the licensors for license fees, milestones, license maintenance fees and royalties. The Company is also responsible for patent prosecution costs.
	As of June 30, 2014, the Company is obligated to make milestone payments of up to $18,950 upon reaching certain pre-commercialization milestones, such as clinical trials and government approvals, and up to $12,500 upon reaching certain product commercialization milestones. Under one of the license agreements, the Company is also obligated to pay up to $1,250 with respect to each subsequent licensed product, if any, that is a new chemical entity. In addition, the Company will owe single-digit royalties on sales of commercial products developed using these licensed technologies, if any. The Company is also obligated to pay to the licensors a percentage of fees received if and when the Company sublicenses the technology. As of June 30, 2014, the Company has not yet developed a commercial product using the licensed technologies and it has not entered into any sublicense agreements for the technologies. The Company reasonably anticipates that it may be required to pay $6,700 of milestone payments in 2014, provided various development milestones are achieved.
	Indemnification Agreements
	In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners, and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of June 30, 2014.

Retirement_Plan

Retirement Plan	6 Months Ended
	Jun. 30, 2014
Compensation And Retirement Disclosure [Abstract]	'
Retirement Plan	'
	8. Retirement Plan
	The Company has a Savings Incentive Match Plan for employees. Under the terms of the plan, the Company contributes 2% of an employee’s annual base salary, up to a maximum of the annual Internal Revenue Service compensation limits, for all full-time employees.
	During the three months ended June 30, 2014 and 2013, the Company recognized $13 and $7, respectively, of expense related to its contributions to this plan. During the six months ended June 30, 2014 and 2013, the Company recognized $26 and $14, respectively, of expense related to its contributions to the plan.

Australia_Research_and_Develop

Australia Research and Development Tax Incentive	6 Months Ended
	Jun. 30, 2014
Research And Development [Abstract]	'
Australia Research and Development Tax Incentive	'
	9. Australia Research and Development Tax Incentive
	The Company’s wholly owned subsidiary, Zafgen Australia Pty Limited, which conducts core research and development activities on behalf of the Company is eligible to receive a 45% refundable tax incentive for qualified research and development activities. For the three months ended June 30, 2014 and 2013, $47 and $418, respectively, was recorded as a reduction to research and development expenses in the consolidated statements of operations and, for the six months ended June 30, 2014 and 2013, $73 and $1,198, respectively, was recorded as a reduction to research and development expenses in the consolidated statements of operations. These amounts represented 45% of the Company’s qualified research and development spending in Australia. The refund is denominated in Australian dollars and, therefore, the receivable is re-measured into U.S. dollars as of each reporting date. For the three months ended June 30, 2014 and 2013, the Company recorded in its consolidated statements of operations unrealized foreign currency exchange (gains) losses of $(22) and $210, respectively, related to this tax incentive receivable. For the six months ended June 30, 2014 and 2013, the Company recorded in its consolidated statements of operations unrealized foreign currency exchange (gains) losses of $(64) and $205, respectively, related to this tax incentive receivable. As of June 30, 2014 and December 31, 2013, the Company’s tax incentive receivable from the Australian government was $1,222 and $1,617, respectively.

Nature_of_the_Business_and_Bas1

Nature of the Business and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Unaudited Interim Financial Information	'
	Unaudited Interim Financial Information
	The consolidated balance sheet at December 31, 2013 was derived from audited financial statements, but does not include all disclosures required by GAAP. The accompanying unaudited consolidated financial statements as of June 30, 2014 and for the three months and six months ended June 30, 2014 and 2013 have been prepared by the Company, pursuant to the rules and regulations of the SEC for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2013 included in the Company’s Registration Statement on Form S-1, File Number 333-195391 on file with the SEC. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s consolidated financial position as of June 30, 2014 and consolidated results of operations for the three and six months ended June 30, 2014 and 2013 and consolidated cash flows for the six months ended June 30, 2014 and 2013 have been made. The results of operations for the three and six months ended June 30, 2014 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2014.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the accrual of research and development expenses and the valuation of common stock prior to the IPO and stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.
Cash Equivalents	'
	Cash Equivalents
	The Company considers all short-term, highly liquid investments with original maturities of ninety days or less at acquisition date to be cash equivalents. Cash equivalents, which consist of money market accounts, are stated at fair value.
Concentration of Credit Risk and of Significant Suppliers	'
	Concentration of Credit Risk and of Significant Suppliers
	Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company has all cash and cash equivalents balances at one accredited financial institution, in amounts that exceed federally insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships.
	The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs.
Fair Value Measurements	'
	Fair Value Measurements
	Certain assets and liabilities are carried at fair value under GAAP. 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 must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:
		•		Level 1—Quoted prices in active markets for identical assets or liabilities.
		•		Level 2—Observable inputs (other than Level 1 quoted prices) such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.
		•		Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques.
	The Company’s cash equivalents of $120,000 and $26,501 as of June 30, 2014 and December 31, 2013, respectively, were carried at fair value based on quoted prices in active markets, a Level 1 measurement. The carrying values of accounts payable and accrued expenses approximate their fair value due to the short-term nature of these liabilities. The Company’s carrying value of outstanding debt issued in the first quarter of 2014 approximates fair value based on the recent execution date of the credit facility agreement, and is considered a Level 2 measurement.
Deferred Offering Costs	'
	Deferred Offering Costs
	The Company capitalizes certain legal, accounting and other third-party fees that are directly associated with in-process equity financings as other assets until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ equity (deficit) as a reduction of additional paid-in capital generated as a result of the offering or as a reduction to the carrying value of preferred stock issued. As of December 31, 2013, the Company had recorded $743 of deferred offering costs, included in other assets in the accompanying consolidated balance sheet in contemplation of the Company’s IPO of its common stock which closed in June 2014. The Company has no deferred offering costs as of June 30, 2014.
Property and Equipment	'
	Property and Equipment
	Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over a five-year estimated useful life for both furniture and fixtures and office equipment. Expenditures for repairs and maintenance of assets are charged to expense as incurred. Upon retirement or sale, the cost and related accumulated depreciation of assets disposed of are removed from the accounts and any resulting gain or loss is included in loss from operations.
Impairment of Long-Lived Assets	'
	Impairment of Long-Lived Assets
	Long-lived assets consist of property and equipment. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of an asset are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset over its fair value, determined based on discounted cash flows. To date, the Company has not recorded any impairment losses on long-lived assets.
Research and Development Costs	'
	Research and Development Costs
	Research and development costs are expensed as incurred. Included in research and development expenses are wages, stock-based compensation and benefits of employees, third-party license fees and other operational costs related to the Company’s research and development activities, including facility-related expenses and external costs of outside vendors engaged to conduct both pre-clinical studies and clinical trials. The Company records research and development expenses net of any research and development tax incentives the Company is entitled to receive from government authorities.
Research Contract Costs and Accruals	'
	Research Contract Costs and Accruals
	The Company has entered into various research and development contracts with research institutions and other companies both inside and outside of the United States. These agreements are generally cancelable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs.
Patent Costs	'
	Patent Costs
	All patent-related costs incurred in connection with filing and prosecuting patent applications are recorded as general and administrative expenses as incurred, as recoverability of such expenditures is uncertain.
Accounting for Stock-Based Compensation	'
	Accounting for Stock-Based Compensation
	The Company measures all stock options and other stock-based awards granted to employees and directors at the fair value on the date of the grant using the Black-Scholes option-pricing model. The fair value of the awards is recognized as expense, net of estimated forfeitures, over the requisite service period, which is generally the vesting period of the respective award. The straight-line method of expense recognition is applied to all awards with service-only conditions.
	For stock-based awards granted to consultants and nonemployees, compensation expense is recognized over the period during which services are rendered by such consultants and nonemployees until completed. At the end of each financial reporting period prior to completion of the service, the fair value of these awards is re-measured using the then-current fair value of the Company’s common stock and updated assumption inputs in the Black-Scholes option-pricing model.
	The Company classifies stock-based compensation expense in its consolidated statement of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified or in which the award recipients’ service payments are classified.
	The Company recognizes compensation expense for only the portion of awards that are expected to vest. In developing a forfeiture rate estimate, the Company has considered its historical experience to estimate pre-vesting forfeitures for service-based awards. The impact of a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual forfeiture rate is materially different from the Company’s estimate, the Company may be required to record adjustments to stock-based compensation expense in future periods.
Income Taxes	'
	Income Taxes
	The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in the Company’s tax returns. Deferred taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies.
	The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
Segment Data	'
	Segment Data
	The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is on advancing novel therapeutics for patients suffering from severe obesity and obesity-related disorders. No revenue has been generated since inception, and all tangible assets are held in the United States.
Comprehensive Loss	'
	Comprehensive Loss
	Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. For the three and six months ended June 30, 2014 and 2013, there was no difference between net loss and comprehensive loss.
Net Income (Loss) Per Share	'
	Net Income (Loss) Per Share
	Upon the closing of the Company’s IPO in June 2014, all of the Company’s outstanding redeemable convertible preferred shares were converted into shares of common stock. Prior to this conversion, the Company followed the two-class method when computing net income (loss) per share as the Company had issued shares that meet the definition of participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common shareholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. The Company’s redeemable convertible preferred shares contractually entitled the holders of such shares to participate in dividends, but did not contractually require the holders of such shares to participate in losses of the Company. Accordingly, the two-class method did not apply for periods in which the Company reported a net loss or a net loss attributable to common shareholders resulting from dividends or accretion related to its redeemable convertible preferred shares.
	Basic net income (loss) per share attributable to common shareholders is computed by dividing the net income (loss) attributable to common shareholders by the weighted average number of common shares outstanding for the period. Diluted net income (loss) per share attributable to common shareholders is computed by dividing the diluted net income (loss) attributable to common shareholders by the weighted average number of common shares, including potential dilutive common shares assuming the dilutive effect of outstanding stock options and unvested restricted common shares, as determined using the treasury stock method. For periods in which the Company has reported net losses, diluted net loss per common share attributable to common shareholders is the same as basic net loss per common share attributable to common shareholders, since dilutive common shares are not assumed to have been issued if their effect is antidilutive.
	The Company reported a net loss attributable to common stockholders for the three and six months ended June 30, 2014 and 2013.
	The following common stock equivalents outstanding as of June 30, 2014 and 2013, were excluded from the computation of diluted net loss per share for the three and six months ended June 30, 2014 and 2013, because they had an anti-dilutive impact:
			As of June 30,
			2014		2013
	Options to purchase common stock			1,839,895		1,283,264
	Redeemable convertible preferred stock			—		78,372,931
	Total options and redeemable convertible preferred stock exercisable or convertible into common stock			1,839,895		79,656,195
Recently Issued and Adopted Accounting Pronouncements	'
	Recently Issued and Adopted Accounting Pronouncements
	In June 2014, the FASB issued Accounting Standards Update No. 2014-10, Development Stage Entities (Topic 915): Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation. The amendments in this guidance remove all incremental financial reporting requirements for development stage entities. Among other changes, this guidance will no longer require development stage entities to present inception-to-date information about income statement line items, cash flows, and equity transactions. This guidance is effective for public companies in the first annual period beginning after December 15, 2014. Early application is permitted for interim and annual periods for which financial statements have not yet been issued. The Company elected to apply this disclosure guidance to its consolidated financial statements for the three months ended June 30, 2014 and as a result, no longer discloses inception-to-date information in its Consolidated Statements of Operations and Comprehensive Loss, Cash Flows and Stockholders’ Deficit and the related notes thereto.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Summary of Common Stock Equivalents Outstanding	'
	The following common stock equivalents outstanding as of June 30, 2014 and 2013, were excluded from the computation of diluted net loss per share for the three and six months ended June 30, 2014 and 2013, because they had an anti-dilutive impact:
		As of June 30,
		2014		2013
	Options to purchase common stock		1,839,895		1,283,264
	Redeemable convertible preferred stock		—		78,372,931
	Total options and redeemable convertible preferred stock exercisable or convertible into common stock		1,839,895		79,656,195

Accrued_Expenses_Tables

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2014
Payables And Accruals [Abstract]	'
Schedule of Accrued Expenses	'
	Accrued expenses consisted of the following:
		June 30,		December 31,
		2014		2013
	Accrued payroll and related expenses	$	465	$	49
	Accrued research and development expenses		592		616
	Accrued professional fees		657		196
	Accrued interest expense		266		—
	Accrued other		65		39
		$	2,045	$	900

Notes_Payable_Tables

Notes Payable (Tables)	6 Months Ended
	Jun. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of Estimated Future Principal Payments Due under Term Loan	'
	Estimated future principal payments due under the Term Loan A are as follows:
	Years Ending December 31,
	2014	$	—
	2015		1,381
	2016		2,936
	2017		3,183
	Total	$	7,500

StockBased_Awards_Tables

Stock-Based Awards (Tables)	6 Months Ended
	Jun. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Summary of Stock-Based Compensation Expense Related to Stock Options and Restricted Common Stock	'
	The Company recorded stock-based compensation expense related to stock options and restricted common stock in the following expense categories of its statements of operations:
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2014		2013		2014		2013
	Research and development	$	99	$	43	$	168	$	69
	General and administrative		169		60		276		84
		$	268	$	103	$	444	$	153

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Schedule of Future Minimum Lease Payments for Operating Leases	'
	Future minimum lease payments for its operating leases as of June 30, 2014 are as follows:
	Year Ending December 31,
	2014	$	106
	2015		229
	2016		235
	2017		139
	Total	$	709

Nature_of_the_Business_and_Bas2

Nature of the Business and Basis of Presentation - Additional Information (Detail) (USD $)	0 Months Ended	6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 24, 2014	Jun. 30, 2014	Jun. 30, 2013	Jun. 24, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'	'	'	'
Entity incorporation date	'	22-Nov-05	'	'
Initial public offering, common stock issued, shares	6,900,000	'	'	'
Initial public offering, common stock issued per share	'	'	'	$16
Net proceeds from initial public offering	$102,672	$102,672	'	'
Offering costs incurred	$2,508	'	'	'

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Summary Of Significant Accounting Policies [Line Items]	'	'
Short-term investments maturity, description	'Ninety days or less	'
Deferred offering costs	$0	$743
Estimated useful life	'5 years	'
Impairment losses on long-lived assets	0	'
Percentage of likelihood to be realized upon ultimate settlement, description	50.00%	'
Quoted prices in active markets, Level 1 [Member]	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'
Cash equivalents carried at fair value	$120,000	$26,501

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Summary of Common Stock Equivalents Outstanding (Detail)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total options and redeemable convertible preferred stock exercisable or convertible into common stock	1,839,895	79,656,195
Options to purchase common stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total options and redeemable convertible preferred stock exercisable or convertible into common stock	1,839,895	1,283,264
Redeemable convertible preferred stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total options and redeemable convertible preferred stock exercisable or convertible into common stock	'	78,372,931

Accrued_Expenses_Schedule_of_A

Accrued Expenses - Schedule of Accrued Expenses (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]	'	'
Accrued payroll and related expenses	$465	$49
Accrued research and development expenses	592	616
Accrued professional fees	657	196
Accrued interest expense	266	'
Accrued other	65	39
Accrued expenses	$2,045	$900

Notes_Payable_Additional_Infor

Notes Payable - Additional Information (Detail) (USD $)

0 Months Ended

3 Months Ended

6 Months Ended

0 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Mar. 31, 2014

Jun. 30, 2014

Mar. 31, 2014

Jun. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Jun. 30, 2014

Jun. 30, 2014

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Term Loan A [Member]

Term Loan A [Member]

Term Loan A [Member]

Term Loan A [Member]

Term Loan A [Member]

Term Loan B And C [Member]

Term Loan B [Member]

Term Loan C [Member]

Debt Discount And Finance Costs [Member]

Debt Discount And Finance Costs [Member]

Qualified IPO [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility initiation date

'

'

'

31-Mar-14

'

'

'

'

'

'

'

'

'

Current line of credit

'

'

'

'

'

'

'

$7,500

'

'

$12,500

'

'

Additional line of credit

'

'

'

'

'

'

'

'

'

'

12,500

7,500

5,000

Maximum line of credit

'

'

'

'

20,000

'

'

'

'

'

'

'

'

Proceeds from issuance of promissory notes

'

'

'

'

'

7,500

'

'

'

'

'

'

'

Credit facility maturity date

'

'

'

1-Dec-17

'

'

'

'

'

'

'

'

'

Line of credit facility description

'

'

'The Company was obligated to make monthly, interest-only payments on any term loans funded under the Credit Facility until December 1, 2014 and, thereafter, to pay 36 consecutive, equal monthly installments of principal and interest from January 1, 2015 through December 1, 2017. As per the terms of the agreement, in June 2014, upon the completion of the Companybs IPO, the term of monthly, interest-only payments has been extended until June 1, 2015.

'On March 31, 2014, the Company received proceeds of $7,500 from the issuance of promissory notes under the Term Loan A. Of the additional $12,500 amount that was available, $7,500 (bTerm Loan Bb) is available to be drawn down until September 30, 2014 and $5,000 (bTerm Loan Cb) was available to be drawn down for a 30-day period upon the completion of the Companybs IPO that occurred in June 2014. The Company elected not to draw down Term Loan C and this amount is no longer available to the Company. All promissory notes issued under the Credit Facility are due on December 1, 2017 and are collateralized by substantially all of the Companybs personal property, other than its intellectual property.

'

'

'

'

'

'

'

'

'

Line of credit facility annual interest rate

'

'

'

8.10%

'

'

'

'

'

'

'

'

'

Line of credit facility additional fee percentage

'

'

'

6.00%

'

'

'

'

'

'

'

'

'

Charges to interest expense of debt outstanding

'

'

'

'

'

'

450

'

'

'

'

'

'

Net of debt discount

'

'

'

'

'

114

'

'

'

'

'

'

'

Deferred financing costs

'

'

'

'

'

'

'

49

'

'

'

'

'

Interest expense

'

443

445

'

'

'

'

'

19

19

'

'

'

Additional interest expense for IPO

'

'

'

225

'

'

'

'

'

'

'

'

'

Covenants under credit facility

'

'

0

'

'

'

'

'

'

'

'

'

'

Sale of voting equity threshold

'

'

'

50.00%

'

'

'

'

'

'

'

'

'

Credit facility default amount

'

'

'

250

'

'

'

'

'

'

'

'

'

Interest expense on credit facility

'

443

445

'

'

'

'

'

'

'

'

'

'

Credit facility, amount outstanding

$0

'

'

'

'

'

'

'

'

'

'

'

'

Notes_Payable_Schedule_of_Esti

Notes Payable - Schedule of Estimated Future Principal Payments Due under Term Loan (Detail) (Term Loan A [Member], USD $)	Jun. 30, 2014
In Thousands, unless otherwise specified
Term Loan A [Member]	'
Line of Credit Facility [Line Items]	'
2014	$0
2015	1,381
2016	2,936
2017	3,183
Total	$7,500

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	0 Months Ended	6 Months Ended				6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 24, 2014	Jun. 30, 2014	Jun. 30, 2013	Jun. 24, 2014	Dec. 31, 2013	Jun. 30, 2013	Jun. 19, 2014
						Restricted common stock [Member]	IPO [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'
Reverse stock split, description	'	'Company effected a 1-for-6.28 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each series of redeemable convertible preferred stock.	'	'	'	'	'
Initial public offering, common stock issued, shares	6,900,000	'	'	'	'	'	'
Initial public offering, common stock issued per share	'	'	'	$16	'	'	'
Net proceeds from initial public offering	$102,672	$102,672	'	'	'	'	'
Offering costs	$2,508	'	'	'	'	'	'
Redeemable convertible preferred stock converted into common stock shares	'	'	'	'	'	'	15,077,621
Preferred stock, shares authorized	'	5,000,000	'	'	0	'	'
Preferred stock, par value	'	$0.00	'	'	$0.00	'	'
Common stock, shares authorized	'	115,000,000	'	'	115,000,000	'	'
Common stock, par value	'	$0.00	'	'	$0.00	'	'
Reacquired and retired shares of restricted common stock	'	'	'	'	'	6,635	'

StockBased_Awards_Additional_I

Stock-Based Awards - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended					6 Months Ended			0 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 05, 2014
			Employees [Member]	Consultant [Member]	Nonemployee Service Based Options [Member]	Nonemployee Performance Based Options [Member]	2006 Stock Option Plan [Member]	2006 Stock Option Plan [Member]	2014 Stock Option and Incentive Plan [Member]	2014 Employee Stock Purchase Plan [Member]	2014 Employee Stock Purchase Plan [Member]
								Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Percentage of exercise price per share of stock options in fair market value of share of common stock	'	'	'	'	'	'	100.00%	'	'	'	'
Number of shares of common stock that could be issued under stock option plan	'	'	'	'	'	'	1,889,150	'	'	'	'
Shares of common stock reserved for issuance	'	'	'	'	'	'	168,221	'	2,168,221	'	265,000
Maximum term of stock option	'	'	'	'	'	'	'	'10 years	'	'	'
Percentage of outstanding shares of common stock	'	'	'	'	'	'	'	'	4.00%	'	'
Offering periods	'	'	'	'	'	'	'	'	'	'0 years	'
Number of outstanding unvested shares held by nonemployees	'	'	'	'	17,513	796	'	'	'	'	'
Unrecognized stock-based compensation cost	'	$2,798	'	'	'	'	'	'	'	'	'
Stock-based compensation recognized weighted average period	'3 years 7 months 6 days	'	'	'	'	'	'	'	'	'	'
Stock based compensation ,stock options granted	'	326,542	324,950	1,592	'	'	'	'	'	'	'

StockBased_Awards_Summary_of_S

Stock-Based Awards - Summary of Stock-Based Compensation Expense Related to Stock Options and Restricted Common Stock (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Total stock-based compensation expense	$268	$103	$444	$153
Research and development [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Total stock-based compensation expense	99	43	168	69
General and administrative [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Total stock-based compensation expense	$169	$60	$276	$84

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)

3 Months Ended

6 Months Ended

0 Months Ended

6 Months Ended

In Thousands, unless otherwise specified

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

15-May-14

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Office Two [Member]

Office Two [Member]

Before Amendment [Member]

After Amendment [Member]

Pre-commercialization milestones [Member]

Product commercialization milestones [Member]

Subsequent licensed product [Member]

Development milestones [Member]

Office One [Member]

Office One [Member]

Commitment And Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Lease expiration period

'

'

'

'

'

31-Jul-17

31-Jul-13

31-Jul-14

'

'

'

'

Lease extension period

'

'

'

'

'3 years

'

'

'

'

'

'

'

Operating lease, rental expense

$27

$32

$52

$64

'

'

'

'

'

'

'

'

Milestone payments

'

'

'

'

'

'

'

'

18,950

12,500

'

6,700

Licensing fees per product maximum

'

'

'

'

'

'

'

'

'

'

$1,250

'

Commitments_and_Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Lease Payments for Operating Leases (Detail) (USD $)	Jun. 30, 2014
In Thousands, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]	'
2014	$106
2015	229
2016	235
2017	139
Total	$709

Retirement_Plan_Additional_Inf

Retirement Plan - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Compensation And Retirement Disclosure [Abstract]	'	'	'	'
Percentage of employer's contribution on employee's base salary	'	'	2.00%	'
Contribution expense	$13	$7	$26	$14

Australia_Research_and_Develop1

Australia Research and Development Tax Incentive - Additional Information (Detail) (USD $)	6 Months Ended			3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
				Tax incentive [Member]	Tax incentive [Member]	Tax incentive [Member]	Tax incentive [Member]	Tax incentive [Member]	Tax incentive [Member]	Tax incentive [Member]	Tax incentive [Member]
								Australia [Member]	Australia [Member]	Australia [Member]	Australia [Member]
Operating Loss Carryforwards [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Percentage of refundable tax incentive	45.00%	'	'	'	'	'	'	'	'	'	'
Reduction to research and development expenses	'	'	'	'	'	'	'	$47	$418	$73	$1,198
Unrealized foreign currency exchange (gains) losses	-64	205	'	-22	210	-64	205	'	'	'	'
Tax incentive receivable	$1,222	'	$1,617	'	'	'	'	'	'	'	'
Percentage of reduction in research and development costs	45.00%	'	'	'	'	'	'	'	'	'	'