Summary of significant accounting policies and recent accounting pronouncements	3 Months Ended
Mar. 31, 2015
Accounting Policies [Abstract]
Summary of significant accounting policies and recent accounting pronouncements	Summary of significant accounting policies and recent accounting pronouncements The accompanying unaudited condensed consolidated financial statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the condensed consolidated financial statements. As of March 31, 2015, the Company’s significant accounting policies, which are detailed in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2014 (the “2014 10-K”), have not changed. Unaudited interim financial information Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s 2014 10-K. The unaudited condensed consolidated financial statements as of March 31, 2015 and March 31, 2014, for the three months ended March 31, 2015 and for the period from February 26, 2014 (inception) to March 31, 2014 and the related information contained within the notes to the condensed consolidated financial statements are unaudited. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements, and in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s consolidated financial position as of March 31, 2015, and the condensed consolidated statements of operations and comprehensive loss and cash flows for the three months ended March 31, 2015 and for the period from February 26, 2014 (inception) to March 31, 2014. The results for the three months ended March 31, 2015 are not necessarily indicative of results to be expected for the year ending December 31, 2015, or any other future annual or interim periods. Initial public offering On February 3, 2015, the Company completed its IPO, whereby the Company sold 5,491,191 shares of its common stock (inclusive of 91,191 shares of common stock sold by the Company pursuant to the exercise of an overallotment option granted to the underwriters in connection with the IPO) at a price of $16.00 per share. The shares began trading on the Nasdaq Global Market on January 29, 2015. The aggregate net proceeds received by the Company from the IPO were approximately $79,900,000, after deducting underwriting discounts and commissions and other offering expenses payable by the Company. Upon the closing of the IPO, all outstanding shares of convertible preferred stock converted into 6,971,108 shares of common stock. Additionally, the Company is now authorized to issue 100,000,000 shares of common stock. Deferred IPO issuance costs, which primarily consisted of direct incremental legal and accounting fees related to the Company's IPO, were previously capitalized at December 31, 2014. Upon the closing of the IPO in February 2015, IPO issuance costs, which totaled $1,848,737, were offset against the IPO proceeds within additional paid-in capital. Reverse stock split On January 15, 2015, the Company effected a one-for-4.2825 reverse stock split of its issued and outstanding common stock. All share and per share amounts related to issued and outstanding common stock and stock options included in the Company's condensed consolidated financial statements and notes to the condensed consolidated financial statements have been retroactively adjusted for all periods presented to reflect this reverse stock split, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in-capital. The conversion ratios of the Company's previously outstanding shares of convertible preferred stock were also adjusted to reflect the reverse stock split. Basis of presentation and use of estimates The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("GAAP"). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification ("ASC") and Accounting Standards Update ("ASU") of the Financial Accounting Standards Board ("FASB"). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, the Company's management evaluates its estimates, which include, but are not limited to, estimates related to clinical study accruals, stock-based compensation expense, and amounts of expenses during the reported period. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results may differ from those estimates or assumptions. Prior to the completion of its IPO in February 2015, the Company utilized significant estimates and assumptions in determining the fair value of its common stock. The Company utilized various valuation methodologies in accordance with the framework of the 2004 and 2013 American Institute of Certified Public Accountants Technical Practice Aids, Valuation of Privately-Held Company Equity Securities Issued as Compensation, to estimate the fair value of its common stock. Each valuation methodology included estimates and assumptions that required the Company's judgment. These estimates and assumptions included a number of objective and subjective factors, including external market conditions affecting the biotechnology industry sector, the prices at which the Company sold shares of preferred stock, the superior rights and preferences of securities senior to the Company's common stock at the time and the likelihood of achieving a liquidity event, such as an initial public offering or a sale of the Company. Significant changes to the key assumptions used in the valuations could result in different fair values of common stock at each valuation date and materially affect the financial statements. Principles of consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiary, TK Pharma, Inc., a Massachusetts Securities Corporation. All significant intercompany balances and transactions have been eliminated in consolidation. Recent accounting pronouncements In June 2014, the FASB issued ASU 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". Under this ASU, the definition of a development stage entity was removed from the ASC, thereby removing the financial reporting distinction between development stage entities and other reporting entities under GAAP. This standard is effective for annual reporting periods beginning after December 15, 2014. Early adoption is permitted for certain entities. The Company was eligible for early adoption and adopted this standard in the accompanying financial statements. In August 2014, the FASB issued ASU No. 2014-15 "Presentation of Financial Statements - Going Concern (Subtopic 205-40)". The ASU requires all entities to evaluate for the existence of conditions or events that raise substantial doubt about the entity's ability to continue as a going concern within one year after the issuance date of the financial statements. The accounting standard is effective for interim and annual periods ending after December 15, 2016, and will not have a material impact on the consolidated financial statements, but may impact the Company's footnote disclosures. The Company believes that the impact of other recently issued standards that are not yet effective will not have a material effect on its consolidated financial position or results of operations upon adoption.

Summary of significant accounting policies and recent accounting pronouncements

The accompanying unaudited condensed consolidated financial statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the condensed consolidated financial statements. As of March 31, 2015, the Company’s significant accounting policies, which are detailed in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2014 (the “2014 10-K”), have not changed.

Unaudited interim financial information

Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s 2014 10-K.

The unaudited condensed consolidated financial statements as of March 31, 2015 and March 31, 2014, for the three months ended March 31, 2015 and for the period from February 26, 2014 (inception) to March 31, 2014 and the related information contained within the notes to the condensed consolidated financial statements are unaudited. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements, and in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s consolidated financial position as of March 31, 2015, and the condensed consolidated statements of operations and comprehensive loss and cash flows for the three months ended March 31, 2015 and for the period from February 26, 2014 (inception) to March 31, 2014. The results for the three months ended March 31, 2015 are not necessarily indicative of results to be expected for the year ending December 31, 2015, or any other future annual or interim periods.

Initial public offering

On February 3, 2015, the Company completed its IPO, whereby the Company sold 5,491,191 shares of its common stock (inclusive of 91,191 shares of common stock sold by the Company pursuant to the exercise of an overallotment option granted to the underwriters in connection with the IPO) at a price of $16.00 per share. The shares began trading on the Nasdaq Global Market on January 29, 2015. The aggregate net proceeds received by the Company from the IPO were approximately $79,900,000, after deducting underwriting discounts and commissions and other offering expenses payable by the Company. Upon the closing of the IPO, all outstanding shares of convertible preferred stock converted into 6,971,108 shares of common stock. Additionally, the Company is now authorized to issue 100,000,000 shares of common stock.

Deferred IPO issuance costs, which primarily consisted of direct incremental legal and accounting fees related to the Company's IPO, were previously capitalized at December 31, 2014. Upon the closing of the IPO in February 2015, IPO issuance costs, which totaled $1,848,737, were offset against the IPO proceeds within additional paid-in capital.

Reverse stock split

On January 15, 2015, the Company effected a one-for-4.2825 reverse stock split of its issued and outstanding common stock. All share and per share amounts related to issued and outstanding common stock and stock options included in the Company's condensed consolidated financial statements and notes to the condensed consolidated financial statements have been retroactively adjusted for all periods presented to reflect this reverse stock split, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in-capital. The conversion ratios of the Company's previously outstanding shares of convertible preferred stock were also adjusted to reflect the reverse stock split.

Basis of presentation and use of estimates

The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("GAAP"). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification ("ASC") and Accounting Standards Update ("ASU") of the Financial Accounting Standards Board ("FASB"). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, the Company's management evaluates its estimates, which include, but are not limited to, estimates related to clinical study accruals, stock-based compensation expense, and amounts of expenses during the reported period. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results may differ from those estimates or assumptions.

Prior to the completion of its IPO in February 2015, the Company utilized significant estimates and assumptions in determining the fair value of its common stock. The Company utilized various valuation methodologies in accordance with the framework of the 2004 and 2013 American Institute of Certified Public Accountants Technical Practice Aids, Valuation of Privately-Held Company Equity Securities Issued as Compensation, to estimate the fair value of its common stock. Each valuation methodology included estimates and assumptions that required the Company's judgment. These estimates and assumptions included a number of objective and subjective factors, including external market conditions affecting the biotechnology industry sector, the prices at which the Company sold shares of preferred stock, the superior rights and preferences of securities senior to the Company's common stock at the time and the likelihood of achieving a liquidity event, such as an initial public offering or a sale of the Company. Significant changes to the key assumptions used in the valuations could result in different fair values of common stock at each valuation date and materially affect the financial statements.

Principles of consolidation

The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiary, TK Pharma, Inc., a Massachusetts Securities Corporation. All significant intercompany balances and transactions have been eliminated in consolidation.

Recent accounting pronouncements

In June 2014, the FASB issued ASU 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". Under this ASU, the definition of a development stage entity was removed from the ASC, thereby removing the financial reporting distinction between development stage entities and other reporting entities under GAAP. This standard is effective for annual reporting periods beginning after December 15, 2014. Early adoption is permitted for certain entities. The Company was eligible for early adoption and adopted this standard in the accompanying financial statements.

In August 2014, the FASB issued ASU No. 2014-15 "Presentation of Financial Statements - Going Concern (Subtopic 205-40)". The ASU requires all entities to evaluate for the existence of conditions or events that raise substantial doubt about the entity's ability to continue as a going concern within one year after the issuance date of the financial statements. The accounting standard is effective for interim and annual periods ending after December 15, 2016, and will not have a material impact on the consolidated financial statements, but may impact the Company's footnote disclosures.

The Company believes that the impact of other recently issued standards that are not yet effective will not have a material effect on its consolidated financial position or results of operations upon adoption.