Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation and Use of Estimates The accompanying unaudited condensed financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 8 of the Securities and Exchange Commission ("SEC") Regulation S-X. Accordingly, they should be read in conjunction with the audited financial statements and notes thereto for the fiscal year ended December 31, 2014, included in the Company's Annual Report on Form 10-K filed with the SEC on March 16, 2015. The unaudited financial statements contain all normal recurring accruals and adjustments that, in the opinion of management, are necessary to present fairly the condensed balance sheet of the Company at March 31, 2015, the condensed statements of operations and comprehensive loss for the three months ended March 31, 2015, and the condensed statement of cash flows for the three months ended March 31, 2015. Estimates were made relating to useful lives of fixed assets, valuation allowances, impairment of assets, share-based compensation expense and accruals for clinical trial and research and development expenses. Actual results could differ materially from those estimates. The results of operations for the three months ended March 31, 2015 are not necessarily indicative of the results to be expected for the full year or any future interim periods. Certain amounts previously reported in the financial statements have been reclassified to conform to the current year presentation. Such reclassifications did not affect net loss, shareholders' equity or cash flows.
Use of Estimates	Basis of Presentation and Use of Estimates The accompanying unaudited condensed financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 8 of the Securities and Exchange Commission ("SEC") Regulation S-X. Accordingly, they should be read in conjunction with the audited financial statements and notes thereto for the fiscal year ended December 31, 2014, included in the Company's Annual Report on Form 10-K filed with the SEC on March 16, 2015. The unaudited financial statements contain all normal recurring accruals and adjustments that, in the opinion of management, are necessary to present fairly the condensed balance sheet of the Company at March 31, 2015, the condensed statements of operations and comprehensive loss for the three months ended March 31, 2015, and the condensed statement of cash flows for the three months ended March 31, 2015. Estimates were made relating to useful lives of fixed assets, valuation allowances, impairment of assets, share-based compensation expense and accruals for clinical trial and research and development expenses. Actual results could differ materially from those estimates. The results of operations for the three months ended March 31, 2015 are not necessarily indicative of the results to be expected for the full year or any future interim periods. Certain amounts previously reported in the financial statements have been reclassified to conform to the current year presentation. Such reclassifications did not affect net loss, shareholders' equity or cash flows.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity from the date of purchase of less than three months to be cash equivalents. The carrying value of the Company's money market funds is included in cash equivalents and approximates the fair value.
Restricted Cash	Restricted Cash Under the terms of the leases of the Company's facilities, there is a requirement to maintain a certificate of deposit as security during the terms of such leases.
Property and Equipment	Property and Equipment Property and equipment is stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which range from two to seven years.
Clinical Trial Expenses	Clinical Trial Expenses Payments in connection with the Company's clinical trials are often made under contracts with multiple contract research organizations that conduct and manage clinical trials on its behalf. The financial terms of these agreements are subject to negotiation and vary from contract to contract and may result in uneven payment flows. Generally, these agreements set forth the scope of work to be performed at a fixed fee, unit price or on a time and materials basis. Payments under these contracts depend on factors such as the successful enrollment or treatment of patients or the completion of other clinical trial milestones. As of March 31, 2015 and December 31, 2014, the prepaid clinical expenses of $1,449,000 and $1,528,000 on the balance sheets represent the initial upfront payments to a clinical research organization for two clinical trials that commenced in 2015. The Company amortizes prepayments to expense based on estimates regarding work performed, including actual level of patient enrollment, completion of patient studies and progress of the clinical trials. Expenses related to clinical trials are accrued based on estimates regarding work performed, including actual level of patient enrollment, completion of patient studies and progress of the clinical trials. Other incidental costs related to patient enrollment or treatment are accrued when reasonably certain. If the contracted amounts are modified, the accruals are modified accordingly on a prospective basis. Revisions in the scope of a contract are charged to expense in the period in which the facts that give rise to the revision occur.
Research and Development Expenses	Research and Development Expenses Research and development expenses include salaries and benefits, facilities and other overhead expenses, research-related manufacturing expenses, contract services and clinical and preclinical-related services performed by clinical research organizations, research institutions and other outside service providers. Research and development expenses are charged to operations as incurred when these expenditures relate to the Company's research and development efforts and have no alternative future uses. In accordance with certain research and development agreements, the Company is obligated to make certain upfront payments upon execution of the agreement. Advance payments, including nonrefundable amounts, for materials or services that will be used or rendered for future research and development activities are deferred and capitalized. Such amounts will be recognized as an expense as the related goods are delivered or the related services are performed. Acquisition or milestone payments that the Company makes in connection with in-licensed technology are expensed as incurred when there is uncertainty in receiving future economic benefits from the licensed technology. The Company considers the future economic benefits from the licensed technology to be uncertain until such licensed technology is incorporated into products that are approved for marketing by the Food and Drug Administration (the "FDA") or when other significant risk factors are abated. For accounting purposes, management has viewed future economic benefits for all of the Company's licensed technology to be uncertain.
Share-Based Compensation	Share-Based Compensation The Company accounts for share-based payment arrangements in accordance with Accounting Standards codification ("ASC") 718, Compensation - Stock Compensation and ASC 505-50, Equity - Equity Based Payments to Non-Employees, which requires the recognition of compensation expense, using a fair-value based method, for all costs related to share-based payments, including stock options and restricted stock awards. These standards require companies to estimate the fair value of share-based payment awards on the date of the grant using an option-pricing model. See Note 3 for further discussion of the Company's share-based compensation plans.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated based on the weighted-average number of common shares outstanding. Diluted net loss per share is calculated using the weighted-average number of common shares outstanding and common stock equivalents. Outstanding convertible preferred stock, stock options and unvested restricted stock awards are considered common stock equivalents and are included in the calculation of diluted net loss per share using the treasury stock method when their effect is dilutive. Common stock equivalents are not included in the computation of diluted net loss per share if the inclusion of these securities is anti-dilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2014, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update ("ASU") No. 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the date that the financial statements are available to be issued when applicable) and to provide related footnote disclosures. The ASU provides guidance to an organization’s management, with principles and definitions that are intended to reduce diversity in the timing and content of disclosures that are commonly provided by organizations today in the financial statement footnotes. The ASU is effective for annual periods ending after December 15, 2016, and interim periods within annual periods beginning after December 15, 2016, which for the Company is January 1, 2017. Early adoption is permitted. The Company does not intend to early adopt this standard. The adoption of this standard will not have a material impact on the Company's financial position or results of operations. In June 2014, the FASB issued ASU No. 2014-12, Compensation - Stock Compensation (Topic 781): Accounting for Share-Based Payments When the Terms of an Award Provide that a Performance Target Could be Achieved after the Requisite Service Period. This update requires that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. As such, the performance target should not be reflected in estimating the grant date fair value of the award. This update further clarifies that compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the periods for which the requisite service has already been rendered. This update is effective for annual reporting periods (including interim reporting periods within those periods) beginning after December 15, 2015, which for the Company is January 1, 2016. Early adoption is permitted. Entities may apply the amendments in this update either: (a) prospectively to all awards granted or modified after the effective date; or (b) retrospectively to all awards with performance targets that are outstanding as of the beginning of the earliest annual period presented in the financial statements and to all new or modified awards thereafter. The adoption of this standard will not have a material impact on the Company's financial position or results of operations. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). This update outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This new revenue recognition model provides a five-step analysis in determining when and how revenue is recognized. The new model will require revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration a company expects to receive in exchange for those goods or services. This guidance was originally effective for annual reporting periods (including interim reporting periods within those periods) beginning after December 15, 2016, which for the Company is January 1, 2017; early adoption was not permitted. In April 2015, the FASB voted to propose a deferral of the effective date of the new standard by one year, but to permit companies to adopt one year earlier if they choose. The standard may be adopted using a full retrospective or a modified retrospective (cumulative effect) method. The Company does not anticipate that the adoption of this update will have a material impact on its financial position or results of operations.