Liquidity	6 Months Ended
Liquidity	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Liquidity	Liquidity Since inception, the Company has incurred recurring losses and negative cash flows from operations and, as of June 30, 2021, has an accumulated deficit of $124.9 million. During the six months ended June 30, 2021, the Company used $15.2 million of cash in operations which included a net loss of $7.0 million, a $1.9 million increase in prepaid expenses and other assets primarily for insurance and prepaid clinical trial costs, a $5.6 million decrease in deferred revenue due to the recognition of licensing revenues and a $2.5 million decrease in accounts payable and accrued expenses and other current liabilities, partially offset by a $1.1 million decrease of contract acquisition costs related to the out-licensing of intellectual property rights and transfer of technical know-how and various net non-cash charges of $0.7 million. The Company expects to continue to generate operating losses and negative cash flows for the next few years and will need additional funding to support its planned operating activities through profitability. The transition to profitability is dependent upon the successful development, approval, and commercialization of the Company's product candidates and the achievement of a level of revenues adequate to support its cost structure. On April 16, 2021, the Company entered into a Controlled Equity OfferingSM Sales Agreement (the "Sales Agreement") with Cantor Fitzgerald & Co. (the "Agent"). From time to time during the term of the Sales Agreement, the Company may offer and sell shares of common stock having an aggregate offering price up to a total of $50.0 million in gross proceeds. The Agent will collect a fee equal to 3% of the gross sales price of all shares of common stock sold. Shares of common stock sold under the Sales Agreement will be offered and sold pursuant to the Company's registration statement on Form S-3, which was filed with the SEC on April 16, 2021 and was declared effective on April 29, 2021. During the three months ended June 30, 2021, the Company sold 786,927 shares of common stock pursuant to the Sales Agreement at an average price of $12.04 per share for aggregate net proceeds of approximately $9.0 million, of which approximately $2.2 million in net proceeds were received in July 2021 and classified as a stock subscription receivable as of June 30, 2021. Other than the Sales Agreement, the Company currently does not have any commitments to obtain additional funds. The Company received $1.0 million and $2.0 million during the three and six months ended June 30, 2021, respectively, for the achievement of certain development milestones pursuant to the Company's Exclusive License Agreement (the "3DMed License Agreement) with 3D Medicines, Inc. ("3DMed"). An additional $192.5 million in potential future certain development, regulatory, and sales milestones remains under the 3DMed License Agreement, which milestones are variable in nature and not under the Company's control. As of June 30, 2021, the Company had cash and cash equivalents of approximately $29.9 million, restricted cash and cash equivalents of $0.1 million, and $2.2 million of stock subscription receivable which cash was received in July 2021. In accordance with Accounting Standards Codification ("ASC") 205-40, Presentation of Financial Statements - Going Concern, the Company evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern within one year after the consolidated financial statements are issued. The Company expects its cash and cash equivalents, together with access to the Sales Agreement to sell common stock, will be sufficient to fund current planned operations for at least the next 12 months from the date of issuance of these financial statements, though it may pursue additional capital resources through public or private equity or debt financings or by entering into additional license agreements or collaborations with other companies. Management's expectations with respect to its ability to fund current planned operations is based on estimates that are subject to risks and uncertainties. If actual results are different from management's estimates, the Company may need to seek additional strategic or financing opportunities sooner than would otherwise be expected. There is no guarantee that any of these strategic or financing opportunities will be executed or executed on favorable terms, and some could be dilutive to existing stockholders. If the Company is unable to obtain additional funding on a timely basis, it may be forced to significantly curtail, delay, or discontinue one or more of its planned research and development programs or be unable to expand its operations or otherwise prepare for the potential regulatory approval and commercialization of its product candidates, assuming positive data.