1. Nature of the Business Surface Oncology, Inc. (the Company or Surface) is a clinical-stage immuno-oncology company focused on using its specialized knowledge of the biological pathways critical to the immunosuppressive tumor microenvironment (TME) for the development of next-generation cancer therapies. Surface was incorporated in April 2014 under the laws of the State of Delaware. The Company is subject to risks common to early-stage companies in the biotechnology industry including, but not limited to, development by competitors of new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the ability to obtain additional financing to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical 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. Even if the Companys development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. On April 6, 2018, the Company effected a one-for-2.2 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 the Companys Redeemable Convertible Preferred Stock. Accordingly, all share and per share amounts for all periods presented in the accompanying condensed consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect this reverse stock split and adjustment of the preferred stock conversion ratios. On April 23, 2018, the Company completed its initial public offering of its common stock by issuing 7,200,000 shares of common stock, at $15.00 per share for gross proceeds of $108,000, or net proceeds of $97,209 after deducting underwriting discounts, commissions and offering expenses. Concurrent with the initial public offering, the Company issued Novartis Institutes for Biomedical Research, Inc. (Novartis) 766,666 shares of its common stock at $15.00 per share for proceeds of $11,500, in a private placement. Upon the closing of the Companys initial public offering on April 23, 2018, all shares of Series A and A-1 redeemable convertible preferred stock (the Series A Preferred Stock and Series A-1 Preferred Stock, respectively) automatically converted into 16,863,624 shares of common stock. On May 1, 2019, the Company entered into a Capital on Demand TM Sales Agreement (the Sales Agreement) with JonesTrading Institutional Services LLC (JonesTrading) to issue and sell shares of the Companys common stock of up to $30,000 in gross proceeds, from time to time during the term of the a Sales Agreement, through an at-the-market equity offering program under which JonesTrading will act as the Companys agent and/or principal (the ATM Facility). The ATM Facility provides that JonesTrading will be entitled to compensation for its services in an amount of up to 3.0% of the gross proceeds of any shares sold under the ATM Facility. The Company has no obligation to sell any shares under the ATM Facility and may, at any time, suspend solicitation and offers under the Sales Agreement. As of June 30, 2019, the Company had not sold any shares under the ATM Facility. The Companys financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. The Company has primarily funded its operations with proceeds from the sales of redeemable convertible preferred stock, proceeds from a collaboration agreement with Novartis, and proceeds from the Companys initial public offering of common stock. The Company has incurred losses and negative cash flows from operations since its inception. As of June 30, 2019, the Company had an accumulated deficit of $88,763. The Company expects that its operating losses and negative cash flows will continue for the foreseeable future. As of August 7, 2019, the issuance date of this Quarterly Report on Form 10-Q, the Company expects that its cash, cash equivalents and marketable securities of $126,290, will be sufficient to fund its operating expenses and capital expenditure requirements for at least the next 12 months. The future viability of the Company beyond that date is dependent on its ability to raise additional capital to finance its operations. The Company will seek additional funding through public financings, debt financings, collaboration agreements, strategic alliances, and licensing arrangements. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into collaborations or other arrangements. The terms of any financing may adversely affect the holdings or the rights of the Companys stockholders. If the Company is unable to obtain funding, the Company could be required to delay, reduce or eliminate research and development programs, product portfolio expansion, or future commercialization efforts, which could adversely affect its business prospects. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.