1. NATURE OF OPERATIONS AND BASIS OF PRESENTATION Business Acer Therapeutics Inc., a Delaware corporation (the Company), formerly known as Opexa Therapeutics, Inc. (the Registrant), is a pharmaceutical company focused on the acquisition, development, and commercialization of therapies for serious rare and life-threatening diseases with significant unmet medical needs. The Companys pipeline includes three clinical-stage candidates: EDSIVO (celiprolol) for the treatment of vascular Ehlers-Danlos syndrome (vEDS) in patients with a confirmed type III collagen (COL3A1) mutation; ACER-001 (a fully taste-masked, immediate release formulation of sodium phenylbutyrate) for the treatment of various inborn errors of metabolism, including urea cycle disorders (UCD) and Maple Syrup Urine Disease (MSUD); and osanetant for the treatment of induced vasomotor symptoms (iVMS) where hormone replacement therapy (HRT) is likely contraindicated. The Companys product candidates are believed to present a comparatively de-risked profile, having one or more of a favorable safety profile, clinical proof-of-concept data, mechanistic differentiation, and/or accelerated paths for development through specific programs and procedures established by the United States Food and Drug Administration (FDA). Since its inception, the Company has devoted substantially all of its efforts to business planning, research and development, recruiting management and technical staff, acquiring operating assets and raising capital. The Company has not generated any product revenue to date and may never generate any product revenue in the future. The Company believes that its existing cash and cash equivalents of approximately $23.5 million at June 30, 2019, will be sufficient to allow the Company to fund its current operating plan through the end of 2020 and, as a result, through at least twelve months from the filing of the Companys Quarterly Report on Form 10-Q for the quarter ended June 30, 2019. There can be no assurance, however, that the current operating plan will be achieved in the time frame anticipated by the Company, or that its cash resources will fund the Companys operating plan for the period anticipated by the Company. Until the Company can generate a sufficient amount of product revenue to finance its cash requirements, which would require the Company to obtain regulatory approval for and successfully commercialize one or more of its product candidates, the Company expects to finance its future cash needs primarily through the issuance of additional equity and potentially through borrowing and strategic alliances. On June 24, 2019, the Company received a Complete Response Letter from the FDA regarding its new drug application (NDA) for EDSIVO TM (celiprolol) for the treatment of vEDS. The Complete Response Letter stated that it will be necessary to conduct an adequate and well-controlled trial to determine whether celiprolol reduces the risk of clinical events in patients with vEDS. The Company had previously devoted a substantial majority of its research, development, clinical, and pre-commercial efforts and financial resources towards the development of EDSIVO. In order to reduce operating expenses and conserve cash resources while it continues to dialogue with the FDA to fully understand its response and work toward the goal of approval of EDSIVO, on June 28, 2019, the Company implemented a corporate restructuring which included a reduction of approximately 60% of its full-time workforce of 48 employees and halted pre-commercial activities of EDSIVO TM . Depending on its progress in discussions with the FDA, which may include a formal dispute resolution request to appeal the Complete Response Letter, as well as our available resources and needs, the Company may decide at any time not to continue development of EDSIVO, which could have a material adverse effect on its business operations and financial prospects. Merger and Reverse Stock Split On September 19, 2017, the Registrant completed its business combination with Acer Therapeutics Inc., a Delaware corporation (Private Acer), in accordance with the terms of the Agreement and Plan of Merger and Reorganization, dated as of June 30, 2017, by and among the Registrant, Opexa Merger Sub, Inc. (Merger Sub) and Private Acer (the Merger Agreement), pursuant to which Merger Sub merged with and into Private Acer, with Private Acer surviving as a wholly-owned subsidiary of the Registrant (the Merger). Also on September 19, 2017, in connection with, and prior to the completion of, the Merger, the Registrant effected a 1-for-10.355527 reverse stock split of its then outstanding common stock (the Reverse Split) and immediately following the Merger, the Registrant changed its name to Acer Therapeutics Inc. pursuant to amendments to its certificate of formation filed with the Texas Secretary of State on September 19, 2017. All share numbers have been adjusted to reflect the Reverse Split. Following the completion of the Merger, the business conducted by the Registrant became primarily the business conducted by Private Acer. Delaware Reincorporation and Subsidiary Merger On May 15, 2018, the Company changed its state of incorporation from the State of Texas to the State of Delaware pursuant to a plan of conversion, dated May 15, 2018. As a result of this reincorporation, the par value of the Companys preferred stock was changed to $0.0001 from no par value and the par value of the Companys common stock was reduced to $0.0001 from $0.01. Immediately following the Reincorporation, the holding company structure was eliminated by merging wholly-owned subsidiary Private Acer with and into the Company (the Subsidiary Merger). The Company was the surviving corporation in connection with the Subsidiary Merger. Basis of Presentation Accounting principles generally accepted in the United States (GAAP) require that a company whose security holders retain the majority voting interest in the combined business be treated as the acquirer for financial reporting purposes. Accordingly, the Merger was accounted for as a reverse acquisition whereby Private Acer was treated as the acquirer for accounting and financial reporting purposes. Private Acer was incorporated on December 26, 2013, as part of a reorganization whereby Acer Therapeutics, LLC was converted into a corporation organized under the laws of the State of Delaware. All intercompany balances and transactions have been eliminated in consolidation. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB). The accompanying unaudited condensed consolidated financial statements are unaudited and have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Regulation S-X. The unaudited condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for the fair presentation of the Companys financial position, results of operations, stockholders equity and cash flows for the periods presented. The results of operations for the three and six months ended June 30, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or for any other future annual or interim period. The condensed consolidated balance sheet as of December 31, 2018, included herein, was derived from the audited consolidated financial statements as of that date but does not include all disclosures required by GAAP. These unaudited condensed consolidated financial state ments should be read in conjunction with the Companys audited consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2018.