CMPX Compass Therapeutics Inc

Compass Therapeutics, Inc. (Nasdaq: CMPX), a clinical-stage, oncology-focused biopharmaceutical company developing proprietary antibody-based therapeutics to treat multiple human diseases, today announced that the first patient has been dosed in its Phase 1 dose-escalation clinical trial of CTX-8371, a PD-1 x PD-L1 bispecific antibody, in patients with solid tumors.

“Dosing the first patient in the CTX-8371 Phase 1 represents the advancement of our third program into the clinic, which is an important milestone for the company,” said Vered Bisker-Leib, PhD, Chief Executive Officer. “We recently published preclinical data in the peer-reviewed journal, OncoImmunology, supporting the novel mechanism of action of CTX-8371: proteolytic cleavage and subsequent loss of cell surface PD-1. We believe this mechanism drives the enhanced anti-tumor activity of CTX-8371 in preclinical models when compared to approved anti-PD-1 and PD-L1 therapies and warrants its evaluation in patients.”

CTX-8371 is a next generation bispecific checkpoint inhibitor that simultaneously targets PD-1 and PD-L1 and exhibits a unique mechanism-of-action that involves cleavage of cell surface PD-1. CTX-8371 received FDA clearance of the IND in October 2023. The Phase 1 CTX-8371 study design includes five ascending doses (0.1, 0.3, 1.0, 3.0, and 10 mg/kg) and the study is enrolling patients with melanoma, non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC), Hodgkin Lymphoma, and triple negative breast cancer (TNBC) who have progressed on at least one prior regimen containing checkpoint blocker.

About Compass Therapeutics

Compass Therapeutics, Inc. is a clinical-stage oncology-focused biopharmaceutical company developing proprietary antibody-based therapeutics to treat multiple human diseases. Compass’s scientific focus is on the relationship between angiogenesis, the immune system, and tumor growth. The company pipeline of novel product candidates is designed to target multiple critical biological pathways required for an effective anti-tumor response. These include modulation of the microvasculature via angiogenesis-targeted agents, induction of a potent immune response via activators on effector cells in the tumor microenvironment, and alleviation of immunosuppressive mechanisms used by tumors to evade immune surveillance. Compass plans to advance its product candidates through clinical development as both standalone therapies and in combination with proprietary pipeline antibodies based on supportive clinical and nonclinical data. The company was founded in 2014 and is headquartered in Boston, Massachusetts. For more information, visit the Compass Therapeutics website at https://www.compasstherapeutics.com.

Forward-Looking Statements

This press release contains forward-looking statements. Statements in this press release that are not purely historical are forward-looking statements. Such forward-looking statements include, among other things, references to Compass’s product candidates, including CTX-8371, and its development and clinical trial milestones such as the expected trial design, timing of enrollment, patient dosing and data readouts, regulatory plans with respect to Compass’s product candidates and the therapeutic potential thereof. Actual results could differ from those projected in any forward-looking statements due to numerous factors. Such factors include, among others, Compass’s ability to raise the additional funding it will need to continue to pursue its business and product development plans, the inherent uncertainties associated with developing product candidates and operating as a development stage company, Compass’s ability to identify additional product candidates for development, Compass’s ability to develop, complete clinical trials for, obtain approvals for and commercialize any of its product candidates, competition in the industry in which Compass operates and market conditions. These forward-looking statements are made as of the date of this press release, and Compass assumes no obligation to update the forward-looking statements, or to update the reasons why actual results could differ from those projected in the forward-looking statements, except as required by law. Investors should consult all of the information set forth herein and should also refer to the risk factor disclosure set forth in the reports and other documents Compass files with the U.S. Securities and Exchange Commission (SEC) available at www.sec.gov, including without limitation Compass’s latest Annual Report on Form 10-K, Quarterly Report on Form 10-Q and subsequent filings with the SEC.

Investor Contactir@compasstherapeutics.com

Media Contact Anna Gifford, Senior Communications Manager media@compasstherapeutics.com617-500-8099