Compass Therapeutics Announces First Patient Dosed in the Phase 1 Study of CTX-8371 in Patients with Solid Tumors

• The first patient was dosed in the Phase 1 dose escalation trial of CTX-8371.This study is conducted in patients with advanced solid tumors who progressed on at least one prior regimen containing a checkpoint blocker.  
• CTX-8371 is a novel dual checkpoint blocker that simultaneously targets the programmed death receptor PD-1 and its ligand PD-L1.
• Compass advanced CTX-8371 to the clinic following pre-clinical observations of superior activity when compared with approved checkpoint blockers.
  

BOSTON, April 16, 2024 (GLOBE NEWSWIRE) -- 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.