Compass Therapeutics, Inc. 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. CTX-8371 is a next generation bispecific checkpoint inhibitor that simultaneously targets PD-1 and PD-L1 and showcases 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.