(RTTNews) - Compass Therapeutics, Inc. (CMPX), a clinical-stage, oncology-focused biopharmaceutical company, reported a poster presentation of promising Phase 1 results of CTX-8371 in patients with advanced malignancies treated in post-checkpoint inhibitor setting. The results will be presented at 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, held between May 29 and June 2, 2026, in Chicago, Illinois.
CTX-8371
CTX-8371 is a bispecific antibody which simultaneously targets the program death receptor (PD-1) and programmed death ligand receptor (PD-L1) expressed on immune cells and malignant cells.
Trial Details
Phase 1 is an ongoing, open-label, first-in-human study evaluating CTX-8371 in patients with metastatic or locally advanced malignancies.
Based on responses observed in the dose-escalation phase, patients with non-small cell lung cancer (NSCLC), triple negative breast cancer (TNBC), and Hodgins Lymphoma (HL) are enrolled into the expansion cohort. In the Phase 1 study, 15 patients have completed the dose-limiting toxicity (DLT) evaluation period and at least had one post-baseline disease assessment in the dose escalation cohort.
Key Findings
According to the firm the trial results showed three responses, one patient with TNBC achieved more than 90% reduction in targeted tumor lesions. One patient with HL achieved a partial metabolic response. Following initial pseudo-progression, NSCLC patient achieved complete resolution of target lesions.
Notably in 2 of 6 evaluable patients, the drug showed 33% Overall Response Rate (ORR) at the two highest dose levels 3mg/Kg and 10mg/Kg.
Responses were significantly durable at the two dose highest dose levels, 10.5+ months for TNBC and 7.5+ months for HL. Further results to the study attributed both these patients continue durability.
Across the dose-levels, CTX-8371 was generally well tolerated with no dose-limiting toxicities observed, noted the firm.
The company will present its results in the Developmental Therapeutic - Immunology session held on May 30,2026 under the title "Phase 2 Dose Escalation of CTX08371, a novel PD-1×PD-L1 bispecific antibody, in patients with advanced malignancies post checkpoint inhibition."
The firm further added that data from the initiated cohort expansions in NSCLC, TNBC, and HL is expected to be reported in the fourth quarter of 2026.
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