Compass Therapeutics says tovecimig meets primary endpoint in Phase 2/3 study

Compass Therapeutics (CMPX) announced statistically significant top-line data on the primary efficacy endpoint for COMPANION-002, the Company’s ongoing Phase 2/3 randomized trial of tovecimig in combination with paclitaxel in patients with advanced BTC.Biliary tract cancer is estimated to affect approximately 23,000 patients annually in the United States. For the approximately 85% of patients with BTC whose tumors do not harbor an actionable mutation with an approved targeted therapy, there is currently no FDA-approved treatment in the second line setting. The combinations of therapeutics used in this setting, which are not labeled for this indication, generally have an ORR of ~5% or less and patients face a median overall survival of approximately six months. COMPANION-002: Top-Line Results: The trial is a Phase 2/3 randomized, controlled study of tovecimig in patients with unresectable advanced, metastatic or recurrent biliary tract cancers who have received one prior systemic chemotherapy regimen. The study enrolled 168 adult patients, randomized in a 2:1 ratio to receive tovecimig plus paclitaxel or paclitaxel alone. All patients were dosed with 80 mg/m2 of paclitaxel on days 1, 8 and 15 of every 28-day cycle. Patients in the tovecimig arm were also dosed with 10 mg/kg of tovecimig on days 1 and 15 of each 28-day cycle. The primary endpoint of the trial is ORR as confirmed by independent central radiology review and secondary endpoints include PFS, OS and DoR, among others. Patients in the paclitaxel-only arm who progressed could cross over to the tovecimig plus paclitaxel arm after centrally confirmed progression if they also still met the enrollment criteria for the study. Top-line results of the study are summarized below, and the Company expects to announce additional data, including key secondary endpoints, in Q4 2025: Primary Endpoint. 17.1% ORR for tovecimig in combination with paclitaxel including one complete response, compared to 5.3% for paclitaxel alone , in patients with BTC in the second line setting. This 11.8% relative improvement in ORR for those receiving the combination was statistically significant. Secondary Endpoints. The COMPANION-002 study is ongoing and the data are not yet mature for the analyses of the secondary outcome measures. The trial requires a threshold of events in 80% of patients to trigger the secondary endpoint analyses. Based on current projections, the Company anticipates this pre-specified number of events to be reached in Q3 2025, and expects to report data from the secondary endpoints in Q4 2025. Safety & Tolerability. The safety profile of tovecimig in this study to date is consistent with prior studies of tovecimig. An independent Data Monitoring Committee has reviewed safety data at four separate DMC meetings and, after each meeting, recommended continuation of the study without modification. The Company expects to report detailed safety data with the analyses of secondary endpoints in Q4 2025.