BeOne Reports 36% Response Rate for Liver Cancer Drug in Phase 1

BeOne Medicines Ltd. presented updated Phase 1 results for its investigational liver cancer drug BGB-B2033 on Oct. 24, reporting a 36% confirmed objective response rate at the 450-milligram dose. The result is an early clinical signal as the company prepares to test the drug in larger trials.

The response rate came from 25 patients evaluable for response who received 450 milligrams every three weeks. The data cutoff was Sept. 22. Nine patients in that dose group had a confirmed response. Among those nine, the estimated six-month duration-of-response rate was 74.1%, with a 95% confidence interval of 28.9% to 93.0%. That estimate describes the responders, not all patients who received the dose.

Across dose levels, 5.3% of patients had treatment-related adverse events of Grade 3 or higher. Treatment-related adverse events led to treatment discontinuation in 2.1% of patients.

Previously, 93.6% of patients had received PD-(L)1 therapy; 61.7% had also received a tyrosine kinase inhibitor. BGB-B2033 is a bispecific antibody designed to target GPC3 on tumor cells and 4-1BB, a receptor involved in T-cell activity. The approach is intended to activate T cells near GPC3-expressing tumor cells.

“Continues to be well tolerated and demonstrates durable activity with longer follow up,” said Mark Lanasa, BeOne’s chief medical officer for solid tumors.

BeOne plans to begin global registrational trials in late-line liver cancer by the end of 2026. A planned randomized, open-label Phase 3 study is designed to enroll about 492 patients and compare BGB-B2033 with investigator-selected sorafenib or lenvatinib. Overall survival is the primary endpoint. The trial was not yet recruiting as of Sept. 23.

The Phase 1 results do not establish whether BGB-B2033 improves survival or performs better than other treatments. The planned Phase 3 study is designed to compare treatments and measure overall survival.