The trial is testing GSK5764227, a novel therapy targeting B7-H3, a protein overexpressed in aggressive prostate tumors and other solid tumors. This global Phase I study could lead to a breakthrough for patients with limited options.

GSK5764227, also known as HS-20093, is an antibody-drug conjugate (ADC) that combines a B7-H3-targeting antibody with a cancer-killing toxin. The antibody binds to B7-H3, prevalent in prostate cancer but rare in healthy tissues, delivering the toxin directly to tumor cells. Earlier studies in Asia (NCT05276609, NCT05830123) showed promising antitumor activity.

The trial, is enrolling about 280 adults with advanced solid tumors, including mCRPC, who have progressed on or cannot tolerate standard treatments. Patients must have measurable disease and good performance status, with no prior B7-H3 therapy. The trial has two parts: Phase 1a tests GSK5764227 alone and with standard treatments like cisplatin or pembrolizumab, given intravenously every three weeks, focusing on safety and side effects. Phase 1b expands to specific cancers, including mCRPC, measuring tumor response rates, progression-free survival, and other outcomes.

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