The FDA has granted breakthrough therapy designation to GSK5764227, a B7-H3–targeted antibody-drug conjugate, for treating extensive-stage small cell lung cancer (ES-SCLC) that has progressed after platinum-based chemotherapy

The phase 1 ARTEMIS-001 study demonstrated that GSK5764227 had a manageable toxicity profile and showed early efficacy, with an objective response rate of 63.6% and a disease control rate of 81.8% in patients with SCLC

The study found a median progression-free survival of 4.7 months and a 3-month progression-free survival rate of 72.7% in SCLC patients, indicating promising activity even in those previously treated with camptothecin derivatives

The dose-escalation phase of the study aimed to determine the maximum tolerated dose of GSK5764227, with the final dose identified as 12.0 mg/kg, while the dose-expansion phase will assess the agent’s efficacy across various solid tumors

GlaxoSmithKline plans to initiate global phase 1/2 studies in the second half of 2024 to further support the development and potential registration of GSK5764227, having acquired worldwide rights to the drug from Hansoh Pharma