AstraZeneca Launches Phase III Trial of B7-H4 ADC Puxitatug Samrotecan for Endometrial Cancer

▎Armstrong

On June 30, 2025, AstraZeneca registered the Phase III clinical trial Bluestar-Endometrial01 of Puxitatug Samrotecan (AZD8205) as a monotherapy or in combination with chemotherapy for the treatment of endometrial cancer on the Clinicaltrials.gov website.

This Phase III clinical trial plans to enroll 700 patients with endometrial cancer and is expected to be preliminarily completed by 2027.

AZD8205 is administered intravenously once every three weeks at a dose of 2.4 mg/kg.

AZD8205 is a self-developed ADC by AstraZeneca, using TOP1i as the payload. It demonstrated excellent therapeutic potential in Phase 1/2 clinical trials for endometrial cancer, with an ORR of 34.6-38.5% and an mPFS of 7.0 months. In terms of safety, it showed lower hematological toxicity, with no adverse events leading to treatment discontinuation.

Summary

In February last year, Pfizer announced the termination of the development of B7H4 ADC. Hansoh Pharma (overseas rights licensed to GlaxoSmithKline) and AstraZeneca were the first to advance to Phase III clinical trials. Duality Biologics’ B7H4 ADC, licensed to BeiGene, is also actively advancing clinical development.