Puxitatug Samrotecan Demonstrated Promise for Patients With B7-H4–Positive Advanced or Recurrent Endometrial Cancer
According to results from the phase 1/2a BLUESTAR study, puxitatug samrotecan, a novel B7-H4–directed topoisomerase I inhibitor antibody-drug conjugate, demonstrated promising efficacy and safety among patients with advanced or recurrent endometrial cancer.
These results were presented by Stephanie Gaillard, MD, PhD, Johns Hopkins Medicine, Baltimore, Maryland, at the 2025 Society of Gynecologic Oncology (SGO) Annual Meeting on Women’s Cancer in Seattle, Washington.
In this study, 51 patients with B7-H4–positive advanced or recurrent endometrial cancer who experienced disease progression on prior platinum-based first-line therapy were assigned to receive either 2.0 mg/kg (n = 26) or 2.4 mg/kg (n = 25) of intravenous puxitatug samrotecan every 3 weeks until disease progression or unacceptable toxicity. Primary end points included objective response rate (ORR), disease control rate, progression-free survival (PFS), and safety.
At analysis, the ORR was 23.5% in the 2.0 mg/kg arm and 42.1% in the 2.4 mg/kg arm and the disease control rate was 82.4% and 84.2%, respectively. Median PFS was 7 months in the 2.0 mg/kg arm and 6.9 months in the 2.4 mg/kg arm.
Grade ≥3 treatment-related adverse events occurred in 11 patients in the 2.0 mg/kg arm and 9 patients in the 2.4 mg/kg arm. The most common adverse events included decreased neutrophil count, anemia, and decreased white blood cell count. No adverse events led to treatment discontinuation. Dose reductions due to treatment-related adverse events occurred in 3 patients in the 2.0 mg/kg arm and 4 patients in the 2.4 mg/kg arm.
“[Puxitatug samrotecan] shows promising preliminary efficacy and a manageable safety profile in patients with advanced/recurrent [endometrial cancer],” concluded Dr Gaillard. “Further development is ongoing.”
Source:
Gaillard S, Guo R, Finkelstein K, et al. Safety and preliminary efficacy of puxitatug samrotecan (AZD8205) in patients with endometrial cancer: A first-in-human phase I/IIa study. Presented at the 2025 SGO Annual Meeting on Women’s Cancer. March 14-17, 2025; Seattle, WA. Abstract 933087.
