Atezolizumab Efficacy and Safety Differ in Asian Patients with Endometrial Cancer

Strategic Insights -

A new study on endometrial cancer has found significant differences in the efficacy and safety of atezolizumab between Asian and non-Asian patients. The research analyzed data from the AtTEnd trial, a phase III double-blind randomized placebo-controlled trial of atezolizumab in combination with carboplatin and paclitaxel in women with advanced/recurrent endometrial carcinoma. The study was conducted by researchers from the Mario Negri Institute for Pharmacological Research and published in the Journal of Gynecologic Oncology.

Key Takeaways:

  • The study found that Asian patients showed a better prognostic profile in terms of age, body mass index, Eastern Cooperative Oncology Group performance status, disease status, and previous treatments compared to non-Asian patients.
  • The prognostic impact of Asian race on progression-free survival (PFS) was confirmed in the placebo arm, with an adjusted hazard ratio (HR) of 0.41 (95% CI = 0.24-0.70).
  • In proficient mismatch repair (pMMR) tumors, the HRs for PFS comparing atezolizumab to placebo were 0.82 (95% CI = 0.63-1.05) in non-Asians and 1.42 (95% CI = 0.80-2.50) in Asians.
  • Asians showed a higher occurrence of severe adverse events in the atezolizumab arm compared to the placebo arm (82.1% vs. 64.3%, p = 0.036).
  • The study concluded that Asian patients seem to have a lower cumulative incidence of new lesions when primary tumor regrowth was considered a competing risk, and a higher cumulative incidence of primary tumor regrowth when new lesions appearance was the competing risk.

Statistics:

  • 20.4% of the 549 patients in the AtTEnd trial were Asian.
  • Asians showed a better prognostic profile in terms of age, body mass index, Eastern Cooperative Oncology Group performance status, disease status, and previous treatments.
  • The adjusted hazard ratio (HR) for PFS in the placebo arm was 0.41 (95% CI = 0.24-0.70) for Asian patients.
  • In pMMR tumors, the HR for PFS comparing atezolizumab to placebo was 0.82 (95% CI = 0.63-1.05) in non-Asians and 1.42 (95% CI = 0.80-2.50) in Asians.
  • Asians showed a higher occurrence of severe adverse events in the atezolizumab arm compared to the placebo arm (82.1% vs. 64.3%, p = 0.036).

Sources:

  • NewsRx. Mario Negri Institute for Pharmacological Research Reports Findings in Endometrial Cancer (Phase III double-blind randomized placebo controlled trial of atezolizumab in combination with carboplatin and paclitaxel in women with ...). Chemicals & Chemistry. July 18, 2025; p 1871.
  • Phase III double-blind randomized placebo controlled trial of atezolizumab in combination with carboplatin and paclitaxel in women with advanced/recurrent endometrial carcinoma: the Asian cohort of the AtTEnd/ENGOT-EN7 trial. Journal of Gynecologic Oncology, 2025;36(4).