Article Text
Abstract
Introduction/Background AtTEnd is a phase III randomized international academic trial showing the efficacy of atezolizumab in addition to standard carboplatin and paclitaxel (CP) in patients (pts) with advanced/recurrent endometrial cancer. The potential for differences of efficacy based on ethnicity is unknown.
Methodology In this post hoc analysis, we analyzed differences in the efficacy of atezolizumab in combination with CP and as maintenance vs CP alone comparing Asian cohort (AC) to non-Asian cohort (nAC).
Results From Oct 2018 to Jan 2022, 549 pts were randomized and included in the primary analysis, of these, 112 (20%) were of Asian ethnicity. AC in comparison with nAC showed a lower median age (63 vs. 67 years), a lower BMI (23.1 vs. 28.7), a better performance status (performance status of 0: 82% vs 66%), a lower prevalence of mismatch repair (MMR) deficient tumors (20% vs 24%) and a higher prevalence of PD-L1 positive pts (68.2% vs 38.8%). Forty-five percent of AC was enrolled as newly diagnosed metastatic compared to 30% of nAC and in this population primary surgery was performed in 82% of AC vs. 42% of nAC. In the recurrent population previous radiation therapy was administered to 16% of AC vs. 50% of nAC. Progression free survival (PFS) in placebo arm was longer in AC than in nAC (median PFS: 11.8 vs 8.5 months). PFS according to MMR status in AC and nAC is reported in figure 1. AC showed a higher occurrence of grade 3–5 adverse events (AE) (75% vs. 63%), serious AE (44% vs. 34%) and serious AE related to treatment (28% vs 17%).
Conclusion This analysis suggests that the addition of atezolizumab to standard CP chemotherapy can improve the PFS independently of Asian ethnicity in MMR deficient tumors, while in proficient its efficacy seems to be affected by ethnicity.
Disclosures The Mario Negri Institute for Pharmacological Research of Milan, Italy is the legal entity responsible for the governance, coordination, and execution of the study on behalf of Mario Negri Gynecologic Oncology (MaNGO) group. The study is funded by F. Hoffmann-La Roche Ltd. The trial protocol number is NCT03603184; 2018–001072-37.