Anti-PD-L1 Avelumab + VEGFR TKI Axitinib Delivers 40% ORR in MMR-Proficient Endometrial Cancer

In a two-stage Phase 2 study (NCT02912572) anti-PD-L1 Avelumab plus the VEGFR1-3 tyrosine kinase inhibitor, axitinib, was evaluated in 35 patients with recurrent or persistent mismatch-repair-proficient endometrial cancer (roughly 70–80% of endometrial cancers) with no prior exposure to immunotherapy. Among 28 evaluable patients, the combo achieved a 40% ORR (1 confirmed CR, 8 confirmed PRs) with median PFS of 7 months, and median confirmed DOR of 13.8 months; responses were higher in TP53-mutant tumors (48%). Grade ≥3 hypertension occurred in 37%, transaminase elevation in 6%, and 14% discontinued due to toxicity, but no treatment-related deaths were reported.