Subsequent therapy following pembrolizumab + axitinib or sunitinib treatment for advanced renal cell carcinoma (RCC) in the phase III KEYNOTE-426 study

Background: In the phase III KEYNOTE-426 study, pembrolizumab + axitinib showed significant improvement in OS, PFS, and ORR vs sunitinib in patients with RCC. This analysis assessed subsequent treatment in patients enrolled in KEYNOTE-426. Methods: Treatment-naive patients with clear cell RCC, KPS score �70%, and measurable disease (RECIST v1.1) were randomly assigned 1:1 to receive pembrolizumab 200 mg IV every 3 weeks for up to 35 doses + axitinib 5 mg orally twice daily or sunitinib 50 mg once daily (4 weeks on/2 weeks off) until progression, toxicity, or withdrawal. Type of and time to subsequent therapy were assessed. Results: Of patients in the pembrolizumab + axitinib arm and in the sunitinib arm, 81.4% (349/432) and 90.6% of patients (385/429), respectively, discontinued treatment; radiologic or clinical PD was the most common reason for discontinuation in both (pembrolizumab + axitinib: 65.0% [227/349]; sunitinib: 68.1% [262/385]). Of patients who discontinued, 58.5% of patients (204/349) in the pembrolizumab + axitinib arm and 73.0% (281/385) in the sunitinib arm received subsequent therapy (Table). Although a similar proportion of patients in both arms received subsequent therapy with a VEGF/VEGFR inhibitor (pembrolizumab + axitinib: 88.2% [180/204]; sunitinib: 68.7% [193/281]), a greater proportion of patients in the sunitinib arm (74.4% [209/281]) received subsequent PD-1/PD-L1 inhibitor therapy than in the pembrolizumab + axitinib arm (21.6% [44/204]). Of patients in the pembrolizumab + axitinib arm and the sunitinib arm, 32.4% (66/204) and 22.8% (64/281), respectively, received other therapies