Efficacy and safety of subsequent molecular targeted therapy after immuno-checkpoint therapy, retrospective study of Japanese patients with metastatic renal cell carcinoma (AFTER I-O study).

Objectives: Guidelines for treatment of mRCC recommend nivolumab monotherapy (NIVO) for treated patients, and nivolumab plus ipilimumab combination therapy (NIVO+IPI) for untreated IMDC intermediate and poor-risk mRCC patients. Although molecular-targeted therapies (TTs) such as VEGFR-TKIs and mTORi are recommended as subsequent therapy after NIVO or NIVO+IPI, their efficacy and safety remain unclear.

Methods: Outcome of Japanese patients with mRCC who received TT after NIVO (CheckMate 025) or NIVO+IPI (CheckMate 214) were retrospectively analyzed. Primary endpoints were investigator-assessed ORR of the first TT after either NIVO or NIVO+IPI. Secondary endpoints included TFS, PFS, OS and safety of TTs.

Results: Twenty six patients in CheckMate 025 and 19 patients in CheckMate 214 from 20 centers in Japan were analyzed. As the first subsequent TT after NIVO or NIVO+IPI, axitinib was the most frequently treated regimen for both CheckMate 025 (54%) and CheckMate 214 (47%) patients. The ORRs of TT after NIVO and NIVO+IPI were 27 and 32% (all risks), and median PFSs were 8.9 and 16.3 months, respectively. During the treatment of first TT after either NIVO or NIVO+IPI, 98% of patients experienced treatment-related adverse events, including grade 3-4 events in 51% of patients, and no treatment-related deaths occurred.

Conclusions: TTs have favorable antitumor activity in patients with mRCC after ICI, possibly via changing the mechanism of action. Safety signals of TTs after ICI were similar to previous reports. These results indicate that sequential TTs after ICI may contribute for long survival benefit.