Treatment outcomes of molecular targeted therapy following nivolumab in metastatic renal cell carcinoma

Objective The purpose of this study was to assess the therapeutic efficacy of molecular targeted therapies following nivolumab in metastatic renal cell carcinoma and to examine the relationship between therapeutic efficacy and the specific molecular targeted therapy used. Methods We retrospectively reviewed the medical records of 115 metastatic renal cell carcinoma patients who were treated with nivolumab at our institution and five affiliated hospitals. Among them, 52 patients who received subsequent molecular targeted therapy following nivolumab were selected to survey treatment outcomes. Progression-free survival and overall survival were estimated with Kaplan-Meier curves, and differences were analyzed by the log-rank test. Results Among the 52 eligible patients, 40 (76.9%) were treated with tyrosine kinase inhibitors and 12 (23.1%) were treated with mammalian target of rapamycin inhibitor. The median time to treatment failure and progression-free survival of subsequent molecular targeted therapy were 5.6 and 8.0 months, respectively. The median overall survival from the initiation of first-line therapy was not reached. The disease control rate of subsequent molecular targeted therapy was 69.2% (partial response: 25.0%, stable disease: 44.2%). The median progression-free survival of subsequent tyrosine kinase inhibitor and mammalian target of rapamycin inhibitor were 9.2 and 8.0 months, respectively (P = 0.37). The progression-free survival of patients whose best response to prior nivolumab was either progressive disease or stable disease/partial response were 6.3 and 11.3 months, respectively (P = 0.36). Conclusions Molecular targeted therapies following nivolumab had comparatively better therapeutic efficacy, which was confirmed regardless of the type of molecular targeted agent used.