The efficacy of molecular targeted therapy and nivolumab therapy for metastatic non‐clear cell renal cell carcinoma: A retrospective analysis using the Michinoku Japan urological cancer study group database.

Objectives: To investigate the efficacy of pharmacotherapy for metastatic non‐clear cell renal cell carcinoma (nccRCC) in Japanese population. Methods: In this retrospective analysis, we compared the time to treatment failure (TTF) for molecular‐targeted agents as first‐line therapy, or nivolumab therapy as sequential therapy between ccRCC and nccRCC using the data of Japanese metastatic RCC patients registered in the Michinoku Japan Urological Cancer Study Group database. Results: In total, 511 cases of ccRCC and 77 cases of nccRCC were treated with pharmacotherapy. After excluding the patients who received cytokine therapy, chemotherapy, or others, there were 391 ccRCC patients and 60 nccRCC patients who were treated with tyrosine kinase inhibitors (TKIs), and 7 ccRCC patients and 7 nccRCC patients who were treated with mammalian‐target of rapamycin inhibitors (mTORIs). In addition, 132 ccRCC patients and 16 nccRCC patients received nivolumab. There was no significant difference in IMDC risk classification before first‐line therapy between ccRCC and nccRCC groups, or in each subgroup within the nccRCC group. TTF for TKIs (161 days, 95% CI: 75‐212 days) and mTORIs (21 days, 95% CI: 9‐31 days) didn't differ significantly between nccRCC and ccRCC groups (205 days, 95% CI: 174‐243 days and 33 days, 95% CI: 8‐113 days, respectively). TTF for TKIs was significantly longer than that for mTORIs in nccRCC group (p<0.01). There was no significant difference in TTF between the different TKIs in nccRCC group. In addition, no significant difference in TTF for nivolumab was seen between ccRCC and nccRCC groups. Conclusions: The results showed that the efficacy of molecular‐targeted agents as first‐line therapy was similar oncological outcomes between metastatic nccRCC and ccRCC in Japanese patients. TKIs may be more effective than mTORIs in metastatic nccRCC patients. Nivolumab administration might also be as effective in nccRCC patients as in ccRCC patients in Japanese population. [ABSTRACT FROM AUTHOR]