Presentation Authors: Hiroki Ishihara*, Toshio Takagi, Tsunenori Kondo, Tokyo, Japan, Chie Homma, Yachiyo, Japan, Hidekazu Tachibana, Hironori Fukuda, Kazuhiko Yoshida, Junpei Iizuka, Hirohito Kobayashi, Masayoshi Okumi, Hideki Ishida, Kazunari Tanabe, Tokyo, Japan
Introduction: Immune-related adverse events (irAEs) develop in some patients with metastatic renal cell carcinoma (mRCC) on immune checkpoint inhibitor therapy. The association of irAEs with prognosis has been reported in melanoma and non-small cell lung cancer, but remains unclear in mRCC. This study aimed to evaluate the association of irAEs with prognosis in patients with mRCC treated with nivolumab.
Methods: We retrospectively evaluated 47 mRCC patients treated with nivolumab following systematic therapy. The irAEs involved the liver, kidney, pancreas, and skin, and endocrine, pulmonary, and gastrointestinal systems, with grading based on the CTCAE v4.0. Progression-free survival (PFS) and overall survival (OS) after nivolumab initiation were compared according to irAE development.
Results: irAEs developed in 23 patients (48.9%). Median time from therapy initiation to irAE development was 1.38 months. Rash/pruritus was the most frequent event (n=11, 23.4%). irAEs with grade â‰¥3 were observed in 9 patients (19.1%). PFS and OS were significantly longer in patients with irAEs than in those without irAEs (median 2 year-PFS: 44% vs. 5.89%, p=0.0002; 2 year-OS: 76.9% vs. 53.4%, p=0.0130). Multivariate analyses showed that irAE development was independently associated with longer PFS and OS (PFS: HR 0.27, p=0.0011; OS: HR 0.27, p=0.0472). Furthermore, objective response rate was significantly higher in patients with irAEs than in those without irAEs (63.6% vs. 13.0%, p=0.0005). In addition, median OS after irAE development was 23.0 months.
Conclusions: This retrospective study showed that patients with irAEs had favorable outcomes after nivolumab therapy. The data showed that irAE development might be an effective surrogate marker of patient survival on nivolumab.