*Article* **Retrospective E**ffi**cacy Analysis of Immune Checkpoint Inhibitor Rechallenge in Patients with Non-Small Cell Lung Cancer**

**Yuki Katayama 1,**†**, Takayuki Shimamoto 1,**†**, Tadaaki Yamada 1,\*, Takayuki Takeda 2, Takahiro Yamada 3, Shinsuke Shiotsu 4, Yusuke Chihara 5, Osamu Hiranuma 6, Masahiro Iwasaku 1, Yoshiko Kaneko 1, Junji Uchino <sup>1</sup> and Koichi Takayama <sup>1</sup>**


Received: 9 December 2019; Accepted: 29 December 2019; Published: 31 December 2019

**Abstract:** Little is known regarding the effectiveness and tolerability of immune checkpoint inhibitor (ICI) rechallenge after disease progression following initial ICI treatments. To identify eligible patients for ICI rechallenge, we retrospectively analyzed the relationship between clinical profiles and the effect of ICI rechallenge in patients with non-small cell lung cancer (NSCLC). We enrolled 35 NSCLC patients at six different institutions who were retreated with ICIs after discontinued initial ICI treatments due to disease progression. Cox proportional hazards models were used to assess the impact of clinical profiles on overall survival (OS) and progression-free survival (PFS). Median PFS and OS were 81 d (95% confidence interval, CI, 41–112 d) and 225 d (95% CI 106–361 d), respectively. The objective response rate was 2.9%, and the disease control rate was 42.9%. Multivariate analysis demonstrated that Eastern Cooperative Oncology Group Performance Score (ECOG-PS) ≥ 2 (hazard ratio, HR, 2.38; 95% CI 1.03–5.52; *p* = 0.043) and body mass index (BMI) > 20 (HR 0.43, 95% CI 0.19–0.95, *p* = 0.036) were significantly associated with PFS of ICI rechallenge. Our observations suggest that poor ECOG-PS and low BMI at intervention with ICI rechallenge may be negative predictors for ICI rechallenge treatment in patients with NSCLC.

**Keywords:** immunotherapy; rechallenge; non-small cell lung cancer; retrospective analysis
