Real-world efficacy and safety data of anti-PD-1 plus anti-CTLA-4 combination therapy in Chinese patients with advanced melanoma.

Abstract

e21530 Background: Combination of anti-PD-1 plus anti-CTLA-4 has shown superior efficacy over monotherapy in advanced melanoma among Caucasian populations. However, it has not been evaluated in Chinese patients, and data on acral and mucosal melanoma are limited. We aimed to assess the efficacy and safety of anti-PD-1 antibody plus ipilimumab therapy in Chinese patients with advanced melanoma in clinical practice. Methods: Advanced melanoma patients treated with anti-PD-1 antibody combined with ipilimumab in Sun-Yat sen University Cancer Center from May 2015 to October 2022 were retrospectively assessed. Patient baseline characteristics, tumor responses (RECIST), progression-free survival (PFS), and overall survival (OS) were estimated using Kaplan-Meier analysis. Toxicity was assessed to estimate safety. Results: Altogether, 86 patients were included. The primary site was cutaneous, acral, mucosal, uveal and central nervous system (CNS) in 34, 21, 20, six and five patients, respectively. Among them, 21 patients were treatment-naive, 65 patients were previously treated, and 54 patients progressed of front-line ani-PD-1 therapy. 12 patients received ipilimumab 3mg/kg combined with low dose anti-PD-1 (Nivolumab 80mg or Pembrolizumab 1mg/kg) Q3w for four doses, and the other 74 patients received standard dose of anti-PD-1 plus ipilimumab 1mg/kg Q3w therapy. There were 25(29%) patients with liver metastasis and 26(30.2%) patients with CNS metastasis at baseline. The overall response rate (ORR) was 15.1% in the whole cohort, with complete response observed in six (6%) patients, partial response in 7 (8.1%), stable disease in 28 (32.6%). The response rate in the treatment-naive and prior systemic therapy group was 23.8% and 12.3%, respectively. For those treated with anti-PD-1 followed by the anti-PD-1+ ipilimumab as subsequent therapy after disease progression, the ORR was 11.1%. The response rate for cutaneous melanoma was 23.5%, and 37.5% in the naïve group. Response rates for acral, uveal, CNS and mucosal melanoma were 19.0%, 16.7%,0% and 0% respectively. The median progression-free survival (PFS) and overall survival (OS) in all patients was 4.5 (3.6-5.4) months and 22.0 (12.4-31.6) months, respectively. The 3-year OS were 100% in patients who achieved ORR. There were no significant differences in PFS or OS for patients with cutaneous or acral melanoma. mucosal primary tumor type, liver metastasis and elevated LDH were predictive of shorter PFS and OS. CNS metastasis, previous treatment, BRAF/NRAS mutation status and sex were not found to be related to survival. Adverse events occurred in 71% of patients and 13% were grade 3 or worse. Conclusions: The efficacy of anti-PD-1+ ipilimumab combination therapy in Chinese patients tended to be inferior compared to global studies but was well tolerated. OS were good in cases with CR or PR.