Real-world data on the incidence of immune-related adverse events associated with anti-PD-1/PD-L1 treatment in Russia

Abstract

Background. PD-1 and PD-L1 immune checkpoint inhibitors (ICI) show efficacy in many tumor types, and the indications for their use continue to expand. Meanwhile, treatment with ICI is often accompanied by specific immune-related adverse events (irAEs). The real-world data of the incidence of irAEs in Russian patients is lacking. Objectives. The study aimed to characterize the frequency and profile of irAEs registered in Russian patients. Materials and methods. The retrospective study included patients with various solid malignancies who received immunotherapy in N.N. Petrov National Research Institute of Oncology or other oncological institutions of St. Petersburg during 2018–2021. The following treatment regimens were used: monotherapy with anti-PD-1 monoclonal antibody (nivolumab, pembrolizumab or prolgolimab), anti-PD-L1 monoclonal antibody (atezolizumab) or combination therapy with anti-PD-1 and anti-CTLA-4 antibodies (nivolumab and ipilimumab). The frequency and spectrum of irAEs were evaluated depending on the treatment regimen. Results. Any-grade irAEs were registered in 58 out of 178 (32.6%) analyzed patients. The most common adverse events were liver toxicity (11.2%) and thyroid dysfunction (10.1%). Severe irAEs (≥3 grade) occurred in 15.7% of cases. There was one fatal outcome due to grade 5 immune-mediated hepatitis. Combined immunotherapy was associated with a higher frequency of immune-related toxicity compared to monotherapy anti-PD-1/PD-L1 monoclonal antibodies (70.6% vs 23.6%, respectively, p<0.0001). Conclusions. The reported frequency of adverse events of PD-1 and PD-L1 inhibitors in Russian patients was lower than in the majority of the foreign studies.