Real-life safety of PD-1 and PD-L1 inhibitors in older patients with cancer: An observational study

Introduction: To compare the real-world safety profile of programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1) inhibitors between younger and older patients.

Materials and methods: All patients receiving pembrolizumab, nivolumab, atezolizumab or durvalumab between September 2016 and September 2019 at Haga Teaching Hospital, The Hague, The Netherlands were included in this retrospective study. Immune-related adverse drug reactions (irADRs) were manually retrieved from the electronic patient files. The cumulative incidence of irADRs were compared between younger (<65 years) and older (≥65 years) patients using a Pearsons Chi-square test.

Results: We identified 217 patients who were treated with at least one dose of PD-(L)1 inhibitor. 58% were 65 years or older at the start of immunotherapy. 183 patients (84.3%) received monotherapy PD-(L)1 inhibitors and 34 (15.7%) received chemo-immunotherapy. A total of 278 irADRs were registered. Cutaneous irADRs (53.9%), thyroid gland disorders (20.3%), and non-infectious diarrhoea/colitis (17.5%) were the most frequently reported irADRs. The majority of the irADRs were mild to moderate and no fatal irADRs were observed. 61 (21.9%) of the irADRs needed systemic treatment, of which 19 (6.8%) required treatment with corticosteroids. 18 irADRs (6.5%) were severe and resulted in hospitalisation. The cumulative incidence of cutaneous irADRs was different between the age groups: 45.7% of the patients <65 years and in 60.0% of the patients ≥65 years (p = 0.036). No statistical difference was found in the cumulative incidence of other irADRs between the two age groups.

Discussion: Advanced age is not associated with immune-related adverse drug reactions of PD-1 and PD-L1 inhibitors.