Efficacy and safety of immune checkpoint inhibitor immunotherapy in elderly cancer patients

Purpose There is limited evidence on the efficacy and safety of anti-programmed cell death protein 1 (PD-1)-/anti-programmed death-ligand 1 (PD-L1)-based immunotherapy in the elderly, particularly those aged over 75 years. Methods/patients The clinical response and toxicity profile of anti-PD-1-/anti-PD-L1-based immunotherapy in patients aged over 75 years were assessed in this retrospective observational study conducted in the Medical Oncology Service of a tertiary level hospital. The associations among clinical responses, adverse events, and geriatric syndromes were evaluated. Results In total, 20 patients aged between 75 and 94 years were evaluated. Pembrolizumab and nivolumab were the most commonly used drugs. A clinical benefit (stable disease, partial response or complete response) was documented in 13 patients (65%). This proportion was 80% in patients aged between 75 and 79 years, and 50% in those aged over 79 years (p = 0.236). The adverse events were similar to those reported in younger patients. At least one clinical adverse event (cAE) and one laboratory adverse event (lAE) was reported in 75% and 55% of patients, respectively. Polypharmacy was observed for all patients and multi-morbidity in 95%. Patients without gait disorders showed more responses to immunotherapy. The number of lAEs was significantly associated with the number of commonly prescribed drugs (slope = 0.218, p = 0.010), the Eastern Cooperative Oncology Group score, and the number of cAEs. Conclusions The elderly can obtain benefits from anti-PD-1-/anti-PD-L1-based immunotherapy. The toxicity profile was similar to that reported in younger counterparts.