Impact of sex of the patient on efficacy and safety of cancer immunotherapy: A retrospective audit

Abstract

Background: It has been established that women usually mount a stronger immune response than men of the same age. Data for the efficacy of immune checkpoint inhibitors (ICIs) based on the patient's' sex are scarce. Objectives: We aimed to evaluate the impact of the patients' sex on the efficacy and toxicity of ICIs. Materials and Methods: Aretrospective audit of a prospectively collected database of patients receiving ICIs for advanced solid tumors between August 2015 and November 2018 was performed at the Tata Memorial Hospital in Mumbai, India. The categorical and continuous variables were evaluated using descriptive statistics. The Kaplan–Meier estimator was used to analyze the progression-free survival (PFS) and overall survival (OS). Results: Atotal of 155 patients were included in the study, of which 36 (23.2%) were female and 119 (76.8%) were male. The median PFS was 2.8 months (95% confidence interval [CI], 1.4–4.2) for the male patients and 1.9 months (95% CI, 1.0–2.8) for the female patients (hazard ratio [HR], 1.06; 95% CI, 0.69–1.66; P = 0.764). The median OS was 5.9 months (95% CI, 1.5–10.2) for the male patients and 4.2 months (95% CI, 1.1–7.3) for the female patients (HR, 1.27; 95% CI, 0.77–2.12; P = 0.342). The rates of all toxicities, except for pneumonitis, were similar between the male and female patients. All-grade pneumonitis occurred in a total of 7 (5.8%) male patients, while it was not reported in any female patients. All-grade immune-related adverse effects occurred in 24 (20.2%) male and 4 (18.1%) female patients (P = 0.216). Conclusions: This study shows that the efficacy and toxicity of ICIs are similar in the male and female patients. However, future trials with a balanced number of male and female patients are required to ensure an unbiased estimation of the efficacy and safety of ICIs.