Sex differences in risk of severe adverse events in SWOG cancer clinical trials

Women have more adverse events (AEs) from chemotherapy than men, but few studies have investigated sex differences in AEs from immune or targeted therapies. Analyses of 23,296 patients in 202 SWOG phase 2 and 3 trials conducted between 1980 and 2019 (excluding sex-specific cancer studies) found that women compared with men experienced an increased risk of severe AEs among all treatments (OR 1.34; p<0.001), especially immunotherapy (OR 1.49; p<0.001). Women receiving chemotherapy or immunotherapy experienced increased severe symptomatic hematologic AEs. No statistically significant sex differences in risk of nonhematologic AEs were found. These findings support the idea that sex may independently modulate drug toxicity.