Despite this, sex is rarely taken into account when new therapeutic approaches are tested, the authors said.
They also commented on the fact that there was a relatively low number of women included in each trial, an issue that was recognized as far back as the 1990s as a major problem in medical trials.
“Our results further highlight this problem, showing clinically relevant differences in the efficacy of two important classes of immunological drugs, namely anti–CTLA-4 and anti–PD-1 antibodies, when compared with controls in male and female patients with advanced solid tumors,” they wrote.
They noted that they couldn’t exclude the possibility that the effect may be the result of other variables that were distributed differently between the sexes. However, they also qualified this by saying that variables known to affect the efficacy of immune checkpoint inhibitors, such as PD-L1 expression and mutation status, were not likely to explain the results.