The largest study yet of adverse events from checkpoint inhibitor therapy for cancer suggests doctors should be alert for nine serious adverse events.

The meta-analysis or more than 100 clinical trials and nearly 19,000 patients found one in seven cancer patients treated with either programmed cell death (PD-1) inhibitors or programmed cell death ligand-1 (PD-L1) inhibitors experienced a severe adverse event (grade 3 or worse according to National Cancer Institute criteria).

While two-thirds of the patients had any adverse event – with fatigue and pruritus being the most common – serious adverse events tended to be immune-related and often mimicked auto-immune diseases, the authors reported in JAMA Oncology.

The nine most common immune-related severe adverse events were: