Thinking Critically About Classifying Adverse Events: Incidence of Pancreatitis in Patients Treated With Nivolumab + Ipilimumab

The Common Terminology Criteria for Adverse Events (CTCAE) were developed to document the adverse effects of chemotherapy but are now also used to document immune-related adverse events (irAE). Characterization of irAE by the CTCAE has implications for determining dose-limiting toxicity (DLT) and, consequently, the recommended phase II dose (RP2D) of investigational agents. In the phase I trial of nivolumab + ipilimumab, an asymptomatic increase in lipase was the primary DLT that informed the RP2D. We performed a retrospective study of 119 patients with melanoma who were treated at Memorial Sloan Kettering Cancer Center with the combination of nivolumab + ipilimumab to investigate the relationship between asymptomatic grade 3 or higher increases in amylase and/or lipase and pancreatitis, a known irAE. Of the 119 patients, there were only two cases of pancreatitis, representing 20% of patients with grade 3 or higher amylase, 6.3% of patients with grade 3 or higher lipase, and 20% of patients with grade 3 or higher elevations of both enzymes. The application of the CTCAE, especially in grading independent lab values, should be considered carefully in clinical trials of novel immunotherapeutic agents.