Pyrexia in patients treated with dabrafenib plus trametinib across clinical trials in BRAF-mutant cancers

Background: Dabrafenib plus trametinib has demonstrated clinical benefit across multiple BRAF-mutant tumours, leading to approval for resected stage III and metastatic melanoma, non–small-cell lung cancer (NSCLC) and anaplastic thyroid cancer. Pyrexia is a common adverse event in patients treated with dabrafenib plus trametinib. Here, we characterise the incidence, patterns and management of pyrexia in patients receiving dabrafenib plus trametinib in clinical trials. Methods: Patients (N = 1076) included in the analysis received dabrafenib plus trametinib in the following clinical trials: phase II registration trial in advanced NSCLC (N = 82), phase III COMBI-AD study in resectable stage III melanoma (N = 435) and phase III COMBI-d and COMBI-v studies in unresectable or metastatic melanoma (N = 209 and N = 350, respectively). Results: Among the 1076 patients enrolled in the clinical trials, 61.3% developed pyrexia, 5.7% developed grade 3/4 pyrexia and 15.6% developed a protocol-defined serious pyrexia event. Among the 660 patients with pyrexia, 33.0% had 1 occurrence, 19.8% had 2 occurrences and 47.1% had ≥3 occurrences. The incidence of pyrexia was highest early in treatment and decreased with time on treatment. Temporary dose interruption of dabrafenib or trametinib was the most common and effective management strategy. Conclusions: Pyrexia is the most common adverse event associated with dabrafenib plus trametinib but is manageable with dose interruption. Trial registration: ClinicalTrials.gov (Phase II NSCLC, NCT01336634; COMBI-AD, NCT01682083; COMBI-d, NCT01584648; COMBI-v, NCT01597908).