Patients With Rare Brain Tumor Respond to Targeted Treatment in New Study

In a small study, 94 percent of patients with BRAF mutation-positive papillary craniopharyngiomas had a durable partial or better response to BRAF-MEK inhibitor combination therapy. Previous work found that nearly 95 percent of papillary craniopharyngioma patients have BRAF V600E mutations, suggesting that they might benefit from such treatment. As they report in the New England Journal of Medicine, a research team from Brigham and Women's Hospital, the Mayo Clinic, and elsewhere enrolled 16 patients with histologically proven BRAF V600E-mutant papillary craniopharyngioma into a Phase II trial in which they were treated with both vemurafenib and cobimetinib. Following treatment, 15 of the 16 patients had a volumetric response, with a median 91 percent reduction in tumor volume, and there was 87 percent progression-free survival at 12 months. Six of the seven patients who received no treatment after vemurafenib-cobimetinib had no evidence of tumor progressed at a median follow-up of 23 months. "This study demonstrated that national, biomarker-driven trials are feasible for patients with brain tumors," first author Priscilla Brastianos from the Mass General Cancer Center says in a statement. The researchers note, though, that 12 patients had grade 3 adverse events and two had grade 4 adverse events.