Dabrafenib Shows Promising Activity in BRAF+ Low-grade Glioma

Targeted therapy with dabrafenib is active and well-tolerated among patients with relapsed or refractory BRAF V600 mutation-positive pediatric low-grade glioma, according to a study presented at the European Society for Medical Oncology (ESMO) 2016 Congress.¹

Approximately 15% to 20% of children with low-grade glioma harbor BRAF V600 mutations, and these patients have historically worse survival and lower objective response rates to first- and second-line chemotherapy relative to patients with BRAF V600 wild-type disease. Researchers evaluated the activity of targeted BRAF inhibition with dabrafenib among pediatric patients with recurrent or progressive disease.

For the open-label, phase 1/2a study (ClinicalTrials.gov Identifier: NCT01677741), investigators enrolled 32 patients aged 2 to 17 years with BRAF V600-mutant relapsed or refractory low-grade glioma. Overall, 24 patients received the recommended phase 2 dose of second-line dabrafenib.

The overall response rate was 41% (95% CI, 24-59) per independent review, which included 2 complete responses and 11 partial responses. Median duration of response was 11 months and 8 responses were ongoing at the time of analysis.

Thirteen additional patients had stable disease for 6 months longer.

The confirmed overall response rate per investigator assessment was 72% (95% CI, 53-86), which included 1 complete response and 2 partial responses.

No new safety signals were observed and there were no reports of cutaneous squamous cell carcinoma. The most common adverse events were low-grade pyrexia, vomiting, fatigue, headache, and rash. Three patients experienced grade 3 to 4 pneumonia.                              

Reference

1. Kieran MW, Bouffet E, Tabori U, et al. The first study of dabrafenib in pediatric patients with BRAF V600-mutant relapsed or refractory low-grade gliomas. Paper presented at: European Society for Medical Oncology (ESMO) 2016 Congress; October 7-11, 2016; Copenhagen, Denmark.