Treatment With Encorafenib/Binimetinib Leads to Improved, Longer Responses in Patients With BRAF Mutations

Patients with BRAF mutations administered treatment with encorafenib/binimetinib trended toward improved and longer responses than patients who received dabrafenib/trametinib.

Patients with BRAF mutations administered treatment with encorafenib/binimetinib (EB) trended toward improved and longer responses than patients who received dabrafenib/trametinib (DT). The findings were presented through a poster at the Hematology/Oncology Pharmacy Association (HOPA) conference by Rachel Swisher, a PY2 oncology pharmacy resident at the University of Louisville Health James Graham Brown Cancer Center.

Approximately half of patients with metastatic melanoma have a BRAF mutation, which promotes tumor progression. BRAF-MEK inhibitor combinations are now recommended as first- or second-line therapies for advanced BRAF-mutant melanoma. Of the 3 combinations, EB was shown to have the longest progression-free survival (PFS) compared with vemurafenib alone.

However, there are currently no head-to-head trials comparing the efficacy and safety of these combination therapies. Therefore, the study’s objective was to determine the efficacy and safety of EB in the treatment of BRAF-mutant melanoma compared with DT.

Researchers evaluated patients at the University of Louisville Health James Graham Brown Cancer Center who were diagnosed with BRAF-mutant melanoma and treated with DT or EB from April 1, 2015, to August 31, 2019. The primary outcome was overall response (OR), while additional outcomes included PFS, duration of response, laboratory monitoring adherence, dose modifications, adverse events (AEs), and medication adherence.

A total of 16 patients met inclusion criteria at the interim analysis, with 7 in the EB group and 9 in the DT group. Almost all patients received immunotherapy prior to BRAF-MEK inhibitors. At each response assessment, patients treated with EB trended toward a higher absolute and percentage of OR than patients treated with DT. Median PFS for all patients was 5.38 months and was not significantly different between groups.

Patients treated with DT trended toward more documented AEs overall. Additionally, these patients experienced a higher incidence of pyrexia and gastrointestinal disturbances, whereas patients treated with EB experienced a higher incidence of rash and myalgias. Patients treated with DT also trended toward more hospitalizations and death.

Data will be re-analyzed to include a total of 28 patients, as Swisher noted that a larger sample size and longer follow-up time is necessary to evaluate definitive differences in efficacy and safety between these 2 regimens.

Reference

  • Efficacy and Safety of Encorafenib plus Binimetinib Versus Dabrafenib plus Trametinib for the Treatment of BRAF-Mutant Melanoma. Poster Presentation. HOPA conference. Published March 13, 2020. https://www.eventscribe.com/2020/HOPAahead/PosterTitles.asp?pfp=PosterTitles. Accessed April 21, 2020.