Encorafenib Plus Binimetinib Shows ‘Prolonged Efficacy’ in Metastatic NSCLC

Encorafenib plus binimetinib showed “prolonged efficacy” in patients who have metastatic non-small cell lung cancer (NSCLC) with the BRAF V600E mutation, according to an update on the PHAROS study presented at the European Society of Medical Oncology (ESMO) 2024 Congress.

Gregory J. Riely, MD, PhD, presented the updated analysis of PHAROS with an additional 18 months of follow-up during a mini oral session on metastatic NSCLC during the ESMO Congress. The primary analysis of the PHAROS study met its main endpoint, with an objective response rate (ORR) per independent radiology review of 75% in patients who were treatment-naïve, and 46% in those with previously treated disease. Based on the trial results, the US Food and Drug Administration approved the combination treatment in 2023 for patients who had NSCLC with the BRAF V600E mutation.

The ongoing, open-label, single-arm trial enrolled 98 patients who had NSCLC with the BRAF V600E mutation. All patients were treatment-naïve (n=59) or had received 1 prior systemic therapy (n=39). All patients received encorafenib 450 mg once daily plus binimetinib 45 mg.

At the data cut-off date for the updated analysis, 19% of patients who were treatment-naïve and 10% of patients who received previous treatment continued to receive the combination therapy. The median duration of the therapy was 16.3 months in patients who were treatment-naïve, compared to 5.5 months in those who had received previous treatment.

The median progression-free survival (PFS) was 30.2 months (95% CI, 15.7 to not estimable) with a median duration of response of 40 months (95% CI, 23.1 to not estimable) at a median follow-up of 33.3 months among patients who were treatment-naïve. The median overall survival was not estimable (95% CI, 31.3 to not estimable) in patients who were treatment-naïve and was 22.7 months (95% CI, 14.1 to 32.2) in those who had received previous treatment. See Table 1 for a full comparison of the primary analysis and updated analysis.

Table 1. Primary versus updated analysis outcomes of the PHAROS study.

Nausea, diarrhea, and fatigue remained the most common treatment-related adverse events, occurring in at least 30% of patients. The safety profile of encorafenib plus binimetinib was “consistent with that observed in the primary analysis,” according to the trial investigators.

The study investigators concluded that encorafenib plus binimetinib showed “prolonged efficacy, especially in treatment-naïve patients,” and that the combination showed a “manageable safety profile” in patients who have NSCLC with the BRAF V600E mutation.

Reference

Riely GJ, Ahn M-J, Clarke J, et al. Updated efficacy and safety from the phase II PHAROS study of encorafenib plus binimetinib in patients with BRAF V600E-mutant metastatic NSCLC (mNSCLC). LBA56. Presented at the European Society of Medical Oncology 2024 Congress; September 13-17, 2024; Barcelona, Spain.