BRAF Inhibitors in Non-Small Cell Lung Cancer

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• RAF proteins are key serine-threonine kinases in the MAPK pathway, crucial for cell processes.
• MAPK pathway deregulation is implicated in numerous cancers, with BRAF mutations found in 1.5-3.5% of NSCLC.
• Prior success of BRAF/MEK inhibitor combinations in melanoma prompted investigation in NSCLC.

Purpose of the Study:

• To evaluate the efficacy and safety of combining dabrafenib (BRAF inhibitor) and trametinib (MEK inhibitor) in BRAF-mutant NSCLC patients.
• To assess this combination in both pretreated and first-line settings.

Main Methods:

• The BRF113928 trial enrolled pretreated (cohort B) and first-line (cohort C) NSCLC patients with BRAF mutations.
• Patients received a combination of dabrafenib and trametinib.
• Outcomes measured included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS).

Main Results:

• In pretreated patients (cohort B), the combination yielded an ORR of 68.4%, DCR of 80.7%, median PFS of 10.2 months, and median OS of 18.2 months.
• In the first-line setting (cohort C), ORR was 63.9%, DCR 75%, with median PFS and OS of 10.2 and 17.3 months, respectively.
• The treatment was generally well-tolerated, with common adverse events including pyrexia, nausea, diarrhea, fatigue, edema, and vomiting.

Conclusions:

• The combination of dabrafenib and trametinib is effective and well-tolerated for BRAF V600E metastatic NSCLC.
• This regimen has led to regulatory approval for BRAF-mutated NSCLC patients, irrespective of prior treatment.
• Future research will explore next-generation inhibitors and combinations for acquired resistance and other treatment strategies.