PD‐L1‐negative non‐small cell lung cancer harbouring a rare BRAF mutation with successful treatment of first‐line pembrolizumab plus chemotherapy: A case report and review the literature

Abstract

BRAF mutations are uncommon in non‐small cell lung cancer (NSCLC), accounting for less than 5% of all NSCLC cases. The utilization of targeted therapies in non‐V600E BRAF mutant NSCLC is considered controversial, although non‐V600E genotype is reported in ~50% of all BRAF mutant patients. We document the case of a 63‐year‐old patient with NSCLC harbouring a rare BRAF E501Q mutation, who had prolonged response to immunotherapy combined with chemotherapy in Vietnam. The patient was diagnosed with metastatic PD‐L1‐negative lung adenocarcinoma and received pembrolizumab plus chemotherapy as first‐line treatment. After completing 35 cycles of pembrolizumab and pemetrexed, his disease has remained stable during the treatment‐free follow‐up period, and he is alive 38 months after treatment initiation at the latest follow‐up. Immune‐based therapy is an appropriate option for lung adenocarcinoma with rare non‐V600E BRAF mutation. Further clinical studies are necessary to determine the effectiveness of using immune‐based therapy in this specific population.

Outcomes of non-small cell lung cancer patients with non-V600E BRAF mutations: a series of case reports and literature review

“…A population of 37 patients with non V600E BRAF -mutant NSCLC, reported by Murciano-Goroff et al, treated with ICI, showed an ORR of 26% ( 29 ). A case of NSCLC harboring a rare BRAF E501Q mutation and PD-L1 negative expression reported a durable response after first-line treatment with ICIs and pemetrexed; the patient was alive 38 months after treatment initiation ( 30 ). Rittberg et al.…”

“…A population of 37 patients with non V600E BRAF-mutant NSCLC, reported by Murciano-Goroff et al, treated with ICI, showed an ORR of 26% (29). A case of NSCLC harboring a rare BRAF E501Q mutation and PD-L1 negative expression reported a durable response after first-line treatment with ICIs and pemetrexed; the patient was alive 38 months after treatment initiation (30). Rittberg et al demonstrated prolonged disease control over 4 years with ICI monotherapy in a 61-year-old patient with advanced NSCLC harboring the BRAF G469A mutation and PD-L1 expression >50% (31).…”