The FDA companion diagnostic designation for the FoundationOne CDx and FoundationOne Liquid CDx may improve access to treatment with encorafenib plus binimetinib for those with BRAF V600E-mutated non–small cell lung cancer.
The FDA has granted approval to FoundationOne CDx and FoundationOne Liquid CDx as companion diagnostics to identify patients with metastatic non–small cell lung cancer (NSCLC) harboring a BRAF V600E mutation who may be eligible to receive treatment with encorafenib (Braftovi) plus binimetinib (Mektovi), according to a press release from Foundation Medicine Inc.1
“Foundation Medicine’s FDA-approved companion diagnostic tests offer physicians a high-quality diagnostic tool to support their personalized treatment planning,” Mia Levy, MD, PhD, chief medical officer at Foundation Medicine, said in the press release. “We are thrilled to see both tests approved simultaneously for the same indication, which will expand access to this therapy option to more patients [with NSCLC] who harbor a BRAF V600E mutation.”
According to the press release, FoundationOne CDx and FoundationOne Liquid CDx are intended exclusively for prescription use to determine patients who may benefit from the combination’s treatments. Additionally, developers caution that a negative result with either companion diagnostic does not disqualify the potential presence of a genomic alteration. When using FoundationOne Liquid CDx, testing with plasma samples is only suitable when tumor tissue is unavailable.
The FDA previously approved encorafenib plus binimetinib as a treatment for those with BRAF V600E-mutated metastatic NSCLC as detected with an FDA-approved test in October 2023.2 The approval was based on findings from the phase 2 PHAROS study (NCT03915951), in which the regimen produced an objective response rate (ORR) of 75% (95% CI, 62%-85%) and a median duration of response (DOR) that was not estimable (NE; 95% CI, 23.1 months to NE) among 59 patients who were treatment-naïve. Additionally, investigators reported an ORR of 46% (95% CI, 30%-63%) and a median DOR of 16.7 months (95% CI, 7.4-NE) in a cohort of 39 patients who received previous treatment.
The most common adverse effects (AEs) among patients receiving encorafenib plus binimetinib included fatigue, nausea, diarrhea, musculoskeletal pain, and abdominal pain.
The recommended dose for the treatment combination was 450 mg of encorafenib capsules once a day plus 45 mg of binimetinib tablets twice a day as part of 28-day treatment cycles.
The study’s primary end point was ORR per RECIST v1.1 criteria in treatment-naïve and previously treated patient groups. Secondary end points included DOR, disease control rate, progression-free survival, overall survival, and AEs.
Patients 18 years and older with a histologically confirmed diagnosis of stage IV NSCLC and the presence of a BRAF V600E mutation as detected by a local laboratory assay were eligible for enrollment on the trial. Additional eligibility criteria included having measurable disease based on RECIST v1.1 criteria; adequate bone marrow, hepatic, and renal function; and an ECOG performance status of 0 or 1.
“We are grateful to see continued efforts to develop more treatment options for patients [with] a [NSCLC] diagnosis. It’s especially exciting to see that patients can be matched to this combination therapy from either a blood or tissue-based test, which expands avenues for more access to this treatment option,” Danielle Hicks, chief patient officer at GO2 for Lung Cancer, concluded.
These data support less restrictive clinical trial eligibility criteria for those with metastatic NSCLC. This is especially true regarding both targeted therapy and immunotherapy treatment regimens.