Pfizer announces follow-up results from Phase 2 single-arm PHAROS trial

Pfizer announced longer-term follow-up results from the Phase 2 single-arm PHAROS clinical trial evaluating the efficacy and safety of BRAFTOVI in combination with MEKTOVI for patients with BRAF V600E-mutant metastatic non-small cell lung cancer (NSCLC). After an additional 18 months of follow-up, the objective response rate and the median duration of response as assessed by independent radiology review were 75% and 40 months in treatment-naive patients and 46% and 16.7 months in previously treated patients, respectively. In addition, after approximately three years of follow-up in treatment-naive patients, the median progression-free survival with BRAFTOVI + MEKTOVI was 30.2 months, while median overall survival was not yet reached. These data will be presented today during a late-breaking oral session at the European Society for Medical Oncology Congress 2024 in Barcelona, Spain. Lung cancer is the number one cause of cancer-related death around the world.1 NSCLC accounts for approximately 80-85% of lung cancers, with BRAF V600E mutations occurring in about 2% of patients with NSCLC. Understanding the role of the mitogen-activated protein within the pathway including BRAF V600E-mutant metastatic NSCLC. The Phase 2 PHAROS trial is an open-label, multicenter, single arm study examining BRAFTOVI + MEKTOVI combination therapy in treatment-naive and previously treated patients with BRAF V600E-mutant metastatic NSCLC. Notably, upon longer-term follow-up in previously treated patients, BRAFTOVI + MEKTOVI showed a median PFS of 9.3 months and a median OS of 22.7 months, with a safety profile that was consistent with previous findings; no new safety concerns were identified. In this analysis, treatment-related adverse events led to dose reduction in 26% of patients, and to permanent discontinuation in 16% of patients. Nausea, diarrhea, and fatigue remained the most common treatment-related AEs. In addition to PHAROS, safety lead-in data from the ongoing Phase 3 BREAKWATER study investigating BRAFTOVI in combination with cetuximab and FOLFIRI chemotherapy in previously untreated BRAF V600E-mutant metastatic colorectal cancer (CRC) will also be presented as a mini-oral session at ESMO.