Use of signal transduction inhibitors as single agents to treat cancer leads to resistance because of the plasticity of intracellular signaling, and combination therapy can overcome this. We describe the first-in-human trial of avutometinib (RAF-MEK clamp) and defactinib (focal adhesion kinase inhibitor) in patients with solid tumors. The trial met its primary endpoint and recommended a phase 2 dose and schedule. The recommended phase 2 dose and schedule for a 28-day cycle was determined to be avutometinib 3.2 mg once a day, twice weekly (Monday and Thursday or Tuesday and Friday), and defactinib 200 mg twice a day, seven days a week. Both drugs were administered orally on a 3 weeks 'on' and 1 week 'off' basis. The pharmacokinetics and pharmacodynamics were consistent with previous reports of avutometinib and defactinib used as single agents. Key findings include an objective response rate of 42.3% (11 of 26; 95% confidence interval 23.4-63.1) and a median progression-free survival of 20.1 months (95% confidence interval 11.2-43.9) in patients with low-grade serous ovarian cancer. This study demonstrates the importance of intermittent dosing schedules in combined targeting of the mitogen-activated protein kinase and focal adhesion kinase pathways to improve tolerability, and has acquired proof of concept of anti-tumor activity against low-grade serous ovarian cancer, a tumor relatively resistant to chemotherapy. ClinicalTrials.gov identifier NCT03875820 .
© 2025. The Author(s).