Approximately 55 NSCLC subjects with PD-L1 tumor proportion score (TPS) ≥ 1% are expected to be enrolled in this study. Subjects' TPS will be determined by PD-L1 IHC 22C3 pharmDx assay performed according to local laboratory regulations prior to study enrollment.~Subjects who received adjuvant or neoadjuvant therapy are permitted onto the study if the therapy was completed at least 12 months prior to the development of metastatic disease.~Eligible subjects will receive:~• Vactosertib 300 mg orally (PO) BID for 5 days with 2 days off period (5 days on/2days off) and pembrolizumab 200 mg IV on Day 1 of every 3-week cycle (Q3W).
This is Phase 2, open label, multi-center study to assess safety and efficacy of vactosertib in combination with pembrolizumab as 1st line treatment for subjects with advanced or metastatic, PD-L1 positive, non-small cell lung cancer (NSCLC) who have not previously received systemic therapy for advanced disease and in whom EGFR, ALK, BRAF, ROS1-directed therapy is not indicated.