Libtayo, or cemiplimab-rwlc, a PD-1 inhibitor developed by Regeneron Pharmaceuticals and Sanofi, was approved by the FDA as a first-line treatment for certain patients with advanced non-small cell lung cancer. Conditions for use include having a high PD-L1 expression, metastatic tumors not eligible for surgical resection or definitive chemoradiation, and tumors without EGFR, ALK or ROS1 aberrations.