Although analyst forecasts ranged from exuberant to temperate, all agreed that approval of Libtayo (cemiplimab-rwlc, previously REGN-2810) marked a new chapter for longtime partners Regeneron Pharmaceuticals Inc. and Sanofi SA. The anti-PD-1 sneaked under the third-quarter wire, a month ahead of its PDUFA date, as the first FDA-approved therapy to treat advanced cutaneous squamous cell carcinoma (CSCC) or locally advanced CSCC in individuals who are not candidates for curative surgery or radiation.