Royalty Pharma plc (NSDQ:RPRX) will acquire residual royalty interest in Vertex Pharmaceuticals’ cystic fibrosis (CF) treatments, which the Cystic Fibrosis Foundation owns. Royalty Pharma will pay $575 million in the deal and could shell out an additional $75 million in milestone payments. The company had already owned 50% of the foundation’s royalty stream. Once a…