U.S. FDA Approves FoundationOne®CDx as a Companion Diagnostic for KEYTRUDA® (pembrolizumab) to Identify Patients with Microsatellite Instability-High (MSI-H) Solid Tumors – Business Wire Leave a Comment / Blogs / By adm 1 U.S. FDA Approves FoundationOne®CDx as a Companion Diagnostic for KEYTRUDA® (pembrolizumab) to Identify Patients with Microsatellite Instability-High (MSI-H) Solid Tumors Business Wiresource