Finding ways to turn “cold” tumors “hot” remains an ambition pursued by drug developers with differing approaches – combination regimens hold particular appeal – and one up-and-comer in the effort that has gained the notice of Wall Street lately is Carisma Therapeutics Inc. Philadelphia-based Carisma is advancing CT-0508, an autologous HER2-targeted CAR-macrophage therapy in phase I, used alongside Keytruda (pembrolizumab), the PD-1 receptor binder from Merck & Co. Inc.