The FDA expanded fast track designation for invikafusp alfa (STAR0602), positioning the asset across TMB-H solid tumors that have progressed after prior therapy, including checkpoint inhibitor-refractory settings. The company said the expanded status reinforces its strategy to develop a tissue-agnostic immuno-oncology backbone selected by biomarker. In previously reported phase 1/2 results highlighted in the release context, invikafusp alfa showed objective response rates around 20% overall in TMB-H tumors, with higher activity signals in gastrointestinal cancer subsets and metastatic colorectal cancer cohorts. Marengo framed the response pattern alongside disease control rates. With fast track in place, attention will shift to how quickly the program can mature to registration-enabling data and whether the biomarker selection criteria remain consistent across tumor types.