This regulatory milestone follows early signals from the ongoing Phase 1/2 STARt-001 study, which demonstrated objective responses across a spectrum of cancers, including lung, gastric, breast, and head and neck. Unlike standard PD-1 inhibitors that release existing T-cell checkpoints, invikafusp alfa acts as a bispecific dual T-cell agonist designed to actively expand new effector memory T cells. This mechanism aims to bypass the resistance often seen in patients previously treated with checkpoint blockades.

Eric Rubin, a member of Marengo’s Scientific Advisory Board, noted that the candidate addresses the clinical gap for patients who remain unresponsive to PD-1-directed therapies despite having high mutational burdens. The company plans to present updated Phase 2 data from the STARt-001 trial during an oral session at the ESMO Congress 2026 in Madrid on October 23. This designation provides Marengo with increased access to FDA consultation and potential pathways for accelerated approval, reinforcing the company's strategy to position the drug as a backbone for next-generation immuno-oncology.