CAMBRIDGE, Mass. — Marengo Therapeutics announced that the U.S. Food and Drug Administration has granted a second Fast Track designation to its experimental cancer immunotherapy, invikafusp alfa, expanding its potential use to a broader range of advanced solid tumors that have progressed following previous treatments.
The designation covers patients with unresectable, locally advanced or metastatic solid tumors characterized by high tumor mutational burden (TMB-H) that have progressed after prior therapy, including immune checkpoint inhibitors, and for whom satisfactory treatment options are unavailable.
The new designation expands on the drug’s initial Fast Track status, granted in January 2025 for TMB-H colorectal cancer, to include solid tumors regardless of their tissue of origin.
Marengo said the expanded designation is supported by clinical responses observed across several cancer types in its ongoing Phase 1/2 STARt-001 study, including colorectal, gastric, breast, bladder, endometrial, gastroesophageal, head and neck, and lung cancers.
Updated Phase 2 results are scheduled for presentation at the European Society for Medical Oncology Congress in Madrid on October 23.
“A second Fast Track Designation, now in a pan-tumor setting, reinforces our conviction that invikafusp alfa can become a next-generation, tissue-agnostic immuno-oncology backbone,” said Dr. Ke Liu, chief development officer of Marengo Therapeutics.
“Across multiple clinical data sets, invikafusp alfa has shown encouraging monotherapy activity in heavily pretreated patients across tumor types that were either insensitive to checkpoint inhibitors or progressed after PD-1–directed therapy,” Liu added.
Invikafusp alfa, also known as STAR0602, is an investigational bispecific T-cell agonist designed to stimulate specific immune cells to recognize and attack tumors.
Unlike checkpoint inhibitors, which work by releasing restrictions on existing immune responses, the drug is designed to activate and expand populations of T cells capable of targeting cancer.
Dr. Eric Rubin, a member of Marengo’s scientific advisory board and former senior vice president of global clinical oncology at Merck, said the approach could provide an alternative for patients whose cancers no longer respond to existing immunotherapies.
“Invikafusp alfa takes a fundamentally different approach: rather than releasing a checkpoint on exhausted T cells, it directly expands new T cells that can act on that antigen-rich landscape,” Rubin said.
Tumor mutational burden measures the number of genetic mutations within a tumor. Cancers with high mutational burden, generally defined as at least 10 mutations per megabase, may be more recognizable to the immune system but do not always respond to checkpoint inhibitor treatments.
Marengo is evaluating invikafusp alfa in its global STARt-001 trial, which includes patients with advanced solid tumors resistant to PD-1-directed therapies. The Phase 2 portion is examining treatment responses across multiple cancer types using biomarkers to identify patients who may benefit.
The company is also investigating the drug in combination with existing cancer treatments, including an antibody-drug conjugate, as part of efforts to evaluate its potential in earlier stages of therapy.
FDA Fast Track designation is intended to accelerate the development and review of treatments for serious conditions with unmet medical needs. It allows more frequent interaction with regulators and may provide eligibility for expedited review pathways.
Invikafusp alfa remains investigational and has not been approved by the FDA or any other regulatory authority.
