MB-388

MB-388 is an investigational, orally administered small-molecule dual inhibitor of the protein tyrosine phosphatases PTPN2 (protein tyrosine phosphatase non-receptor type 2) and PTPN1 (protein tyrosine phosphatase non-receptor type 1). Developed by Mondego Bio, MB-388 is designed to overcome resistance to cancer immunotherapy by acting on both tumor cells and immune cells. Preclinically, it has demonstrated the ability to restore interferon-gamma signaling, increase antigen presentation, and enhance T-cell and natural killer (NK) cell function. In head-to-head preclinical studies against osunprotafib, MB-388 showed a higher unbound fraction in human plasma, higher oral exposure, and longer target coverage, along with more than 1,000-fold selectivity over unrelated targets. It is being evaluated in a Phase 1a clinical trial in healthy volunteers, with plans to initiate a Phase 1b study in patients with advanced solid tumors as a monotherapy and in combination with PD-(L)1 checkpoint inhibitors.