PharmAbcine Inc. announced the initiation of patient dosing in the Phase 1a/b clinical trial of PMC-309 in patients with advanced or metastatic solid tumors. PMC-309 is an IgG1 monoclonal antibody with specific binding to VISTA in immunosuppressive cells, exhibiting excellent binding affinity at various pH conditions within the tumor microenvironment (TME). By inhibiting VISTA, PMC-309 presents a differentiated mechanism of action contributing to anti-cancer effects through activation of T cells, activation of monocytes, and proliferation of M1 macrophages.

This open-label clinical trial comprises two phases, Phase 1a and Phase 1b. Phase 1a involves PMC-309 monotherapy and combination therapy with KEYTRUDA®? (pembrolizumab), determining the maximum tolerated dose (MTD) and the recommended Phase 2 dose (RP2D).

In Phase 1b, safety and tolerability of PMC-309 mon therapy with KEYTRUDA?? at the RP2D will be evaluated. The clinical trial, spanning four institutions in Australia, aims to enroll a total of 67 patients.