Pipeline

MST-0300

Recently, the presence of Tertiary Lymphoid Structures (TLSs) in tumors has been shown to be strongly predictive of both significantly improved patient outcomes and better responses to therapy for cancer patients across multiple solid tumor types. These striking observations have been seen in several thousand cancer patients, indicating the remarkable therapeutic potential of inducing TLSs^1,2,3,4. TLSs are aggregates of immune cells that form in tumor tissue as part of our bodies’ natural anti-cancer mechanisms, and drive powerful immune responses by recruiting, educating, and activating new anti-tumor T and B cells. 

MST-0300 is a FAP-LTBR bispecific antibody, designed to conditionally agonizes lymphotoxin beta receptor (LTBR) in the tumor on co-engagement of fibroblast activation protein (FAP), a tumor-specific marker expressed by cancer associated fibroblasts, to induce the formation of TLSs in solid tumors. Conditional LTBR agonism using a FAP-LTBR bispecific antibody promotes TLSs and drives robust immune cell recruitment, education, and tumor access leading to potent anti-tumor responses in preclinical models [AACR 2024 Poster]. MST-0300 has been developed to promote improved anti-tumor immune responses, enabling better outcomes for patients either alone or in combination with current treatments, and to provoke new anti-tumor responses in patients resistant to standard of care. An Investigational New Drug (IND) filing is anticipated in the second half of 2025. 

M402

M402 is a first-in-class stromal checkpoint agonist antibody, focused on dampening down myeloid-driven biology in inflammatory disease. Checkpoint receptors are found on immune cells and act as brakes on the immune system to regulate immune activity. Increasing checkpoint function via receptor agonism in inflammatory disease patients, where immune cells are over-active, has shown promising activity in early clinical trials. Our goal is to significantly improve outcomes for inflammatory disease patients by dampening down the immune system’s overactive state⁵.

M402 is designed to inhibit specific immune cell populations, including myeloid cells, important drivers of auto-immune and inflammatory disease not effectively targeted by current therapeutics.  This program has the potential to benefit patients across inflammatory diseases including rheumatoid arthritis, lupus, Sjogrens, graft-versus-host disease and others. 

References:
1) Fridman et al., Nature Reviews 2019
2) Vanhersecke et al., Nature Communications 2021
3) Cabrita et al., Nature 2020
4) Asrir et al., Nature 2022
5) Paluch et al., Frontiers in Immunology 2018