Definition

An orally bioavailable inhibitor of mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), with potential immunomodulating and antineoplastic activities. Upon oral administration, MALT1 inhibitor ABBV-525 targets, binds to, and inhibits the activity of MALT1. This inhibits MALT1-dependent CARD11-BCL10-MALT1 (CBM) signaling, thereby inhibiting the immunosuppressive function of regulatory T cells (Tregs) and upregulating the production of interferon-gamma (IFN-g) by Tregs in the tumor microenvironment (TME). This results in the inhibition of Janus kinase/signal transducers and activators of transcription (JAK/STAT) and nuclear factor-kappa B (NF-kB) signaling, induces apoptosis, and inhibits tumor cell growth. MALT1 belongs to the caspase family of proteases and is the active component of the CBM signaling complex. It plays an essential role in mediating the immunosuppressive activities of Tregs, and is overactivated in certain tumor cells, including non-Hodgkin B-cell lymphomas.