Welcome to Abacus Bioscience

CD180 is at the backbone of the Abacus technology. CD180 is a pattern recognition receptor (PRR) expressed on the surface of all antigen-presenting cells (APCs). CD180 normally functions to recognize pathogens and, together with other PRRs, to program APCs to induce effective and potent protective immune responses. Abacus has harnessed the CD180 program by creating novel immunotherapeutic proteins that both bind to CD180 and deliver virus or cancer antigens (Ags) into the immune system. Our recombinant Ag-CD180 proteins induce strong protective and therapeutic immune responses against both viruses and cancers. Abacus has developed an immunotherapeutic for the treatment of patients infected with hepatitis B virus (HBV), a major cause of liver cancer. Our HBV-CD180 drug, SB-301, induces potent immune responses in nonhuman primates (NHPs) and is ready for clinical development.

Abacus was founded in 2015 from technology originally developed by Edward A Clark at the University of Washington (UW). Dr. Clark’s lab has helped to discover and characterize important drug targets on immune cells including CD20, CD40 and CD80. During the last 10 years, the Clark lab screened a variety of monoclonal antibodies (mAbs) to cell surface receptors for their ability to deliver antigens (Ags) attached to the mAbs into the immune system and program effective immune responses, a method called ‘antigen-targeting’. They found that the CD180 (RP105) receptor met all their criteria for an ideal antigen targeting receptor. First, a single inoculation of an Ag attached to a mAb to CD180 (Ag-CD180) could program strong Ag-specific antibody and cytotoxic T cell responses, without the need for the addition of a nonspecific immunostimulant (adjuvant) that might induce toxic side effects. Second, Ag-CD180 not only activated dendritic cells (DCs), the antigen-presenting cells most immunotherapeutic approaches have focused on, but also programmed a second class of APCs, B cells. This is an important finding since B cell APCs are especially effective at overcoming immunosuppressive effects of viruses and cancers.