MBS303/MSC303

MBS303/MSC303 (MBS303 as the intravenous formulation, MSC303 as the subcutaneous formulation) is an innovative CD20/CD3 T-cell engager. MBS303 has initiated clinical trials for the treatment of CD20-positive B-cell non-Hodgkin lymphoma, while MSC303 has received approval for clinical IND to treat immune-mediated glomerulonephritis.

MBS303/MSC303 is based on our bispecific antibody technology platform, utilizing a 2:1 structure of CD20 and CD3. The product has received patent authorization in China and Hong Kong, with additional patents filed in the United States, South Korea, Japan, Europe, Australia, and Canada.

The estimated NHL patients in China is approximately 363,000 in 2023. Immune-mediated glomerular diseases are characterized by glomerular lesions caused by abnormalities in humoral immunity, cellular immunity, or complement activation. These include a variety of conditions such as membranous nephropathy, IgA nephropathy, ANCA-associated vasculitis, and lupus nephritis, leading to a large patient population.

Currently, treatment primarily involves corticosteroids and immunosuppressants. However, some patients experience suboptimal responses to approved biologics and/or standard regimens, may not tolerate existing therapies, or have a high risk of relapse after discontinuation. There is an urgent need for new targeted therapies.