Plamotamab (CD20 x CD3)
CD20 x CD3 bispecific T-cell engager in Phase 1b development for rheumatoid arthritis
Plamotamab is an investigational CD20 x CD3 bispecific T-cell engager designed to redirect T cells to target and deplete CD20-expressing B cells. Xencor is conducting a Phase 1b, open-label, dose-escalation study of subcutaneously administered plamotamab in patients with moderately to severely active rheumatoid arthritis whose disease has not been adequately controlled with prior therapies. The study is evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics and immunogenicity of plamotamab.
In a prior Phase 1 study in patients with B-cell malignancies, plamotamab demonstrated preliminary antitumor activity and deep depletion of circulating B cells. Xencor believes these findings, together with the established role of B cells in certain autoimmune diseases, support its evaluation in autoimmune diseases.