Plamotamab (previously XmAb13676) is a tumor-targeted antibody that contains both a CD20 binding domain and a cytotoxic T-cell binding domain (CD3). Xencor’s XmAb® Bispecific Fc Domain serves as the scaffold for these two antigen binding domains and confers long circulating half-life, stability and ease of manufacture on plamotamab. CD20 is highly expressed on B-cell tumor cells, including non-Hodgkin lymphoma (NHL) cells. Engagement of CD3 by plamotamab activates T cells for highly potent and targeted killing of CD20-expressing tumor cells.
Preliminary safety and anti-tumor activity from the Phase 1 study indicated that plamotamab was generally well tolerated and demonstrated encouraging clinical activity as a monotherapy.