Peering into the Anti-CD3 Setback

The lack of efficacy of an anti-CD3 mAb from MacroGenics Inc. in a pivotal Phase II/III trial for Type I diabetes is not an indictment of the approach, according to Tolerx Inc., the other company with an anti-CD3 mAb in late-stage trials. Indeed, Tolerx believes differences in its product, dosing and trial design will yield positive Phase III data beginning in 2Q11.

Companies developing drugs for autoimmune disease have pursued CD3 because it is a part of the T cell receptor complex and is involved in T cell activation. In Type I diabetes, T cells are thought to mediate the destruction of insulin-producing pancreatic beta cells...