Trial Information

A Phase I/II Study of Immunotherapy With Humanized Anti-CD20 Antibody, IMMU-106 (hA20), in Adult Patients With Chronic Immune Thrombocytopenic Purpura

The goal of current treatment guidelines for most patients with chronic adult ITP is to
maintain platelet levels above 30 x 109/L. The conventional first-line therapy is
corticosteroids with or without intravenous immunoglobulins, but many patients relapse when
steroids are tapered. Standard therapy then is splenectomy, but patients with refractory
ITP who do not respond require further therapy. Unfortunately, immunosuppressive agents or
other available treatments typically produce only short-term responses. Because of the lack
of medical options after first-line therapy, the target population for this first study of
anti-CD20 immunotherapy with hA20 are adult patients with chronic ITP who failed at least
one standard ITP therapy (i.e., received at least one standard ITP therapy and now present
with platelet levels below 30 x 109/L).

In autoimmune disease, rituximab as well as other anti-CD20 antibodies currently being
considered for commercialization have focused on a different dosing schedule in rheumatoid
arthritis, and use fixed dosages rather than variable doses based on body surface area. In
addition, recent studies of these newer anti-CD20 antibodies in rheumatoid arthritis have
reported that lower doses indeed appear effective when administered twice, 2 weeks apart.
Based upon these considerations, patients in this study will receive hA20 twice, 2 weeks
apart, and administered at one of 3 dose levels.