A Phase I/II Study of Immunotherapy with Humanized Anti-CD20
Antibody, IMMU-106 (hA20), in Adult Patients with Chronic Immune
Idiopathic thrombocytopenic purpura (ITP) is a condition in which the patient has very low platelet counts. It is believed that this is caused by the body's own immune system destroying the platelets. Initial treatment is with steroids and if this is not successful, removal of the spleen may be performed. Sometimes, the patient is refractory to all forms of therapy. CD20 is an antigen that is found on B cells. B cells are important in the immune system. Anti-CD20 is an antibody that targets the CD20 site on the B cell and can bind to this site inhibiting an important step in the proliferation of B cells thereby causing a depletion of these cells. The purpose of this study is to determine the optimal dose of the experimental agent IMMU-106 (an anti-CD-20 antibody) in patients with ITP. This is a Phase I/II study in which 3 different doses ( administered twice, 2 weeks apart, intravenously or by subcutaneous injection) will be evaluated for safety and to determine the optimal dose for later studies. An additional dosing schedule with hA20 administered by subcutaneous injection at a dose of 320 mg given once weekly for 4 consecutive weeks has been implemented. Initial subjects will be given infusions of the drug at the lowest of the three doses. If there is no significant toxicity, the next group of subjects will receive a higher dose and if there is again no significant toxicity, the third group will receive the highest dose. The subjects will be monitored for response to the drug, adverse effects, labs, physical exams, medical status and EKGs.