For refractory patients with idiopathic thrombocytopenia purpura (ITP), a disorder characterized by immune-mediated platelet destruction, treatment with Rituxan rituximab represents a new option that generated significant interest at the American Society of Hematology meeting in Orlando last week.

New treatments for ITP patients have been few and far between, with steroids, chemotherapy, and splenectomy as the most common alternatives for patients who fail first line treatment with intravenous immunoglobulin (IVIG) or anti-D (immunoglobulin therapy with antibodies against the Rh-D red blood cell antigen).

One alternative therapy is the Prosorba column, marketed by Cypress Biosciences Inc. (CYPB, San Diego, Calif.) and partner Fresenius AG (Bad Homburg, Germany). The column, which removes circulating immunoglobulins from blood, requires the patient's plasma to be run through the column ex-vivo.

At ASH, a series of presentations on the use of Rituxan showed that B cell depletion gave durable responses in some patients. The anti-CD20 monoclonal antibody is marketed by Idec Pharmaceuticals Inc. (IDPH, San Diego, Calif.) and partner Genentech Inc. (DNA, South San Francisco, Calif.) to treat non-Hodgkin's lymphoma (NHL).

IDPH presented data showing that refractory ITP patients treated with 150 or 375 mg/m2 Rituxan for 4 infusions had responses, with platelet levels rising above 30,000/mL, that lasted for up to 24 months. Separately, researchers with Cornell Medical School presented data showing that patients with or without prior splenectomy had responses that lasted up to 45 weeks.