Rituximab in the Treatment of Autoimmune Hemolytic Anemia

Based on a previously published experience (Blood 92:3409, 1998), 5 additional patients with autoimmune hemolytic anemia (AIHA) have since been treated with rituximab (Rituxan). We present a summary of all 6 patients (5 female, 1 male; median age: 64 years [range: 22 to 83 years]). Of the 6 patients, 3 had cold agglutinin disease and 3 had warm AIHA. Three patients had low-grade lymphomas (2 cold, 1 warm) identified during the course of treatment and follow-up for AIHA. All patients had prior therapy for AIHA, and had had disease for anywhere from 3 months to 20 years.

Prior therapy consisted of steroids in all patients. The 3 patients with warm AIHA had no other therapies before rituximab. The 3 patients with cold AIHA had chemotherapy (2 patients), splenectomy (2), and plasmapheresis (1). Those with warm AIHA were steroid-dependent at the time of treatment with rituximab; 2/3 cold AIHA patients were resistant to treatment when given rituximab. Treatment was 4 weekly doses of rituximab given at 375 mg/m². No unusual toxicity or complications have occurred.

Five patients have had complete hematologic responses, defined as hemoglobin and hematocrit increase into the normal range, and 1 patient is too early to evaluate for response. One patient required a second course of treatment, and one was given six doses (again, at weekly intervals) because of responding but not yet normal values at the end of the planned four doses of rituximab. The duration of response has ranged from 4 months to 2.7 years. As noted, 1 patient required a second treatment after 5 months, and has continued in response for an additional 10 months subsequently. No other patients have had recurrent hemolysis.

CONCLUSION: Rituximab is an active agent in the treatment of both warm and cold AIHA. Patients with long-standing disease responded (20 years after diagnosis), as did patients with or without non-Hodgkin’s lymphoma. The use of rituximab should be considered early in the course of AIHA. More experience is needed to better define response rates and duration.

Click here to read Dr. Bruce Cheson's commentary on this abstract.