Hemolytic anemia after fludarabine therapy for chronic lymphocytic leukemia

Purpose: A report of the clinical features, treatment, and outcome of patients who developed hemolytic anemia (HA) temporally associated with fludarabine (Fludara; Berlex Laboratories, Richmond, CA) therapy for chronic lymphocytic leukemia (CLL). Patients and Methods: Data on 24 patients who developed HA related to fludarabine therapy were collected from the Spontaneous Reporting System of the Food and Drug Administration (FDA) and the Walter Reed Army Medical Center (Washington, DC). Results: Seventeen (71%) patients developed HA after either the first, second, or third cycle of this drug. The longest duration of fludarabine therapy before HA occurred was six cycles. The median decline in hematocrit from baseline during the hemolytic episode was 14.1 (range, 8.0 to 28.9) for the 18 patients for whom this information was available. For the 11 patients for wham transfusion requirements were known, the number of transfusions administered ranged between three and 36. Seven (29%) patients died of medical complications associated with the HA. Seven of eight patients who were re-challenged with fludarabine after an episode of HA developed recurrent HA, and three of these patients died. Conclusion: HA associated with fludarabine therapy appears to be uncommon, but it can be severe and fatal, especially if a patient is re-treated with this drug after a previous episode of HA. The mechanism of this toxicity is unknown, but it may be caused by the release of a suppressed auto-antibody to a native red cell antigen.