Hairy cell leukemia is a rare indolent B-cell lymphoid malignancy. Durable remission can be obtained with purine analogues, but relapse is inevitable, and effective treatment options may be limited. Moxetumomab pasudotox is a recombinant CD22-targeting immunotoxin that has recently been approved by the United States Food and Drug Administration for the treatment of relapsed or refractory hairy cell leukemia. Approval was based on a pivotal phase III study in this unique patient population. Rationale for use, clinical trial data, and current treatment recommendations are detailed. Common adverse effects are reviewed, and management strategies for select adverse effects are suggested. Implications for contemporary practitioners are also provided, as use of this novel agent is likely to increase as follow-up studies are reported.
Keywords: Hairy cell leukemia; immunotoxin; leukemia; moxetumomab pasudotox.