Severe and prolonged myeloid haematopoietic toxicity with myelodysplastic features following alemtuzumab therapy in patients with peripheral T‐cell lymphoproliferative disorders

Alemtuzumab is effective therapy for B- and T-cell lymphoproliferative disorders (LPD) but is associated with prolonged lymphopenia. Myeloid haematological toxicities are less well described, especially in T-cell disorders, and are usually transient. We report myeloid toxicities in a phase II trial of alemtuzumab for T-cell LPD. Five of 11 patients treated developed severe neutropenia and thrombocytopenia. Three cases had prolonged cytopenias (32-88+ weeks), including two with severe marrow hypoplasia. We observed three incidences of trilineage morphological myelodysplasia, two with new clonal cytogenetic abnormalities. Alemtuzumab can be associated with prolonged severe multilineage cytopenias, marrow hypoplasia and myelodysplasia in T-cell LPD.