Mogamulizumab as Bridge to Thiotepa-Based Allogeneic Haematopoietic Stem Cell Transplantation in Sézary Syndrome: A Single-Centre Experience

Introduction: Sézary syndrome (SS) is an aggressive cutaneous T-cell lymphoma for which allogeneic haematopoietic stem cell transplantation (allo-HSCT) represents the only potentially curative treatment. Methods: We report a single-centre series of three consecutive SS patients treated with mogamulizumab as bridging therapy to allo-HSCT using thiotepa-based reduced-intensity conditioning. Results: Mogamulizumab induced rapid clearance of circulating Sézary cells and significant clinical improvement. All patients achieved early and stable full donor chimerism and complete remission. Post-transplant GVHD occurred but was manageable with standard therapy. Conclusion: Early use of mogamulizumab may provide effective disease control and facilitate successful allo-HSCT in SS. Trial registration: The authors have confirmed clinical trial registration is not needed for this submission.