Mogamulizumab-induced vitiligo in patients with Sezary syndrome: three cases

Background Mogamulizumab is a novel defucosylated monoclonal antibody targeting the C-C chemokine receptor 4 (CCR4) that eradicates Sezary cells via antibody-dependent cellular cytotoxicity. Treatment of Sezary syndrome with mogamulizumab has recently shown an increase in progression-free survival compared to vorinostat in patients previously treated for cutaneous T-cell lymphoma. Objectives To investigate immune side effects of mogamulizumab in patients with Sezary syndrome. Materials & Methods Three patients with Sezary syndrome, treated with mogamulizumab, who developed clinically confirmed vitiligo, were investigated. Results Case 1 was a 66-year-old woman from Tunisia. Seven months after the administration of mogamulizumab, she developed vitiligo on her face and hands while still in complete remission for Sezary syndrome. Case 2 was a 72-year-old woman from Martinique, with no history of autoimmune disease, who was diagnosed with Stage IVA1 Sezary syndrome. The patient received multiple lines of treatment with no improvement. After six months of mogamulizumab treatment, while still on treatment, the patient progressively developed well-demarcated depigmented patches on the scalp, upper limbs, and trunk, consistent with vitiligo. Case 3 was a 38-year-old woman from France, who was diagnosed with Sezary syndrome in October 2019. Mogamulizumab therapy was started in December 2019. Eight months later, she developed histologically-confirmed vitiligo on her legs. Conclusion Vitiligo can be another autoimmune manifestation associated with mogamulizumab, and the occurrence of vitiligo could be a favourable predictive factor for response to treatment.