Dramatic efficacy of brentuximab vedotin in two patients with epidermotropic cutaneous T-cell lymphomas after treatment failure despite variable CD30 expression

Funding sources: none. Conflicts of interest: none declared. Dear Editor, Brentuximab vedotin (BV), a monomethyl auristatin E‐conjugated anti‐CD30 monoclonal antibody, has been shown to be efficacious in patients with Hodgkin and anaplastic large‐cell lymphomas (ALCLs). We report our experience with BV in two patients, one with transformed mycosis fungoides (MF) and the other with transformed Sézary syndrome (SS). Patient 1, a man in his 70s, was followed for 10 years for histologically proven MF. His main clinical history included hypertension, morbid obesity, restrictive lung disease, noninsulin‐dependent diabetes mellitus and ischaemic heart disease. After a 3‐year evolution of his MF, he developed tumours. Histopathological analysis showed the presence of large cells exceeding 25% of the total infiltrate. CD30 was expressed in 5% of the large cells. He had previously been treated with acitretin, interferon‐α, bexarotene, radiotherapy, caryolysine and carmustine, pegylated liposomal doxorubicin and vorinostat. At initiation of BV he had a European Organization of Research and Treatment of Cancer/International Society for Cutaneous Lymphomas stage IIB‐transformed MF (T3 N0 M0 B0) (Fig. 1a); his modified severity weighted assessment tool (mSWAT) score was 69. After eight treatment cycles, his mSWAT score decreased to 11 (Fig. 1b). The patient was considered to be in almost complete remission, and treatment was discontinued. Six weeks later, the lesions were reactivated and the treatment was reinitiated. It is currently ongoing (13 treatment cycles). Regarding the safety of BV, the patient experienced erysipelas on the lower limb after the first infusion of BV, and a grade 2 sensorimotor axonal neuropathy after five treatment cycles.