Romidepsin-induced durable remission for relapsed nodal peripheral T-cell lymphoma with T follicular helper phenotype after allogeneic hematopoietic cell transplantation.

Patients with recurrent peripheral T-cell lymphoma (PTCL) after allogeneic hematopoietic cell transplantation (HCT) have dismal outcomes. Nodal PTCL with the T follicular helper phenotype (PTCL-TFH) is uniquely sensitive to histone deacetylase inhibitors compared to non-TFH phenotypes. We report the case of a 19-year-old man who experienced recurrence of PTCL-TFH shortly after allogeneic HCT and subsequently achieved durable remission with romidepsin. Before HCT, the patient had refractory disease after CHOP and ESHAP chemotherapies but achieved a partial response after two cycles of romidepsin as salvage treatment. HLA-haploidentical peripheral blood stem cell transplantation was performed using conditioning with fludarabine 180 mg/sqm, melphalan 80 mg/sqm, and total body irradiation 2 Gy, and graft-versus-host disease (GVHD) prophylaxis with post-transplantation cyclophosphamide. One month after HCT, disease progression was observed in the lung. Romidepsin was readministered every 2 weeks at a reduced dose of 12 mg/sqm. After two cycles of romidepsin, the patient achieved a complete metabolic response without severe GVHD or other non-hematological toxicities. Romidepsin was discontinued after seven treatment cycles due to prolonged lymphopenia. The patient remains in complete remission 30 months after the last dose of romidepsin. Our experience suggests that romidepsin could be safely administered soon after allogeneic transplantation.