Post-Allograft Romidepsin Maintenance Mitigates Relapse Risk and Stimulates the Graft-Versus-Malignancy Effect through Enhanced NK-Cell Cytotoxicity in Patients with T-Cell Malignancies: Final Results of a Phase I/II Trial

Background: For patients with high risk, and relapsed/refractory T-cell malignancies allogeneic stem cell transplant (allo-SCT) is the only available potentially curative therapy. The efficacy of allo-SCT is limited in this population by high rates of relapse, with rates up to 55-60% post-allo-SCT. We designed a phase I/II trial, evaluating the combination of the histone deacetylases inhibitor romidepsin (rom) with busulfan/fludarabine (BuFlu) conditioning, followed by romidepsin maintenance (m-rom) in patients receiving allo-SCT for T-cell malignancies (NCT02512497). Here we present final clinical results of this therapeutic approach, including an evaluation of the stimulatory effects of m-rom on the graft-versus-malignancy effect through NK-cells post-allo-SCT. Methods: This was a phase I/II clinical trial. Eligible patients had: a diagnosis of T-cell leukemia (including T-acute lymphoblastic leukemia) or T-cell lymphoma (TCL, cutaneous or peripheral) in at least a partial remission requiring an allo-SCT,