Allogeneic haematopoietic cell transplantation after nonmyeloablative conditioning in patients with T‐cell and natural killer‐cell lymphomas

Patients with T‐cell and natural killer‐cell lymphomas have poor outcomes. This study examined the role of allogeneic haematopoietic cell transplantation (allo‐HCT) after nonmyeloablative conditioning in this setting. Seventeen patients with T‐cell lymphoma or NK‐cell lymphoma, including three patients in first complete remission, received allo‐HCT after 2 Gy total‐body irradiation and fludarabine. The median age was 57 (range, 18–73) years. The median number of prior therapies was 3 (range, 1–7), six patients (35%) had failed prior autologous HCT, and five patients (29%) had refractory disease at the time of allograft. Postgrafting immunosuppression was provided with mycophenolate mofetil with ciclosporin or tacrolimus. After a median follow‐up of 3·3 (range, 0·3–8·0) years among surviving patients, the estimated probabilities of 3‐year overall and progression‐free survival were 59% and 53%, respectively, while the estimated probabilities of non‐relapse mortality and relapse at 3 years were 19% and 26%, respectively. Sixty‐five percent of patients developed grades 2–4 acute graft‐versus‐host disease and 53% of patients developed chronic graft‐versus‐host disease. Allo‐HCT after nonmyeloablative conditioning is a promising salvage option for selected patients with T‐cell and NK‐cell lymphomas. These results suggest that graft‐versus‐T‐cell lymphoma activity is responsible for long‐term disease control.