A randomized trial designed to compare autologous to allogeneic stem cell transplantation as first-line therapy in younger patients with peripheral T-cell lymphoma was discontinued early because nearly 40% of the patients had early disease progression and did not undergo transplantation.
Peripheral T-cell lymphoma generally yields a poor prognosis when treated with conventional chemotherapy, but autologous or allogeneic stem cell transplants were thought to be an option for patients with relapsing or refractory disease. Based on this hypothesis, the AATT ( Autologous or Allogeneic Transplantation in T-Cell Lymphoma ) study explored stem cell transplant as a first-line therapy, enrolling 104 patients aged 18-60 between 2011 and 2014.
All patients received four courses of chemotherapy with CHOEP-14 (cyclophosphamide, adriamycin, vincristine, etoposide, and prednisone).
Those in the autologous stem cell group and those without a suitable donor proceeded to one course of DHAP (high-dose ara-C, cis-platinum, and dexamethasone) and stem cell collection. Patients randomized to autologous transplantation received high dose therapy (BCNU, etoposide, cytarabine, melphalan: BEAM) followed 4-6 weeks later by transplantation of autologous stem cells.
Patients randomized to allogeneic transplantation received high dose therapy (fludarabine, busulfan, cyclophosphamide: FBC) followed by transplantation of allogeneic stem cells. GvHD prophylaxis included antithymocyte globuline (ATG), cyclosporine A, and mycophenolate mofetil.
Among the 58 patients eligible for the interim analysis, the mean age was 50 and 64% were male. Thirteen of the 28 patients randomized for allogeneic transplants underwent transplants; the others were not allografted because of progressive disease or lack of a donor. Of the 30 patients randomized to autologous SCT, 19 had the procedure; 11 did not receive transplants because of progressive disease or infection, Dr. Norbert Schmitz of Asklepios Klinik St. Georg, Hamburg, Germany, reported at the International Congress on Malignant Lymphoma in Lugano, Switzerland.
The primary outcome, 1-year event-free survival (EFS), was 41% in the intent-to-treat population (95% CI, 27%–54%).
Causes of death included lymphoma (seven autologous, five allogeneic), salvage therapy (two), early or late infections (four), and graft vs. host disease (two).
Survival rates did not significantly differ in the two stem cell transplant groups, but the findings lend themselves to limited interpretation as more than 30% of patients did not receive the procedure. Based on the low probability of meeting the primary outcome, the data safety monitoring board decided to stop patient accrual and discontinue the trial.