In a final analysis from the Autologous or Allogeneic Transplantation in T-Cell Lymphoma (AATT) trial, researchers found no differences in survival outcomes between consolidation with autologous or allogeneic hematopoietic cell transplantation (autoHCT; alloHCT) in patients with peripheral T cell lymphoma (PTCL). The study results were presented by Norbert Schmitz, MD, from University Hospital Münster, Germany, at the 2019 American Society of Clinical Oncology annual meeting.
“Firstline therapy of T cell lymphoma remains mostly disappointing,” Dr. Schmitz said during his presentation, noting that, while consolidative HCT after chemotherapy has shown promising results, there are no comparisons between transplant type. The AATT trial was designed to evaluate differences in survival benefit between autoHCT and alloHCT in patients with newly diagnosed PTCL.
A total of 103 patients (median age = 50 years; range = 24-60 years) were enrolled: 54 had received autoHCT and 49 had received alloHCT. Only patients who had previously achieved complete response, partial response, or stable disease following four courses of CHOEP (cyclophosphamide, doxorubicin, etoposide, vincristine, prednisone courses and one course of DHAP (cisplatin, cytosine arabinoside, dexamethasone) were included in the study population.
The most common diagnoses at time of enrollment were:
- PTCL (n=30)
- angioimmunoblastic T-cell lymphoma (n=37)
- anaplastic large cell lymphoma (ALK-negative; n=14)
Patients undergoing autoHCT received conditioning with BEAM (carmustine 300 mg/m2, etoposide 800 mg/m2, cytarabine 1,600 mg/m2, melphalan 140 mg/m2). Patients undergoing alloHCT with a matched-related or unrelated donor received myeloablative conditioning (fludarabine 125 mg/m2, busulfan 12 mg/kg, and cyclophosphamide 120 mg/kg).
Of the 103 participants scheduled for HCT, only two-thirds (n=67; 65%) completed the study through transplantation; the remaining 36 patients were off study before HCT (20 in the alloHCT group and 16 in the autoHCT group), mostly due to progressive disease.
During a median follow-up of 42 months (range not provided), there was no significant difference in three-year event-free survival (EFS) or three-year overall survival (OS) between the two transplant groups:
- three-year EFS: 43% for alloHCT and 38% for autoHCT (p=0.58)
- three-year OS: 57% for alloHCT and 70% for autoHCT (p=0.41)
In the cohort of 67 patients who proceeded to transplant, three-year EFS remained similar between the cohorts (65% for alloHCT and 61% for autoHCT; p=0.43).
While there were no relapses in the overall cohort, eight patients (16%) in the alloHCT cohort had transplant-related mortality (TRM). Conversely, there was no TRM in the autoHCT cohort (p value not provided). Other causes of death included lymphoma (24% with autoHCT and 22% with alloHCT) and secondary neoplasia (2% and 0%).
Given the lack of significant differences in survival outcomes between the transplant groups, Dr. Schmitz concluded that “we have to do something different if we want to change this disease.” However, he noted that each transplant type had a different clinical profile: AutoHCT is characterized by low toxicity, but more relapses; alloHCT is characterized by better tumor control, counterbalanced by higher incidence of transplant-related morbidity and mortality.
The findings of this study are limited by the large portion of patients who did not proceed to transplant.
The authors reported no relevant conflicts of interest.
Schmitz N, Truemper L, Ziepert M, et al. First-line therapy of T-cell lymphoma: Allogeneic or autologous transplantation for consolidation—final results of the AATT study. Abstract #7503. Presented at the 2019 American Society of Clinical Oncology Annual Meeting, June 4, 2019; Chicago, Illinois.