Allogeneic Stem Cell Transplantation for T-Cell Lymphomas in the Modern Era: A Single Center Experience

Introduction T-cell lymphomas are heterogenous group of neoplasms associated with generally unfavorable outcomes. High dose chemotherapy and autologous stem cell transplant (SCT) consolidation is a standard approach in first remission while allogeneic SCT (alloSCT) is recommended in the relapsed/refractory setting. Data on outcomes after alloSCT are limited, particularly in the era of brentuximab. Methods We retrospectively analyzed data from patients (pts) with T-cell lymphomas who underwent alloSCT in our institution from 11/2010–6/2018. Patient and disease characteristics were summarized using median and range for continuous data, and frequency and percentage for categorical data. Kaplan-Meier analysis was used to estimate progression free survival (PFS) and overall survival (OS) from the day of receipt of transplant. Survival probabilities were expressed by 95% confidence limits (CI). Results Thirty-three pts received alloSCT. Median age at transplant was 57 years (range [R], 22-73). T-cell lymphoma types included: cutaneous T-cell lymphoma, n = 12; NK-T cell, n = 4; peripheral T-cell lymphoma subtypes, n = 9; angioimmunoblastic T lymphoma, n = 6; T-cell rich B-cell, n = 2. Median lines of therapy prior to alloSCT were 4 (R, 2-13), including six with prior autologous SCT. Sixteen pts were transplanted in CR1, five in CR2, and three in CR3. Pentostatin/TBI was the most common pretransplant conditioning regimen (n = 23) followed by haplo regimen of Flu/TBI/Cy (n = 4). Donor transplant sources were MRD (16), MUD (8); Haplo (4), MMUD (5). Median days to neutrophil and platelet engraftment were 12 (R, 10-19) and 13 (R, 10-30), respectively. Cumulative incidence of grade II-IV acute and chronic GVHD were 24.2% and 45.4%, respectively. One-year PFS and OS probabilities were 69.5% (95% CI, 54.7- 88.4) and 87.1% (95% CI, 54.7-88.4), respectively. With a median follow up of 53 months (R, 2-97), 25 (75%) are alive and 24 are disease free. Four died from transplant related mortality (TRM) and 3 from relapse. The median time to relapse was 3.9 months [R, 2.2-12.5]). The cumulative incidence of GVHD was higher among patients who were relapse-free (71% vs 22% in relapsed pts, p=0.02). Seven of the 9 who relapsed were treated with brentuximab vedotin; of these 4 responded, including two patients who had haplo transplants. Conclusions Results from our study suggest that alloSCT in T-cell lymphomas with reduced intensity regimens are associated with overall favorable outcomes. Treatment of post-transplant relapse with brentuximab is feasible and should be explored further in long-term prospective studies.