Outcomes of Related Donor HLA-Identical or HLA-Haploidentical Allogeneic Blood or Marrow Transplantation for Peripheral T Cell Lymphoma
BACKGROUND: The role of allogeneic blood or marrow transplantation (alloBMT) for peripheral T-cell lymphoma (PTCL) remains to be defined. There is growing interest in reduced-intensity conditioning (RIC) regimens and/or utilization of HLA-haploidentical (haplo) grafts given concerns about treatment-associated toxicities and donor availability. METHODS: We reviewed the outcomes of 44 consecutive, related donor alloBMTs for PTCL performed at Johns Hopkins Hospital from 1994-2011, including 18 RIC/haplo alloBMTs. RESULTS: Patients receiving RIC (n=24) were older with median age of 59 years (range 24-70) than patients receiving myeloablative conditioning (MAC, n=20) with median age of 46 years (range 18-64), p=0.01. The median age at RIC/haplo alloBMT was 60 years. The estimated 2-year progression-free survival (PFS) was 40% (95% confidence interval (CI) 26-55%) and overall survival (OS) was 43% (95% CI 28-59%). In older patients (> 60, n=14), the estimated 2-year PFS and OS were 38% (CI 18-79%) and 45% (CI 24-86%). On unadjusted analysis, there was a tendency towards superior outcomes for alloBMT in first remission versus beyond first remission, with an estimated 2-year PFS of 53% (95% CI 33-77%) versus 29% (95% CI 9-45%), p=0.08. On competing risk analysis, the 1-year cumulative incidence of relapse was 38% for MAC/HLA-identical alloBMTs and 34% for RIC/haplo alloBMTs. Estimated 1-year non-relapse mortality was 10% for MAC and 8% for RIC (11% for RIC/haplo alloBMT). On unadjusted landmark analysis, patients with acute grade II-IV or chronic GVHD had a 17% probability of relapse (95% CI 0-39%), compared to 66% (95% CI 48-84%) in patients without GVHD, p=0.04. CONCLUSIONS: Utilization of RIC and alternative donors expands treatment options in PTCL to those who are older and unable to tolerate high-dose conditioning, with outcomes comparable to approaches using myeloablative regimens and HLA-matched donors. AlloBMT may be appropriate in first remission in select high-risk cases.