Allogeneic Blood or Marrow Transplantation with Post-Transplantation Cyclophosphamide for Peripheral T Cell Lymphoma: The Importance of Graft Source.

The use of post-transplantation cyclophosphamide (PTCy) for graft-versus host-disease (GVHD) prophylaxis has revolutionized allogeneic blood or marrow transplantation (alloBMT), but there is limited published experience in peripheral T cell lymphoma (PTCL). We sought to assess outcomes in patients with PTCL who underwent alloBMT with PTCy. We reviewed the charts of all adult patients age ≥18 years who underwent alloBMT with nonmyeloablative conditioning and PTCy-based GVHD prophylaxis at the Sidney Kimmel Comprehensive Cancer Center between January 2004 and December 2020. Sixty-five patients were identified. The median age was 59 years (range, 24 to 75 years). Lymphoma histology included PTCL not otherwise specified (n = 24), anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (n = 14), angioimmunoblastic T cell lymphoma (n = 7), enteropathy-associated T cell lymphoma (n = 6), hepatosplenic T cell lymphoma (n = 4), and others (n = 10). Eleven patients were in first complete remission (17%); the remaining patients were in first partial remission or underwent salvage therapy to at least PR prior to transplantation. Forty-eight patients underwent alloBMT from a haploidentical related donor (74%), 10 from a fully matched donor (15%), and 7 from a mismatched unrelated donor (11%). All patients received fludarabine, cyclophosphamide, and total body irradiation (TBI). The graft source was bone marrow (BM) in 46 patients (71%) and peripheral blood (PB) in 19 patients (29%); all patients in the BM cohort received 200 cGy TBI, and most patients in the PB cohort (15 of 19) received 400 cGy TBI. GVHD prophylaxis comprised PTCy, mycophenolate mofetil, and a calcineurin inhibitor or sirolimus. With a median follow-up of 2.8 years (range, 290 days to 14.2 years), the 2-year progression-free survival (PFS) for the entire cohort was 49% (95% confidence interval [CI], 38% to 64%), and the 2-year overall survival (OS) was 55% (95% CI, 44% to 69%). Outcomes were significantly improved in those receiving PB compared to those receiving BM, including a 2-year PFS of 79% (95% CI 63% to 100%) versus 39% (95% CI, 27% to 56%), 2-year OS of 84% (95% CI, 69% to 100%) versus 46% (95% CI, 33% to 63%), and 1-year cumulative incidence of relapse of 5% (95% CI, 0 to 16%) versus 33% (95% CI, 19% to 46%), with no difference in GVHD and nonrelapse mortality. AlloBMT with PTCy is safe and well-tolerated in patients with PTCL. Our data suggest that increasing the TBI dose to 400 cGy and using PB allografts may offer improved disease control and better survival outcomes, though additional studies are needed to confirm these findings.

Allogeneic Haploidentical Blood or Marrow Transplantation with Post-Transplantation Cyclophosphamide in Chronic Lymphocytic Leukemia.

Allogeneic blood or marrow transplantation (allo-BMT) remains the only treatment for chronic lymphocytic leukemia (CLL) with curative potential. Although post-transplantation cyclophosphamide (PTCy) reduces allo-BMT toxicity by decreasing the risk of graft-versus-host disease (GVHD), its effect on CLL allo-BMT outcomes is unknown. We studied 64 consecutive patients with CLL who underwent nonmyeloablative (NMA) haploidentical allo-BMT at Johns Hopkins Sidney Kimmel Comprehensive Cancer Center. In this cohort, the 4-year overall survival was 52% (95% confidence interval [CI], 40% to 68%), and progression-free survival was 37% (95% CI, 26% to 54%). Six patients experienced engraftment failure. PTCy prophylaxis was associated with a modest cumulative incidence of 1-year grade II-IV acute GVHD (27%; %95% CI, 15% to 38%) and %%%2-year chronic GVHD (17%; 95% CI, 7% to 26%). We demonstrate that NMA haploidentical allo-BMT with PTCy is a safe and effective treatment option.

Post-Transplantation Cyclophosphamide and Ixazomib Combination Rescues Mice Subjected to Experimental Graft-versus-Host Disease and Is Superior to Either Agent Alone.

Lapses in the prevention of graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT) warrant novel approaches. Such approaches include, among others, the use of post-transplantation cyclophosphamide (PTC) and proteasome inhibitors. Although PTC alone consistently produces low rates of chronic GVHD, the incidence of acute GVHD remains significant. Inversely, prolonged post-transplantation administration of proteasome inhibitors carries a risk of paradoxical aggravation of GVHD. We examined whether the combination of cyclophosphamide and ixazomib addresses the limitations of each of these agents when used alone to prevent GVHD in mice subjected to allogeneic HSCT across MHC barriers. We chose ixazomib, an orally bioavailable proteasome inhibitor, because of its favorable physiochemical characteristics. The combination of cyclophosphamide and ixazomib improved overall survival of mice in comparison to an untreated control group and to groups receiving either cyclophosphamide alone or ixazomib alone. Furthermore, cyclophosphamide prevented the surge of IL-1ß, GVHD aggravation, and sudden death associated with prolonged administration of ixazomib after HSCT. Finally, we demonstrated that although ixazomib was administered before cyclophosphamide, it did not impair the preferential depletion of proliferating as opposed to resting donor T cells. Our data suggest that the combination of cyclophosphamide and ixazomib for the prevention of GVHD after allogeneic HSCT is promising and merits further investigation in clinical trials.

Results of a 2-arm, phase 2 clinical trial using post-transplantation cyclophosphamide for the prevention of graft-versus-host disease in haploidentical donor and mismatched unrelated donor hematopoietic stem cell transplantation.

BACKGROUND: High-dose, post-transplantation cyclophosphamide (PTCy) to prevent graft-versus-host disease (GVHD) has improved outcomes in haploidentical (HAPLO) stem cell transplantation (SCT). However, it remains unclear whether this strategy is effective in SCT from 1-antigen human leukocyte antigen (HLA)-mismatched unrelated donors (9/10 MUD) and how the outcomes of these patients compare with those of haploidentical transplantation recipients. METHODS: A parallel, 2-arm, nonrandomized phase 2 clinical trial was conducted of melphalan-based reduced-intensity conditioning with PTCy, tacrolimus, and mycophenolate mofetil to prevent GVHD in patients with high-risk hematologic malignancies who underwent HAPLO (n = 60) or 9/10 MUD (n = 46) SCT. RESULTS: The 1-year overall and progression-free survival rates were 70% and 60%, respectively, in the HAPLO arm and 60% and 47%, respectively, in the 9/10 MUD arm. The day +100 cumulative incidence of grade II to IV acute GVHD and grade III to IV acute GVHD was 28% and 3%, respectively, in the HAPLO arm and 33% and 13%, respectively, in the 9/10 MUD arm. The 2-year cumulative incidence of chronic GVHD was 24% in the HAPLO arm and 19% in the 9/10 MUD arm. The 1-year cumulative incidence of nonrelapse mortality was 21% in the HAPLO arm and 31% in the 9/10 MUD arm, and the 1-year relapse rate was 19% in the HAPLO arm and 25% in the 9/10 MUD arm. CONCLUSIONS: Although this was a nonrandomized study and could not serve as a direct comparison between the 2 groups, the authors conclude that PTCy-based GVHD prophylaxis is effective for both HAPLO and 9/10 MUD SCTs. Prospective randomized trials will be required to compare the efficacies of alternative donor options for patients lacking HLA-matched donors. Cancer 2016;122:3316-3326. © 2016 American Cancer Society.