Clinical Practice Recommendations for Hematopoietic Cell Transplantation and Cellular Therapies in Follicular Lymphoma: A Collaborative Effort on behalf of The American Society of Transplantation and Cellular Therapy and the European Society of Blood and Marrow Transplantation.

Follicular lymphoma (FL) is the most common indolent B-cell non-Hodgkin lymphoma (NHL), accounting for nearly one-third of all NHL. The therapeutic landscape for patients with FL has significantly expanded over the past decade, but the disease continues to be considered incurable. Hematopoietic cell transplantation (HCT) is potentially curative in some cases. Recently, the emergence of chimeric antigen receptor T-cell therapy (CAR-T) for patients with relapsed/refractory (R/R) FL has yielded impressive response rates and long-term remissions, but definitive statement on the curative potential of CAR-T is currently not possible due to limited patient numbers and relatively short follow up. A consensus on the contemporary role, optimal timing, and sequencing of HCT (autologous or allogeneic) and cellular therapies in FL is needed. As a result, the American Society of Transplantation and Cellular Therapy (ASTCT) Committee on Practice Guidelines endorsed this effort to formulate consensus recommendations to address this unmet need. The RAND-modified Delphi method was used to generate 15 consensus statements/recommendations. Of note, the use of bispecific antibodies in R/R FL was not in the scope of this project. Key statements/recommendations are as follows: 1) Autologous HCT is recommended as an option for consolidation therapy in patients with progression of untransformed disease within 24 months of front line chemoimmunotherapy and upon achieving a complete (CR) or partial response (PR) to salvage second line therapies; 2) CAR-T is considered as a treatment option for patients who did not achieve CR or PR after second or subsequent lines of therapies; 3) Allogeneic HCT is considered as consolidative treatment in relapsed FL patients with chemosensitive disease who have received 3 or more lines of systemic therapy and are the following clinical scenarios: post CAR-T failure; lack of access to CAR-T or have therapy related myeloid neoplasm. These clinical practice recommendations will help guide clinicians managing patients with FL.

Reduced-Intensity Transplantation for Lymphomas Using Haploidentical Related Donors Versus HLA-Matched Sibling Donors: A Center for International Blood and Marrow Transplant Research Analysis.

PURPOSE: Related donor haploidentical hematopoietic cell transplantation (Haplo-HCT) using post-transplantation cyclophosphamide (PT-Cy) is increasingly used in patients lacking HLA-matched sibling donors (MSD). We compared outcomes after Haplo-HCT using PT-Cy with MSD-HCT in patients with lymphoma, using the Center for International Blood and Marrow Transplant Research registry. MATERIALS AND METHODS: We evaluated 987 adult patients undergoing either Haplo-HCT (n = 180) or MSD-HCT (n = 807) following reduced-intensity conditioning regimens. The haploidentical group received graft-versus-host disease (GVHD) prophylaxis with PT-Cy with or without a calcineurin inhibitor and mycophenolate. The MSD group received calcineurin inhibitor-based GVHD prophylaxis. RESULTS: Median follow-up of survivors was 3 years. The 28-day neutrophil recovery was similar in the two groups (95% v 97%; P = .31). The 28-day platelet recovery was delayed in the haploidentical group compared with the MSD group (63% v 91%; P = .001). Cumulative incidence of grade II to IV acute GVHD at day 100 was similar between the two groups (27% v 25%; P = .84). Cumulative incidence of chronic GVHD at 1 year was significantly lower after Haplo-HCT (12% v 45%; P < .001), and this benefit was confirmed on multivariate analysis (relative risk, 0.21; 95% CI, 0.14 to 0.31; P < .001). For Haplo-HCT v MSD-HCT, 3-year rates of nonrelapse mortality (15% v 13%; P = .41), relapse/progression (37% v 40%; P = .51), progression-free survival (48% v 48%; P = .96), and overall survival (61% v 62%; P = .82) were similar. Multivariate analysis showed no significant difference between Haplo-HCT and MSD-HCT in terms of nonrelapse mortality (P = .06), progression/relapse (P = .10), progression-free survival (P = .83), and overall survival (P = .34). CONCLUSION: Haplo-HCT with PT-Cy provides survival outcomes comparable to MSD-HCT, with a significantly lower risk of chronic GVHD.

Reduced-Intensity Allografting as First Transplantation Approach in Relapsed/Refractory Grades One and Two Follicular Lymphoma Provides Improved Outcomes in Long-Term Survivors.

This study was conducted to compare long-term outcomes in patients with refractory/relapsed grades 1 and 2 follicular lymphoma (FL) after allogeneic (allo) versus autologous (auto) hematopoietic cell transplantation (HCT) in the rituximab era. Adult patients with relapsed/refractory grades 1 and 2 FL undergoing first reduced-intensity allo-HCT or first autograft during 2000 to 2012 were evaluated. A total of 518 rituximab-treated patients were included. Allo-HCT patients were younger and more heavily pretreated, and more patients had advanced stage and chemoresistant disease. The 5-year adjusted probabilities, comparing auto-HCT versus allo-HCT groups for nonrelapse mortality (NRM) were 5% versus 26% (P < .0001); relapse/progression: 54% versus 20% (P < .0001); progression-free survival (PFS): 41% versus 58% (P < .001), and overall survival (OS): 74% versus 66% (P = .05). Auto-HCT was associated with a higher risk of relapse/progression beyond 5 months after HCT (relative risk [RR], 4.4; P < .0001) and worse PFS (RR, 2.9; P < .0001) beyond 11 months after HCT. In the first 24 months after HCT, auto-HCT was associated with improved OS (RR, .41; P < .0001), but beyond 24 months, it was associated with inferior OS (RR, 2.2; P = .006). A landmark analysis of patients alive and progression-free at 2 years after HCT confirmed these observations, showing no difference in further NRM between both groups, but there was significantly higher risk of relapse/progression (RR, 7.3; P < .0001) and inferior PFS (RR, 3.2; P < .0001) and OS (RR, 2.1; P = .04) after auto-HCT. The 10-year cumulative incidences of second hematological malignancies after allo-HCT and auto-HCT were 0% and 7%, respectively. Auto-HCT and reduced-intensity-conditioned allo-HCT as first transplantation approach can provide durable disease control in grades 1 and 2 FL patients. Continued disease relapse risk after auto-HCT translates into improved PFS and OS after allo-HCT in long-term survivors.

Impact of Pretransplantation (18)F-fluorodeoxy Glucose-Positron Emission Tomography Status on Outcomes after Allogeneic Hematopoietic Cell Transplantation for Non-Hodgkin Lymphoma.

Assessment with (18)F-fluorodeoxy glucose (FDG)-positron emission tomography (PET) before hematopoietic cell transplantation (HCT) for lymphoma may be prognostic for outcomes. Patients with chemotherapy-sensitive non-Hodgkin lymphoma (NHL) undergoing allogeneic HCT reported to the Center of International Blood and Marrow Transplantation Registry between 2007 and 2012 were included. Pre-HCT PET status (positive versus negative) was determined by the reporting transplantation centers. We analyzed 336 patients; median age was 55 years and 60% were males. Follicular lymphoma (n = 104) was more common than large cell (n = 85), mantle cell (n = 69), and mature natural killer or T cell lymphoma (n = 78); two thirds of the cohort received reduced-intensity conditioning; one half had unrelated donor grafts. Patients underwent PET scanning a median of 1 month (range, .07 to 2.83 months) before HCT; 159 were PET positive and 177 were PET negative. At 3 years, relapse/progression, progression-free survival (PFS), and overall survival (OS) in PET-positive versus PET-negative groups were 40% versus 26%; P = .007; 43% versus 47%; P = .47; and 58% versus 60%; P = .73, respectively. On multivariate analysis, a positive pretransplantation PET was associated with an increased risk of relapse/progression (risk ratio [RR], 1.86; P = .001) but was not associated with increased mortality (RR, 1.29, 95% confidence interval [CI], .96 to 1.7; P = .08), therapy failure (RR, 1.32; 95% CI, .95 to 1.84; P = .10), or nonrelapse mortality (RR, .75; 95% CI, .48 to 1.18; P = .22). PET status conferred no influence on graft-versus-host disease. A positive PET scan before HCT is associated with increased relapse risk but should not be interpreted as a barrier to a successful allograft. PET status does not appear to predict survival after allogeneic HCT for NHL.