Clinical Practice Recommendations for Hematopoietic Cell Transplantation and Cellular Therapies in Follicular Lymphoma: A Collaborative Effort on Behalf of the American Society for Transplantation and Cellular Therapy and the European Society for 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. These clinical practice recommendations will help guide clinicians managing patients with FL. Of note, the use of bispecific antibodies in R/R FL was not in the scope of this project.

Autologous transplant vs. CAR-T therapy in patients with DLBCL treated while in complete remission.

In patients with relapsed DLBCL in complete remission (CR), autologous hematopoietic cell transplantation (auto-HCT) and CAR-T therapy are both effective, but it is unknown which modality provides superior outcomes. We compared the efficacy of auto-HCT vs. CAR-T in patients with DLBCL in a CR. A retrospective observational study comparing auto-HCT (2015-2021) vs. CAR-T (2018-2021) using the Center for International Blood & Marrow Transplant Research registry. Median follow-up was 49.7 months for the auto-HCT and 24.7 months for the CAR-T cohort. Patients ages 18 and 75 with a diagnosis of DLBCL were included if they received auto-HCT (n = 281) or commercial CAR-T (n = 79) while in a CR. Patients undergoing auto-HCT with only one prior therapy line and CAR-T patients with a previous history of auto-HCT treatment were excluded. Endpoints included Progression-free survival (PFS), relapse rate, non-relapse mortality (NRM) and overall survival (OS). In univariate analysis, treatment with auto-HCT was associated with a higher rate of 2-year PFS (66.2% vs. 47.8%; p < 0.001), a lower 2-year cumulative incidence of relapse (27.8% vs. 48% ; p < 0.001), and a superior 2-year OS (78.9% vs. 65.6%; p = 0.037). In patients with early (within 12 months) treatment failure, auto-HCT was associated with a superior 2-year PFS (70.9% vs. 48.3% ; p < 0.001), lower 2-year cumulative incidence of relapse (22.8% vs. 45.9% ; p < 0.001) and trend for higher 2-year OS (82.4% vs. 66.1% ; p = 0.076). In the multivariable analysis, treatment with auto-HCT was associated with a superior PFS (hazard ratio 1.83; p = 0.0011) and lower incidence of relapse (hazard ratio 2.18; p < 0.0001) compared to CAR-T. In patients with relapsed LBCL who achieve a CR, treatment with auto-HCT is associated with improved clinical outcomes compared to CAR-T. These data support the consideration of auto-HCT in select patients with LBCL achieving a CR in the relapsed setting.

Outcomes of r/r B-cell NHL patients with limited (<5 Sites) pre-CART Disease Bridged With or Without Radiotherapy.

Unirradiated relapsed/refractory (r/r) B-cell non-Hodgkin lymphoma (NHL) patients who undergo anti-CD19 Chimeric Antigen Receptor T-cell Therapy (CART) have a predominant localized pattern of relapse, the significance of which is heightened in individuals with limited/localized pre-CART disease. This study reports on the outcomes of r/r NHL patients with limited (<5 involved sites) disease bridged with or without radiotherapy (BRT). A multi-center retrospective review of 150 patients with r/r NHL who received CART with <5 disease sites prior to leukapheresis was performed. Bridging treatment, if any, was administered between leukapheresis and CART infusion. Study endpoints included relapse free-survival (RFS), event-free survival (EFS) and overall survival (OS). Prior to CART infusion, 48 (32%) patients received BRT and 102 (68%) did not. The median follow-up was 21 months. Following CART infusion, BRT patients had higher objective response (92% vs 78%, p=0.046) and sustained complete response (54% vs 33%, p=0.015) rates. Local relapse in sites present prior to CART was lower in the BRT group (21% vs. 46%, p=0.003). BRT patients had improved 2-year RFS (53% vs 44%, p=0.023) and 2-year EFS (37% vs 34%, p=0.039) compared to no BRT patients. The impact of BRT was most prominent in patients who had ≤2 pre-CART involved disease sites, with 2-year RFS of 62% in patients who received BRT compared to 42% in those who did not (p=0.002). BRT prior to CART for patients with limited (<5 involved disease sites) r/r NHL improves response rate, local control, RFS, and EFS without causing significant toxicities.

Assessing the efficacy of allogeneic hematopoietic cell transplantation in VEXAS syndrome: results of a systematic review and meta-analysis.

VEXAS syndrome is an X-linked monogenic disease with adult-onset inflammatory disease and myeloid dysplasia, with clinical presentation ensuing in the fifth decade of life or later. Inflammatory symptoms associated with VEXAS syndrome are treated with several lines of therapy, eventually requiring allogeneic hematopoietic cell transplantation (allo-HCT). No evidence from randomized controlled trials exists on allo-HCT versus other treatments in patients not responding to front-line therapy(ies). We show results of a systematic review/meta-analysis (SR/MA) following a search using EMBASE, PUBMED/MEDLINE and Web of Science on April 5, 2024. We extracted outcomes based on benefits (overall response rate (ORR), complete remission (CR), event-free survival (EFS) and overall survival (OS), and harms (non-relapse mortality (NRM) and acute and chronic graft-versus-host disease (GVHD)). The search identified 88 studies. Four studies (39 patients) met inclusion criteria. Median follow-up time after allo-HCT ranged from 8 to 18.5 months. Pooled EFS and OS rates were 56% and 86%, respectively. Pertaining to harms, pooled NRM rate was 14%. Pooled rates of acute and chronic GVHD were 42% and 13%, respectively. Allo-HCT is an effective treatment for VEXAS syndrome. We hope these results would increase awareness about this underdiagnosed and underreported disease.

Autologous Stem Cell Transplant in Fit Patients With Late Relapsed Diffuse Large B-Cell Lymphoma That Responded to Salvage Chemotherapy.

The standard of care (SOC) for fit patients with relapsed diffuse large B-cell lymphoma (DLBCL) ≥12 months after completing frontline therapy is salvage chemotherapy (ST) followed by autologous stem cell transplant (ASCT). However, this strategy may not be optimal for patients with certain clinical characteristics. We retrospectively studied 151 patients with DLBCL that relapsed ≥12 months after R-CHOP or R-CHOP-like frontline therapy who underwent ST and ASCT at Mayo Clinic between July 2000 and December 2017 or the University of Iowa between April 2003 and April 2020. Clinical characteristics, treatment information, and outcome data were abstracted. Progression-free survival (PFS) and overall survival (OS) from the time of ASCT were analyzed using the Kaplan-Meier method. The median time from frontline therapy completion to 1st relapse was 26.9 months. The median line of ST was 1 (range 1-3), and 17 (11%) patients required >1 line of ST. Best response before ASCT was partial response (PR) in 60 (40%) and complete response (CR) in 91 (60%) patients. The median age at ASCT was 64 yr (range 19-78), and 36 (24%) patients were of ≥70 yr. The median follow-up after ASCT was 87.3 months. The median PFS and OS were 54.5 and 88.9 months, respectively. There was no significant difference in PFS and OS based on the age at ASCT (including patients aged ≥70-78 yr), sex, transplant era, time to relapse, LDH, extranodal site involvement, and central nervous system/nerve involvement at relapse. However, patients with advanced-stage relapse had inferior PFS than those with early-stage relapse (median 45.3 versus 124.7 months, P = .045). Patients who required > 1 line of ST, compared to those requiring 1 line, had significantly inferior PFS (median 6.1 versus 61.4 months, P < .0001) and OS (17.8 versus 111.7 months, P = .0004). There was no statistically significant difference in survival in patients who achieved PR versus CR, though numerically inferior in the former, with median PFS of 38.9 versus 59.3 months (P = .23) and median OS of 78.3 versus 111.7 months (P = .62). Patients achieving CR after 1 line of ST had excellent post-ASCT outcomes, with median PFS of 63.7 months. In conclusion, survival after ASCT was unfavorable in patients with late relapsed DLBCL (≥12 months) who required more than 1 line of ST to achieve PR or CR, and such patients should be treated with alternative therapies. Conversely, survival was favorable in patients who required only 1 line of ST, supporting the current clinical practice of ASCT consolidation in these patients. Moreover, outcomes were favorable in patients aged ≥70 to 78 yr at ASCT, similar to younger patients, highlighting the safety and feasibility of this approach in such patients.

Donor Types and Outcomes of Transplantation in Myelofibrosis: A CIBMTR Study.

We aim to evaluate impact of donor types on outcomes of hematopoietic cell transplantation (HCT) in myelofibrosis, using CIBMTR registry data for HCTs done between 2013 and 2019. In all 1597 undergoing HCT for myelofibrosis, the use of haploidentical donors increased from 3% in 2013 to 19% in 2019. In study eligible, 1032 patients who received peripheral blood grafts for chronic phase myelofibrosis, 38% recipients of haploidentical-HCT were of non-White/Caucasian ethnicity. Matched sibling donor (MSD)-HCTs were independently associated with superior overall survival (OS) in the first 3 months [reference MSD, haploidentical HR 5.80 (95% CI 2.52-13.35), matched unrelated HR 4.50 (95% CI 2.24-9.03), and mismatched unrelated HR 5.13 (95% CI 1.44-18.31), P<0.001]. This difference in OS aligns with lower graft failure with MSD [haploidentical HR 6.11 (95%CI 2.98-12.54), matched unrelated HR 2.33 (95%CI 1.20-4.51), mismatched unrelated HR 1.82 (95%CI 0.58-5.72). There was no significant difference in OS among haploidentical, matched unrelated, and mismatched unrelated donor HCTs in the first 3 months. Donor type was not associated with differences in OS beyond 3 months post-HCT, relapse, disease-free survival or OS among patients who underwent HCT within 24 months of diagnosis. Patients who experienced graft failure had more advanced disease and commonly used nonmyeloablative conditioning. While MSDs remain a superior donor option due to improved engraftment, there is no significant difference in HCT outcomes from haploidentical and matched unrelated donors. These results establish haploidentical-HCT with posttransplantation cyclophosphamide as a viable option in myelofibrosis, especially for ethnic minorities underrepresented in the donor registries.

Comprehensive Bridging Radiotherapy for Limited Pre-CART Non-Hodgkin Lymphoma.

This cohort study examines the role of comprehensive bridging radiotherapy in the setting of chimeric antigen receptor T-cell therapy for non-Hodgkin lymphoma.

Autologous Hematopoietic Cell Transplantation Consolidation for First Response is Associated With Longer Survival Among Patients With Nodal Peripheral T Cell Lymphoma.

Nodal peripheral T cell lymphomas (PTCLs) are challenging subsets of non-Hodgkin lymphomas characterized by their heterogeneity and aggressive clinical behavior. Given the mixed outcomes reported in previous studies, the efficacy of autologous hematopoietic cell transplantation (auto-HCT) as a consolidation strategy following initial chemotherapy response remains uncertain. This study aims to evaluate the impact of upfront auto-HCT consolidation on overall survival (OS) and event-free survival (EFS) among patients with nodal PTCL who achieved a complete or partial response to initial chemotherapy. A retrospective cohort study was conducted at Moffitt Cancer Center, involving 123 patients with nodal PTCL treated between February 2005 and February 2021. Patients were stratified into 2 groups based on whether they received auto-HCT as part of their initial treatment strategy. Kaplan-Meier method and Cox proportional hazard models were used for statistical analysis to compare OS and EFS between groups. Patients undergoing auto-HCT after first response demonstrated significantly longer median OS (12.3 versus 4.3 yr; P = .035) and EFS (6.2 versus 2.2 yr; P = .003) compared to those who did not. Multivariate analyses indicated that auto-HCT at first response and younger age at diagnosis were favorable prognostic factors. The findings suggest that upfront auto-HCT consolidation can significantly improve long-term outcomes in patients with nodal PTCL, supporting the strategy of early auto-HCT consideration and referral following initial chemotherapy response. These results underscore the importance of integrating upfront auto-HCT into the treatment paradigm for nodal PTCL, emphasizing early referral to transplantation services to optimize patient outcomes.

Real-world and clinical trial outcomes in large B-cell lymphoma with axicabtagene ciloleucel across race and ethnicity.

ABSTRACT: Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory (R/R) large B-cell lymphoma (LBCL). Despite extensive data supporting its use, outcomes stratified by race and ethnicity groups are limited. Here, we report clinical outcomes with axi-cel in patients with R/R LBCL by race and ethnicity in both real-world and clinical trial settings. In the real-world setting, 1290 patients who received axi-cel between 2017 and 2020 were identified from the Center for International Blood and Marrow Transplant Research database; 106 and 169 patients were included from the ZUMA-1 and ZUMA-7 trials, respectively. Overall survival was consistent across race/ethnicity groups. However, non-Hispanic (NH) Black patients had lower overall response rate (OR, 0.37; 95% CI, 0.22-0.63) and lower complete response rate (OR, 0.57; 95% CI, 0.33-0.97) than NH White patients. NH Black patients also had a shorter progression-free survival vs NH White (HR, 1.41; 95% CI, 1.04-1.90) and NH Asian patients (HR, 1.67; 95% CI, 1.08-2.59). NH Asian patients had a longer duration of response than NH White (HR, 0.56; 95% CI, 0.33-0.94) and Hispanic patients (HR, 0.54; 95% CI, 0.30-0.97). There was no difference in cytokine release syndrome by race/ethnicity; however, higher rates of any-grade immune effector cell-associated neurotoxicity syndrome were observed in NH White patients than in other patients. These results provide important context when treating patients with R/R LBCL with CAR T-cell therapy across different racial and ethnic groups. ZUMA-1 and ZUMA-7 (ClinicalTrials.gov identifiers: #NCT02348216 and #NCT03391466, respectively) are registered on ClinicalTrials.gov.

A comprehensive review of the role of bone marrow biopsy and PET-CT in the evaluation of bone marrow involvement in adults newly diagnosed with DLBCL.

Diffuse large B cell lymphoma (DLBCL) is one of the most prevalent subtypes of non-Hodgkin lymphoma (NHL) and is known for commonly infiltrating extra-nodal sites. The involvement of the bone marrow by lymphoma cells significantly impacts the staging, treatment, and prognosis among the extra-nodal sites in DLBCL. Bone marrow biopsy has been considered the standard diagnostic procedure for detecting bone marrow involvement. However, advancements in imaging techniques, such as positron emission tomography-computed tomography (PET-CT), have shown an improved ability to detect bone marrow involvement, making the need for bone marrow biopsy debatable. This review aims to emphasize the importance of bone marrow evaluation in adult patients newly diagnosed with DLBCL and suggest an optimal diagnostic approach to identify bone marrow involvement in these patients.

ASTCT Committee on Practice Guidelines Survey on Evaluation and Management of Relapsed/Refractory Multiple Myeloma after Failure of Chimeric Antigen Receptor T Cell Therapy.

Chimeric antigen receptor T cell therapy (CAR-T) has revolutionized the management of relapsed and/or refractory multiple myeloma (RRMM). However, CAR-T treatment failure is not uncommon and remains a major therapeutic challenge. There is substantial variability across transplantation and cellular therapy programs in assessing and managing post-CAR-T failures in patients with RRMM. The American Society for Transplantation and Cellular Therapy (ASTCT) Committee on Practice Guidelines conducted an online cross-sectional survey between September 2023 and December 2023 to determine myeloma, transplantation, and cellular therapy physicians' practice patterns for the surveillance, diagnosis, and management of CAR-T failure. The intent of this survey was to understand clinical practice patterns and identify areas for further investigation. Email surveys were sent to 1311 ASTCT physician members, of whom 80 (6.1%) completed the survey. The respondents were 58% white and 66% male, and 51% had >10 years of clinical experience. Most (89%) respondents were affiliated with a university/teaching center, and 56% had a myeloma-focused transplantation and/or cellular therapy practice. Post-CAR-T surveillance laboratory studies were commonly done every 4 weeks, and surveillance bone marrow biopsies and/or imaging surveillance were most commonly done at 3 months. Sixty-four percent of the respondents would often or always consider biopsy or imaging to confirm relapse. The most popular post-CAR-T failure rescue regimen was GPRC5D-directed immunotherapy (30%) for relapses occurring ≤3 months and BCMA-directed bispecific therapies (32.5%) for relapse at >3 months. Forty-one percent of the respondents endorsed post-CAR-T prolonged cytopenia as being "often" or "always" a barrier to next-line therapy; 53% had offered stem cell boost as a mitigation approach. Substantial across-center variation in practice patterns raises the need for collaborative studies and expert clinical recommendations to describe best practices for post-CAR-T disease surveillance, optimal workup for treatment failure, and choice of rescue therapies.

Assessment of chimerism by next generation sequencing: A comparison to STR/qPCR methods.

Chimerism analysis is used to evaluate patients after allogeneic hematopoietic stem cell transplant (allo-HSCT) for engraftment and minimal measurable residual disease (MRD) monitoring. A combination of short-tandem repeat (STR) and quantitative polymerase chain reaction (qPCR) was required to achieve both sensitivity and accuracy in the patients with various chimerism statuses. In this study, an insertion/deletion-based multiplex chimerism assay by next generation sequencing (NGS) was evaluated using 5 simulated unrelated donor-recipient combinations from 10 volunteers. Median number of informative markers detected was 8 (range = 5 - 11). The limit of quantitation (LoQ) was determined to be 0.1 % recipient. Assay sample number/batch was 10-20 and total assay time was 19-31 h (manual labor = 2.1 h). Additionally, 50 peripheral blood samples from 5 allo-HSCT recipients (related: N = 4; unrelated: N = 1) were tested by NGS and STR/qPCR. Median number of informative markers detected was 7 (range = 4 - 12). Results from both assays demonstrated a strong correlation (Y = 0.9875X + 0.333; R2 = 0.9852), no significant assay bias (difference mean - 0.08), and 100 % concordant detection of percent recipient increase ≥ 0.1 % (indicator of increased relapse risk). NGS-based chimerism assay can support all allo-HSCT for engraftment and MRD monitoring and simplify clinical laboratory workflow compared to STR/qPCR.

Efficacy of Autologous and Allogeneic Hematopoietic Cell Transplantation in Adults with Acute Promyelocytic Leukemia: Results of a Systematic Review and Meta-Analysis.

Despite therapeutic advances for acute promyelocytic leukemia (APL) with the emergence of all-trans retinoic acid, arsenic trioxide, and gemtuzumab-ozogamycin, approximately 10% of patients still experience disease relapse, typically occurring within 24 to 36 months following completion of front-line treatment. Traditionally, both allogeneic (allo) and autologous (auto) hematopoietic cell transplantation (HCT) have been considered reasonable treatment options for relapsed APL; however, no randomized controlled studies have been conducted comparing allo-HCT and auto-HCT in patients with relapsed APL. We performed a systematic review/meta-analysis to assess the totality of evidence pertaining to allo-HCT or auto-HCT in relapsed APL. Our search identified 1158 references, of which 23 met our inclusion criteria. While acknowledging the limitations of comparing these 2 treatment modalities indirectly, based on results from separate meta-analyses, it appears that pooled rates of event-free survival (71% versus 54%), progression-free survival (63% versus 43%), and overall survival (82% versus 58%) are higher after auto-HCT. This difference can be explained in part by the higher risk of pooled nonrelapse mortality (NRM) in patients undergoing allo-HCT (29% versus 5%), owing to inherent risks associated with this modality. In the absence of a randomized prospective clinical trial comparing allo-HCT and auto-HCT, our results show that both modalities are acceptable in patients with relapsed APL. The higher pooled NRM rate with allo-HCT is an important consideration when choosing this option. Additionally, the comparable pooled relapse rate for auto-HCT and allo-HCT (24% versus 23%) provides a rationale for evaluating post-HCT consolidative strategies to mitigate this risk.

Harmonizing definitions for hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism in allogeneic hematopoietic cell transplantation: a report on behalf of the EBMT, ASTCT, CIBMTR, and APBMT.

Despite emergence of novel therapies to treat hematologic malignancies, allogeneic hematopoietic cell transplantation (allo-HCT) remains an essential treatment modality capable of curing these diseases. Allo-HCT has been also shown to be curative in benign hematologic disorders such as aplastic anemia, sickle cell disease, and thalassemia, among others. Recently, the American Society for Transplantation and Cellular Therapy (ASTCT) published standardized definitions for hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism. To attempt broader international consensus, a panel of adult and pediatric physician transplant experts was assembled from European Society for Blood and Marrow Transplantation (EBMT), ASTCT, the Center for International Blood and Marrow Transplant Research (CIBMTR), and Asia-Pacific Blood and Marrow Transplantation (APBMT). Consensus was defined as ≥70% of voting members strongly agreeing or somewhat agreeing with a definition. With few exceptions, there was a consensus to endorse the prior ASTCT definitions. Importantly, we revised existing EBMT and CIBMTR data collection forms to align with these harmonized definitions that will facilitate research and international collaboration among transplant researchers and across transplant registries.