Comparison of Thiotepa-based Conditioning Regimens for Older Adults with Primary Diffuse Large B-cell Lymphoma of the Central Nervous System Undergoing Autologous Hematopoietic Cell Transplantation.

In this study, we compare outcomes of older patients with primary diffuse large B-cell lymphoma of the central nervous system (PCNSL) undergoing autologous hematopoietic cell transplantation (autoHCT) with either thiotepa/carmustine (BCNU/Thio) or thiotepa/busulfan/cyclophosphamide (TBC) conditioning. We used a postpublication dataset made available by the Center for International Blood and Marrow Transplantation Research including patients who were ≥65 years in age with PCNSL and underwent autoHCT as consolidation with TBC or BCNU/Thio conditioning. Out of 147 patients; n = 84 received BCNU/Thio and n = 63 received TBC. The 1-year NRM in the BCNU/Thio group was 10% versus 22% in the TBC group (P = .05) and the 2-year relapse rate was 5% versus 5%, respectively (P = 1.00). The 2-year progression-free survival (PFS) in the BCNU/Thio group was 85% versus 71% in the TBC group (P = .05) and 2-year overall survival (OS) was 86% versus 74% (P = .08). In a multivariable regression model, BCNU/Thio was associated with a lower risk for NRM (hazard ratio [HR], 0.33, P = .009), improved PFS (HR, 0.41, P = .008) and OS (HR, 0.37, P = .007), but there was no association with relapse risk. We found that in older adults with PCNSL undergoing consolidation with autoHCT, BCNU/Thio conditioning is associated with lower NRM and improved OS compared to TBC.

CD19-directed CART therapy for T-cell/histiocyte-rich large B-cell lymphoma.

ABSTRACT: T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is a rare histologic variant of LBCL. Limited data regarding CD19-directed chimeric antigen receptor T-cell (CART) therapy in relapsed/refractory (R/R) THRLBCL suggest poor efficacy. We investigated CART outcomes for R/R THRLBCL through the Center for International Blood and Marrow Transplant Research registry. A total of 58 adult patients with R/R THRLBCL who received commercial CD19-CART therapy between 2018 and 2022 were identified. Most patients (67%) had early relapse of disease (45% primary refractory) with a median of 3 (range, 1-7) prior therapies and were treated with axicabtagene ciloleucel (69%). At median follow-up of 23 months after CART therapy, 2-year overall and progression-free survival were 42% (95% confidence interval [CI], 27-57) and 29% (95% CI, 17-43), respectively. In univariable analysis, poor performance status before CART therapy was associated with higher mortality (hazard ratio, 2.35; 95%CI, 1.02-5.5). The 2-year cumulative incidences of relapse/progression and nonrelapse mortality were 69% and 2%, respectively. Grade ≥3 cytokine release syndrome and immune effector cell-associated neurologic syndrome occurred in 7% and 15% of patients, respectively. In this largest analysis of CD19-CART therapy for R/R THRLBCL, ∼30% of patients were alive and progression free 2 years after CART therapy. Despite a high incidence of progression (69% at 2 years), these results suggest a subset of patients with R/R THRLBCL may have durable responses with CARTs.

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.

Chimeric antigen receptor T-cell infusion for large B-cell lymphoma in complete remission: a center for international blood and marrow transplant research analysis.

CD19 CAR T-cell (CAR-T) therapy is commonly administered to patients with relapsed or refractory large B-cell lymphomas (LBCL), but salvage or bridging therapy can sometimes lead to a complete response (CR) prior to infusion. Limited studies have assessed the outcomes of patients infused in CR. A total of 134 patients with LBCL in CR prior to CAR-T infusion were identified from the CIBMTR registry, with median prior lines of therapy of 3 (range 2-9). At two years post-infusion, the probability of progression-free survival was 43.5% (95% CI 34.4-52.8) and the probability of overall survival was 63.8% (95% CI 54.4-72.6). The cumulative incidence rates of non-relapse mortality and relapse/progression at two years were 9.2% (95% CI 4.5-15.4) and 47.3% (95% CI 38.2-56.6), respectively. The rate of grade 3 or higher cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were 2.2% and 8.2%, respectively. In summary, CAR-T in heavily pretreated patients with LBCL who are in CR following two or more lines of prior therapy demonstrate that a subset of patients may remain free of progression at two years. Additionally, the toxicity profile was impressive with very low rates of grade 3 CRS and ICANS.

Impact of thiotepa dose-intensity in primary diffuse large B-cell lymphoma of the central nervous system undergoing autologous hematopoietic cell transplant with thiotepa/carmustine conditioning.

Thiotepa/carmustine (TT-BCNU) is a commonly used autologous transplant (ASCT) conditioning regimen for primary DLBCL of the CNS (PCNSL). The total thiotepa dose varies among TT-BCNU recipients, with some centers administering a total dose of 20 mg/kg, while others using 10 mg/kg. We retrospectively assessed the impact of thiotepa dose intensity on ASCT outcomes in 218 adult PCNSL patients who underwent a first ASCT with TT-BCNU conditioning and received either a total thiotepa dose of 10 mg/kg (TT-10 group; N = 90), or 20 mg/kg (TT-20 group; N = 128). The median follow-up of survivors was 22 months. The cumulative incidence of 1-year non-relapse mortality (NRM) for TT-10 and TT-20 cohorts were 6% (95%CI = 2-12%) vs. 4% (95%CI = 1-8%), respectively (p = 0.66). The 3-year cumulative incidence of relapse (15% vs. 13%; p = 0.67), progression-free survival (PFS) (71% vs. 80%; p = 0.25) and overall survival (OS) (79% vs. 83%; p = 0.56) were similar in the TT-10 and TT-20 groups, respectively. On multivariate analysis compared to TT-10, the TT-20 cohort was not associated with significantly different risk of NRM (Hazard ration [HR] = 0.77; p = 0.64), relapse/progression (HR = 0.87; p = 0.74), PFS (HR = 0.80; p = 0.48) or OS (HR = 1.10; p = 0.80). In conclusion thiotepa dose-intensity in TT-BCNU conditioning does not impact ASCT outcomes of PCNSL patients.

Allogeneic haematopoietic cell transplant in patients with relapsed/refractory anaplastic large cell lymphoma.

The prognosis of relapsed/refractory (R/R) anaplastic large cell lymphoma (ALCL) is poor. Large studies evaluating outcomes of allogeneic haematopoietic cell transplantation (allo-HCT) in systemic R/R ALCL are not available. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) database, we evaluated outcomes of 182 adults (aged ≥18 years) with R/R ALCL undergoing allo-HCT between 2008 and 2019. Non-relapse mortality (NRM), disease relapse/progression (REL), progression-free survival (PFS), and overall survival (OS) were modelled using Cox proportional hazards models. The median (range) follow-up of survivors was 62 (3-148) months. The 1-year NRM was 18%. The 5-year REL, PFS and OS were 32%, 41% and 56% respectively. On multivariable regression analysis African American race (hazard ratio [HR] 2.7, 95% confidence interval [CI] 1.6-4.8; p < 0.001) and refractory disease at allo-HCT (HR 3.2, 95% CI 1.6-6.2; p < 0.001) were predictive of inferior OS. Similarly, African-American race (HR 2.1, 95% CI 1.3-3.4; p = 0.003), other minority race (HR 2.5, 95% CI 1.2-5.3; p = 0.02) and refractory disease (HR 2.2, 95% CI 1.2-4.3; p = 0.01) were predictive of inferior PFS. These data, demonstrate that allo-HCT can result in durable disease control in a sizable proportion of patients with R/R ALCL. Refractory disease and racial minority status predicted inferior allo-HCT outcomes. Whether the inferior outcomes of racial minorities with R/R ALCL after allo-HCT are driven by differences in disease biology or disparities in post allo-HCT care, or both, requires further investigation.

KIR-favorable TCR-αß/CD19-depleted haploidentical HCT in children with ALL/AML/MDS: primary analysis of the PTCTC ONC1401 trial.

We performed a prospective multicenter study of T-cell receptor αß (TCR-αß)/CD19-depleted haploidentical hematopoietic cell transplantation (HCT) in children with acute leukemia and myelodysplastic syndrome (MDS), to determine 1-year disease-free survival (DFS) and compare 2-year outcomes with recipients of other donor cell sources. Fifty-one patients aged 0.7 to 21 years were enrolled; donors were killer immunoglobulin-like receptor (KIR) favorable based on ligand mismatch and/or high B content. The 1-year DFS was 78%. Superior 2-year DFS and overall survival (OS) were noted in patients <10 years of age, those treated with reduced toxicity conditioning (RTC) rather than myeloablative conditioning, and children with minimal residual disease <0.01% before HCT. Multivariate analysis comparing the KIR-favorable haploidentical cohort with controls showed similar DFS and OS compared with other donor cell sources. Multivariate analysis also showed a marked decrease in the risk of grades 2 to 4 and 3 to 4 acute graft versus host disease (aGVHD), chronic GVHD, and transplant-related mortality vs other donor cell sources. Ethnic and racial minorities accounted for 53% of enrolled patients, and data from a large cohort of recipients/donors screened for KIR showed that >80% of recipients had a KIR-favorable donor by our definition, demonstrating that this approach is broadly applicable to groups often unable to find donors. This prospective, multicenter study showed improved outcomes using TCR-αß/CD19-depleted haploidentical donors using RTC for children with acute leukemia and MDS. Randomized trials comparing this approach with matched unrelated donors are warranted. This trial was registered at https://clinicaltrials.gov as #NCT02646839.

Outcomes of Autologous Hematopoietic Cell Transplantation in Older Patients with Diffuse Large B-Cell Lymphoma.

Data for outcomes after autologous hematopoietic cell transplantation (auto-HCT) in diffuse large B-cell lymphoma (DLBCL) patients ≥70 years are limited. Auto-HCT is feasible in older DLBCL patients. Using the Center for International Blood and Marrow Transplant Research database, we compared outcomes of auto-HCT in DLBCL patients aged 60 to 69 years (n = 363) versus ≥70 years (n = 103) between 2008 and 2019. Non-relapse mortality (NRM), relapse/progression (REL), progression-free survival (PFS), and overall survival (OS) were modeled using Cox proportional hazards models. All patients received BEAM conditioning (carmustine, etoposide, cytosine arabinoside and melphalan). On univariate analysis, in the 60 to 69 years versus ≥70 years cohorts, 100-day NRM was 3% versus 4%, 5-year REL was 47% versus 45%, 5-year PFS 40% versus 38% and 5-year OS 55% versus 41%, respectively. On multivariate analysis, patients ≥70 had no significant difference in NRM (hazard ratio [HR] 1.43, 95% confidence interval [CI] 0.85-2.39), REL (HR 1.11, 95% CI 0.79-1.56), PFS (HR 1.23, 95% CI 0.92-1.63) compared to patients 60 to 69 years. Patients ≥70 years had a higher mortality (HR 1.39, 95% CI 1.05-1.85, p=0.02), likely because of inferior post-relapse OS in this cohort (HR 1.82, 95% CI 1.27-2.61, P = .001). DLBCL was the major cause of death in both cohorts (62% versus 59%). Older patients should not be denied auto-HCT solely on the basis of chronological age.

Impact of conditioning regimen intensity on the outcomes of peripheral T-cell lymphoma, anaplastic large cell lymphoma and angioimmunoblastic T-cell lymphoma patients undergoing allogeneic transplant.

There have been no large studies comparing reduced-intensity/non-myeloablative conditioning (RIC/NMA) to myeloablative conditioning (MAC) regimens in T-cell non-Hodgkin lymphoma (T-NHL) patients undergoing allogeneic transplant (allo-HCT). A total of 803 adults with peripheral T-cell lymphoma, anaplastic large cell lymphoma and angioimmunoblastic T-cell lymphoma (age 18-65 years), undergoing allo-HCT between 2008-2019 and reported to the Center for International Blood and Marrow Transplant Research with either MAC (n = 258) or RIC/NMA regimens (n = 545) were evaluated. There were no significant differences between the two cohorts in terms of patient sex, race and performance scores. Significantly more patients in the RIC/NMA cohort had peripheral blood grafts, haematopoietic cell transplantation-specific comorbidity index (HCT-CI) of ≥3 and chemosensitive disease compared to the MAC cohort. On multivariate analysis, overall survival (OS) was not significantly different in the RIC/NMA cohort compared to the MAC cohort (hazard ratio (HR) = 1.01, 95% confidence interval (CI) = 0.79-1.29; p = 0.95). Similarly, non-relapse mortality (NRM) (HR = 0.85, 95% CI = 0.61-1.19; p = 0.34), risk of progression/relapse (HR = 1.29; 95% CI = 0.98-1.70; p = 0.07) and therapy failure (HR = 1.14; 95% CI = 0.92-1.41, p = 0.23) were not significantly different between the two cohorts. Relative to MAC, RIC/NMA was associated with a significantly lower risk of grade 3-4 acute graft-versus-host disease (HR = 0.67; 95% CI = 0.46-0.99, p = 0.04). Among chemorefractory patients, there was no difference in OS, therapy failure, relapse, or NRM between RIC/NMA and MAC regimens. In conclusion, we found no association between conditioning intensity and outcomes after allo-HCT for T-cell NHL.

Effect of time to relapse on overall survival in patients with mantle cell lymphoma following autologous haematopoietic cell transplantation.

In young and fit patients with mantle cell lymphoma (MCL), intensive induction therapy followed by a consolidative autologous haematopoietic cell transplant (autoHCT) is the standard of care in the front-line setting. Recently, time-to-event analysis has emerged as an important risk assessment tool in lymphoma, though its impact in MCL is not well defined. We utilized the Center for International Blood and Marrow Transplant Research database to evaluate the effect of post-autoHCT time to relapse on overall survival (OS) over time in 461 patients who underwent autoHCT within 12 months of MCL diagnosis. On multivariate analysis, the impact of relapse on OS was greatest at the six-month [hazard ratio (HR) = 7·68], 12-month (HR = 6·68), and 18-month (HR = 5·81) landmark timepoints. Using a dynamic landmark model we demonstrate that adjusted OS at five years following each landmark timepoint improved with time for relapsing and non-relapsing patients. Furthermore, early relapse (<18 months) following autoHCT defines a high-risk group with inferior post-relapse OS. This retrospective analysis highlights the impact of time to relapse on OS in MCL patients undergoing up-front autoHCT and emphasizes the need to consider novel therapeutic approaches for patients suffering early relapse.

Outcomes and Utilization Trends of Front-Line Autologous Hematopoietic Cell Transplantation for Mantle Cell Lymphoma.

Although autologous hematopoietic cell transplantation (auto-HCT) has become a common practice for eligible patients in the front-line setting with mantle cell lymphoma (MCL), there are limited data regarding trends in auto-HCT utilization and associated outcomes. This study used the Center for International Blood and Marrow Transplant Research (CIBMTR) database to evaluate survival outcomes and auto-HCT utilization in adults age ≥18 years who underwent auto-HCT within 12 months of diagnosis of MCL between January 2000 and December 2018. The 19-year period from 2000 to 2018 was divided into 4 separate intervals-2000 to 2004, 2005 to 2009, 2010 to 2014, and 2015 to 2018-and encompassed 5082 patients. To evaluate transplantation utilization patterns, we combined MCL incidence derived from the SEER 21 database with CIBMTR- reported auto-HCT activity within 12 months of diagnosis of MCL. Primary outcomes included overall survival (OS) along with the auto-HCT utilization rate. The cumulative incidence of nonrelapse mortality at 1 year decreased from 7% in the earliest cohort (2000 to 2004) to 2% in the latest cohort (2015 to 2018). Mirroring this trend, OS outcomes improved continually with time, with a 3-year OS of 72% in the earliest cohort improving to 86% in the latest cohort. In addition, we noted an increase in auto-HCT utilization from 2001 to 2018, particularly in patients age ≤65 years. This large retrospective analysis highlights trends in auto-HCT utilization and outcomes in patients with MCL and emphasizes the need to optimize pretransplantation and post-transplantation treatment strategies to enhance survival outcomes.

Outcomes Associated With Thiotepa-Based Conditioning in Patients With Primary Central Nervous System Lymphoma After Autologous Hematopoietic Cell Transplant.

IMPORTANCE: Primary central nervous system lymphoma (PCNSL) requires induction and consolidation to achieve potential cure. High-dose therapy and autologous hematopoietic cell transplant (AHCT) is an accepted and effective consolidation strategy for PCNSL, but no consensus exists on the optimal conditioning regimens. OBJECTIVE: To assess the outcomes in patients with PCNSL undergoing AHCT with the 3 most commonly used conditioning regimens: thiotepa/busulfan/cyclophosphamide (TBC), thiotepa/carmustine (TT-BCNU), and carmustine/etoposide/cytarabine/melphalan (BEAM). DESIGN, SETTING, AND PARTICIPANTS: This observational cohort study used registry data from the Center for International Blood and Marrow Transplant Research registry. The Center is a working group of more than 380 transplantation centers worldwide that contributed detailed data on HCT to a statistical center at the Medical College of Wisconsin, Milwaukee. The participant data were from 603 adult patients with PCNSL who underwent AHCT as initial, or subsequent, consolidation between January 2010 and December 2018. Patients were excluded if they had a non-Hodgkin lymphoma subtype other than diffuse large B-cell lymphoma, systemic non-Hodgkin lymphoma, or HIV; received an uncommon conditioning regimen; or were not in partial remission or complete remission prior to AHCT. Statistical analysis was performed from July 5, 2020, to March 1, 2021. INTERVENTIONS: Patients received 1 of 3 conditioning regimens: TBC (n = 263), TT-BCNU (n = 275), and BEAM (n = 65). MAIN OUTCOMES AND MEASURES: The primary outcome was progression-free survival. Secondary outcomes included hematopoietic recovery, incidence of relapse, nonrelapse mortality, and overall survival. RESULTS: Of 603 patients, the mean age was 57 (range, 19-77) years and 318 (53%) were male. The 3-year adjusted progression-free survival rates were higher in the TBC cohort (75%) and TT-BCNU cohort (76%) compared with the BEAM cohort (58%) (P = .03) owing to a higher relapse risk in the BEAM cohort (hazard ratio [HR], 4.34; 95% CI, 2.45-7.70; P < .001). In a multivariable regression analysis, compared with the TBC cohort, patients who received TT-BCNU had a higher relapse risk (HR, 1.79; 95% CI, 1.07-2.98; P = .03), lower risk of nonrelapse mortality (NRM) (HR, 0.50; 95% CI, 0.29-0.87; P = .01), and similar risk of all-cause mortality more than 6 months after HCT (HR, 1.54; 95% CI, 0.93-2.55; P = .10). Age of 60 years or older, Karnofsky performance status less than 90, and an HCT-comorbidity index greater than or equal to 3 were associated with lower rates of survival across all 3 cohorts. Subgroup analyses demonstrated that patients aged 60 years and older had considerably higher NRM with TBC. CONCLUSIONS AND RELEVANCE: In this cohort study, thiotepa-based conditioning regimen was associated with higher rates of survival compared with BEAM, despite higher rates of early toxic effects and NRM; these findings may assist clinicians in choosing between TBC or TT-BCNU based on patient and disease characteristics.

Impact of Reduced-Intensity Conditioning Regimens on Outcomes in Diffuse Large B Cell Lymphoma Undergoing Allogeneic Transplantation.

Reduced-intensity conditioning (RIC) regimens are frequently used for allogeneic hematopoietic cell transplantation (allo-HCT) in patients with diffuse large B cell lymphoma (DLBCL). However, the RIC regimen with the best risk/benefit profile for allo-HCT in DLBCL is not known. This is particularly important because patients with DLBCL undergoing allo-HCT in the future would be enriched for those whose lymphoma has failed chimeric antigen receptor T cell (CAR-T) therapy or other novel immunotherapies, with potentially more advanced disease and suboptimal performance scores. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) database, we report the outcomes of the 3 most commonly used allo-HCT RIC regimens in patients with DLBCL. Our analysis included a total of 562 adult DLBCL patients in the CIBMTR registry undergoing allo-HCT using matched related or unrelated donors, between 2008 and 2016. Patients received 1 of 3 RIC regimens: fludarabine/i.v. busulfan ~6.4 mg/kg (Flu/Bu), fludarabine/melphalan 140 mg/m2 (Flu/Mel140), or BCNU/etoposide/cytarabine/melphalan (BEAM). Accordingly, the study group was divided into 3 groups: Flu/Bu (n = 151), Flu/Mel140 (n = 296), and BEAM (n = 115). Relative to Flu/Bu, the Flu/Mel140 (hazard ratio [HR], 2.33; 95% confidence interval [CI], 1.42 to 3.82; P = .001) and BEAM (HR, 2.54; 95% CI, 1.34 to 4.80; P = .004) regimens were associated with a risk of higher nonrelapse mortality (NRM). Although the risk of relapse with Flu/Mel140 was lower than that with Flu/Bu (HR, .70; 95% CI, .52 to .95; P = .02), this did not translate to improved progression-free survival (HR, 1.04) or overall survival (HR, 1.30). There was a significantly higher risk of grade III-IV acute graft-versus-host disease with BEAM compared with Flu/Bu (HR, 2.19; 95% CI, 1.10 to 4.35; P = .03). In the chemosensitive subset, multivariate analysis showed a significantly higher mortality risk with Flu/Mel140 (HR, 1.48; 95% CI, 1.07 to 2.04; P = .02) relative to Flu/Bu conditioning. In the largest analysis comparing the impact of various RIC regimens on the survival of DLBCL patients undergoing allo-HCT, our results suggest that Flu/Bu is a better RIC choice in less fit or heavily pretreated patients due to lowest NRM risk.

Is autologous transplant in relapsed DLBCL patients achieving only a PET+ PR appropriate in the CAR T-cell era?

For relapsed chemosensitive diffuse large B-cell lymphoma (DLBCL), consolidation with autologous hematopoietic cell transplantation (auto-HCT) is a standard option. With the approval of anti-CD19 chimeric antigen receptor T cells in 2017, the Center for International Blood and Marrow Transplant Research (CIBMTR) reported a 45% decrease in the number of auto-HCTs for DLBCL in the United States. Using the CIBMTR database, we identified 249 relapsed DLBCL patients undergoing auto-HCT from 2003 to 2013 with a positive positron emission tomography/computed tomography (PET/CT)+ partial response prior to transplant were identified. The study cohort was divided into 2 groups: early chemoimmunotherapy failure (ECF), defined as patients with primary refractory disease (PRefD) or relapse within 12 months of diagnosis and late chemoimmunotherapy failure, defined as patients relapsing after ≥12 months. Primary outcome was overall survival (OS). Secondary outcomes included progression-free survival (PFS) and relapse. A total of 182 patients had ECF, whereas 67 did not. Among ECF cohort, 79% had PRefD. The adjusted 5-year probabilities for PFS and OS (ECF vs no ECF) were not different: 41% vs 41% (P = .93) and 51% vs 63% (P = .09), respectively. On multivariate analysis, ECF patients had an increased risk for death (hazard ratio, 1.61; 95% confidence interval, 1.05-2.46; P = .03) but not for PFS or relapse. In conclusion, for relapsed chemosensitive DLBCL patients with residual PET/CT+ disease prior to auto-HCT, the adjusted 5-year PFS (41%) was comparable, irrespective of time to relapse. These data support ongoing application of auto-HCT in chemosensitive DLBCL.

Impact of type of reduced-intensity conditioning regimen on the outcomes of allogeneic haematopoietic cell transplantation in classical Hodgkin lymphoma.

Reduced-intensity conditioning (RIC) allogeneic haematopoietic cell transplantation (allo-HCT) is a curative option for select relapsed/refractory Hodgkin lymphoma (HL) patients; however, there are sparse data to support superiority of any particular conditioning regimen. We analyzed 492 adult patients undergoing human leucocyte antigen (HLA)-matched sibling or unrelated donor allo-HCT for HL between 2008 and 2016, utilizing RIC with either fludarabine/busulfan (Flu/Bu), fludarabine/melphalan (Flu/Mel140) or fludarabine/cyclophosphamide (Flu/Cy). Multivariable regression analysis was performed using a significance level of <0·01. There were no significant differences between regimens in risk for non-relapse mortality (NRM) (P = 0·54), relapse/progression (P = 0·02) or progression-free survival (PFS) (P = 0·14). Flu/Cy conditioning was associated with decreased risk of mortality in the first 11 months after allo-HCT (HR = 0·28; 95% CI = 0·10-0·73; P = 0·009), but beyond 11 months post allo-HCT it was associated with a significantly higher risk of mortality, (HR = 2·46; 95% CI = 0·1.32-4·61; P = 0·005). Four-year adjusted overall survival (OS) was similar across regimens at 62% for Flu/Bu, 59% for Flu/Mel140 and 55% for Flu/Cy (P = 0·64), respectively. These data confirm the choice of RIC for allo-HCT in HL does not influence risk of relapse, NRM or PFS. Although no OS benefit was seen between Flu/Bu and Flu/Mel 140; Flu/Cy was associated with a significantly higher risk of mortality beyond 11 months from allo-HCT (possibly due to late NRM events).

Higher Total Body Irradiation Dose Intensity in Fludarabine/TBI-Based Reduced-Intensity Conditioning Regimen Is Associated with Inferior Survival in Non-Hodgkin Lymphoma Patients Undergoing Allogeneic Transplantation.

Disease relapse is the most common cause of therapy failure in patients with non-Hodgkin lymphoma (NHL) undergoing reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (allo-HCT). It is not known whether or not increasing total body irradiation (TBI) dose from 2 to 4 Gy in a RIC platform can provide improved disease control without increasing nonrelapse mortality (NRM). Using the Center for International Blood & Marrow Transplant Research (CIBMTR) database, we evaluated the outcomes of patients with NHL receiving RIC allo-HCT with either fludarabine (Flu)/2-Gy TBI versus Flu/4-Gy TBI. In the CIBMTR registry, 413 adult patients with NHL underwent a first allo-HCT using either a matched related or unrelated donor between 2008 and 2017, using a RIC regimen with either Flu/2-Gy TBI (n = 349) or Flu/4-Gy TBI (n = 64). The primary endpoint was overall survival (OS). Secondary endpoints included acute (a) and chronic (c) graft-versus-host disease (GVHD), NRM, relapse/progression, and progression-free survival (PFS). At baseline, the Flu/2-Gy TBI cohort had significantly fewer patients with Karnofsky performance status ≥90 and significantly more patients had a higher HCT-comorbidity index. On multivariate analysis, the 2 conditioning cohorts were not significantly different in terms of risk of grade 3 to 4 aGVHD or cGVHD. Compared to Flu/2-Gy TBI, the Flu/4-Gy TBI conditioning was associated with a significantly higher risk of NRM (hazard ratio [HR], 1.79; 95% confidence interval [CI], 1.11 to 2.89; P = .02) and inferior OS (HR, 1.51; 95% CI, 1.03 to 2.23, P = .03). No significant differences were seen in the risk of relapse/progression (HR, 0.78; 95% CI, 0.47 to 1.29, P = .33) or PFS (HR, 1.09; 95% CI, 0.78 to 1.54, P = .61) between the 2 regimens. Comparing Flu/2-Gy TBI versus Flu/4-Gy TBI cohorts, the 5-year adjusted outcomes were NRM (28% versus 47%; P = .005), relapse/progression (35% versus 29%; P = .28), PFS (37% versus 24%; P = .03), and OS (51% versus 31%; P = .001), respectively. Relapse was the most common cause of death in both cohorts. In patients with NHL undergoing Flu/TB I-based conditioning, augmenting TBI dose from 2 to 4 Gy is associated with higher NRM and inferior OS, without any significant benefit in terms of disease control. The optimal dose is 2-Gy in the RIC Flu/TBI platform for lymphomas.

Outcomes of rituximab-BEAM versus BEAM conditioning regimen in patients with diffuse large B cell lymphoma undergoing autologous transplantation.

BACKGROUND: Although rituximab-based high-dose therapy is frequently used in diffuse large B cell lymphoma (DLBCL) patients undergoing autologous hematopoietic cell transplantation (auto-HCT), data supporting the benefits are not available. Herein, we report the impact of rituximab-based conditioning on auto-HCT outcomes in patients who have DLBCL. METHODS: Using the Center for International Blood and Marrow Transplant Research (CIBMTR) registry, 862 adult DLBCL patients undergoing auto-HCT between 2003 and 2017 using BEAM (BCNU, etoposide, cytarabine, melphalan) conditioning regimen were included. All patients received frontline rituximab-containing chemoimmunotherapy and had chemosensitive disease pre-HCT. Early chemoimmunotherapy failure was defined as not achieving complete remission (CR) after frontline chemoimmunotherapy or relapse within 1 year of initial diagnosis. The primary outcome was overall survival (OS). RESULTS: The study cohort was divided into 2 groups: BEAM (n = 667) and R-BEAM (n = 195). On multivariate analysis, no significant difference was seen in OS (P = .83) or progression-free survival (PFS) (P = .61) across the 2 cohorts. No significant association between the use of rituximab and risk of relapse (P = .15) or nonrelapse mortality (P = .12) was observed. Variables independently associated with lower OS included older age at auto-HCT (P < .001), absence of CR at auto-HCT (P < .001) and early chemoimmunotherapy failure (P < .001). Older age (P < .0002) and non-CR pre-HCT (P < .0001) were also associated with inferior PFS. There was no significant difference in early infectious complications between the 2 cohorts. CONCLUSION: In this large registry analysis of DLBCL patients undergoing auto-HCT, the addition of rituximab to the BEAM conditioning regimen had no impact on transplantation outcomes. Older age, absence of CR pre auto-HCT, and early chemoimmunotherapy failure were associated with inferior survival.

Lower Graft-versus-Host Disease and Relapse Risk in Post-Transplant Cyclophosphamide-Based Haploidentical versus Matched Sibling Donor Reduced-Intensity Conditioning Transplant for Hodgkin Lymphoma.

Classic Hodgkin lymphoma (cHL) patients with relapsed or refractory disease may benefit from allogeneic hematopoietic cell transplantation (allo-HCT), but many lack a matched sibling donor (MSD). Herein, we compare outcomes of 2 reduced-intensity conditioning (RIC) HCT platforms in cHL: T cell-replete related donor haploidentical (haplo) HCT with a post-transplant cyclophosphamide (PTCy)-based approach versus an MSD/calcineurin inhibitor (CNI)-based approach. The study included 596 adult patients who underwent a first RIC allo-HCT for cHL between 2008 and 2016 using either a haplo-PTCy (n = 139) or MSD/CNI-based (n = 457) approach. Overall survival (OS) was the primary endpoint. Secondary endpoints included acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD), nonrelapse mortality (NRM), relapse/progression, and progression-free survival (PFS). On multivariate analysis, there was no significant difference between haplo/PTCy and MDS/CNI-based approaches in terms of OS (hazard ratio [HR], 1.07; 95% confidence interval [CI], .79 to 1.45; P = .66) or PFS (HR, .86; 95% CI, .68 to 1.10; P = .22). Haplo/PTCy was associated with a significantly higher risk of grades II to IV aGVHD (odds ratio [OR], 1.73, 95% CI, 1.16 to 2.59; P = .007), but the risk of grades III to IV aGVHD was not significantly different between the 2 cohorts (OR, .61; 95% CI, .29 to 1.27; P = .19). The haplo/PTCy platform provided a significant reduction in cGVHD risk (HR, .45; 95% CI, .32 to .64; P < .001), and a significant reduction in relapse risk (HR, .74; 95% CI, .56 to .97; P = .03). There was a statistically nonsignificant trend toward higher NRM with a haplo/PTCy approach (HR, 1.65; 95% CI, .99 to 2.77; P = .06). Haplo/PTCy-based approaches are associated with lower incidences of cGVHD and relapse, with PFS and OS outcomes comparable with MSD/CNI-based approaches. There was a leaning toward higher NRM with a haplo/PTCy-based platform. These data show that haplo/PTCy allo-HCT in cHL results in survival comparable with MSD/CNI-based allo-HCT.