Ahmed, Sairah

Abstract Waldenström macroglobulinemia (WM) is a rare B‐cell lymphoproliferative malignancy. Autologous hematopoietic cell transplantation (auto‐HCT) is considered in a subset of WM patients with relapsed disease. While registry data has shown a benefit for auto‐HCT in relapsed WM, there is a paucity of data on outcomes of patients relapsing after auto‐HCT. Eligibility criteria included adult patients with relapsed/refractory WM who underwent auto‐HCT between 2007 and 2017. The primary endpoint was post‐relapse overall survival (PR‐OS). Secondary endpoints were to identify factors prognostic of PR‐OS. Of the 48 patients with WM who underwent auto‐HCT, 22 (46%) experienced relapse following auto‐HCT. Median PR‐OS of relapsed WM patients after auto‐HCT ( n = 22) was not reached (NR) (95% confidence interval [CI]: 17.5 months‐NR). Among patients who relapsed <1 year versus ≥1 year from auto‐HCT, the median PR‐OS was 18.4 months (95%CI: 0.8‐NR) months and NR (95%CI: 17.5‐NR), respectively ( p = 0.06). Of note, disease status at the time of transplant, CR/VGPR versus partial remission did not appear to impact PR‐OS. The median PR‐OS was significantly longer in patients who received ibrutinib in the post‐transplant setting compared to those who did not (NR vs. 18.4 months, 95%CI: 9.1‐NR, p = 0.02). On univariable analysis, the presence of complex karyotype (RR = 4.87, 95% CI = 1.22–19.53) and a higher number of prior lines of therapy (RR = 1.81, 95% CI = 1.23–2.67) were associated with a significantly higher risk of relapse. This is the only study to date that evaluated outcomes of WM patients who relapsed following auto‐HCT and provides a benchmark for future trials evaluating survival following auto‐HCT relapse.

7552 Background: Axi-cel is approved in the US for the treatment of adult patients with relapsed or refractory LBCL after 2 or more lines of systemic therapy. Post-market long term follow up study of commercial Axi-cel recipients using the Center for International Blood and Marrow Transplant Research was recently completed. Methods: From October 2017 to August 2020, 1,500 Axi-cel recipients from 79 centers were enrolled. Of these, 1001 patients with at least 6 months of follow-up were included in this analysis. Outcomes include complete and overall responses rates (CR and ORR), duration of response (DOR), progression-free and overall survival (PFS and OS), cytokine release syndrome (CRS) (Lee D 2014 and American Society for Transplantation and Cellular Therapy [ASTCT]), immune effector cell associated neurotoxicity syndrome (ICANS), hematologic recovery and subsequent neoplasm (SN). Subgroup analysis by sensitivity to therapy, defined as responsive to the last line of therapy prior to Axi-cel. Median follow-up was 12 months (range, 6-28 months). Results: The median age overall was 62 years, 37% were ≥ 65 years, 83% with Eastern Cooperative Oncology Group (ECOG) performance score 0-1, 28% with transformed lymphoma, 14% with high grade lymphoma, 29% with prior autologous transplant, and 66% with chemotherapy-resistant disease prior to Axi-cel. The median time from diagnosis to Axi-cel infusion was 15 months. Best ORR was 70% (CR 53%). Landmark analysis of patients in CR at 6 months post Axi-cel demonstrates a low number of subsequent progression/death events. With respect to outcomes for chemotherapy-sensitive disease versus resistant disease, the ORR, CR, 12-month PFS and OS were 78% vs. 66%, 60% vs. 48%, 55% (95% CI, 48-62%) vs. 40% (95% CI, 37-44%), and 70% (95% CI, 63-76%) vs. 54% (95% CI, 50-58%), respectively. CRS of any grade was reported in 83% of patients. Incidence of Grades ≥ 3 CRS was 10% according to Lee et al 2014, and 13% according to ASTCT Consensus Grading. Median time to any grade CRS was 4 days (range, 1-28 days), and 93% of CRS cases resolved with a median duration of 7 days (range, 1-121 days). ICANS were reported in 576 (57%) patients, grade >3 was 26%. The median time to onset of ICANS was 7 days (range, 1-82 days), and 86% resolved with a median duration of 9 days (range, 1 to 115 days). Twenty-nine patients (2.9%) reported SN: hematologic (N = 17), solid tumors (N = 12). Conclusions: This is the largest report on Axi-cel in the real-world setting and demonstrates consistent efficacy outcomes and further characterizes safety outcomes. Patients in CR at 6 months have sustained disease control with low number of relapse events. Although patients with therapy-sensitive disease experience better outcomes than patients with therapy-resistant, the overall outcomes on both groups of patients are favorable.

SummaryReduced‐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).

Introduction: Reduced-intensity and non-myeloablative (RIC/NMA) conditioning regimens are frequently used in alloHCT for NHL, because they are associated with decreased non-relapse mortality (NRM) risk in comparison with myeloablative conditioning regimens and allow older patients and patients with comorbidities to receive alloHCT. However, the optimal RIC/NMA regimen in allo-HCT for NHL is not known. Using the CIBMTR database we compared the transplant outcomes between the commonly used RIC/NMA regimens in NHL. Methods: 1823 adult (≥18 years) NHL patients in CIBMTR registry undergoing alloHCT using matched related or unrelated donors, between 2008-2016 were included. Analysis was limited to patients receiving four commonly used RIC/NMA regimens: fludarabine/ i.v. busulfan (6.4mg/kg) (Flu/Bu), fludarabine/melphalan (140mg/m^2) (Flu/Mel 140), fludarabine/cyclophosphamide (Fly/Cy) and Flu/Cy with 2Gy Total Body Irradiation (Flu/Cy/TBI). Graft-versus-host disease (GVHD) prophylaxis was limited to calcineurin inhibitor-based regimens. Patients who received post transplantation cyclophosphamide for GVHD prophylaxis were excluded. The primary outcome was overall survival (OS). Secondary outcomes included cumulative incidence of NRM, relapse, progression-free survival (PFS) and cumulative incidence of acute and chronic GVHD. Probabilities of OS and PFS were calculated using the Kaplan-Meier estimator. Multivariable regression analysis was performed for GVHD, relapse/progression, NRM, PFS, and OS. Covariates with a p&lt;0.01 were considered significant. Results: The study cohort was divided into 4 groups; Flu/Bu (n=458), Flu/Cy/TBI (n=89), Flu/Mel 140 (n=885) and Flu/Cy (n=391). The baseline characteristics are shown in Table 1. The 4 cohorts were comparable with respect to median patient age, gender, donor type, remission status at alloHCT, and use of prior auto HCT. There was no interaction between NHL histological subtype and type of conditioning regimen. Results of multivariate analysis are shown in Table 2. The Flu/Mel 140 regimen was associated with a higher NRM (HR 1.78, 95% CI 1.37-2.31; p&lt;0.001) when compared to Flu/Bu. Although the risk of relapse with Flu/Mel 140 was lower when compared to Flu/Bu (HR 0.79, 95% CI 0.66-0.94); p=0.007), this did not result in an improvement in PFS. Moreover, the Flu/Mel 140 cohort had an inferior OS (HR 1.34, 95% CI 1.13-1.59; p&lt;0.001) when compared to Flu/Bu. There was no significant difference in terms of OS, PFS, relapse and NRM between Flu/Bu, Flu/Cy and Flu/Cy/TBI. There was no difference in risk of grade 3-4 acute GVHD across the four cohorts and compared to Flu/Cy/TBI, Flu/Mel 140 had a higher risk of chronic GVHD (HR 1.38, 95% CI 1.15-1.65; p&lt;0.001). Four year adjusted PFS was 38% for Flu/Bu, 51% for Flu/Cy/TBI, 39% for Flu/Mel 140 and 35% for Flu/Cy (p=0.07). Four year adjusted OS was 58% for Flu/Bu, 67% for Flu/Cy/TBI, 49% for Flu/Mel 140 and 63% for Flu/Cy (p&lt;0.001). Disease relapse was the most common cause of death across all 4 cohorts. Conclusion: This is the largest analysis comparing the impact of various RIC/NMA conditioning regimens on the outcomes of NHL patients undergoing alloHCT. We report that the choice of RIC/NMA conditioning regimen significantly impacted OS. The most commonly used conditioning regimen, Flu/Mel 140 was associated with a higher NRM and an inferior OS. The Flu/Bu, Flu/Cy, and Flu/CY/TBI conditioning regimens appear to provide comparable OS. Disclosures Ghosh: Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Speakers Bureau; Gilead: Consultancy, Honoraria, Speakers Bureau; SGN: Consultancy, Honoraria, Research Funding, Speakers Bureau; TG Therapeutics: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Research Funding; Genentech: Research Funding; Forty Seven Inc: Research Funding; AstraZeneca: Honoraria, Speakers Bureau. Kharfan-Dabaja:Pharmacyclics: Consultancy; Daiichi Sankyo: Consultancy. Sureda:Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria; Sanofi: Honoraria; Takeda: Consultancy, Honoraria, Speakers Bureau; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Support; Novartis: Honoraria; Roche: Honoraria. Hamadani:Merck: Research Funding; ADC Therapeutics: Consultancy, Research Funding; Celgene: Consultancy; Otsuka: Research Funding; Medimmune: Consultancy, Research Funding; Takeda: Research Funding; Pharmacyclics: Consultancy; Janssen: Consultancy; Sanofi Genzyme: Research Funding, Speakers Bureau.

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.

(Text above this line is not copy/pasted in the abstract body) INTRODUCTION Allogeneic HCT using RIC regimens is the standard treatment for patients with relapsed/refractory cHL, however there is significant heterogeneity amongst the different regimens and a lack of data supporting a preferred RIC regimen. Using the CIBMTR database we evaluate the outcomes of the 3 most commonly used RIC regimens for cHL. METHODS In the CIBMTR registry, 492 adult patients underwent a first alloHCT using either a matched related or unrelated donor for cHL between 2008-2016, utilizing a RIC regimen with either fludarabine/ i.v. busulfan (6.4mg/kg) (Flu/Bu, n=102), fludarabine/melphalan 140mg/m^2 (Flu/Mel140, n=318) or fludarabine/cyclophosphamide (Flu/Cy, n=72). Graft-versus-host disease (GVHD) prophylaxis was calcineurin inhibitor (CNI) plus methotrexate, mycophenolate mofitil (MMF) or other agents, however post transplantation cyclophosphamide (post-CY) was excluded. The primary endpoint was overall survival (OS). Secondary endpoints included acute (a) and chronic (c) GVHD, non-relapse mortality (NRM), relapse/progression and progression-free survival (PFS). Probabilities of OS and PFS were calculated using the Kaplan-Meier estimator. Multivariable regression analysis was performed for GVHD, relapse/progression, NRM, PFS, and OS. Covariates with a p<0.01 were considered significant. RESULTS Baseline characteristics are shown in Table 1. The median patient age of the complete study cohort was only 33 years, with more than 80% receiving a prior autologous HCT. On multivariate analysis (Table 2), the 3 conditioning regimen cohorts were not statistically different in either risk of cGVHD nor risk of grade 3-4 aGVHD. No significant differences were seen in the NRM risk between the three regimens (p=0.54). Similarly, the risk of relapse (p=0.02) and PFS was comparable between regimens (p=0.14). Flu/Cy conditioning was associated with decreased risk of mortality in first 11months after alloHCT (OR 0.28, 95% CI 0.10-0.73, p=0.009, but beyond 11 months post alloHCT it was associated with a significantly higher risk of mortality, (OR 2.46, 95% CI 0.1.32-4.61, p=0.005; Figure 1) [11months post alloHCT cutoff chosen on the basis of the maximum likelihood value in the Cox model]. Four year adjusted PFS and OS were similar across the three regimens at 29% for Flu/Bu, 37% for Flu/Mel140 and 25% for Flu/Cy (p=0.07) for PFS and 62% for Flu/Bu, 59% for Flu/Mel140 and 55% for Flu/Cy (p=0.64) for OS, respectively. Relapse was the most common cause of death across all the regimens, followed by organ failure and GVHD. CONCLUSIONS The most commonly used RIC regimen in alloHCT for cHL is Flu/Mel140, which was compared to Flu/Bu and Flu/Cy, the next most frequently used regimens. The choice of conditioning regimen, in these young cHL patients (median age 33 years) did not confer any benefit in terms of the risk of relapse, decrease in NRM or improvement in PFS. There was no OS benefit between, Flu/Bu and Flu/Mel 140, but Flu/Cy was associated with a significantly higher risk of mortality in patients beyond 11 months from allo-HCT. Novel approaches are still needed to decrease post-HCT relapse risk and improve overall results. Figure 1 Disclosures Ghosh: Seattle Genetics: Consultancy, Speakers Bureau; Genentech: Research Funding; Gilead/Kite: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy, Research Funding, Speakers Bureau; T G Therapeutics: Consultancy, Research Funding; Celgene: Consultancy, Research Funding, Speakers Bureau; Forty Seven Inc: Research Funding; Spectrum: Consultancy, Speakers Bureau; AbbVie: Consultancy, Speakers Bureau; Astra Zeneca: Speakers Bureau. Kharfan-Dabaja:Daiichi Sankyo: Consultancy; Pharmacyclics: Consultancy. Sureda:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Support; Gilead: Honoraria; Novartis: Honoraria; Amgen: Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria; Roche: Honoraria; Sanofi: Honoraria; Takeda: Consultancy, Honoraria, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Hamadani:Merck: Research Funding; Janssen: Consultancy; Otsuka: Research Funding; Takeda: Research Funding; Medimmune: Consultancy, Research Funding; ADC Therapeutics: Consultancy, Research Funding; Celgene: Consultancy; Sanofi Genzyme: Research Funding, Speakers Bureau; Pharmacyclics: Consultancy.

Key Points There was no difference in overall survival after allogeneic transplant between patients aged 55-64 years and patients ≥65 years. Age alone should not be a determinant for allogeneic transplant eligibility among older non-Hodgkin lymphoma patients.

BACKGROUNDEarly treatment failure (ETF) in follicular lymphoma (FL), defined as relapse or progression within 2 years of frontline chemoimmunotherapy, is a newly recognized marker of poor survival and identifies a high‐risk group of patients with an expected 5‐year overall survival (OS) rate of approximately 50%. Transplantation is an established option for relapsed FL, but its efficacy in this specific ETF FL population has not been previously evaluated.METHODSThis study compared autologous hematopoietic stem cell transplantation (auto‐HCT) with either matched sibling donor (MSD) or matched unrelated donor (MUD) allogeneic hematopoietic cell transplantation (allo‐HCT) as the first transplantation approach for patients with ETF FL (age ≥ 18 years) undergoing auto‐HCT or allo‐HCT between 2002 and 2014. The primary endpoint was OS. The secondary endpoints were progression‐free survival, relapse, and nonrelapse mortality (NRM).RESULTSFour hundred forty FL patients had ETF (auto‐HCT, 240; MSD hematopoietic stem cell transplantation [HCT], 105; and MUD HCT, 95). With a median follow‐up of 69 to 73 months, the adjusted probability of 5‐year OS was significantly higher after auto‐HCT (70%) or MSD HCT (73%) versus MUD HCT (49%; P = .0008). The 5‐year adjusted probability of NRM was significantly lower for auto‐HCT (5%) versus MSD (17%) or MUD HCT (33%; P < .0001). The 5‐year adjusted probability of disease relapse was lower with MSD (31%) or MUD HCT (23%) versus auto‐HCT (58%; P < .0001).CONCLUSIONSPatients with high‐risk FL, as defined by ETF, undergoing auto‐HCT for FL have low NRM and a promising 5‐year OS rate (70%). MSD HCT has lower relapse rates than auto‐HCT but similar OS. Cancer 2018;124:2541‐51. © 2018 American Cancer Society.