Majhail, Navneet S.

Abstract There is marked paucity of data regarding late effects in adolescents and young adults (AYAs) who undergo myeloablative conditioning (MAC) allogeneic hematopoietic cell transplantation (HCT) for acute myeloid leukemia (AML). We evaluated late effects and survival in 826 1-year disease-free survivors of MAC HCT for AYA AML, with an additional focus on comparing late effects based upon MAC type (total body irradiation [TBI] vs high-dose chemotherapy only). The estimated 10-year cumulative incidence of subsequent neoplasms was 4% (95% confidence interval [CI], 2%-6%); 10-year cumulative incidence of nonmalignant late effects included gonadal dysfunction (10%; 95% CI, 8%-13%), cataracts (10%; 95% CI, 7%-13%), avascular necrosis (8%; 95% CI, 5%-10%), diabetes mellitus (5%; 95% CI, 3%-7%), and hypothyroidism (3%; 95% CI, 2%-5%). Receipt of TBI was independently associated with a higher risk of cataracts only (hazard ratio [HR], 4.98; P < .0001) whereas chronic graft-versus-host disease (cGVHD) was associated with an increased risk of cataracts (HR, 3.22; P = .0006), avascular necrosis (HR, 2.49; P = .006), and diabetes mellitus (HR, 3.36; P = .03). Estimated 10-year overall survival and leukemia-free survival were 73% and 70%, respectively, and did not differ on the basis of conditioning type. In conclusion, late effects among survivors of MAC HCT for AYA AML are frequent and are more closely linked to cGVHD than type of conditioning.

e19503 Background: The risk of venous thromboembolic events (VTE) despite mandatory thromboprophylaxis (TPx) in patients with multiple myeloma (MM) receiving contemporary lenalidomide (Len)-based regimens is not well-defined. Methods: Medline, Embase, and CENTRAL databases were queried to identify phase 1-3 clinical trials of Len-based regimens with mandatory TPx published until April 2018. Random effects meta-analysis was performed using CMAv3 software to obtain crude, and per 100 patient-cycle incidence rate (IR). Prespecified subgroup analyses were performed to obtain IR for VTE by (1) line of treatment (newly diagnosed [ND], relapsed/refractory [RR] and maintenance [Mx] phase) and (2) different Len-based regimens. Results: We screened 1069 citations and analyzed data from 43 trials with 8696 patients, including 17 in ND, 23 in RR and 3 in Mx phase. 12 out of 43 were Phase 3 randomized controlled trials. The overall incidence of VTE in 8696 patients was 4.6% (95% CI, 3.7-5.8%), with 1.0 event (95% CI, 0.7-1.4%) per 100 patient cycles. In patients with NDMM (n = 3295), 193 (5.9%) experienced VTE with a pooled IR of 0.9 (95% CI, 0.3-2.3) per 100 patient-cycle. Among RRMM patients (n = 3981), 251 (6.3%) experienced VTE with a pooled IR of 1.0 (95% CI, 0.4-2.3) per 100 patient-cycle. The incidence of VTE was highest with the following triplet regimens: Rd + Proteasome inhibitor (PIs) and Rd + Anthracycline (Ac) [+/- Vincristine], with the latter having a high risk of VTE regardless of the treatment phase (table). With Len Mx (n = 1420), 38 (2.7%) patients had VTE, with a pooled IR of 0.2 (95% CI, 0-2.1) per 100 patient-cycle. Conclusions: Patients with MM undergoing treatment with Len-based regimens remain at risk of VTE despite current TPx strategies. The estimates of VTE IR provided by this analysis can guide clinicians in assessing treatment-related risk of VTE in this setting. [Table: see text]

Introduction: Rituximab-based high-dose therapy (HDT) is frequently prescribed to DLBCL patients (pts) undergoing auto-HCT. However data supporting the benefit of adding R to auto-HCT conditioning are not available. Herein, we report the impact of R-based conditioning on auto-HCT outcomes of DLBCL pts. Methods: Using the Center for International Blood and Marrow Transplant Research registry, 862 adult (≥18 years) DLBCL pts undergoing auto-HCT, between 2003-2017 were included. Analysis was limited to pts receiving BEAM (BCNU, etoposide, cytarabine, melphalan)-based HDT, as R was infrequently used with non-BEAM conditioning regimens. All pts received R-containing chemoimmunotherapy in the frontline setting and had chemosensitive disease prior to HCT. Early chemoimmunotherapy failure (ECitF) was defined as not achieving a complete remission (CR) after frontline chemoimmunotherapy or relapsing within 1 year of initial diagnosis. Primary outcome was overall survival (OS). Secondary outcomes included non-relapse mortality (NRM), relapse, progression-free survival (PFS) and infectious complications within 100 days post-HCT. Results: The study cohort was divided into 2 groups; BEAM (n=667) and R-BEAM (n=195). The baseline characteristics of the 2 cohorts were comparable including age at auto-HCT, disease stage, Karnofsky performance score, extranodal involvement, time from diagnosis to auto-HCT, number of prior therapies, remission status, and ECitF. However, significantly more R-BEAM cohort patients received R as part of last therapy line before auto-HCT (75% vs. 86%; P=0.001). Median follow-up of survivors was 48 (range 1-171) and 64 (range 3-142) months in the BEAM and R-BEAM cohorts, respectively. On univariate analysis, the 4 year cumulative incidence of relapse (41% vs 44%), NRM (11% vs 9%), PFS (48% vs 47%; Figure 1) and OS (58% vs 61%; Figure 2) were similar in the R-BEAM and BEAM groups, respectively (Table 1). On multivariate analysis, no significant difference was seen in OS (HR 0.81; 95% CI 0.81-1.31; P=0.83) or PFS (HR 0.94; 95% CI 0.76-1.18; P=0.61) (Table 1) between the two cohorts. Addition of R had no impact on risk of relapse (HR 0.83; 95% CI 0.65-1.07; P=0.15) or NRM (HR 1.43; 95% CI 0.909-2.26; P=0.12). Variables independently associated with lower OS included older age (HR 3.05; 95% CI 1.81-5.13; P<0.001), not being in CR at auto-HCT (HR 1.67, 95% CI 1.39-2.07; P<0.001) and presence of ECitF (HR 1.52, 95% CI 0.54-3.26; P<0.001). Older age (HR 2.26, 95% CI 1.48-3.45; P<0.0002) and not being in CR at auto-HCT (HR 1.78, CI 1.47-2.14; P<0.0001) were also associated with inferior PFS. There was no significant difference in the 100-day cumulative incidence of bacterial, viral or fungal infections between the two cohorts. Disease relapse was the main cause of death in both BEAM and R-BEAM cohorts (66% vs 55%). Conclusion: In this large registry analysis of DLBCL pts undergoing auto-HCT, adding R to BEAM conditioning had no impact on transplantation outcomes. Older age, absence of CR and ECitF were associated with inferior survival. Disclosures Majhail: Mallinckrodt: Honoraria; Incyte: Consultancy; Nkarta: Consultancy; Anthem, Inc.: Consultancy; Atara Bio: Consultancy. Sureda:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Support; Gilead: Honoraria; Amgen: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria; BMS: Honoraria; Roche: Honoraria; Sanofi: Honoraria; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Kharfan-Dabaja:Daiichi Sankyo: Consultancy; Pharmacyclics: Consultancy. Hamadani:ADC Therapeutics: Consultancy, Research Funding; Merck: Research Funding; Takeda: Research Funding; Pharmacyclics: Consultancy; Celgene: Consultancy; Medimmune: Consultancy, Research Funding; Janssen: Consultancy; Otsuka: Research Funding; 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.

Background Thromboprophylaxis is routinely used with lenalidomide‐based regimens in multiple myeloma because of a substantial risk of venous thromboembolism (VTE). However, little is known about the incidence of VTE with contemporary lenalidomide‐based regimens. The objective of the current study was to estimate the incidence of VTE despite thromboprophylaxis with currently used lenalidomide‐based regimens in patients with myeloma. Methods The Ovid MEDLINE, Embase, and Cochrane databases were queried from study inception to January 2019 for keywords to cover the following concepts: “lenalidomide,” “venous thromboembolism,” and “multiple myeloma.” Phase 1, 2, and 3 clinical trials evaluating lenalidomide‐based regimens with thromboprophylaxis were included. The pooled incidence rate of VTE was estimated using a random‐effects model. Results The search generated 1372 citations, with 51 clinical trials and 9069 patients included for analysis. The most common thromboprophylaxis agents were aspirin, low‐molecular‐weight heparin or warfarin, administered either per risk‐stratification or at investigators' discretion. The pooled incidence of VTE in trials of patients who had newly diagnosed and relapsed/refractory myeloma was 6.2% (95% CI, 5.4%‐7.1%) over median treatment durations ranging from 2 to 34 cycles, which translated into 1.2 VTE events per 100 patient‐cycles (95% CI, 0.9‐1.7 VTE events per 100 patient‐cycles). Among contemporary regimens, the risk of VTE was low with combined lenalidomide and low‐dose dexamethasone (0.2 [95% CI, 0.1‐0.6] events/100 patient‐cycles) and lenalidomide maintenance (0.0 [95% CI, 0.0‐0.7] events per 100 patient‐cycles). VTE risk was higher with combined lenalidomide and low‐dose dexamethasone plus proteasome inhibitors (1.3 [95% CI, 0.7‐2.3] events per 100 patient‐cycles). Conclusions Despite adequate thromboprophylaxis, lenalidomide‐based regimens have a substantial risk of VTE in controlled clinical trial settings. Further studies are needed on new thromboprophylaxis strategies with regimens that have a high VTE risk.

Abstract Introduction: Allogeneic stem cell transplant is an intensive procedure, offered in a limited number of medical centres. We sought to describe how sociodemographic variables impacted access to transplant across the United States, and if disadvantaged populations had inferior access to transplant. Methods: Data from the Surveillance, Epidemiology and End Results Program (SEER) and the Center for International Blood and Marrow Transplant Research (CIBMTR) was integrated to determine the rate of unrelated donor transplantation between 2000 and 2010 in each of the 612 counties included in the SEER registry. Patients under the age of 65 with AML, ALL, and MDS were included, and the analysis was restricted to unrelated donors due to limited availability of ZIP code in CIBMTR data. New incident cases were determined from SEER, and the number of transplants was determined from CIBMTR. The transplant rate was calculated (transplants performed divided by incident cases) for each county. County attributes (percent minority, rural/urban status, percentage below the poverty line, and median family size) were obtained from US Census data. Poisson regression was used to describe how county attributes impacted transplant rates. Transplant rates were calculated separately for AML, White residents, and pediatric ALL. Results: 3147 patients were identified in the CIBMTR dataset that met inclusion criteria. The estimated ZIP code completeness was 75%. There were 30,468 new incident diagnoses of ALL, AML, and MDS. For AML, patients from rural areas (less than 20,000 residents) and patients from areas with higher poverty levels had lower transplant rates (Table 1). Minority status and family size did not impact transplant rate. In regression models, higher levels of poverty remained associated with lower transplant rates, while rurality did not (Table 2). The results were similar among White residents. In contrast, in pediatric ALL, no county attributes (poverty, rurality, percent minority, and family size) were significantly associated with a difference in transplant rate (Table 1). However, numbers of transplants were smaller, limiting power. Discussion: Patients with AML from disadvantaged areas had lower rates of unrelated donor transplant. While patients from disadvantaged areas were also more likely to be non-White, and non-White Americans are less likely to have an available unrelated donor, this difference was also seen in White Americans from disadvantaged areas. This suggests the lower transplant rate is due impaired access to transplant. Poverty rate was the most important predictor of transplant rate. The results of this study suggest that improving access to transplant in disadvantaged populations should be a priority for health care administrators. Based on these results, approximately 2500 Americans do not undergo allogeneic transplant annually due to inferior access associated with higher poverty rates. Table 1 Univariate Analysis Table 1. Univariate Analysis Table 2 Acute Myeloid Leukemia, Regression Model * Metropolitan = county > 50,000 people, micropolitan = county > 20,000, rural county < 20,000. Table 2. Acute Myeloid Leukemia, Regression Model. / * Metropolitan = county > 50,000 people, micropolitan = county > 20,000, rural county < 20,000. Disclosures Hahn: Novartis: Equity Ownership; NIH: Research Funding.

Abstract HCT entails substantial TRM justifying continued efforts to better risk stratify patients. Single institutional studies have suggested several clinically available biomarkers of CRP, ferritin and albumin influence TRM if not overall survival (OS). We sought to confirm the independent prognostic value of these biomarkers in a large multi-institutional cohort. The study population consisted of 784 adults with AML in remission (80%) or MDS (20%) undergoing unrelated donor HCT between 2008 and 2010 and available cryopreserved samples through the Center for International Blood and Marrow Transplant Research (CIBMTR) repository. CRP and ferritin were centrally quantified by ELISA from cryopreserved plasma whereas albumin levels obtained from center reported data. Correlation studies for biomarkers required log transformation of CRP and ferritin to produce a normal distribution. Multivariate models were fitted separately for each biomarker applying protocol specified thresholds generated from the literature of CRP > 10 mg/L, ferritin > 2500 ng/mL, albumin < 3.5 g/dL on TRM. Further analysis explored optimal cutpoints for this cohort for all significant clinical variables for TRM. HCT characteristics included a median age of 50 (range 18-78) years, HCT-CI (co-morbidity index) 3 or more in 35%, single allele/antigen mismatch (7/8) in 23%, PB as stem cell source in 83%, and myeloablative conditioning in 72%. Biomarker data were available in 783, 781 and 695 cases for CRP, ferritin and albumin respectively. The median values and ranges for each biomarker were as follows: 5.0 mg/L (0.3 - 316) for CRP, 1148 ng/mL (51 – 14,298) for ferritin and 3.6 g/dL (0.6-5.3) for albumin. Log transformed CRP and ferritin showed a modest correlation (r=0.35, P<0.001), and log CRP was marginally associated with albumin (r=-0.12, P=0.002). HCT-CI had no correlation to CRP and albumin. Higher ferritin was associated with HCT-CI (P=0.014) and disease (P<.001). In the entire population, TRM and overall survival (OS) at 2 years were 23% and 54%, respectively. The table shows the independent association of each biomarker with TRM and OS. Ferritin had no association with these outcomes but only 12% had levels above 2500 by ELISA. The optimal cutpoints for TRM were defined as follows: CRP > 3.67 (HR=1.75, P=0.001); albumin < 3.4 (HR 1.70, P <0.001); and ferritin as a continuous variable (HR 1.30, P = 0.008). A risk score was created modeling optimal biomarker thresholds to predict TRM based on the following formula: risk score = 0.44633*I(CRP>3.67)+0.18330*ln(Ferritin)+0.44730*I(albumin<3.4), where “I” is an indicator function and represent 1 or 0 depending on the presence of the abnormal biomarker level in parenthesis. The risk score included adjustment for HCT-CI. The biomarkers did not influence the incidence of relapse or graft-versus-host disease with any of these models. Elevated CRP and ferritin and decreased albumin prior to HCT were associated with impaired transplant survival, primarily through higher TRM. Integration of a biomarker panel in clinical practice once validated can enhance risk-stratification, improve adjustment for comparative studies and point towards the design of biomarker driven trials. Abstract 422. Table: Multivariate analysis of TRM and OS for biomarkers, and biomarker panel risk score* Abnormal, N (%) Transplant related mortality Overall Survival Biomarker HR 95% CI P HR 95% CI P Protocol defined CRP >10 mg/L 184 (24) 1.52 1.11 – 2.07 0.008 1.22 0.98 – 1.53 0.072 Ferritin >2500 ng/mL 93 (12) 1.26 0.84 – 1.88 0.27 1.15 0.86 – 1.54 0.35 Albumin < 3.5 g/dL 290 (42) 1.48 1.10 – 2.0 0.010 1.39 1.13 – 1.72 0.002 Optimal threshold, combined model ** CRP >3.67 mg/L 497 (64) 1.56 1.11 – 2.19 0.010 1.24 1.00 – 1.55 0.054 Log(Ferritin), linear n/a 1.20 0.99 – 1.46 0.07 1.20 1.04 – 1.38 0.010 <3.4 g/dL 203 (29.5) 1.58 1.16 – 2.15 0.004 1.37 1.10 – 1.72 0.005 Biomarker Score ** N Low (<1.5) 200 1.0 - - 1.0 Intermediate (1.5-2.0) 331 1.66 1.10-2.49 0.015 1.38 1.06-1.80 0.017 High (>2.0) 159 2.72 1.77-4.19 <0.001 2.01 1.51-2.70 <0.001 * biomarkers adjusted for significant covariates of BMI, disease, mismatch, and CMV serostatus and stratified on conditioning regimen ** combined model includes all biomarkers and HCT-CI Disclosures No relevant conflicts of interest to declare.

Abstract Background: The association of clinical trial participation with outcomes in cancer patients is controversial, with some studies reporting better outcomes for trial participants while others do not. It is possible that the difference in outcomes is due to differences in baseline characteristics of participants and non-participants. The Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0201 trial was a large randomized, multi-center study comparing peripheral blood (PB) with bone marrow (BM) for hematopoietic cell transplantation (HCT) from HLA-matched or 1 allele mismatched unrelated donors (URD) in patients with acute leukemia, chronic myeloid leukemia and myelodysplastic syndromes. The trial reported no significant survival differences between PB and BM; there was decreased risk of graft failure but increased risk of chronic graft-versus-host disease (GVHD) with PB grafts (Anasetti et al NEJM 2012). Methods: We compared characteristics of BMT CTN 0201 study participants (n=494) with HCT recipients who did not participate on the trial (n=1384) but were potentially eligible by virtue of known characteristics. These patients received similar conditioning and GVHD prophylaxis as trial participants at 38 United States trial centers during the study time-period. Centers that had no eligible non-trial participants were excluded. Outcomes between patients on and off trial were compared using Cox proportional hazards regression models. Data were obtained from the Center for International Blood and Marrow Transplant Research (CIBMTR) that collects patient data on all trial and non-trial allogeneic HCT recipients through its registry function. Results: Approximately 29% [494/1878] of apparently eligible patients were randomized and analyzed as part of the trial. There were no significant differences between study participants and non-participants in age or sex distribution, disease types, HLA or sex matching, comorbidities, or interval from diagnosis to HCT. Higher proportions of non-participants were Hispanic, had a lower performance status and lower disease risk, and received myeloablative conditioning and antithymocyte globulin (ATG) or Campath than the study participants. PB was used more commonly as the graft source in the non-participants as compared to the study participants (65% vs. 50%, p<0.001). In multivariate models, overall mortality (HR 1.09, 95% CI 0.95-1.25, p=0.22), transplant-related mortality (HR 1.08, 95% CI 0.89-1.32, p=0.42) and risks of acute grade II-IV (HR 0.96, 95% CI 0.82-1.12, p=0.57) and chronic GVHD (HR 1.06, 95% CI 0.92-1.23, p=0.41) were comparable between study non-participants and participants. Non-participants were at higher risk for relapse than participants (HR 1.24, 95%CI 1.04-1.49, p=0.02) in the multivariate analysis adjusted for disease risk and other clinical variables. Center effect was examined and was not found to be significant (p=0.10). There was no significant interaction between graft source and trial participation (P=0.22) and the risk of mortality was comparable for BM (HR 0.99, 95% CI 0.80-1.22, p=0.90) and PB recipients (HR 1.17, 95% CI 0.97-1.41, p=0.09) whether on trial or off trial. (Figure) Conclusion: Approximately 29% of patients who appeared eligible and were treated with conditioning and GVHD prophylaxis regimens allowed on the trial were enrolled. Despite some differences in clinical characteristics, most of the outcomes of non-trial participants were comparable to trial participants, suggesting that there is no definitive evidence that the outcomes of patients in a clinical trial are superior to those of the non-participants treated in a similar fashion. The comparable outcomes also indicate that the results of this trial were not seriously affected by selection bias and are therefore representative of the larger population. Figure 1: Adjusted overall survival in BMT CTN 0201 trial participants and non-participants Figure 1:. Adjusted overall survival in BMT CTN 0201 trial participants and non-participants Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

Key Points Compared with parous female sibling donors, male URDs confer more aGVHD in all patients and more cGVHD in females. There was no difference in survival, relapse, or transplant mortality between recipients of parous female sibling or male URD grafts.