Murthy, Hemant S.

Abstract We examined the risk of subsequent neoplasms (SNs) and late mortality in children and adolescents undergoing allogeneic hematopoietic cell transplantation (HCT) for nonmalignant diseases (NMDs). We included 6028 patients (median age, 6 years; interquartile range, 1-11; range, <1 to 20) from the Center for International Blood and Marrow Transplant Research (1995-2012) registry. Standardized mortality ratios (SMRs) in 2-year survivors and standardized incidence ratios (SIRs) were calculated to compare mortality and SN rates with expected rates in the general population. Median follow-up of survivors was 7.8 years. Diagnoses included severe aplastic anemia (SAA; 24%), Fanconi anemia (FA; 10%), other marrow failure (6%), hemoglobinopathy (15%), immunodeficiency (23%), and metabolic/leukodystrophy syndrome (22%). Ten-year survival was 93% (95% confidence interval [95% CI], 92% to 94%; SMR, 4.2; 95% CI, 3.7-4.8). Seventy-one patients developed SNs (1.2%). Incidence was highest in FA (5.5%), SAA (1.1%), and other marrow failure syndromes (1.7%); for other NMDs, incidence was <1%. Hematologic (27%), oropharyngeal (25%), and skin cancers (13%) were most common. Leukemia risk was highest in the first 5 years posttransplantation; oropharyngeal, skin, liver, and thyroid tumors primarily occurred after 5 years. Despite a low number of SNs, patients had an 11-fold increased SN risk (SIR, 11; 95% CI, 8.9-13.9) compared with the general population. We report excellent long-term survival and low SN incidence in an international cohort of children undergoing HCT for NMDs. The risk of SN development was highest in patients with FA and marrow failure syndromes, highlighting the need for long-term posttransplantation surveillance in this population.

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: Axi-cel is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy that is approved for treatment of relapsed/refractory (R/R) large B-cell lymphoma and is associated with high response rates and durable remissions. Recent data show that axi-cel is effective across various adverse prognostic features, namely cell of origin, disease bulkiness, and extranodal disease, among others. Hypoalbuminemia is a known adverse prognostic factor in lymphomas. It is unknown if axi-cel overcomes the adverse prognostic feature of hypoalbuminemia in R/R large B-cell or transformed follicular lymphoma. METHODS: We conducted a retrospective analysis of patients treated with axi-cel across three Mayo Clinic campuses (Rochester, Jacksonville, and Phoenix) from 06/01/2018 until 04/01/2019. The primary objective of this analysis was to assess the impact of hypoalbuminemia (defined at day 0, prior to infusion) on outcome after axi-cel therapy. RESULTS: A total of 50 (male=37, 74%) patients (pts), median age of 53 (26-67) years received axi-cel. The median number of prior lines of therapy was 3 (2-8) (Table 1). Two pts had no available serum albumin levels at time of axi-cel infusion. Seven (15%) of 48 pts had serum albumin levels lower than 3.5 g/dL (median= 3.3 g/dL (range 2.6-3.4)) and the median follow up of survivors was 7.6 (1.9-14.3) months. The best overall response rate (ORR) and complete remission (CR) rates in these pts were 57% and 57%, respectively. One (14%) patient had stable disease and 2 (29%) had disease progression. The median overall survival (OS) for pts with hypoalbuminemia was not reached. On the other hand, 41 (85%) pts had a normal serum albumin level (median=4.0 (range 3.5-5.1) g/dL) and the median follow up for survivors was 6.3 months. The best objective response rate (ORR) and complete remission (CR) rates in these pts were 82% and 44%, respectively. The median OS for pts with normal serum albumin was 14 (95%CI=6.3-29.6) months. There was no significant difference at 6-months and 1-year OS between pts with hypoalbuminemia vs. those with normal baseline serum albumin levels [6-month=100% vs. 79%(95%CI=64-93%); 1-year (100% vs. 54% (95%CI=26-82%), p=0.17] (Figure 1). All grades cytokine release syndrome (CRS) was diagnosed in all 7 pts with hypoalbuminemia (100%) and in 38 of 41 (92%) pts without hypoalbuminemia. There was no difference in the median duration of CRS between pts with or without hypoalbuminemia [6 (range 1-11) days vs 5 (range 1-19) days, p=0.89]. Neurotoxicity (all grades) was observed in 5 (71%) pts with hypoalbuminemia compared 26 (63%) with normal albumin levels. There was no statistically significant difference in median duration of neurotoxicity between pts with hypoalbuminemia and those with normal baseline albumin levels [9 (range 1-10) days vs. 3 (range 0-25) days, p= 0.72]. CONCLUSIONS: Hypoalbuminemia does not have a significant impact on the outcomes of axi-cel therapy, including the incidence of CRS or neurotoxicity. These results need to be validated in a large collaborative multicenter study. Further investigation is needed to assess the prognostic impact of severe hypoalbuminemia (<3g/dL) on axi-cel therapy. Disclosures Ansell: Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; Trillium: Research Funding; Trillium: Research Funding; Mayo Clinic Rochester: Employment; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; LAM Therapeutics: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Trillium: Research Funding; Affimed: Research Funding; LAM Therapeutics: Research Funding; Mayo Clinic Rochester: Employment; LAM Therapeutics: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Regeneron: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; Trillium: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Mayo Clinic Rochester: Employment; Trillium: Research Funding; Regeneron: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; Trillium: Research Funding; Trillium: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; Affimed: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; Affimed: Research Funding; Affimed: Research Funding. Bennani:Seattle Genetics: Other: Advisory board; Kite Pharma: Other: Advisory board; Seattle Genetics: Other: Advisory board; Adicet Bio: Other: Advisory board; Seattle Genetics: Other: Advisory board; Purdue Pharma: Other: Advisory board; Adicet Bio: Other: Advisory board; Purdue Pharma: Other: Advisory board; Purdue Pharma: Other: Advisory board; Adicet Bio: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Kite Pharma: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Kite Pharma: Other: Advisory board. Paludo:Verily Life Sciences: Research Funding; Celgene: Research Funding; Verily Life Sciences: Research Funding; Celgene: Research Funding. Tun:DTRM Biopharma: Research Funding; Mundi-pharma: Research Funding; BMS: Research Funding; Celgene: Research Funding; Curis: Research Funding; TG Therapeutics: Research Funding. Foran:Agios: Honoraria, Research Funding. Kharfan-Dabaja:Daiichi Sankyo: Consultancy; Pharmacyclics: Consultancy.

Introduction Renal dysfunction is a recognized risk factor for mortality after HCT, as it is included in the comorbidity index (HCT CI). Yet, further understanding on outcomes in patients with different level of renal dysfunction or undergoing hemodialysis (HD) at time of transplant remains scant. This study explores the impact of different levels renal dysfunction on major HCT outcomes in a large population using data reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). Methods The study population included 8,102 patients age 40 years and older who received HCT for treatment of malignancies from 2008 to 2016, with available pre-transplant creatinine measurement. eGFR, calculated using CKD-EPI (CKD-epidemiology collaboration) method, was used to assigned patients in four categories: eGFR ≥ 90ml/min (eGFR≥ 90, N=4,237, reference), eGFR 60-90ml/min (eGFR 60-90, N=3,158), eGFR 45-59ml/min (eGFR 45-59, N=538) and eGFR <45ml/min(eGFR<45, N=169). A separate cohort of patients on HD at time of HCT (N=46) was analyzed independently. Multivariate analysis models were built for assessment of overall mortality, transplant-related mortality (TRM), disease relapse or progression, graft-versus-host disease (GVHD), hepatic sinusoidal obstructive syndrome (SOS), thrombotic microangiopathy (TMA), idiopathic pneumonia syndrome (IPS) and need of HD post-transplant. Common patient-, disease- and transplant-related covariates were tested on all models and HCT CI was computed without reported renal dysfunction comorbidity to avoid collinearity. Results Patient characteristics are shown in table 1. The groups were comparable on disease risk index, graft and donor source, but patients with eGFR>90 were younger and received myeloablative conditioning more frequently. The cohort of eGFR <45 had a higher proportion of patients with HCT CI ≥3. TRM and overall survival according to eGFR groups are shown in Figure. In the multivariate analysis models eGFR as the main effect was associated with TRM (p<0.0001), overall mortality (p<0.0001), and requirement of HD post HCT (p<0.0001), but not for relapse/progression (p=0.98), GVHD (grades II-IV, p=0.34; III-IV, p=0.70; and chronic, p=0.20), TMA (p=0.46), SOS (p=0.02) or IPS (p=0.06). Compared to eGFR ≥90, the hazard ratio (HR) for TRM for eGFR 60-89 was 1.12 (p=0.07), for eGFR 45-59 was 1.46 (p<0.001) and for eGFR<45 was 1.74 (p=0.004). Corresponding HRs for overall mortality were 1.0 (p=0.9), 1.17 (p=0.03) and 1.63 (p<0.0001), respectively. Similarly, for the need of HD post HCT, HR for eGFR60-89 was 1.29 (p=0.03), eGFR45-59 was 2.45 (p<0.001) and for eGFR<45 was 3.09 (p<0.0001). Only eGFR<45 was associated with higher risk of SOS (HR2.66, p=0.03). Among 46 patients on HD prior to HCT, one-year probability of overall survival was 20% (95% Confidence Interval [CI] 10-32%) and cumulative incidence of TRM at one year was 67% (95% CI, 50-81%). Conclusion These findings indicate that degree of renal dysfunction is an independent predictor of OS, TRM, probability of receiving HD and SOS when adjusted for other risk factors. The impact of eGFR on the need of HD, a complication that increases morbidity post HCT is an important finding. Additionally, the outcomes of a subset of patients on HD at time of transplants are dismal. These results can further assist the prognostic assessment of candidates for an allogeneic HCT. Disclosures Stadtmauer: Celgene: Consultancy; Takeda: Consultancy; Janssen: Consultancy; Amgen: Consultancy; Novartis: Consultancy, Research Funding; Tmunity: Research Funding; Abbvie: Research Funding. Wingard:Ansun: Consultancy; Pluristem: Consultancy; Celgene: Consultancy; Merck: Consultancy; Shire: Consultancy. Ganguly:Seattle Genetics: Speakers Bureau; Daiichi Sankyo: Research Funding; Kite Pharma: Honoraria, Other: Advisory Board; Janssen: Honoraria, Other: Advisory Board. Pasquini:Pfizer: Other: Advisory Board; Amgen: Consultancy; Medigene: Consultancy; BMS: Research Funding; Novartis: Research Funding; Kit Pharma: Research Funding.

Introduction Long-term hematopoietic stem cell transplant (HCT) survivors are burdened by a high prevalence and early onset of chronic diseases. Healthy dietary patterns have been associated with lower risks of chronic health conditions in the general population, yet no study to date has comprehensively documented the adherence of HCT survivors to the Dietary Guidelines for Americans (DGA), specifically designed to provide guidance for making healthy food choices. The aims of this study were to evaluate the extent to which HCT survivors adhere to the DGA and to determine nutrient intake adequacy. A secondary aim was to assess their willingness to take part in a future nutritional program or dietary intervention. Methods The study population included adults (≥18 y), who had undergone autologous or allogeneic HCT for a hematologic disease and were at least 1-year post-transplantation. Dietary intake was assessed using the Block 2014 food frequency questionnaire and diet quality (adherence to the DGA) was estimated using the Healthy Eating Index-2015 (HEI-2015). A HEI score of ≤50 indicates "poor diet quality", 51-80 suggests a "diet that needs improvement", and >81 indicates "good diet quality" out of maximum of 100. HEI-2015 scores by patient and transplant characteristics were analyzed by ANCOVA. Nutrient intake adequacies of the group were estimated by determining the percentage of the group falling below the Estimated Average Requirement (EAR) of the Dietary Reference Intakes. Receptivity to participate in a dietary intervention to stay healthy was measured by the question, "How willing would you be to take part in a healthy nutrition program or diet intervention?" Response categories included, "not at all," "somewhat," and "definitely". Results Between December 2017 and September 2018, 124 survivors were invited to participate, of whom 90 (51 autologous and 39 allogeneic HCT survivors) completed the dietary intake assessment and were included in the analysis. Majority were male (56%), White (72%), married (81%) and completed some college education (57%). Most participants were overweight (34%) or obese (37%). The median time from the HCT was 5.2 years. Mean ±SE HEI-2015 scores were 61.6 ± 1.3 and 60.7 ± 2.2 for the 18-64 y and ≥65 y age groups, respectively, slightly higher than the US general population. Adherence to a good quality diet was reported by only 10% of survivors. The majority of the survivors reported a diet in need of improvement (82%) or a poor-quality diet (8%). Intakes of vitamin A (720 ± 447 mcg/d), vitamin C (82 ± 73 mg/d), vitamin D (4.4 ± 3.4 mcg/d), magnesium (253 ± 133 mg/d), and calcium (781 ± 430 mg/d) suggested inadequacy, as more than 50% of the group fell below the specific EARs. Sodium intake at 2834 ± 1345 mg/d exceeded the DGA recommendation of 2300 mg/d. Fiber intake at 8.9 g per 1000 kcal/d was significantly below the Adequate Intake of 14 g per 1000 kcal/d. "Change in taste" was the only variable associated with lower quality of diet (p=0.02). Interestingly, 29% of HCT survivors reported persistent altered taste sensation. No significant relationships were seen for participant's demographics and diet quality which may be due to a sample population skewed toward older, causations and socioeconomically advantaged individuals. More than two thirds of participants (73%) indicated an interest in participating in dietary intervention. HCT survivors within 2 years of transplant were more likely to be receptive to participation in a diet intervention study compared to survivors beyond 2 years (52% vs 28%, p=0.0013). Conclusion Adult HCT survivors report poor adherence to the 2015 Dietary Guidelines for Americans and have numerous short-fall nutrient intakes. However, the willingness to participate in a nutritional program or dietary intervention in this survivorship population was relatively high. These findings reinforce the need to incorporate nutrition into HCT survivor care. Disclosures Wingard: Celgene: Consultancy; Merck: Consultancy; Shire: Consultancy; Ansun: Consultancy; Pluristem: Consultancy.

Background: Sickle cell disease (SCD) is an inherited hemoglobinopathy which affects over 300,000 children born each year worldwide. In spite of improvement in supportive care in recent years, there is still a lack of effective treatment options. SCD leads to debilitating and cyclic episodes of erythrocyte sickling with progressive organ injury, contributing to lifetime morbidity and shortened life expectancy. Allogeneic HCT (allo-HCT) is a potentially curative therapy for SCD because engraftment is associated with resolution of the clinical phenotype of the disease and abrogation of its complications. Medical literature on allo-HCT for SCD is largely limited to children. Recent studies have evaluated the efficacy of allo-HCT in the adult population. Here, we conduct a systematic review/meta-analysis to assess the totality of evidence pertaining to the efficacy (or lack thereof) of allo-HCT in children and adults. Materials and methods: We performed a comprehensive search of the medical literature using PubMed/Medline, EMBASE and Cochrane library on July 3rd, 2019. We extracted data on clinical outcomes related to benefits (overall [OS] and disease free/event free survival [EFS/DFS]) and harms (non-relapse mortality [NRM] and graft failure [GF]), independently by two authors. Our search strategy identified 1001 references but only 30 studies (n= 1995 patients) were included in this systematic review/meta-analysis. We also performed a sub analysis on clinical outcomes for studies that included only pediatric patients (defined as <18 years) and those in patients ≥18 years of age. Results: Median age for patients enrolled in all the studies was at 10 years. Recurrent veno-occlusive crises represented the most common indication for allo-HCT followed by acute chest syndrome and stroke; nevertheless, most patients had more than one indication. Matched related donors (MRD) were the most common donor source (93%). Bone marrow was the most common source of hematopoietic stem cells (77%). Majority of patients underwent conditioning with myeloablative regimens (77%). Pooled OS rates (n=29 studies, 1681 patients) after allogeneic HCT was 95% (95%CI=93-96%) with low heterogeneity (I2=6.4%) among included studies (Figure 1). Pooled EFS/DFS rates (n=29 studies, 1894 patients) post-allografting was 90% (95%CI=87-93%) with moderate heterogeneity (I2=54%). Pooled NRM rates from 30 studies (1995 patients) was 4% (95%CI=2-6%) with low heterogeneity (I2=29.4%). Pooled GF rates from 28 studies (1851 patients) was 4% (95%CI=2-6%) with moderate heterogeneity (I2=55%). A subset analysis specifically for pediatric patients (n= 11 studies, 1009 patients, median age at 9.7 years) showed a pooled OS rate of 96% (95%CI=94-97%) with low heterogeneity (I2=0%); and for adult patients (n=3 studies, 51 patients, median age at 33.4 years) the pooled OS was 94% (95%CI=80-100%) with moderate heterogeneity (I2=52%). Pooled EFS/DFS for pediatric patients (n= 11 studies, 1009 patients) was at 89 %( 95%CI=84-93%) with moderate heterogeneity (I2=55.1%); and for adult patients (n=2 studies, 30 patients) was at 95% (95%CI=83-100%) with high heterogeneity (I2=96.5%). Pooled NRM from 10 studies with pediatric patients (281 patients) was at 6 % (95%CI=3-10%) with low heterogeneity (I2=0%); and from 3 studies with adult patients (51 patients) was at 1% (95%CI=0-7%) with low heterogeneity (I2=15.1%). Pooled GF from 10 studies with pediatric patients (281 patients) was at 3 % (95%CI=1-7%) with moderate heterogeneity (I2=40%); and from 2 studies with adult patients (30 patients) was at 5% (95%CI=0-17%) with high heterogeneity (I2=95.4%). Conclusions: The results of our systematic review/meta-analysis show excellent OS, EFS/DFS in children and adults undergoing allo-HCT with pooled OS rates exceeding 90%. The main limitation to offering an allo-HCT in SCD remains the availability of a suitable donor as 85% of patients meeting criteria do not have a MRD. We anticipate that with emergence of haploidentical transplantation the number of allo-HCT will increase in the future. GF remains a significant concern in this population and future studies should focus on novel immune suppression strategies to help reduce GF. Disclosures Kharfan-Dabaja: Pharmacyclics: Consultancy; Daiichi Sankyo: Consultancy.

Background: Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the treatment of relapsed/refractory B-cell lymphoid malignancies. Axicabtagene ciloleucel (axi-cel), an anti-CD19 CAR-T not only targets the malignant B-cell, but can potentially also target and eliminate normal B-cells. This can interfere with the normal B-cell repertoire, compromising host humoral immunity such as decreased titers of common vaccines (DTaP, MMR). To assess if this was a clinically significant problem, we evaluated all recipients of axi-cel at our center between 6/2018 through 7/2019. Patients and methods: For patients who received commercial axi-cel, humoral immunity was evaluated both quantitatively [absolute lymphocyte count (ALC)] as well as qualitatively by serology titers [IgG antibodies (Abs)] for diphtheria, tetanus, pertussis, measles, mumps, and rubella, and total Immunoglobulin G (IgG) levels. Data was collected within 30 days prior to CAR-T infusion, then at day +30 and between days +60 and +100 after CAR-T infusion. Results: We identified 10 patients (males = 5, 50%), with a median age of 49.9 years (range 30-65) who received commercial axi-cel during the study period. Patient characteristics and indications for CAR-T therapy are shown in Table 1; the cohort represented a heavily pre-treated aggressive B-cell lymphoma patient population. Baseline information on antibody (Ab) titers was available in 8 patients. At baseline, all patients had positive tetanus IgG Abs (≥0.01 IU/mL), 7 had positive diphtheria IgG Abs (≥0.01 IU/mL), 6 had positive measles IgG Abs (≥ 1.1 AI), 5 had positive rubella IgG Abs (≥ 1.0 AI), 3 had positive mumps IgG Abs (≥ 1.1 AI). None of the patients had a positive pertussis IgG Abs (≥100 IU/mL). At follow-up, all patients with positive Ab at baseline maintained titers in the positive range at day +30 and between days +60 and +100 (Figure 1). None of the patients demonstrated a clinically meaningful decrease in Abs titers, despite a drop in ALC and IgG levels (table 2). Conclusions: Albeit a small sample size, IgG Ab titers for diphtheria, tetanus, measles, mumps, and rubella did not appear to be affected by axi-cel at a short interval follow-up after infusion (up to day +100). We plan to extend this analysis in a larger cohort with a longer-term prospective follow-up to validate our findings, especially in light of dropping absolute lymphocyte counts and IgG levels. Disclosures Ailawadhi: Celgene: Consultancy; Amgen: Consultancy, Research Funding; Cellectar: Research Funding; Janssen: Consultancy, Research Funding; Takeda: Consultancy; Pharmacyclics: Research Funding. Foran:Agios: Honoraria, Research Funding. Tun:Celgene: Research Funding; Curis: Research Funding; TG Therapeutics: Research Funding; Mundi-pharma: Research Funding; DTRM Biopharma: Research Funding; BMS: Research Funding. Chanan-Khan:Pharmacyclics: Research Funding; Merck: Research Funding; Jansen: Research Funding; Mayo Clinic: Employment; Ascentage: Research Funding; Millennium: Research Funding; AbbVie: Research Funding; Xencor: Research Funding. Kharfan-Dabaja:Daiichi Sankyo: Consultancy; Pharmacyclics: Consultancy.

Abstract HLA-haploidentical hematopoietic cell transplantation (Haplo-HCT) using posttransplantation cyclophosphamide (PT-Cy) has improved donor availability. However, a matched sibling donor (MSD) is still considered the optimal donor. Using the Center for International Blood and Marrow Transplant Research database, we compared outcomes after Haplo-HCT vs MSD in patients with acute myeloid leukemia (AML) in first complete remission (CR1). Data from 1205 adult CR1 AML patients (2008-2015) were analyzed. A total of 336 patients underwent PT-Cy–based Haplo-HCT and 869 underwent MSD using calcineurin inhibitor–based graft-versus-host disease (GVHD) prophylaxis. The Haplo-HCT group included more reduced-intensity conditioning (65% vs 30%) and bone marrow grafts (62% vs 7%), consistent with current practice. In multivariable analysis, Haplo-HCT and MSD groups were not different with regard to overall survival (P = .15), leukemia-free survival (P = .50), nonrelapse mortality (P = .16), relapse (P = .90), or grade II-IV acute GVHD (P = .98). However, the Haplo-HCT group had a significantly lower rate of chronic GVHD (hazard ratio, 0.38; 95% confidence interval, 0.30-0.48; P &lt; .001). Results of subgroup analyses by conditioning intensity and graft source suggested that the reduced incidence of chronic GVHD in Haplo-HCT is not limited to a specific graft source or conditioning intensity. Center effect and minimal residual disease–donor type interaction were not predictors of outcome. Our results indicate a lower rate of chronic GVHD after PT-Cy–based Haplo-HCT vs MSD using calcineurin inhibitor–based GVHD prophylaxis, but similar other outcomes, in patients with AML in CR1. Haplo-HCT is a viable alternative to MSD in these patients.

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.