Returning to Work Following Hematopoietic Cell Transplantation: The Survivor's Perspective.

While curing a patient's underlying disease is the primary goal of physicians performing hematopoietic cell transplantation (HCT), the ultimate objective is to provide patients with optimal post-HCT quality of life. For many survivors, this includes returning to work (RTW). We conducted a survey of 1- to 5-yr post-HCT survivors at our center to evaluate their perspective on facilitators and barriers to RTW as well as to gauge interest in potentially useful RTW support interventions. Survivors aged 18 to 65 yrs (n = 994) were sent an annual survey that included 36 supplementary questions about post-HCT RTW. Survey questions were selected from published national cancer survivor surveys and then modified specifically for HCT survivors. Three hundred forty-four (35%) survivors with a mean age of 53 yrs completed the survey, of whom 272 (79%) had worked prior to their diagnosis. Of those 272 patients, 145 (53%) were working currently and another 22 (8%) had attempted to go back to work following HCT but were not presently working. We found that having had an allogeneic versus autologous HCT (P = .006) was associated with a decreased likelihood of currently working, whereas frequent employer communication (>once a month) (P = .070) and having a more supportive employer (P = .036) were associated with a greater chance of currently working. Of survivors currently working, 45% reported that they had made one or more changes to their work schedule (e.g., flexible schedule or part-time work) or environment (e.g., work from home) upon RTW. Ninety-five percent of responders reported that they could have benefited from RTW support provided by the transplant center, but only 13% indicated that they had received it. Education on RTW challenges, information on disability benefits, and access to physical therapy were among the most requested support interventions. To improve post-HCT quality of life for survivors open to assistance, providers should address work status and goals, recognize barriers to successful return, and offer RTW support including working directly with employers. Allogeneic HCT survivors are particularly vulnerable to failing attempts to RTW and should be the target of retention interventions. A previously published manuscript on RTW guidance for providers of stem cell transplant patients endorsed by the American Society of Transplant and Cellular Therapy is available in Open Access and can be used as a tool to counsel and support these patients.

Combined effect of unrelated donor age and HLA peptide-binding motif match status on HCT outcomes.

ABSTRACT: An HLA-mismatched unrelated donor who is class I peptide-binding motif (PBM)-matched is preferred over a PBM-mismatched donor. We hypothesized that using a younger donor (aged ≤35 years vs >35 years) could compensate for the inferior overall survival (OS) associated with PBM mismatches. We compared 6 groups: HLA-matched/younger donor (n = 10 531), HLA-matched/older donor (n = 3572), PBM-matched/younger donor (n = 357), PBM-matched/older donor (n = 257), PBM-mismatched/younger donor (n = 616), and PBM-mismatched/older donor (n = 339) in patients undergoing transplantation with conventional graft-versus-host disease prophylaxis. In multivariate analysis, HLA-matched/younger donors were associated with superior OS relative to any other group. Pairwise comparisons showed that donor age significantly impacted OS in both HLA-matched and HLA-mismatched groups. Moreover, younger donors appeared to negate the detrimental effect of PBM mismatching: the PBM-matched/younger donor group had similar OS as the HLA-matched/older donor group and the PBM-mismatched/younger donor group had similar OS as the PBM-matched/older donor group. Our study suggests that older unrelated donor age and PBM mismatching confer similarly adverse effects on OS and the impacts are additive, a finding which may widen the "acceptable" donor pool. The best OS is observed with HLA-matched/younger donors and the worst with PBM-mismatched/older donors. These findings should be validated with other data sets and with posttransplantation cyclophosphamide-based prophylaxis.

Financial Toxicity, Time Toxicity, and Quality of Life in Multiple Myeloma.

BACKGROUND: Patients with multiple myeloma (MM) may be on therapy for years, which can lead to financial toxicity (FinTox) or time toxicity (TimeTox). The prevalence, predictors, and quality of life (QOL) impacts of FinTox and TimeTox during different phases of MM treatment have not been characterized. PATIENTS AND METHODS: We conducted a single-center cross-sectional survey of patients with MM who had undergone transplantation. FinTox+ was defined as a COST-FACIT score <23, TimeTox+ as MM-related interactions (including phone calls) ≥1x weekly or ≥1x monthly in-person among far-residing patients, QOL using PROMIS Global Health, and functional status using patient-reported Karnofsky performance status (KPS). RESULTS: Of 252 patients, 22% and 40% met FinTox+ and TimeTox+ criteria respectively. Respective FinTox+ and TimeTox+ proportions were 22%/37% for patients on maintenance, 22%/82% with active therapy, and 20%/14% with observation. FinTox+ predictors included annual income (P < .01) and out-of-pocket costs (P < .01). TimeTox+ predictors included disease status (P < .001), caregiver status (P = .01), far-residing status (P < .001), and out-of-pocket costs (P = .03). FinTox+ was associated with a clinically meaningful decrease in mental QOL, while TimeTox+ patients were more likely to have KPS ≤ 80. CONCLUSIONS: In our large study, monetary status but not disease status predicted FinTox. Over a third of patients on maintenance reported TimeTox. FinTox+ was associated with decreased mental health, while TimeTox+ was associated with worse performance status. These two toxicities may negatively impact patient wellbeing, and studies of strategies to mitigate their impact are in development.

Mycophenolate mofetil is associated with inferior overall survival in cytomegalovirus seropositive patients with acute myeloid leukemia undergoing hematopoietic cell transplantation.

Not available.

Azacitidine Post-transplant Maintenance Improves Disease Progression in High-Risk Acute Myeloid Leukemia and Myelodysplastic Syndrome.

BACKGROUND: Maintenance after allogeneic hematopoietic cell transplantation (alloHCT) with hypomethylating agents has yielded conflicting results. MATERIALS AND METHODS: We conducted a single center retrospective matched-control analysis with the study group (5-azacitidine [AZA] group) including adults with FLT3-negative acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) who received post-transplant AZA maintenance off clinical trial (n = 93). A matched control group was comprised of contemporaneous AML/MDS patients who did not receive any maintenance (n = 357). Primary endpoint was disease progression. RESULTS: The AZA and control groups had comparable patient and disease characteristics except for older age (median: 61 vs. 57 years, P = .01) and lower hematopoietic comorbidity index (median: 2 vs. 3, P = .04) in the AZA group. The 3-year cumulative incidence of progression in the AZA and control groups was 29% vs. 33% (P = .09). The protective effect of AZA on progression was limited to patients with high-risk AML/MDS (HR = 0.4, 95% CI = 0.2-0.8, P = .009). This led to improved progression-free survival both in high-risk AML and MDS patients with maintenance (HR = 0.2, 95% CI = 0.1-0.6, P = .004 and HR = 0.4, 95% CI = 0.2-0.9, P = .04). CONCLUSION: AZA maintenance was associated with a lower progression rate in patients with high-risk FLT3-negative AML or MDS, and AZA maintenance should be considered for post-alloHCT maintenance in this subset.

Eltrombopag improves platelet engraftment after haploidentical bone marrow transplantation: Results of a Phase II study.

Slow platelet recovery frequently occurs after haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with bone marrow graft and post-transplant cyclophosphamide (PCy)-based graft-versus-host disease (GVHD) prophylaxis. Improved platelet recovery may reduce the need for transfusions and improve outcomes. We investigated the safety and efficacy of eltrombopag, a thrombopoietin receptor agonist, at enhancing platelet recovery post-haplo-HSCT. The prospective study included patients ≥18 years of age who received haplo-HSCT with bone marrow graft and PCy. Patients received eltrombopag 300 mg/day starting on Day +5. The primary objective was to estimate platelet engraftment (>50 000/µL by Day 60). In a post hoc analysis, they were compared to a contemporary matched control group who did not receive eltrombopag. One hundred ten patients were included in the analysis (30 eltrombopag and 80 control). Seventy-three percent and 50% of patients in the eltrombopag group and control group, respectively, attained >50 000/µL platelet count by Day 60 (p = .043). No eltrombopag-related grade ≥4 adverse events were observed. Median time to platelet recovery (>20 000/µL) was 29 days with eltrombopag and 31 days for controls (p = .022), while its cumulative incidence was 90% (95% confidence interval [CI]: 78%-100%) with eltrombopag versus 67.5% (95% CI: 57%-78%) for controls (p = .014). Number of platelet transfusions received, overall survival, progression-free survival, GVHD rate, relapse rate, and non-relapse mortality were similar between groups. Overall, eltrombopag is safe and improves platelet recovery in patients undergoing haplo-HSCT with bone marrow graft and PCy.

Effect of donor age in patients with acute myeloid leukemia undergoing haploidentical hematopoietic cell transplantation vary by conditioning intensity and recipient age.

We investigated the impact of donor age (younger [≤35 years] vs. older [>35 years]) after accounting for other non-HLA and HLA factors on outcomes of patients with acute myeloid leukemia undergoing HLA-haploidentical hematopoietic cell transplantation (n = 790). The effect differed by conditioning-partly related to the differences in the recipient age in myeloablative (MAC; median 46 years) versus reduced-intensity/non-myeloablative conditioning (RIC/NMA; median 61 years) groups. With MAC (n = 320), donor age had no impact on acute graft-versus-host disease (GVHD), but older donors were associated with a significantly higher risk of chronic GVHD (hazard ratio [HR]: 1.6, 95% confidence interval [CI]: 1.10-2.30, p = .02) independent of recipient age and other factors. Donor age had no impact on either relapse or non-relapse mortality (NRM). The impact of donor/recipient age on overall survival changed over time. Older donors were associated with significantly higher late overall mortality (>6 months) in younger recipients (≤ 50 years; HR: 2.2, 95% CI: 1.03-4.6, p = .04) but not older recipients. With RIC/NMA (n = 470), neither recipient's nor donor's age influenced the risk of GVHD. Donor age had no significant impact on the risk of relapse, but older donors were associated with a significantly higher risk of NRM (HR: 1.6, 95% CI: 1.02-2.6, p = .04) independent of recipient age. Older donor age was associated with significantly higher late overall mortality (>9 months) in older recipients (>50 years; HR: 1.66, 95% CI: 1.0-2.67; p = .049) but not in younger recipients. Donor selection based on donor age may require a tailored approach for a particular recipient.

Characteristics and Outcomes of Patients With Multiple Myeloma Who Developed Therapy-Related Acute Myeloid Leukemia and Myelodysplastic Syndrome After Autologous Cell Transplantation.

Patients with multiple myeloma (MM) who undergo high-dose chemotherapy and autologous hematopoietic cell transplantation (Auto-HCT) have an increased risk of developing therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML). We retrospectively reviewed the medical records of all MM patients who underwent an Auto-HCT at our institution between 1 January and 31 December 2018 and later developed t-MDS/AML. Among the 2982 patients who underwent at least 1 Auto-HCT, 55 (2%) developed t-MDS/AML (MDS, n = 52; AML, n = 3). The median age at t-MDS/AML diagnosis was 66 years (range 43-83 years), and the median time from Auto-HCT to t-MDS/AML diagnosis was 58.5 months (range 6-206 months). At diagnosis, all 3 patients with tAML and 65% of those with therapy-related myelodysplastic syndrome (tMDS) had high-risk disease, per 2022 European LeukemiaNet and R-IPSS, respectively, and 62% had TP53 gene mutations. Patients who developed tMDS/AML were older at MM diagnosis (median 61 versus 59 years; P = .06), more often were male (73% versus 58%; P = .029), received more than 2 years of lenalidomide maintenance (57% versus 39%; P = .014), and experienced complete remission more frequently after Auto-HCT compared to those who did not develop t-MDS/AML (56% versus 40%; P = .012). In a multivariable model, male gender, advanced age at MM diagnosis, experiencing complete remission after Auto-HCT, and lenalidomide maintenance were independent predictors of developing t-MDS/AML. Among the patients who developed t-MDS/AML, 14 (25%) underwent allogeneic hematopoietic stem transplantation (Allo-HCT). After a median follow-up of 9.9 months from t-MDS/AML diagnosis, the median overall survival (OS) after t-MDS/AML diagnosis was 11.8 months for all patients, and 18.2 months versus 11.1 months for Allo-HCT recipients versus nonrecipients, respectively (P = .25). On univariate analysis, receiving an alkylator as induction for MM (hazard ratio [95% confidence interval]: 2.9 [1.3-6.3]; P = .009), age > 60 years (3.1 [1.2-8.2]; P = .025), and higher-risk R-IPSS (2.7 [1.3-6.0]; P=0.011) predicted worse OS after t-MDS/AML diagnosis. None of these retained significance in the multivariable analysis. T-MDS/AML after Auto-HCT for MM is associated with aggressive disease characteristics, including high-risk cytogenetics and TP53 mutations. The outcomes of patients remain poor, even with Allo-HCT. A better understanding of disease biology and novel therapeutic approaches is warranted.

Myeloablative fractionated busulfan for allogeneic stem cell transplant in older patients or patients with comorbidities.

Traditional conditioning regimens for patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) provide suboptimal outcomes, especially for older patients and those with comorbidities. We hypothesized that a fractionated myeloablative busulfan dose delivered over an extended period would reduce nonrelapse mortality (NRM) while retaining antileukemic effects. Here, we performed a phase 2 trial for adults with hematological malignancies receiving matched related or unrelated allo-HCT. Participants received busulfan 80 mg/m2 as outpatients on days -20 and -13 before transplant. Fludarabine 40 mg/m2 was administered on days -6 to -3, followed by busulfan dosed to achieve a target area under the curve of 20 000 mol/min for the whole course. The primary end point was day-100 NRM. Seventy-eight patients were included, with a median age of 61 years (range, 39-70 years), who received transplantation for acute leukemia (24%), myelodysplastic syndrome (27%), or myeloproliferative disease/chronic myeloid leukemia (44%). HCT-specific comorbidity index (HCT-CI) was ≥3 in 34 (44%). With a median follow-up of 36.4 months (range, 2.9-51.5), the 100-day, 1-year, and 3-year NRM rates were 3.8%, 8%, and 9.3%, respectively, without a significant difference in age or HCT-CI score. The 1-year and 3-year relapse incidence was 10% and 18%, respectively. The 3-year overall survival was 80%, without a significant difference in age or HCT-CI score and was similar for patients aged >60 years and those aged <60 years as well as for those with HCT-CI ≥3 and HCT-CI <3. Overall, a myeloablative fractionated busulfan regimen has low NRM without an increase in relapse rate, resulting in promising survival, even in older patients or in patients with comorbidities. This trial was registered at www.clinicaltrials.gov as #NCT02861417.

A Nasal Inflammatory Cytokine Signature Is Associated with Early Graft-versus-Host Disease of the Lung after Allogeneic Hematopoietic Cell Transplantation: Proof of Concept.

Respiratory inflammation in bronchiolitis obliterans syndrome (BOS) after hematopoietic cell transplantation (HCT) is poorly understood. Clinical criteria for early-stage BOS (stage 0p) often capture HCT recipients without BOS. Measuring respiratory tract inflammation may help identify BOS, particularly early BOS. We conducted a prospective observational study in HCT recipients with new-onset BOS (n = 14), BOS stage 0p (n = 10), and recipients without lung impairment with (n = 3) or without (n = 8) chronic graft-versus-host disease and measured nasal inflammation using nasosorption at enrollment and then every 3 mo for 1 y. We divided BOS stage 0p into impairment that did not return to baseline values (preBOS, n = 6), or transient impairment (n = 4). We tested eluted nasal mucosal lining fluid from nasosorption matrices for inflammatory chemokines and cytokines using multiplex magnetic bead immunoassays. We analyzed between-group differences using the Kruskal-Wallis method, adjusting for multiple comparisons. We found increased nasal inflammation in preBOS and therefore directly compared patients with preBOS to those with transient impairment, as this would be of greatest diagnostic relevance. After adjusting for multiple corrections, we found significant increases in growth factors (FGF2, TGF-α, GM-CSF, VEGF), macrophage activation (CCL4, TNF-α, IL-6), neutrophil activation (CXCL2, IL-8), T cell activation (CD40 ligand, IL-2, IL-12p70, IL-15), type 2 inflammation (eotaxin, IL-4, IL-13), type 17 inflammation (IL-17A), dendritic maturation (FLT3 ligand, IL-7), and counterregulatory molecules (PD-L1, IL-1 receptor antagonist, IL-10) in preBOS patients compared to transient impairment. These differences waned over time. In conclusion, a transient multifaceted nasal inflammatory response is associated with preBOS. Our findings require validation in larger longitudinal cohorts.

A prospective phase 2 clinical trial of a C5a complement inhibitor for acute GVHD with lower GI tract involvement.

Involvement of lower gastrointestinal tract (LGI) occurs in 60% of patients with graft-versus-host-disease (GVHD). Complement components C3 and C5 are involved in GVHD pathogenesis. In this phase 2a study, we evaluated the safety and efficacy of ALXN1007, a monoclonal antibody against C5a, in patients with newly diagnosed LGI acute GVHD receiving concomitant corticosteroid. Twenty-five patients were enrolled; one was excluded from the efficacy analysis based upon negative biopsy. Most patients (16/25, 64%) had acute leukemia; 52% (13/25) had an HLA-matched unrelated donor; and 68% (17/25) received myeloablative conditioning. Half the patients (12/24) had a high biomarker profile, Ann Arbor score 3; 42% (10/24) had high-risk GVHD per Minnesota classification. Day-28 overall response was 58% (13/24 complete response, 1/24 partial response), and 63% by Day-56 (all complete responses). Day-28 overall response was 50% (5/10) in Minnesota high-risk and 42% (5/12) in high-risk Ann Arbor patients, increasing to 58% (7/12) by Day-56. Non-relapse mortality at 6-months was 24% (95% CI 11-53). The most common treatment-related adverse event was infection (6/25, 24%). Neither baseline complement levels (except for C5), activity, nor inhibition of C5a with ALXN1007 correlated with GVHD severity or responses. Further studies are needed to evaluate the role of complement inhibition in GVHD treatment.

Impact of type of induction therapy on outcomes in older adults with AML after allogeneic stem cell transplantation.

Although venetoclax-based lower-intensity regimens have greatly improved outcomes for older adults with acute myeloid leukemia (AML) who are unfit for intensive chemotherapy, the optimal induction for older patients with newly diagnosed AML who are suitable candidates for hematopoietic stem cell transplant (HSCT) is controversial. We retrospectively analyzed the post HSCT outcomes of 127 patients ≥60 years of age who received induction therapy at our institution with intensive chemotherapy (IC; n = 44), lower-intensity therapy (LIT) without venetoclax (n = 29), or LIT with venetoclax (n = 54) and who underwent allogeneic HSCT in the first remission. The 2-year relapse-free survival (RFS) was 60% with LIT with venetoclax vs 54% with IC, and 41% with LIT without venetoclax; the 2-year overall survival (OS) was 72% LIT with venetoclax vs 58% with IC, and 41% with LIT without venetoclax. The benefit of LIT with venetoclax induction was greatest in patients with adverse-risk AML (2-year OS: 74%, 46%, and 29%, respectively). Induction with LIT, with or without venetoclax, was associated with the lowest rate of nonrelapse mortality (NRM) (2-year NRM: 17% vs 27% with IC; P = .04). Using multivariate analysis, the type of induction therapy did not significantly affect any of the post HSCT outcomes evaluated; hematopoietic cell transplantation-specific comorbidity index was the only factor that independently predicted RFS and OS. LIT plus venetoclax followed by HSCT is a feasible treatment strategy in older, fit, HSCT-eligible patients with newly diagnosed AML and may be particularly beneficial for those with adverse-risk disease.

Impact of Donor Age in Haploidentical-Post-Transplantation Cyclophosphamide versus Matched Unrelated Donor Post-Transplantation Cyclophosphamide Hematopoietic Stem Cell Transplantation in Patients with Acute Myeloid Leukemia.

Haploidentical hematopoietic cell transplantation (HCT) with post-transplantation cyclophosphamide (PTCy) graft-versus-host-disease (GVHD) prophylaxis is associated with inferior overall survival (OS) compared to HLA-matched unrelated donor (MUD) HCT with PTCy prophylaxis in patients receiving reduced-intensity conditioning (RIC). Given prognostic implications of donor age, we investigated the differences in outcomes of patients with acute myeloid leukemia (AML; n = 775) undergoing RIC-HCT with a younger MUD (age <35 years; n = 84) versus a younger haploidentical donor (age <35 years; n = 302) versus an older haploidentical donor (age ≥35 years; n = 389). The older MUD group was excluded from the analysis because of small numbers. The younger haploidentical donor group (median age, 59.5 years) was somewhat younger than the younger MUD group (median age, 66.8 years) and the older haploidentical donor group (median age, 64.7 years). More patients in the MUD group received peripheral blood grafts (82%) compared to the haploidentical donor groups (55% to 56%). In multivariate analysis, compared to the younger MUD group, the younger haploidentical donor group (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.22 to 3.12; P = .005) and the older haploidentical donor group (HR, 2.36; 95% CI, 1.50 to 3.71; P < .001) had a significantly inferior OS, and the younger haploidentical donor group (HR, 3.72; 95% CI, 1.39 to 9.93; P = .009) and older haploidentical donor group (HR, 6.91; 95% CI, 2.75 to 17.39; P < .001) had a significantly higher risk of nonrelapse mortality. The older haploidentical group had a significantly higher risk of grade II-IV acute GVHD (HR, 2.29; 95% CI, 1.38 to 3.80; P = .001) and grade III-IV acute GVHD (HR, 2.70; 95% CI, 1.09 to 6.71; P = .03). There were no significant differences across the groups in the incidence of chronic GVHD or relapse. Among adult AML patients in CR undergoing RIC-HCT with PTCy prophylaxis, a young MUD may be preferred over a young haploidentical donor.

Bacteroides ovatus alleviates dysbiotic microbiota-induced intestinal graft-versus-host disease.

Acute gastrointestinal intestinal GVHD (aGI-GVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation, and the intestinal microbiota is known to impact on its severity. However, an association between treatment response of aGI-GVHD and the intestinal microbiota has not been well-studied. In a cohort of patients with aGI-GVHD (n=37), we found that non-response to standard therapy with corticosteroids was associated with prior treatment with carbapenem antibiotics and loss of Bacteroides ovatus from the microbiome. In a mouse model of carbapenem-aggravated GVHD, introducing Bacteroides ovatus reduced severity of GVHD and improved survival. Bacteroides ovatus reduced degradation of colonic mucus by another intestinal commensal, Bacteroides thetaiotaomicron, via its ability to metabolize dietary polysaccharides into monosaccharides, which then inhibit mucus degradation by Bacteroides thetaiotaomicron and reduce GVHD-related mortality.

Younger haploidentical donor versus older matched unrelated donor for patients with AML/MDS.

Optimal donor selection is fundamental to successful allogeneic hematopoietic cell transplantation (HCT), and donor age influences survival after both matched unrelated donor (MUD) and haploidentical donor HCT. Though recent studies have shown similar outcomes between MUD and haploidentical HCT, it is unknown if outcomes differ following HCT with younger haploidentical donors compared to HCT with older MUDs. Therefore, we performed a retrospective analysis comparing outcomes of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) patients who underwent HCT with younger (≤35 years) haploidentical donors (n = 494) or older (>35 years) MUDs (n = 1005). Patients in the haploidentical and MUD groups received post-transplant cyclophosphamide (PTCy) and conventional graft-versus-host-disease (GVHD) prophylaxis, respectively. In multivariate analysis, use of younger haploidentical donors was associated with improved overall survival (hazard ratio [HR] 0.81, 95% confidence interval [CI] 0.69-0.95, p = .01) and lower rates of grade II-IV acute GVHD (HR 0.64, 95% CI 0.53-0.77, p < .001), grade III-IV acute GVHD (HR 0.37, 95% CI 0.25-0.53, p < .001), and chronic GVHD (HR 0.49, 95% CI 0.40-0.60, p < .001). Relapse rates were similar among those who received myeloablative conditioning but were higher in patients of the younger haploidentical group who received reduced intensity conditioning (HR 1.49, 95%CI 1.18-1.88, p = .001). The younger haploidentical group had significantly lower non-relapse mortality ≥3 months post-HCT (HR 0.59, 95% CI 0.38-0.90, p = .02). Our data support the use of younger haploidentical donors with PTCy over older MUDs with conventional prophylaxis in patients with MDS or AML. Further studies on the importance of donor age in haploidentical and MUD HCT with PTCy prophylaxis are warranted.

Haploidentical vs matched unrelated donors for patients with ALL: donor age matters more than donor type.

Haploidentical hematopoietic cell transplantation (HCT) with posttransplant cyclophosphamide (PTCy) graft-versus-host-disease (GVHD) prophylaxis yields a similar overall survival (OS) to HLA-matched unrelated donor (MUD) HCT with conventional prophylaxis. Given the prognostic implications of donor age, we investigated the impact of donor age (younger [<35 years, n = 868] vs older [≥35 years, n = 418]) and donor type (haploidentical [n = 373] vs MUD [n = 913]) on OS in adult patients with acute lymphoblastic leukemia (ALL). Older donor age was independently associated with significantly poor OS, whereas donor type was not. Next, we directly compared the outcomes of a younger haploidentical donor (n = 187) vs an older MUD (n = 232). In this cohort, more patients in the haploidentical group had B-cell immunophenotype (89% vs 77%, respectively, P < .001), poor cytogenetics (61% vs 51%, respectively, P = .44), Philadelphia chromosome-negative (53% vs 48%, respectively, P = .38), received bone marrow graft (42% vs 16%, respectively, P < .001), and reduced-intensity conditioning (45% vs 23%, respectively, P < .001). In the multivariate analysis, the older MUD group was associated with a significantly higher risk of chronic GVHD, higher nonrelapse mortality (NRM), lower relapse, and poorer OS. Despite a higher risk of relapse, younger donor haploidentical HCT with PTCy prophylaxis may be preferred over older MUD HCT with conventional prophylaxis in patients with ALL due to lower NRM and better OS. Further analysis comparing the effect of donor age in haploidentical PTCy vs MUD PTCy is warranted.