Treatment responsive acute GVHD after posttransplant cyclophosphamide-based prophylaxis: incidence and clinical outcomes.

BACKGROUND: Post-transplant cyclophosphamide (PTCy) following hematopoietic cell transplantation (HCT) has emerged as standard of care for graft-versus-host disease (GVHD) prevention in adult patients without increasing malignant relapse. We previously defined acute GVHD (aGVHD) treatment response categories as either corticosteroid-sensitive (SS), dependent (SD), or resistant (SR) based on response to first-line corticosteroids and reported their clinical outcomes following non-PTCy based prophylaxis. Over one-third of patients developed aGVHD requiring systemic therapy. Cases were predominantly SR with a 14% overall incidence of SR aGVHD. The incidence and clinical outcomes of these three distinct aGVHD treatment response groups following PTCy-based prophylaxis is not well described. OBJECTIVE: The objective of this retrospective, single-institution, cohort study was to assess the incidence and clinical outcomes of SS, SD, and SR aGVHD following HCT with PTCy-based prophylaxis using a prophylactic regimen of PTCy, tacrolimus, and mycophenolate mofetil (MMF). STUDY DESIGN: We included 196 consecutive (2017-2021) adult and pediatric patients receiving allogeneic HCT for malignant and non-malignant disorders at the University of Minnesota. Patients received PTCy on days +3 and +4 plus tacrolimus and mycophenolate mofetil prophylaxis. Bone marrow (BM) and peripheral blood stem cell (PBSC) graft sources and related and unrelated donors were included. Recipients received myeloablative (MAC) or reduced-intensity conditioning (RIC) regimens. RESULTS: In 196 allografts, 54 (28%) developed aGVHD before day +180 with median time to onset of 50 days (IQR 34-71 days). Of those, 32 patients (16% overall) developed maximum grade II-III aGVHD requiring systemic corticosteroids with the following response: 13 (41%) SS, 10 (31%) SD, and 9 (28%) SR. Overall incidence of SR aGVHD was 4.6%. Only 12 patients (6%) developed maximum grade III aGVHD while none had grade IV aGVHD. 2-year overall survival analyzed from 80 days after initiation of systemic treatment was similar in the SS and SD groups (77 and 75%, respectively), comparable to those without aGVHD (81%), but was lowest in the SR group (20%) with GVHD being the primary cause of death. Non-relapse mortality (NRM) was highest in the SR group. MN high risk and higher GVHD grade at onset were risk factors for developing SR aGVHD. CONCLUSIONS: Overall, we report a low incidence (16%) of aGVHD requiring systemic corticosteroids with PTCy-based prophylaxis. Acute GVHD cases were predominantly SS aGVHD with a lower incidence of SD and SR aGVHD. Our findings suggest that PTCy-based prophylaxis reduces rates of treatment resistant aGVHD. Patients with SR aGVHD had the worst clinical outcomes and poorest survival. Those with SS and SD aGVHD had similar clinical outcomes, both better than SR aGVHD.

Impact of melphalan day -1 vs day -2 on outcomes after autologous stem cell transplant for multiple myeloma.

Background: Melphalan is the most common conditioning regimen used prior to autologous stem cell transplant (ASCT); however, there are varying data on optimal melphalan timing prior to transplant for best safety and efficacy. Historically, ASCT conditioning consisted of melphalan 200 mg/m2 on day 2 (D-2) (48 h prior to ASCT), but many institutions have since adopted a melphalan protocol with administration on day 1 (D-1) (24 h prior to SCT) or split dosing over the 2 days. The optimal timing of melphalan has yet to be determined. Methods: In this single-center retrospective study, we analyzed transplant outcomes for patients between March 2011 and September 2020 admitted for high-dose, single-agent melphalan 200 mg/m2 on D-1 vs. D-2. The primary outcomes were time to neutrophil and platelet engraftment. Secondary outcomes include incidence of hospital readmission within 30 days, 2-year progression-free survival, and 2-year overall survival. Results: A total of 366 patients were studied (D-2 n = 269 and D-1 n = 97). The incidence of high-risk cytogenetics was similar between the two groups (37% vs. 40%). Median days to absolute neutrophil count engraftment was similar at 11 days in the D-2 and D-1 cohort (n = 269, range 0-14, IQR 11-11 vs. n = 97, range 0-14, IQR 11-12). Median days to platelet engraftment >20,000/mcL was 18 days for D-2 melphalan (range: 0-28, IQR 17-20) versus 19 days for D-1 melphalan (range: 0-32, IQR 17-21). Overall survival at 2 years post-transplant was similar in both cohorts (94%; p = 0.76), and PFS was 70% in D-2 compared with 78% in D-1 (p = 0.15). In a multivariable model including age and performance status, hospital readmission within 30 days of transplant was higher in the D-1 cohort (odds ratio 1.9; p = 0.01). Conclusion: This study demonstrates similar neutrophil and platelet engraftment in D-1 and D-2 melphalan cohorts with similar 2-year PFS and OS. Either D-2 or D-1 melphalan dosing schedule is safe and effective.

Phase II, Open-Label Clinical Trial of Urinary-Derived Human Chorionic Gonadotropin/Epidermal Growth Factor for Life-Threatening Acute Graft-versus-Host Disease.

Treatments that aid inflammation resolution, immune tolerance, and epithelial repair may improve outcomes beyond high-dose corticosteroids and other broad immunosuppressants for life-threatening acute graft-versus-host disease (aGVHD). We studied the addition of urinary-derived human chorionic gonadotropin/epidermal growth factor (uhCG/EGF; Pregnyl; Organon, Jersey City, NJ) to standard aGVHD therapy in a prospective Phase II clinical trial (ClinicalTrials.gov identifier NCT02525029). Twenty-two patients with Minnesota (MN) high-risk aGVHD received methylprednisolone 48 mg/m2/day plus 2000 units/m2 of uhCG/EGF s.c. every other day for 1 week. Patients requiring second-line aGVHD therapy received uhCG/EGF 2000 to 5000 units/m2 s.c. every other day for 2 weeks plus standard of care immunosuppression (physician's choice). Responding patients were eligible to receive maintenance doses twice weekly for 5 weeks. Immune cell subsets in peripheral blood were evaluated by mass cytometry and correlated with plasma amphiregulin (AREG) level and response to therapy. Most patients had stage 3-4 lower gastrointestinal tract GVHD (52%) and overall grade III-IV aGVHD (75%) at time of enrollment. The overall proportion of patients with a response at day 28 (primary endpoint) was 68% (57% with complete response, 11% with partial response). Nonresponders had higher baseline counts of KLRG1+ CD8 cells and T cell subsets expressing TIM-3. Plasma AREG levels remained persistently elevated in nonresponders and correlated with AREG expression on peripheral blood T cells and plasmablasts. The addition of uhCG/EGF to standard therapy is a feasible supportive care measure for patients with life-threatening aGVHD. As a commercially available, safe, and inexpensive drug, uhCG/EGF added to standard therapy may reduce morbidity and mortality from severe aGVHD and merits further study.

Phase II Study of Myeloablative 7-8/8-Matched Allotransplantation with Post-Transplantation Cyclophosphamide, Tacrolimus, and Mycophenolate Mofetil.

Graft-versus-host disease (GVHD) is the major toxicity of allogeneic hematopoietic cell transplantation (HCT). We hypothesized that a GVHD prophylaxis regimen of post-transplantation cyclophosphamide (PTCy), tacrolimus (Tac), and mycophenolate mofetil (MMF) would be associated with incidences of acute and chronic GVHD in patients receiving a matched or single antigen mismatched HCT. This Phase II study was conducted at the University of Minnesota using a myeloablative regimen of either total body irradiation (TBI) at a total dose of 1320 cGy, administered in 165-cGy fractions, twice daily from day -4 to day -1, or busulfan (Bu) 3.2 mg/kg daily (cumulative area under the curve, 19,000 to 21,000 µmol/min/L) plus fludarabine (Flu) 40 mg/m2 once daily on days -5 to -2, followed by a GVHD prophylaxis regimen of PTCy 50 mg/kg on days +3 and +4, Tac, and MMF beginning on day +5. The primary endpoint was the cumulative incidence of chronic GVHD necessitating systemic immunosuppression (IST) at 1 year post-transplantation. Between March 2018 and May 2022, we enrolled 125 pediatric and adult patients, with a median follow-up of 813 days. The incidence of chronic GVHD necessitating systemic IST at 1 year was 5.5%. The rate of grade II-IV acute GVHD was 17.1%, and that of grade III-IV acute GVHD was 5.5%. Two-year overall survival was 73.7%, and 2-year graft-versus-host disease-free, relapse-free survival was 52.2%. The 2-year cumulative incidence of nonrelapse mortality was 10.2%, and the rate of relapse was 39.1%. There was no statistically significant difference in survival outcomes between recipients of matched donor transplants versus recipients of 7/8 matched donor transplants. Our data show that myeloablative HCT with PTCy/Tac/MMF results in an extremely low incidence of severe acute and chronic GVHD in well-matched allogeneic HCT.

Frailty in Patients with Chronic Graft-versus-Host Disease.

Frailty is an increasingly recognized clinical diagnosis associated with high risk of disability and mortality. Frailty in patients after hematopoietic cell transplantation (HCT) is associated with increased nonrelapse mortality (NRM) and decreased overall survival (OS). Frailty has not been studied extensively in patients with chronic graft-versus-host disease (cGVHD). The objectives of the present study were to assess the prevalence and clinical correlates of frailty and the association of frailty with NRM and OS in patients enrolled in the Chronic GVHD Consortium. Patients were characterized as frail if they met the Fried definition of ≥3 of the following criteria at enrollment: unintentional weight loss, exhaustion, slow walking speed, low physical activity, and weakness. Frailty was assessed retrospectively using surrogate measures for the 5 domains of frailty. Frailty, cGVHD organ scores, and patient-reported outcomes were measured at the time of enrollment. The study included 399 patients from 9 centers in the United States, with 32% characterized as frail and 68% as not frail. The median duration of follow-up from enrollment was 9 years (interquartile range, 7 to 11 years). Frail patients were more likely to be older (P = .004), to have a lower Karnofsky Performance Status (P < .001), to have severe cGVHD (P < .001), and to have gastrointestinal (P < .001), liver (P = .04), or lung cGVHD (P = .002). In a multivariable analysis, older age, increased cGVHD global severity, and thrombocytopenia were statistically significantly associated with frailty when cGVHD organ involvement was excluded. A separate analysis excluding cGVHD severity and including organ involvement showed that lung and liver cGVHD and older age were associated with frailty. Neither corticosteroid use at the time of enrollment nor the maximum recorded dose of corticosteroids before enrollment was associated with frailty. Frail patients had higher NRM than nonfrail patients (P < .001), with a 10-year cumulative incidence of 41% (95% confidence interval [CI], 32% to 49%) versus 22% (95% CI, 17% to 28%). Reciprocally, frailty also was associated with a significantly lower OS (P < .001), with a 10-year OS of 43% (95% CI, 35% to 53%) in frail patients versus 63% (95% CI, 57% to 69%) in nonfrail patients. In multivariable analysis that included the individual domains of frailty, weakness, low physical activity, and slow walking speed were associated with survival. Frail patients also had worse scores on various measures of patient-reported outcomes, including the Short Form (SF)-36, the Lee Symptom Scale, and the trial outcome of the Functional Assessment of Cancer Therapy-Bone Marrow Transplantation (FACT-BMT) index score. Frail patients with cGVHD have significantly worse outcomes than nonfrail patients. Such clinical features as older age and lung and liver cGVHD are associated with frailty. Earlier clinical recognition of frailty in patients with cGVHD may prompt interventions to counteract frailty that could be beneficial for this population.

Human Effectors of Acute and Chronic GVHD Overexpress CD83 and Predict Mortality.

PURPOSE: Acute and chronic GVHD remain major causes of transplant-related morbidity and mortality (TRM) after allogeneic hematopoietic cell transplantation (alloHCT). We have shown CD83 chimeric antigen receptor (CAR) T cells prevent GVHD and kill myeloid leukemia cell lines. In this pilot study, we investigate CD83 expression on GVHD effector cells, correlate these discoveries with clinical outcomes, and evaluate critical therapeutic implications for transplant recipients. EXPERIMENTAL DESIGN: CD83 expression was evaluated among circulating CD4+ T cells, B-cell subsets, T follicular helper (Tfh) cells, and monocytes from patients with/without acute or chronic GVHD (n = 48 for each group), respectively. CD83 expression was correlated with survival, TRM, and relapse after alloHCT. Differential effects of GVHD therapies on CD83 expression was determined. RESULTS: CD83 overexpression on CD4+ T cells correlates with reduced survival and increased TRM. Increased CD83+ B cells and Tfh cells, but not monocytes, are associated with poor posttransplant survival. CD83 CAR T eliminate autoreactive CD83+ B cells isolated from patients with chronic GVHD, without B-cell aplasia as observed with CD19 CAR T. We demonstrate robust CD83 antigen density on human acute myeloid leukemia (AML), and confirm potent antileukemic activity of CD83 CAR T in vivo, without observed myeloablation. CONCLUSIONS: CD83 is a promising diagnostic marker of GVHD and warrants further investigation as a therapeutic target of both GVHD and AML relapse after alloHCT.

Sarcopenia Predicts Inferior Progression-Free Survival in Lymphoma Patients Treated with Autologous Hematopoietic Stem Cell Transplantation.

Autologous hematopoietic stem cell transplantation (ASCT) improves survival for patients with chemotherapy-sensitive lymphoma. Validated scoring systems are used in the clinical setting to predict treatment toxicity and survival; however, complications related to disease and treatment still occur, highlighting challenges in optimal patient selection and the need for novel predictors. Analysis of body composition and muscle mass can provide an objective assessment to identify vulnerable populations, as sarcopenia and frailty have been reported to predict outcomes in other tumor types. In this retrospective cohort study of patients undergoing ASCT for lymphoma, we investigated associations of sarcopenia with clinically significant outcomes, including overall survival (OS) and progression-free survival (PFS). Computed tomography (CT) images of 78 patients obtained routinely pretransplantation were used to assess skeletal muscle mass and are reported as skeletal muscle index (SMI). OS, PFS, and clinical outcomes of interest were compared between groups. Twenty-seven patients (34.6%) in the cohort met the criteria for sarcopenia. Patients with sarcopenia had a significantly shorter 3-year PFS (59% [95% confidence interval (CI), 38% to 75%] versus 84% [95% CI, 71% to 92%]; P = .02) after 3 years of follow up, whereas there was no difference in OS between patients with and those without sarcopenia (78% [95% CI, 57% to 89%] versus 88% [95% CI, 76% to 95%]; P = .25). Interestingly, no difference in survival was found with stratification based on the Karnofsky Performance Scale or Hematopoietic Cell Transplantation-Specific Comorbidity Index. There also were no significant between-group differences in length of hospital stay and the incidences of other clinical outcomes of interest, including febrile neutropenia, mucositis, total parenteral nutrition requirement, acute kidney injury, rate of readmission, or intensive care unit admission. This is the first study to our knowledge to correlate sarcopenia with disease control and PFS after ASCT in lymphoma. Possible explanations include a higher rate of chemotherapy-related toxicity, leading to disruptions of treatment as well as dysfunction of antitumor immunity secondary to impaired regulations from myokines from the loss of muscle mass or an unknown cause that is yet to be elucidated. Physical therapy programs and personalized regimens for treatment based on the analysis of body composition indices can be further studied and implemented to mitigate treatment-related toxicity and to optimize survival in patients with sarcopenia.

Do Cancer and Cancer Treatments Accelerate Aging?

PURPOSE OF REVIEW: This review focuses on describing the mechanisms and clinical manifestations that underlie accelerated aging associated with cancer and its treatment. RECENT FINDINGS: The direct and indirect effects of cancer and its treatment are associated with late occurrence of comorbidities that happen earlier or more frequently in cancer survivors compared to cancer-free individuals, otherwise known as accelerated aging. Use of senolytics and dietary and exercise interventions including prehabilitation, caloric restriction, and rehabilitation are currently under investigation to reverse or decelerate the aging process and will be covered in this review. Further research on how to decelerate or reverse aging changes associated with cancer and its treatment will be of paramount importance as the number of cancer survivors continues to grow.

Reduced Enterohepatic Recirculation of Mycophenolate and Lower Blood Concentrations Are Associated with the Stool Bacterial Microbiome after Hematopoietic Cell Transplantation.

Mycophenolate mofetil (MMF) is an important immunosuppressant used after allogeneic hematopoietic cell transplantation (HCT). MMF has a narrow therapeutic index, and blood concentrations of mycophenolic acid (MPA), the active component of MMF, are highly variable. Low MPA concentrations are associated with the risk of graft-versus-host disease (GVHD), whereas high concentrations are associated with toxicity. Reasons for variability are not well known and may include the presence of ß-glucuronidase-producing bacteria in the gastrointestinal tract, which enhance MPA enterohepatic recirculation (EHR) by transforming MPA metabolites formed in the liver back to MPA. This study was conducted to determine whether individuals with high MPA EHR have a greater abundance of ß-glucuronidase-producing bacteria in their stool and higher MPA concentrations compared with those with low EHR. We conducted a pharmacomicrobiomics study in 20 adult HCT recipients receiving a myeloablative or reduced-intensity preparative regimen. Participants received MMF 1 g i.v. every 8 hours with tacrolimus. Intensive pharmacokinetic sampling of MMF was conducted before hospital discharge; total MPA, MPA glucuronide (MPAG), and acyl-glucuronide metabolite (acylMPAG) were measured. EHR was defined as the ratio of MPA area under the concentration-versus-time curve (AUC)4-8 to MPA AUC0-8. Differences in stool microbiome diversity and composition, determined by shotgun metagenomic sequencing, were compared above and below the median EHR (22%; range, 5% to 44%). The median EHR was 12% in the low EHR group and 29% in the high EHR group. MPA troughs, MPA AUC4-8, and acyl-glucuronide metabolite (acylMPAG) AUC4-8/AUC0-8 ratio were greater in the high EHR group compared with the low EHR group (1.53 µg/mL versus .28 µg/mL [P = .0001], 7.33 hour·µg/mL versus 1.79 hour·µg/mL [P = .0003], and .33 hour·µg/mL versus .24 hour·µg/mL [P = .0007], respectively). MPA AUC0-8 was greater in the high EHR group than in the low EHR group, and the difference trended toward significance (22.8 hour·µg/mL versus 15.3 hour·µg/mL; P = .06). Bacteroides vulgatus, Bacteroides stercoris, and Bacteroides thetaiotaomicron were 1.2- to 2.4-fold more abundant (P = .039, .024, and .046, respectively) in the high EHR group. MPA EHR was positively correlated with B. vulgatus (⍴ = .58; P ≤ .01) and B. thetaiotaomicron (⍴ = .46; P < .05) and negatively correlated with Blautia hydrogenotrophica (⍴ = -.53; P < .05). Therapeutic MPA troughs were achieved in 80% of patients in the high EHR group but in no patients in the low EHR group. There was a trend toward differences in MPA AUC0-8 and MPA concentration at steady-state (µg/mL) between the high EHR group versus the low EHR group (P = .06). MPA EHR was variable. Patients with high MPA EHR had greater abundance of Bacteroides species in stool and higher MPA exposure compared with patients with low MPA EHR. Therefore, Bacteroides may be protective against poor outcomes, such as graft-versus-host disease, in some patients but may increase the risk of MPA adverse effects in others. These data need to be confirmed and studied after oral MMF therapy.

Association of CD34 Cell Dose with 5-Year Overall Survival after Peripheral Blood Allogeneic Hematopoietic Cell Transplantation in Adults with Hematologic Malignancies.

Higher CD34 cell dose is associated with improved engraftment after peripheral blood allogeneic hematopoietic stem cell transplantation (alloHCT) but also may increase the risk of long-term complications, such as graft-versus-host disease (GVHD). Prior studies examining the relationship between CD34 cell dose and long-term survival outcomes have yielded conflicting results. In this study, we sought to clarify the prognostic impact of CD34 cell dose by examining a large contemporary cohort of patients undergoing alloHCT with a matched sibling peripheral blood stem cell (PBSC) donor. We retrospectively examined the impact of CD34 cell dose on overall survival (OS), neutrophil engraftment, platelet engraftment, treatment-related mortality, relapse, acute GVHD grade II-IV and III-IV, and chronic GVHD in 377 consecutive patients undergoing alloHCT with a PBSC graft source from a matched sibling donor at the University of Minnesota between 2002 and 2015. The patients were classified into 3 groups based on the tertile (T) of CD34 cell dose received: T1, <5 × 106 cells/kg; T2, 5 to 7.5 × 106 cells/kg; and T3, ≥7.5 × 106 cells/kg. Multivariable analysis demonstrated that high CD34 cell dose was associated with superior 5-year OS (hazard ratio [HR], 0.57; P = .01) and more rapid platelet engraftment (HR, 1.70; P < .01). Higher CD34 cell dose also was associated with improved absolute neutrophil count engraftment (T2: HR, 1.54; T3: HR, 1.52; P < .01). There was no association between CD34 cell dose and TRM or relapse at 5 years. Although higher CD34 cell dose was not associated with acute GVHD grade II-IV, it was associated with chronic GVHD (T2: HR, 1.68; T3: HR, 1.50; P = .04). Our data indicate that higher CD34 cell dose (>7.5 × 106/kg) is associated with superior OS at 5 years and improved engraftment but carries an increased risk of chronic GVHD. These data support a target CD34 cell dose goal of 7.5 × 106/kg for sibling PBSC graft donors.

Physical Activity and Sleep Measures Using a Fitness Tracking Device during Hematopoietic Cell Transplantation: A Pilot Study.

Patients undergoing hematopoietic cell transplantation (HCT) experience decline in their physical activity during their transplant admission. There is limited experience with prospective monitoring of transplant recipients. We therefore measured physical activity and sleep patterns of subjects undergoing autologous and allogeneic HCT. Eighty-three patients were consented for this study. Sixty-three patients competed the study and had their physical activity prospectively assessed using the fitness-tracking device Fitbit HR. Outcomes included adherence, physical activity, readmission, hematopoietic engraftment, and 100-day survival. Sixty percent of patients (n = 37) underwent autologous HCT, and 40% (n = 26) underwent allogenic HCT. Both groups had a comparable number of steps at admission to the hospital. The number of daily steps during the study period was lower in the allogeneic group (2159 versus 3008, P = .07), as was the minimum number of steps recorded over the transplant admission (allogeneic HCT = 395 versus autologous HCT = 848, P = .01). Patients undergoing allogeneic HCT were less active on the day before discharge (1956 steps versus 3183 steps, P = .08). In multivariate analysis, physical activity was not associated with HCT-related outcomes. Patients undergoing HCT experience significant decline in their physical activity during their transplant admission that does not recover by the time of discharge. This effect can be objectively measured using fitness tracking devices.

Hematopoietic Cell Transplant-Related Toxicities and Mortality in Frail Recipients.

Frailty is a state characterized by diminished physiologic reserve and increased vulnerability to stress and adversely affects outcomes in older patients. We aimed to determine the relationship between pre-hematopoietic cell transplant (HCT) frailty and grades 3 to 4 nonhematologic toxicities (Common Terminology Criteria for Adverse Events, version 5.0) and mortality in HCT recipients within 1 year after HCT and also examined whether age at HCT moderated that association. In a prospective longitudinal study of 117 patients aged ≥ 40 years undergoing HCT, we performed formal pre-HCT geriatric assessments. Frailty was assessed using Fried's criteria. Post-HCT toxicities were abstracted through medical record reviews. The prevalence of pre-HCT frailty was 21% and was not different in younger (40 to 59 years) versus older (≥60 years) HCT recipients. Overall, frail recipients (versus nonfrail) had a higher cumulative incidence of any grades 3 to 4 nonhematologic toxicity (86% [95% confidence interval {CI}, 62% to 100%] versus 70% [95% CI, 57% to 83%), P = .03) and more organ-specific grades 3 to 4 toxicities, such as non-neutropenic infections (38% [95% CI, 17% to 59%] versus 13% [95% CI, 6% to 20%], P < .01), nervous system disorders (19% [95% CI, 3% to 35%] versus 4% [95% CI, 0 to 8%], P = .02), and pneumonia (38% [95% CI, 17% to 59%] versus 10% [95% CI, 4% to 17%], P < .01). Frail recipients were 1.9-fold (95% CI, 1.1 to 3.4) more likely to develop any grades 3 to 4 toxicities (P = .03), 4-fold more likely to suffer non-neutropenic infections (95% CI, 1.4 to 11) and pneumonia (95% CI, 1.4 to 12; both P = .01), and 8.6-fold (95% CI, 1.6 to 45.3) more likely to suffer nervous system disorders (P = .01). Frail allogeneic HCT recipients also had a 3.1 times (95% CI, .9 to 9.7; P = .06) higher risk of overall mortality as compared with nonfrail allogeneic HCT recipients. The higher toxicity and mortality observed in frail allogeneic recipients needs to be monitored with high attention. Studies focusing on interventions to reduce frailty and manage morbidities are needed.