Decade-long leukaemia remissions with persistence of CD4+ CAR T cells.

The adoptive transfer of T lymphocytes reprogrammed to target tumour cells has demonstrated potential for treatment of various cancers1-7. However, little is known about the long-term potential and clonal stability of the infused cells. Here we studied long-lasting CD19-redirected chimeric antigen receptor (CAR) T cells in two patients with chronic lymphocytic leukaemia1-4 who achieved a complete remission in 2010. CAR T cells remained detectable more than ten years after infusion, with sustained remission in both patients. Notably, a highly activated CD4+ population emerged in both patients, dominating the CAR T cell population at the later time points. This transition was reflected in the stabilization of the clonal make-up of CAR T cells with a repertoire dominated by a small number of clones. Single-cell profiling demonstrated that these long-persisting CD4+ CAR T cells exhibited cytotoxic characteristics along with ongoing functional activation and proliferation. In addition, longitudinal profiling revealed a population of gamma delta CAR T cells that prominently expanded in one patient concomitant with CD8+ CAR T cells during the initial response phase. Our identification and characterization of these unexpected CAR T cell populations provide novel insight into the CAR T cell characteristics associated with anti-cancer response and long-term remission in leukaemia.

Post-Transplantation Cyclophosphamide-Based Graft-versus-Host Disease Prophylaxis.

BACKGROUND: In patients undergoing allogeneic hematopoietic stem-cell transplantation (HSCT), a calcineurin inhibitor plus methotrexate has been a standard prophylaxis against graft-versus-host disease (GVHD). A phase 2 study indicated the potential superiority of a post-transplantation regimen of cyclophosphamide, tacrolimus, and mycophenolate mofetil. METHODS: In a phase 3 trial, we randomly assigned adults with hematologic cancers in a 1:1 ratio to receive cyclophosphamide-tacrolimus-mycophenolate mofetil (experimental prophylaxis) or tacrolimus-methotrexate (standard prophylaxis). The patients underwent HSCT from an HLA-matched related donor or a matched or 7/8 mismatched (i.e., mismatched at only one of the HLA-A, HLA-B, HLA-C, and HLA-DRB1 loci) unrelated donor, after reduced-intensity conditioning. The primary end point was GVHD-free, relapse-free survival at 1 year, assessed in a time-to-event analysis, with events defined as grade III or IV acute GVHD, chronic GVHD warranting systemic immunosuppression, disease relapse or progression, and death from any cause. RESULTS: In a multivariate Cox regression analysis, GVHD-free, relapse-free survival was significantly more common among the 214 patients in the experimental-prophylaxis group than among the 217 patients in the standard-prophylaxis group (hazard ratio for grade III or IV acute GVHD, chronic GVHD, disease relapse or progression, or death, 0.64; 95% confidence interval [CI], 0.49 to 0.83; P = 0.001). At 1 year, the adjusted GVHD-free, relapse-free survival was 52.7% (95% CI, 45.8 to 59.2) with experimental prophylaxis and 34.9% (95% CI, 28.6 to 41.3) with standard prophylaxis. Patients in the experimental-prophylaxis group appeared to have less severe acute or chronic GVHD and a higher incidence of immunosuppression-free survival at 1 year. Overall and disease-free survival, relapse, transplantation-related death, and engraftment did not differ substantially between the groups. CONCLUSIONS: Among patients undergoing allogeneic HLA-matched HSCT with reduced-intensity conditioning, GVHD-free, relapse-free survival at 1 year was significantly more common among those who received cyclophosphamide-tacrolimus-mycophenolate mofetil than among those who received tacrolimus-methotrexate. (Funded by the National Heart, Lung, and Blood Institute and others; BMT CTN 1703 ClinicalTrials.gov number, NCT03959241.).

Hypomethylating agents are associated with high rates of hematologic toxicity in patients with secondary myeloid neoplasms developing after acquired aplastic anemia.

Not available.

Chronic graft-versus-host disease. Part II: Disease activity grading and therapeutic management.

Chronic graft-versus-host disease (cGVHD) is a major complication of allogeneic hematopoietic cell transplantation and a leading cause of long-term morbidity, nonrelapse mortality, and impaired health-related quality of life. The skin is commonly affected and presents heterogeneously, making the role of dermatologists critical in both diagnosis and treatment. In addition, new clinical classification and grading schemes inform treatment algorithms, which now include 3 Federal Drug Administration-approved therapies, and evolving transplant techniques are changing disease epidemiology. Part I reviews the epidemiology, pathogenesis, clinical manifestations, and diagnosis of cGVHD. Part II discusses disease grading and therapeutic management.

Chronic graft-versus-host disease. Part I: Epidemiology, pathogenesis, and clinical manifestations.

Chronic graft-versus-host disease is a major complication of allogeneic hematopoietic cell transplantation and a leading cause of long-term morbidity, nonrelapse mortality, and impaired health-related quality of life. The skin is commonly affected and presents heterogeneously, making the role of dermatologists critical in both diagnosis and treatment. In addition, new clinical classification and grading schemes inform treatment algorithms, which now include 3 U.S. Food and Drug Administration-approved therapies, and evolving transplant techniques are changing disease epidemiology. Part I reviews the epidemiology, pathogenesis, clinical manifestations, and diagnosis of chronic graft-versus-host disease. Part II discusses disease grading and therapeutic management.

Real-world effectiveness of intensive chemotherapy with 7&3 versus venetoclax and hypomethylating agent in acute myeloid leukemia.

Intensive chemotherapy with cytarabine and anthracycline (7&3) remains the standard therapy for patients medically fit for induction, but the assessment of fitness remains controversial. Venetoclax and hypomethylating agent (ven/HMA) combination therapy has improved outcomes in unfit patients but no prospective study has assessed ven/HMA versus 7&3 as initial therapy in older, fit patients. Given no studies and expectation of ven/HMA use in patients outside of trial criteria, we evaluated retrospective outcomes among newly diagnosed patients. A nationwide electronic health record (EHR)-derived database and the University of Pennsylvania EHR identified 312 patients receiving 7&3 and 488 receiving ven/HMA who were 60-75 years old without history of organ failure. Ven/HMA patients were older and more likely to have secondary AML, adverse cytogenetics, and adverse mutations. Median overall survival (OS) for patients receiving intensive chemotherapy was 22 versus 10 months for ven/HMA (HR 0.53, 95% CI 0.40-0.60). Controlling for measured baseline characteristic imbalances reduced survival advantage by half (HR 0.71, 95% CI 0.53-0.94). A sub-group of patients with equipoise, likelihood at least 30%-70% of receiving either treatment, had similar OS outcomes (HR 1.10, 95% CI 0.75-1.6). Regarding safety outcomes, 60-day mortality was higher for ven/HMA (15% vs. 6% at 60 days) despite higher documented infections and febrile neutropenia for 7&3. In this multicenter real-word dataset, patients selected for intensive chemotherapy had superior OS but a large group had similar outcomes with ven/HMA. Prospective randomized studies, controlling for both measured and unmeasured confounders, must confirm this outcome.

One versus two sets of busulfan therapeutic drug monitoring in myeloablative allogeneic hematopoietic cell transplant.

INTRODUCTION: Busulfan is a common component of allogeneic hematopoietic cell transplant (alloHCT) conditioning, however interpatient pharmacokinetic variability can result in enhanced toxicity or increased relapse risk. Therapeutic drug monitoring (TDM) can minimize variability, yet the optimal frequency of TDM is unknown. We compared outcomes for patients with one versus two sets of busulfan TDM during myeloablative conditioning (MAC) prior to alloHCT. METHODS: We analyzed the impact of busulfan TDM frequency and dose adjustments, with the primary outcome being relapse-free survival (RFS). Other outcomes included the incidence of acute and chronic graft versus host disease (GVHD), oral mucositis, pulmonary toxicity, sinusoidal obstruction syndrome (SOS), the cumulative incidence of relapse (CIR), and overall survival (OS). RESULTS: Twenty-two patients underwent one set of sampling while 53 patients underwent two sets. Similar baseline characteristics were observed between the groups. There were no significant differences observed in RFS by day +180 (77.3% vs. 79.2%, p = 1.0), CIR by day +180 (18.2% vs. 17.8%, p = 0.74), or OS (p = 0.73). The incidences of acute GVHD, chronic GVHD, SOS, and severe mucositis were also similar. In each group, 63% received busulfan dose adjustments after one set, with 52.8% receiving further dose adjustments following the second set. CONCLUSION: We observed no significant difference in alloHCT outcomes between patients who underwent one versus two sets of busulfan TDM sampling, suggesting that a single-time TDM and dose adjustment may be adequate to maximize outcomes after MAC alloHCT.

Management of relapsed cutaneous T-Cell lymphoma following allogeneic hematopoietic stem cell transplantation: Review with representative patient case.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment option for patients with refractory cutaneous T-cell lymphoma (CTCL) through replacement of the bone marrow responsible for lymphoma cells and possibly induction of a graft-versus-lymphoma effect. However, allo-HSCT is not always curative; relapse of CTCL occurs in about half of patients post-transplant. Treatment of relapsed CTCL after allo-HSCT is challenging because post-transplant patients are at high risk of graft-versus-host disease, and this condition may be precipitated or exacerbated by standard CTCL therapies. The benefit of each potential therapy must therefore be weighed against its risk of graft versus host disease (GVHD). In this article, we review the management of relapsed CTCL after allo-HSCT. We begin with an exemplative patient whose relapsed Sezary syndrome was successfully treated without development of GVHD. We also report high-throughput T-cell receptor sequencing data obtained during the patient's disease relapse and remission. We then review general guidelines for management of relapsed CTCL and summarize all reported cases and outcomes of relapsed CTCL after transplant. We conclude by reviewing the current CTCL therapies and their risk of GVHD.

Fluconazole-Induced adrenal insufficiency following allogeneic hematopoietic cell transplant.

INTRODUCTION: Adrenal insufficiency (AI) is a potentially life-threatening endocrine abnormality rarely associated with azole antifungals. Patients undergoing allogeneic hematopoietic cell transplantation (alloHCT) are at high risk of invasive fungal infection and frequently receive azoles. Signs and symptoms of AI, such as gastrointestinal symptoms, lethargy, and electrolyte disturbances frequently overlap with common alloHCT toxicities, such that azole-induced AI may be under-reported in this population. CASE REPORT: We report the first published case of azole-induced AI following alloHCT. The patient presented with orthostasis and nonspecific gastrointestinal and failure to thrive symptoms in the setting of roughly 6 weeks of fluconazole prophylaxis. The patient was found to have primary AI diagnosed via low serum cortisol and inadequate response to cosyntropin. MANAGEMENT & OUTCOME: AI symptoms resolved with hydrocortisone supplementation and recurred upon rechallenge with fluconazole. The patient had fluconazole permanently discontinued with resolution of symptoms. We rate this case as a probable adverse drug reaction on the Naranjo scale. DISCUSSION: AI may be underreported and misdiagnosed in the alloHCT population given the presence of multiple toxicities with overlapping features. Clinicians must be diligent in investigating adrenal function in patients undergoing alloHCT on azole antifungals who present with symptoms of AI.

Pentosan polysulfate for the treatment of hemorrhagic cystitis after allogeneic hematopoietic cell transplant.

INTRODUCTION: Hemorrhagic cystitis can commonly occur following an allogeneic hematopoietic cell transplant and treatment options are currently limited. Pentosan polysulfate, a heparin-like, sulfated polysaccharide, is used to relieve bladder pain and discomfort associated with interstitial cystitis. Initial reports in patients with hemorrhagic cystitis demonstrate that pentosan polysulfate may hasten hemorrhagic cystitis resolution and control symptoms. METHODS AND RESULTS: This report includes a retrospective case series of six patients who received pentosan polysulfate for the treatment of hemorrhagic cystitis following an allogeneic hematopoietic cell transplant. Pentosan polysulfate was initiated at a median of 4.5 days (range: 3-18) following hemorrhagic cystitis onset and continued for a median duration of 17.5 days (range: 7-64). Four patients were tested for BK virus and all were found to have BK viremia and viruria around the time of pentosan polysulfate initiation. The median number of red blood cell transfusions seemed to decrease in the patients initiated on pentosan polysulfate. All patients received a multi-agent treatment regimen, which included pentosan polysulfate, and half the patients had symptom resolution. The median time to symptom resolution from pentosan polysulfate initiation was 9 days (range: 7-10). CONCLUSION: Pentosan polysulfate was well-tolerated and seemed to assist with symptom resolution. Future studies are needed to confirm the impact of pentosan polysulfate on the treatment of hemorrhagic cystitis.

Day 4 vs. day 12 G-CSF administration following reduced intensity peripheral blood allogeneic stem cell transplant.

INTRODUCTION: Granulocyte colony-stimulating factor (G-CSF) hastens neutrophil engraftment and reduces infections after allogeneic hematopoietic cell transplant (alloHCT), yet the optimal start date is unknown. Additionally, concurrent G-CSF and methotrexate for graft-vs-host disease (GVHD) prophylaxis may potentiate myelosuppression, and prolonged G-CSF is costly. Our institution changed from day + 4 to day + 12 G-CSF initiation following reduced intensity (RIC) alloHCT with methotrexate GVHD prophylaxis. METHODS: We retrospectively compared day + 4 and day + 12 G-CSF initiation after RIC alloHCT from 2017-2021. The primary endpoint was the time to neutrophil engraftment. Secondary endpoints included length of stay (LOS) and the time to platelet engraftment as well as the incidence of infectious events, acute GVHD (aGVHD), and mucositis. RESULTS: Thirty-two patients were included in each group with similar baseline characteristics. We observed faster neutrophil engraftment (median 12 vs. 15 days, p = 0.01) and platelet engraftment (median 13 vs. 15 days, p = 0.026) with day + 4 vs. day + 12 G-CSF initiation. Median LOS was 23 days (range, 19-32) with day + 4 initiation vs. 24 days (21-30) with day + 12 (p = 0.046). The incidence of culture-negative febrile neutropenia (p = 0.12), any grade aGVHD (p = 0.58), and grade 2-4 mucositis (p = 0.8) were similar between groups. CONCLUSION: Compared to day + 4, day + 12 G-CSF initiation following RIC alloHCT had a longer time to neutrophil and platelet engraftment. Day + 12 initiation also resulted in longer LOS, which while statistically significant, was potentially of limited clinical significance. These findings are hypothesis generating.

The Hematopoietic Cell Transplant Comorbidity Index predicts survival after allogeneic transplant for nonmalignant diseases.

Despite improvements, mortality after allogeneic hematopoietic cell transplantation (HCT) for nonmalignant diseases remains a significant problem. We evaluated whether pre-HCT conditions defined by the HCT Comorbidity Index (HCT-CI) predict probability of posttransplant survival. Using the Center for International Blood and Marrow Transplant Research database, we identified 4083 patients with nonmalignant diseases transplanted between 2007 and 2014. Primary outcome was overall survival (OS) using the Kaplan-Meier method. Hazard ratios (HRs) were estimated by multivariable Cox regression models. Increasing HCT-CI scores translated to decreased 2-year OS of 82.7%, 80.3%, 74%, and 55.8% for patients with HCT-CI scores of 0, 1 to 2, 3 to 4, and ≥5, respectively, regardless of conditioning intensity. HCT-CI scores of 1 to 2 did not differ relative to scores of 0 (HR, 1.12 [95% CI, 0.93-1.34]), but HCT-CI of 3 to 4 and ≥5 posed significantly greater risks of mortality (HR, 1.33 [95% CI, 1.09-1.63]; and HR, 2.31 [95% CI, 1.79-2.96], respectively). The effect of HCT-CI differed by disease indication. Patients with acquired aplastic anemia, primary immune deficiencies, and congenital bone marrow failure syndromes with scores ≥3 had increased risk of death after HCT. However, higher HCT-CI scores among hemoglobinopathy patients did not increase mortality risk. In conclusion, this is the largest study to date reporting on patients with nonmalignant diseases demonstrating HCT-CI scores ≥3 that had inferior survival after HCT, except for patients with hemoglobinopathies. Our findings suggest that using the HCT-CI score, in addition to disease-specific factors, could be useful when developing treatment plans for nonmalignant diseases.

Driving Distance and Patient-Reported Outcomes in Hematopoietic Cell Transplantation Survivors.

Long driving distances to transplantation centers may impede access to care for hematopoietic cell transplantation (HCT) survivors. As a secondary analysis from the multicenter INSPIRE study (NCT01602211), we examined baseline data from relapse-free HCT adult survivors (2 to 10 years after allogeneic or autologous HCT) to investigate the association between driving distances and patient-reported outcome (PRO) measures of distress and physical function. We analyzed predictors of elevated distress and impaired physical function using logistic regression models that operationalized driving distance first as a continuous variable and separately as a dichotomous variable (<100 versus 100+ miles). Of 1136 patients available for analysis from 6 US centers, median driving distance was 82 miles and 44% resided 100+ miles away from their HCT centers. Elevated distress was reported by 32% of patients, impaired physical function by 19%, and both by 12%. Driving distance, whether operationalized as a continuous or dichotomous variable, had no impact on distress or physical function in linear regression modeling (95% confidence interval, 1.00 to 1.00, for both PROs with driving distance as a continuous variable). In contrast, chronic graft-versus-host-disease, lower income, and lack of Internet access independently predicted both elevated distress and impaired physical function. In summary, we found no impact of driving distance on distress and physical function among HCT survivors. Our results have implications for how long-term follow-up care is delivered after HCT, with regard to the negligible impact of driving distances on PROs and also the risk of a "digital divide" worsening outcomes among HCT survivors without Internet access.

Risk of invasive fungal infections in patients with high-risk MDS and AML receiving hypomethylating agents.

Invasive fungal infections (IFI) are a significant source of morbidity and mortality for patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Given the heterogeneity of the population receiving hypomethylating agents (HMA), it is difficult for clinicians to accurately assess their patients' risk of infection. Literature on the incidence of IFI following HMA is limited to several studies of azacitidine. The primary objective of this retrospective study was to establish the incidence of IFI in HMA treated AML/MDS patients at a large U.S. comprehensive cancer center. Secondary objectives included comparing incidence of IFI among pre-specified subgroups to identify potential risk factors for IFI. Two hundred three patients with AML, intermediate to very high risk MDS or chronic myelomonocytic leukemia who received at least two cycles of HMA were included. The incidence of IFI, as defined by the European Organization for Research and Treatment of Cancer / Invasive Fungal Infections Cooperative Group criteria, was 9.6%, with 20 IFI diagnosed following HMA (three proven, four probable, 13 possible). Among the proven cases of IFI, molds included Scedosporium and Fusarium spp. Eleven patients who developed IFIs were neutropenic upon initiating HMA. The majority (17/20) of infections occurred during the first four cycles. Given this incidence, mold-active prophylaxis can be considered in patients who are neutropenic at the start of therapy.

Age and gender differences in financial distress among hematopoietic cell transplant survivors.

PURPOSE: Cancer has long-term financial consequences. Adolescent and young adult (AYA) and middle-aged cancer survivors may experience more financial toxicity than older adults. This study examined age differences in financial distress in hematopoietic cell transplant survivors and whether these differences result from measurement bias, more financial barriers to care, or an overall higher level of distress. METHODS: Hematologic malignancy survivors (n = 1135, 2-10 years post-transplant) completed the Cancer and Treatment Distress Scale (CTXD) and demographics as part of the baseline assessment for a randomized clinical trial. The CTXD has seven subscales, but for this study, we examined the financial distress subscale and the overall score. Item response theory analyses tested for bias by age and gender. Multivariate linear regression tested the association of age and gender with the CTXD scores while controlling for financial barriers to care. RESULTS: No bias was found on the CTXD. AYA (p < 0.01) and middle-aged adults (p < 0.001) reported more financial and overall distress than older (age 65+) adults. The same association of age and financial distress was observed in women (p < 0.01). However, only middle-aged men (p < 0.01) reported more financial and overall distress than older men; AYA men did not (p > 0.18). Financial barriers to care were not associated with financial or overall distress. CONCLUSIONS: Part of the increase in financial distress with younger age may be due to a higher risk of general distress. Policy initiatives to control cancer costs should consider life stage and the unique financial challenges at different ages for men and women.

Oral Vancomycin Prophylaxis Is Highly Effective in Preventing Clostridium difficile Infection in Allogeneic Hematopoietic Cell Transplant Recipients.

BACKGROUND: Clostridium difficile infection (CDI) is a leading cause of infectious complications in allogeneic hematopoietic cell transplant recipients (alloHCT). We sought to evaluate whether prophylactic oral vancomycin reduces the incidence of CDI in alloHCT recipients. METHODS: We conducted a retrospective cohort study to examine the effectiveness of CDI prophylaxis with oral vancomycin, as compared to no prophylaxis, in 145 consecutive adult alloHCT recipients at the University of Pennsylvania between April 2015 and November 2016. Patients received oral vancomycin 125 mg twice daily, starting on admission and continuing until discharge. The primary outcome of interest was the association between oral vancomycin prophylaxis and CDI diagnosis. Secondary outcomes included graft-versus-host disease (GVHD) and relapse. RESULTS: There were no cases of CDI in patients that received prophylaxis (0/90, 0%), whereas 11/55 (20%) patients who did not receive prophylaxis developed CDI (P < .001). Oral vancomycin prophylaxis was not associated with a higher risk of acute, grades 2-4 GVHD (subhazard ratio [sHR] 1.59; 95% confidence interval [CI] 0.88-2.89; P = .12), acute, grades 3-4 GVHD (sHR 0.65; 95% CI 0.25-1.66; P = .36), or acute, grades 2-4 gastrointestinal GVHD (sHR 1.95; 95% CI 0.93-4.07; P = .08) at day 180 post-transplant. No associations between oral vancomycin and relapse or survival were observed. CONCLUSIONS: Prophylaxis with oral vancomycin is highly effective in preventing CDI in alloHCT recipients without increasing the risk of graft-versus-host disease or disease relapse. Further evaluation via a prospective study is warranted.

Extended CCR5 Blockade for Graft-versus-Host Disease Prophylaxis Improves Outcomes of Reduced-Intensity Unrelated Donor Hematopoietic Cell Transplantation: A Phase II Clinical Trial.

Graft-versus-host disease (GVHD) remains the most common treatment-related complication after allogeneic hematopoietic cell transplantation (allo-HCT). Lymphocyte migration plays a critical role in the pathogenesis of GVHD. A previous phase I/II trial demonstrated that CCR5 blockade with maraviroc in the first 30days after allo-HCT resulted in a low incidence of early acute GVHD, primarily in visceral organs, but with no impact on late acute or chronic GVHD. We conducted a phase II trial to examine the efficacy of an extended course of maraviroc, administered through post-transplantation day +90 in addition to standard prophylaxis in 37 recipients of reduced-intensity-conditioned unrelated donor allo-HCT performed to treat hematologic malignancies. Extended maraviroc treatment was safe and feasible. The primary study endpoint, day +180 rate of grade II-IV acute GVHD, was 22 ± 7%, liver GVHD was not observed, and gut GVHD was uncommon. The day +180 rate of grade III-IV acute GVHD was 5 ± 4%. The 1-year rate of moderate to severe chronic GVHD was 8 ± 5% and that of disease relapse was 30 ± 8%. Overall survival at 1 year was 70 ± 8%. Compared with the previously studied short course of maraviroc, the extended course resulted in a significantly higher GVHD-free, relapse-free survival (adjusted hazard ratio [HR], .45; 95% confidence interval [CI], .25 to .82; P = .009) and overall survival (adjusted HR, .48; 95% CI, .24 to .96; P = .037). A combined analysis of both trials showed that high maraviroc trough concentrations on the day of hematopoietic cell infusion were associated with lower rates of acute GVHD. An extended course of maraviroc after reduced-intensity-conditioned unrelated donor allo-HCT is safe and effective in preventing acute and chronic GVHD and is associated with favorable survival.

Comparison of High Doses of Total Body Irradiation in Myeloablative Conditioning before Hematopoietic Cell Transplantation.

Malignancy relapse is the most common cause of treatment failure among recipients of hematopoietic cell transplantation (HCT). Conditioning dose intensity can reduce disease relapse but is offset by toxicities. Improvements in radiotherapy techniques and supportive care may translate to better outcomes with higher irradiation doses in the modern era. This study compares outcomes of recipients of increasing doses of high-dose total body irradiation (TBI) divided into intermediate high dose (IH; 13-13.75 Gy) and high dose (HD; 14 Gy) with standard dose (SD; 12 Gy) with cyclophosphamide. A total of 2721 patients ages 18 to 60 years with hematologic malignancies receiving HCT from 2001 to 2013 were included. Cumulative incidences of nonrelapse mortality (NRM) at 5 years were 28% (95% confidence interval [CI], 25% to 30%), 32% (95% CI, 29% to 36%), and 34% (95% CI, 28% to 39%) for SD, IH, and HD, respectively (P = .02). Patients receiving IH-TBI had a 25% higher risk of NRM compared with those receiving SD-TBI (12 Gy) (P = .007). Corresponding cumulative incidences of relapse were 36% (95% CI, 34% to 38%), 32% (95% CI, 29% to 36%), and 26% (95% CI, 21% to 31%; P = .001). Hazard ratios for mortality compared with SD were 1.06 (95% CI, .94 to 1.19; P = .36) for IH and .89 (95% CI, .76 to 1.05; P = .17) for HD. The study demonstrates that despite improvements in supportive care, myeloablative conditioning using higher doses of TBI (with cyclophosphamide) leads to worse NRM and offers no survival benefit over SD, despite reducing disease relapse.

Higher Donor Apheresis Blood Volumes Are Associated with Reduced Relapse Risk and Improved Survival in Reduced-Intensity Allogeneic Transplantations with Unrelated Donors.

Allogeneic hematopoietic stem cell transplantation (HSCT) with reduced-intensity conditioning (RIC) offers a curative option for patients with hematologic malignancies who are unable to undergo myeloablative conditioning, but its success is limited by high rates of relapse. Several studies have suggested a role for T cell doses in peripheral blood stem cell grafts in RIC HSCT. Because T cell dose is typically not known until after the collection, and apheresis blood volume is easily modifiable, we hypothesized that higher donor apheresis blood volumes would improve transplantation outcomes through an effect on graft composition. Thus, we analyzed the relationships between apheresis volume, graft composition, and transplantation outcomes in 142 consecutive patients undergoing unrelated donor allogeneic RIC HSCT. We found that apheresis volume ≥15 L was associated with a significantly decreased risk of relapse (adjusted hazard ratio [aHR], .48; 95% confidence interval [CI], .28 to .84]; P = .01) and improved relapse-free survival (aHR, .56; 95% CI, .35 to .89; P = .02) and overall survival (aHR, .55; 95% CI, .34 to .91; P = .02). A high apheresis volume was not associated with increased rates of acute or chronic graft-versus-host disease. These results demonstrate that an apheresis volume of at least 15 L is independently predictive of improved transplantation outcomes after RIC allogeneic HSCT.