Late-onset Pneumocystis jirovecii pneumonia post-allogeneic stem cell transplantation after time-dependent discontinuation of prophylaxis.

INTRODUCTION: Pneumocystis jirovecii pneumonia (PJP) is a rare complication of hematopoietic stem cell transplantation (HSCT). Primary prophylaxis for 6-12 months post-HSCT is the standard approach. However, there is no consensus regarding the optimal duration of prophylaxis. METHODS: We identified patients who developed PJP more than 1-year post-HSCT. All patients had previously received 12 months of PJP prophylaxis. PJP was diagnosed based on clinical findings and the detection of P. jirovecii in bronchoalveolar lavage (BAL) using polymerase chain reaction (PCR). The CD4+ T-cell percentage was determined using flow cytometry. Data expressed as median (interquartile range). RESULTS: Ten patients developed PJP at 17.5 months (16-24 months) post-HSCT. PJP diagnosis occurred 5.5 months (3-15 months) after discontinuing prophylaxis. Eight patients received anti-thymocyte globulin (ATG) as graft versus host disease (GVHD) prophylaxis. At diagnosis, only one patient had lymphopenia; all patients had CD4+ T-lymphocyte counts ≥0.2 × 109 /L (median 0.337 × 109 /L). Three patients had concomitant bacterial infections. The clinical presentation was mild; only three required hospitalization, none of them required intensive care and there were no deaths. CONCLUSION: There is a need to develop risk-adapted prophylactic strategies in the contemporary era using ATG-based GVHD prophylaxis.

The association between nutritional risk index and ICU outcomes across hematologic malignancy patients with acute respiratory failure.

Patients with hematological malignancies (HM) are at risk of acute respiratory failure (ARF). Malnutrition, a common association with HM, has the potential to influence ICU outcomes. Geriatric nutritional risk index (G-NRI) is a score derived from albumin and weight, which reflects risk of protein-energy malnutrition. We evaluated the association between G-NRI at ICU admission and ICU mortality in HM patients with ARF. We conducted a single center retrospective study of ventilated HM patients between 2014 and 2018. We calculated G-NRI for all patients using their ICU admission albumin and weight. Our primary outcome was ICU mortality. Secondary outcomes included duration of mechanical ventilation and ICU length of stay. Two hundred eighty patients were admitted to the ICU requiring ventilation. Median age was 62 years (IQR 51-68), 42% (n = 118) were females, and median SOFA score was 11 (IQR 9-14). The most common type of HM was acute leukemia (54%) and 40% underwent hematopoietic cell transplant. Median G-NRI was 87 (IQR 79-99). ICU mortality was 51% (n = 143) with a median duration of ventilation of 4 days (IQR 2-7). Mortality across those at severe malnutrition (NRI < 83.5) was 59% (65/111) compared to 46% (76/164) across those with moderate-no risk (p = 0.047). On multivariable analysis, severe NRI (OR 2.34, 95% CI 1.04-5.27, p = 0.04) was significantly associated with ICU mortality. In this single center, exploratory study, severe G-NRI was prognostic of ICU mortality in HM patients admitted with respiratory failure.

Weight loss post-allogeneic stem cell transplant is associated with increased transplant-related mortality.

PURPOSE: Allogeneic stem cell transplant (allo-HSCT) patients are at risk of malnutrition and weight loss from impaired oral intake resulting from gastrointestinal toxicities, dysgeusia, and psychological effects. METHODS: A retrospective review of 264 adult patients transplanted at Princess Margaret Cancer Centre who achieved relapse-free survival up to 3 months after allo-HSCT was performed. RESULTS: Overall incidence of patients who experienced WL (WL) ≥ 10% from HSCT to 3-month post-transplant was 45.9% and from HSCT to 6 months was 56.6%. Patients with ≥ 10% WL from allo-HSCT at 3 months and 6 months had similar 2-year overall survival (OS) compared to those with < 10% WL, 55.7% vs 62.8% (HR = 1.38, p = 0.11) and 71.1% vs 77.2% (HR = 1.37, p = 0.27), respectively. Patients with ≥ 10% WL 3 and 6 months from allo-HSCT also had similar 2-year relapse-free survival (RFS) compared to those with < 10% WL, 48.1% vs 55.8% (HR = 1.26, p = 0.22), and 62.7% vs 69.8% (HR = 1.29, p = 0.31), respectively. The 2-year transplant-related mortality (TRM) was higher for those with ≥ 10% WL from allo-HSCT to 3 months, 35.4% vs 16.9% (HR = 2.39, p = 0.0007) and 6 months, 22% vs 8% (HR = 3.1, p = 0.0034). Although statistical significance was not observed for OS or RFS, patients who experienced ≥ 10% WL 3- and 6-months post allo-HSCT experienced higher 2-year TRM. These results highlight the importance of early intervention and close monitoring of weight post allo-HSCT. CONCLUSION: Approaches to WL post allo-HSCT should be multifaceted and include members of the interdisciplinary team in order to decrease TRM.

Allogeneic hematopoietic stem cell transplantation in patients with therapy-related hematologic malignancies developing after multiple myeloma.

INTRODUCTION: Increasing survival of patients with multiple myeloma (MM) has resulted in an increased recognition of therapy-related hematological malignancies (t-MDS/AML, t-ALL, and t-CMML). There are limited data on the role of allogeneic hematopoietic stem cell transplantation (HCT) in this patient population. PATIENTS AND METHODS: We retrospectively reviewed patients who underwent HCT for t-MDS/AML, t-ALL, and t-CMML developing after receiving treatment for MM at our center. Patients were analyzed for myeloma characteristics and therapy, time to diagnosis of therapy-related hematological neoplasms, clinical, laboratory characteristics, transplant details, relapse-free survival (RFS), and overall survival (OS). RESULTS: Twenty patients underwent HCT for therapy-related hematological malignancies after MM (t-MDS/AML = 13, t-ALL = 6, t-CMML = 1). Median(range) age at time of transplant was 62.5 (49-73) years and 70% (n = 14) were male. The most common cytogenetic abnormality was complex/monosomal karyotype in 30% (n = 6) followed by monosomy/deletion of chromosome 5 or 7 in 15% (n = 3) of patients each. Donors were human leukocyte antigen matched (10/10 or 6/6) siblings in 30% (n = 6), unrelated in 60% (n = 12) and haploidentical in 10% (n = 2) patients. Estimated 2-year OS and RFS for the whole cohort were 53.1% and 47.2% respectively. There was a trend toward better survival in patients with t-ALL when compared to t-MDS/AML; however, the difference was not statistically significant. We did not find any pre-transplant or post-transplant factors that were predictive of survival outcomes after multivariate analysis. CONCLUSIONS: Allogeneic HCT provides substantial long-term disease-free survival in a proportion of patients with MM-associated therapy-related hematological malignancies. Multicenter studies with more patients and longer follow-up may provide additional information about factors affecting outcomes.

Relationship between certain HLA alleles and the risk of cytomegalovirus reactivation following allogeneic hematopoietic stem cell transplantation.

INTRODUCTION: Evidence is emerging to support an association between certain human leukocyte antigen (HLA) alleles and the risk of cytomegalovirus (CMV) reactivation following allogeneic hematopoietic stem cell transplant (allo-HSCT). The primary aim of this study was to identify HLA alleles associated with resistance or susceptibility to CMV reactivation. METHODS: We studied 586 adults who underwent allo-HSCT for high-risk hematological malignancies. High-resolution HLA typing data were available for recipients and donors. HLA class I and II alleles observed at a frequency of >5% in our population were included in the analysis. A CMV viremia level of more than 200 IU/ml on weekly monitoring was considered to be indicative of CMV reactivation. RESULTS: The median follow-up time in surviving patients was 21 months (range 4-74 months). The cumulative incidence of CMV reactivation at 6 months in the entire cohort was 55% (95% confidence interval [CI] 50.8%-59.2%). Mismatched donors, increasing recipient age, occurrence of acute graft versus host disease and recipient CMV seropositivity were associated with an increased risk of CMV reactivation. HLA B*07:02 (hazard ratio 0.59, 95% CI 0.40-0.83) was associated with a decreased risk of CMV reactivation. Patients who developed CMV reactivation had a lower incidence of relapse, higher transplant-related mortality (TRM) and lower overall survival (OS) than those without CMV reactivation. There was an adverse correlation of OS and TRM with increasing numbers of CMV reactivations. CONCLUSION: We observed that HLA B*07:02 was associated with a decreased risk of CMV reactivation. CMV reactivation was associated with lower relapse post-transplant, but this did not translate into a survival benefit due to higher TRM.

Moderate-severe grade of chronic graft versus host disease and younger age (less than 45 years old) are risk factors for avascular necrosis in adult patients undergoing allogeneic hematopoietic cell transplantation.

Avascular necrosis (AVN) is a debilitating complication of allogeneic hematopoietic cell transplantation (HCT). A retrospective review of 845 patients who underwent HCT was conducted. Cumulative incidence of AVN was 6.3% at 4 years. The following risk factors were significantly associated with AVN risk on univariate analysis: age < 45 (p=0.004), moderate to severe chronic GvHD (p<0.001), reduced intensity conditioning (p=0.02), and a diagnosis of acute leukemia (p=0.045). Multivariate analysis confirmed two risk factors: younger age (<45 years), 9.0% vs 4.4% (p=0.011, hazard ratio (HR) 2.134), and moderate-severe chronic GvHD, 15.4% vs 2.1% (p<0.001, HR 4.950). A risk score model was generated assigning a score to each risk factor. A score of 1 was assigned to moderate-severe GvHD or those with age <45. Total score was calculated, thus dividing patient into three groups: low (score 0, n=349, 41.3%), intermediate (score 1, n=379, 44.9%), and high risk (score 2; n=116, 13.7%). This risk score could stratify the patients according to AVN risk (p<0.001). The risk of AVN was 1.5% in the low risk, 6.2% in the intermediate risk, and 20.8% in the high risk groups. Moderate-severe chronic GvHD and younger age (<45 years) are key risk factors for AVN following allogeneic HCT.

Prolactin, a potential biomarker for chronic GVHD activity.

INTRODUCTION: The polypeptide prolactin (PRL) is a peptide hormone and a cytokine mostly secreted from the anterior pituitary gland. PRL is also synthesized in extra pituitary tissues including thymocytes and T lymphocytes. Considering the need for chronic GVHD (cGVHD) biomarkers, we explored the relationship between hyperprolactinemia and active cGVHD in a cohort of long-term post-alloHCT survivors. METHODS: Three-hundred sixteen adults underwent alloHCT between 2010 and 2016, survived more than 1 year and were included. All patients underwent a regular annual assessment that includes a hormone profile with serum PRL levels. RESULTS: Overall, 236 (74.7%) patients had cGVHD, and in 199 (63%), the grade was moderate or severe. Sixty-five (21%) recipients had active cGVHD at the time of the annual evaluation, and hyperprolactinemia was documented in 63 (19.9%) patients. Hyperprolactinemia correlated with cGVHD activity (Odds Ratio 6.9 (95% CI; 3.6-13.1); P < .001) in the multivariate analysis. In conclusion, patients with hyperprolactinemia were 6.4 times more likely to have active cGVHD in comparison with those patients with normal levels of PRL (P < .001). CONCLUSION: Prolactin may serve as a biomarker for cGVHD activity. Further studies are required to confirm these findings, and to explore if hyperprolactinemia has an impact on cGVHD severity and prognosis.

Less Is More: Superior Graft-versus-Host Disease-Free/Relapse-Free Survival with Reduced-Intensity Conditioning and Dual T Cell Depletion in Acute Myelogenous Leukemia.

In this study, we compared the outcomes of patients with acute myelogenous leukemia (AML) in complete remission treated with myeloablative conditioning (MAC) and those treated with reduced-intensity conditioning (RIC) before allogeneic hematopoietic stem cell transplantation (allo-HCT). In addition, we explored the efficacy of dual T cell depletion using anti-thymocyte globulin (ATG) and post-transplantation cyclophosphamide (PTCy) for the prevention of graft-versus-host disease (GVHD) in patients undergoing RIC allo-HCT. Our study cohort comprised 356 adults with AML in complete remission who underwent allo-HCT between 2013 and 2018. One hundred eleven patients (31.2%) received a MAC regimen, and 245 (68.8%) received an RIC regimen. One hundred seventy-one of the patients who received an RIC regimen (68.4%) received ATG, PTCy, and cyclosporine (ATG-PTCY-CsA) for GVHD prophylaxis in accordance with our institutional protocol. Data were collected retrospectively and updated in July 2019. With a median follow-up of 14.5 months (range, 0 to 76 months), 161 patients (45.2%) died, and 66 (18.5%) relapsed. Two-year overall survival (OS), relapse-free survival (RFS), and GVHD-free/RFS (GRFS) were 55%, 52.6%, and 35%, respectively. The intensity of the conditioning regimen, with or without ATG-PTCY-CsA, did not have a significant impact on OS and RFS. However, RIC in combination with ATG-PTCY-CsA was associated with a significantly lower cumulative incidence of acute GVHD and chronic GVHD. The use of RIC with ATG-PTCy-CsA was a significant predictor for higher GRFS secondary to the reduction of clinically relevant GVHD (P= .0001). In patients with AML, RIC allografts and dual T cell modulation with ATG and PTCy led to superior GRFS. The use of this GVHD prophylaxis strategy, along with mitigation of conditioning toxicity using RIC, may result in better long-term quality of life for allo-HCT recipients.

Outcomes of therapy-related acute lymphoblastic leukemia in adults after allogeneic stem cell transplantation.

INTRODUCTION: Therapy-related acute lymphoblastic leukemia (t-ALL) is an increasingly recognized subset of therapy-related acute leukemia. There are limited data on the role of allogeneic hematopoietic stem cell transplantation (HSCT) in t-ALL. Recent reports suggest comparable outcomes of t-ALL with de novo ALL after HSCT. PATIENTS AND METHODS: We retrospectively reviewed all patients of t-ALL who underwent HSCT at our center. Patients were analyzed for prior malignancy, therapy, time to diagnosis of t-ALL, clinical, laboratory characteristics, transplant details, relapse-free survival (RFS), and overall survival (OS). RESULTS: Eighteen patients (M:F ratio 1:1; Median age 44 years) underwent HSCT for t-ALL. Median latent period from primary malignancy to t-ALL was 44.8 months. 11q23 rearrangement and t(9;22) were present in 33.3% and 22.2% patients, respectively. Stem cell donors were matched related, matched unrelated, and haploidentical in 27.8% (n = 5), 55.6% (n = 10), and 16.7% (n = 3) patients, respectively. Five patients died before D+ 100 (27.8%). Estimated 2-year RFS and OS were 47.1% and 51.8%, respectively. We did not find any pretransplant and post-transplant risk factors that were predictive of improved OS or RFS after multivariate analysis. CONCLUSIONS: Allogeneic HSCT outcomes in t-ALL were comparable to HSCT outcomes in de novo ALL. Multicenter studies with more patients and longer follow-up may provide factors affecting outcome and survival.

Combination of the Centre for International Blood and Marrow Transplant Registry Risk Score and the Global Severity Score Enhances Prognostic Risk Stratification in Patients Receiving Frontline Therapy for Chronic Graft-versus-Host Disease.

The Centre for International Blood and Marrow Transplant Registry (CIBMTR) score has been shown to be prognostic for overall survival (OS) and nonrelapse mortality (NRM) but has been shown in several single-center studies to classify a large proportion of patients with chronic graft-versus-host disease (cGVHD) in the lower risk groups (RG1 to RG2), thereby limiting its prognostic utility for those patients. We evaluate the CIBMTR score, the Global Severity Score (GSS), and a novel risk score developed to improve on the limitations of the CIBMTR with respect to clinically relevant outcomes, including failure-free survival (FFS), in patients receiving frontline systemic treatment for cGVHD. We identified 277 patients between 2002 and 2012 at the Princess Margaret Cancer Centre in Toronto, Canada, who developed cGVHD and were treated with at least 1 line of systemic therapy. cGVHD was graded by GSS, and patients were stratified by CIBMTR. We evaluated OS, NRM, relapse, and FFS within GSS grade groups, as well as CIBMTR RGs, and used a novel prognostic risk score. The median FFS duration was 164 days in the severe GSS group versus 238 days in the moderate-grade group and 304 days in mild-grade group (P= .001). The median FFS duration was 501 days in CIBMTR RG1 versus 291 days in RG2 and 166 days in RG3 to RG6 (P = .003). A novel risk score combining the GSS and CIBMTR scores was prognostic of OS, NRM, and FFS and was able to subdivide patients with cGVHD in CIBMTR RG1 to RG2 into distinct prognostic risk categories. The CIBMTR risk score and the GSS are well correlated with FFS, OS, and NRM following frontline systemic treatment for cGVHD. A new risk score model combining the CIBMTR risk score and the GSS could enhance risk stratification in the lower CIBMTR risk groups.

Sequential liver and haematopoietic stem cell transplantation in a case of fulminant hepatitis associated liver failure and aplastic anaemia.

The management of severe aplastic anaemia is particularly challenging when it occurs in the context of recent liver transplantation. Rapid identification of a suitable donor followed by allogeneic haematopoietic stem cell transplantation is the only curative option. This scenario is often complicated by potentially life-threatening infections that develop as a consequence of immunosuppression. Alternative donor transplantation using suitably matched unrelated donors can be potentially life-saving when suitably matched sibling donors are unavailable. Above all, a dedicated interdisciplinary approach with seamless communication between hepatology, transplant surgery, haematology, and stem cell transplant services is essential to achieving optimal outcomes. Herein, we describe a case of severe hepatitis leading to hepatic failure who was treated with liver transplantation from a deceased donor, and later received an allogeneic haematopoietic stem cell transplantation from a matched unrelated donor for hepatitis-associated aplastic anaemia.

Reduced-intensity conditioning allogeneic transplant with dual T-cell depletion in myelofibrosis.

BACKGROUND: There remains a significant mortality in recipients with MF who undergo allogeneic stem cell transplant (allo-HSCT). The combination of antithymocyte globulin (ATG) and post-transplant cyclophosphamide (PTCy) provides good control of graft-versus-host disease (GVHD) when peripheral blood stem cell grafts are used. METHODS: We report the outcome of 37 recipients with myelofibrosis who underwent reduced-intensity conditioning (RIC) allo-HSCT with ATG and PTCy. Median follow-up was 16.4 months. RESULTS: Nine (24.3%) recipients received 10/10 MRD grafts, 17 (45.9%) 10/10 MUD grafts, 4 (10.8%) 9/10 MUD grafts, and 7 (18.9%) haploidentical donor grafts. Six (16.3%) patients had graft failure. The cumulative incidence of grade II-IV and grade III-IV aGVHD at day +100 and moderate/severe chronic GVHD at 1 year was as follows: 13.5%, 5.4%, and 17%. There were no deaths secondary to GVHD. One-year overall survival (OS), relapse-free survival (RFS), non-relapse mortality (NRM), and GVHD-free/RFS (GRFS) were respectively 74.4%, 71.3%, 23%, and 43.3%. Those recipients who had worse KPS ≤ 80% had worse OS and RFS. CONCLUSION: RIC allo-HSCT with ATG and PTCy results in high OS and RFS in patients with myelofibrosis and absence of mortality secondary to GVHD. Further investigations are required to reduce NRM and graft failure rates.

Reduced intensity allogeneic stem cell transplant with anti-thymocyte globulin and post-transplant cyclophosphamide in acute myeloid leukemia.

OBJECTIVES: We aimed to study the efficacy of reduced intensity conditioning (RIC) allo-HSCT combined with anti-thymocyte globulin (ATG) and post-transplant cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis in AML. METHODS: One hundred forty-seven patients were included. All patients underwent unmanipulated peripheral blood stem cell RIC allo-HSCT. Median follow-up was 12.8 months (range 0.5-39). RESULTS: Median age was 58 years. Twenty-nine (20%) recipients received 10/10 MRD grafts, 69 (47%) 10/10 MUD grafts, 20 (13.6%) 9/10 MMUD, and 29 (20%) haploidentical grafts. The cumulative incidence of grade II-IV and III-IV acute GVHD at day +100, and moderate/severe chronic GVHD at 1-year were as follow: 14.3%, 1.4%, and 8.3%. There were no significant differences according to donor type (P = .46) and cumulative incidence of GVHD. One-year overall survival (OS), relapse-free survival (RFS), non-relapse mortality, and GVHD-free/Relapse-free survival were as follows: 66.9% (95% CI 58.4-74), 59.9%, and 18.7% and 53.7%. KPS ≤ 80 was predictive of worst OS (P = .04). Those recipients who received MUD transplants had better RFS (P = .01). CONCLUSIONS: RIC allo-HSCT combined with ATG and PTCy is safe and a potentially curative strategy and it is associated with impressive GRFS in AML.

Reduced-Intensity Conditioning and Dual T Lymphocyte Suppression with Antithymocyte Globulin and Post-Transplant Cyclophosphamide as Graft-versus-Host Disease Prophylaxis in Haploidentical Hematopoietic Stem Cell Transplants for Hematological Malignancies.

Haploidentical hematopoietic stem cell transplantation (haploHSCT) with conditioning regimens using post-transplant cyclophosphamide (PTCy) for peripheral blood stem cell (PBSC) grafts is limited by comparably higher rates of acute and chronic graft-versus-host disease (GVHD). Antithymocyte globulin (ATG) may mitigate this risk. We evaluated haploHSCT after reduced-intensity conditioning (RIC) with ATG, PTCy, and cyclosporine to prevent rejection and GVHD. Fifty adults underwent haploHSCT from August 2016 to February 2018. RIC included fludarabine (30 mg/m2/day on days -5 to -2), busulfan (3.2 mg/m2/day on days -3 and -2), and total body irradiation (200 cGy) on day -1. Unmanipulated PBSCs were infused on day 0. GVHD prophylaxis included ATG (4.5 mg/kg over days -3 to -1), PTCy (50 mg/kg/day on days +3 and +4), and cyclosporine from day +5. Median age was 56 years (range, 22 to 70 years); 25 (73.5%) patients were in first complete remission (CR1), 5 (14.7%) were in second complete remission (CR2), and 8 (23.5%) had active disease. Median time to neutrophil engraftment was 16 days (range, 8 to 43 days). At day +100, the cumulative incidence of acute GVHD of any grade, and grades III to IV was 38.3% and 5.2%, respectively. Mild chronic GVHD was seen in 15.5%. Cytomegalovirus (CMV) reactivation occurred in 37 (74%) cases and CMV disease occurred in 4 (11.5%) cases. Epstein-Barr virus (EBV) reactivation occurred in 21 (61.8%) patients. The incidence of histologically confirmed post-transplantation lymphoproliferative disorder (PTLD) was 5.8%. Four patients received rituximab. There were no CMV, EBV, or PTLD-related deaths. Six-month and 1-year overall survival (OS), cumulative incidence of relapse (CIR), and nonrelapse mortality (NRM) were 73.9%, 10.2%, and 19.4%, respectively, and 48.1%, 16% and 38.2%, respectively. Infection was the most common cause of death (18%). Unmanipulated haploidentical PBSC transplantation following RIC with ATG, PTCy, and cyclosporine as a GVHD prevention strategy results in low rates of acute and chronic GVHD.

Management of hypereosinophilia in tropical settings.

Hypereosinophilia includes a group of commonly encountered clinical situations with symptoms ranging from mild and clinically innocuous to devastating presentations with high morbidity and mortality. The presentations and complications can be easily missed if the clinician is unaware of the diverse entities responsible for hypereosinophilia. The hypereosinophilic syndromes encompass entities that are associated with varying degrees of organ dysfunction either directly due to eosinophilic infiltration or as a result of substances secreted by the eosinophils. These conditions may be neoplastic or reactive in aetiology and a diligent search for secondary causes is essential. Evaluation and management algorithms in the tropical setting and in developing countries may differ from elsewhere. A review of hypereosinophilia and hypereosinophilic syndromes is presented with a diagnostic and therapeutic decision making algorithm modified for use in the tropical setting.

Treosulfan- Versus Busulfan-based Conditioning in Allogeneic Hematopoietic Cell Transplantation for Myelodysplastic Syndrome: A Single-center Retrospective Propensity Score-matched Cohort Study.

Treosulfan has shown promise in allogeneic hematopoietic cell transplantation (HCT) for its myeloablative properties and low toxicity. In this single-center retrospective propensity score-matched cohort study we compared treosulfan- and busulfan-based conditioning in allogeneic HCT for patients with myelodysplastic syndrome (MDS). This study included 138 adults who underwent allogeneic HCT for MDS or chronic myelomonocytic leukemia at Princess Margaret Hospital, Toronto, from 2015 to 2022. Using propensity score matching, we compared transplant outcomes between 2 well-matched cohorts who received conditioning with either fludarabine-treosulfan (FT) (n = 46) or fludarabine-busulfan with total body irradiation (FBT200) (n = 92). A scoring system based on patient age, Karnofsky performance score, and hematopoietic cell transplant comorbidity index was used to assign patients based on fitness to low-dose (30 g/m2) or high-dose (42 g/m2) treosulfan: 32 (69.6%) received high-dose treosulfan. The racial composition of the 2 groups was similar, with 27.2% and 21.7% of FBT200 and FT recipients, respectively, identifying as non-Caucasian (P = .61). Primary outcomes were analyzed at a median follow-up of 747 days. Of all participants, 116 (84.0%) received graft-versus-host disease (GVHD) prophylaxis with post-transplant cyclophosphamide (PTCY) and antithymocyte globulin (ATG). Patients who received FT had a superior 2-year overall survival (OS) compared to those who received FBT200: 66.9% (95% confidence interval (CI): 46.1 to 81.2) versus 44.5% (95% CI: 34 to 54.4), hazard ratio (HR): 0.43, 95% CI: 0.22 to 0.84 (P = .013). In multivariate analysis (MVA), only the use of fresh grafts (P = .02) and FT (P = .01) were associated with improved OS. FT was associated with superior 2-year relapse-free survival (RFS) compared to FBT200: 63.1% (95% CI: 42.6 to 77.9) versus 39.1% (95% CI: 29.1 to 49.1), HR: 0.44 (95% CI: 0.24 to 0.81), P = .008. In MVA, the use of fresh grafts (P = .03) and FT (P = .009) were associated with improved RFS. Recipients of FT demonstrated superior 2-year graft-versus-host disease relapse-free survival (GRFS) compared to those who received FBT200: 57.4% (95% CI: 37.8 to 72.8) versus 35.1% (95% CI: 25.5 to 45). In MVA, only FT was associated with superior GRFS (P = .02). FT recipients exhibited markedly superior 1-year event-free survival compared to recipients of FBT200 in univariate analysis (40.3% (95% CI: 25.9 to 54.2) versus 9.2% (95% CI: 4.4 to 16.3), HR: 0.47 (95% CI: 0.30 to 0.72), P < .001) and MVA (P = .004). FT was associated with lower 1-year nonrelapse mortality compared to FBT200 in univariate analysis (9.9% (95% CI: 3.0 to 21.8) versus 29.7% (95% CI: 20.6 to 39.3), HR: 0.41 (95% CI: 0.17 to 0.96), P = .04) and MVA (P = .04). Our study utilized propensity score matching to demonstrate superiority of treosulfan- over busulfan-based conditioning in stem cell transplantation of patients with MDS and is the first to evaluate the performance of treosulfan-based conditioning in combination with ATG and PTCY. As such, it contributes to the increasing body of evidence supporting the safety of treosulfan, even at the dose of 42 g/m2.

Pretransplant Blinatumomab Improves Outcomes in B Cell Acute Lymphoblastic Leukemia Patients Who Undergo Allogeneic Hematopoietic Cell Transplantation.

BACKGROUND: Blinatumomab, a bispecific monoclonal antibody, effectively controls refractory B cell acute lymphoblastic leukemia (ALL) and promotes measurable residual disease (MRD) negativity. This study investigated the impact of pretransplant blinatumomab on allogeneic hematopoietic cell transplantation (HCT) outcomes in B cell ALL patients. METHODS: We analyzed the effect of pretransplant blinatumomab on transplant outcomes of 117 adults undergoing allogeneic HCT for B cell ALL at Princess Margaret Hospital, Toronto, between 2010 and 2021. Outcomes assessed included overall survival (OS), graft-versus-host disease and relapse-free survival (GRFS), cumulative incidences of relapse (CIR), and nonrelapse mortality (NRM). RESULTS: The median follow-up was 36 months. Thirty-one participants (26.5%) received blinatumomab. Blinatumomab group had higher proportions of individuals with high disease risk index, primary induction failure and was more likely to receive dual T cell depletion with antithymocyte globulin and post-transplant cyclophosphamide. Two-year OS, GRFS, NRM, and CIR in the blinatumomab and nonblinatumomab groups were, respectively: 65.4% versus 45.6% (P = .05), 42.2% versus 17.3% (P = .01), 3.2% versus 43.0% (P = .007) and 34.4% versus 14.4% (P = .02). Blinatumomab was associated with a lower incidence of day-100 grade 2 to 4 and grade 3 to 4 acute graft-versus-host disease (aGVHD): 27.5% versus 56.7% (P = .009), and 10.9% versus 34.7% (P = .04), respectively. Multivariate analysis confirmed the association between pretransplant blinatumomab and improved OS and NRM. CONCLUSIONS: Pretransplant blinatumomab is associated with improved OS and lower risk of NRM in B cell ALL patients undergoing allogeneic HCT, likely reflecting lower burden of treatment-related toxicity in this population. Larger prospective trials are warranted to validate our findings.

Cell Therapy Transplant Canada (CTTC) Consensus-Based Guideline 2024 for Management and Treatment of Chronic Graft-Versus-Host Disease and Future Directions for Development.

This is a consensus-based Canadian guideline whose primary purpose is to standardize and facilitate the management of chronic graft-versus-host disease (cGvHD) across the country. Creating uniform healthcare guidance in Canada is a challenge for a number of reasons including the differences in healthcare authority structure, funding and access to healthcare resources between provinces and territories, as well as the geographic size. These differences can lead to variable and unequal access to effective therapies for GvHD. This document will provide comprehensive and practical guidance that can be applied across Canada by healthcare professionals caring for patients with cGvHD. Hopefully, this guideline, based on input from GvHD treaters across the country, will aid in standardizing cGvHD care and facilitate access to much-needed novel therapies. This consensus paper aims to discuss the optimal approach to the initial assessment of cGvHD, review the severity scoring and global grading system, discuss systemic and topical treatments, as well as supportive therapies, and propose a therapeutic algorithm for frontline and subsequent lines of cGvHD treatment in adults and pediatric patients. Finally, we will make suggestions about the future direction of cGvHD treatment development such as (1) a mode-of-action-based cGvHD drug selection, according to the pathogenesis of cGvHD, (2) a combination strategy with the introduction of newer targeted drugs, (3) a steroid-free regimen, particularly for front line therapy for cGvHD treatment, and (4) a pre-emptive approach which can prevent the progression of cGvHD in high-risk patients destined to develop severe and highly morbid forms of cGvHD.

Dual T cell depletion for graft versus host disease prevention in peripheral blood haploidentical hematopoietic cell transplantation for adults with hematological malignancies.

The ideal immunosuppressive agents to complement post-transplant cyclophosphamide (PTCy) in PBSC-based haploidentical hematopoietic cell transplantation (haplo-HCT) remain debated. This study looks at our experience with ATG-PTCy-Cyclosporine (CsA) prophylaxis in PB haplo-HCT since 2015. Between October 2015 and December 2021, 157 adults underwent haploidentical hematopoietic cell transplantation (haplo-HCT) using a GVHD prophylaxis regimen comprising rabbit-ATG, PTCy, and CsA. Among these patients, 76.4% received a total ATG dose of 4.5 mg/kg, and 23.5% received 2 mg/kg. T-cell replete peripheral blood stem cell (PBSC) grafts were infused on day 0. The study reported a median follow-up of 32 months (range 0.3-61.64) for survivors. The cumulative incidence of grade II-IV and grade III-IV acute GVHD at day +100 was 26.3% and 9.5%, respectively. Moderate/severe chronic GVHD at 1 year was 19.9%. The 2-year overall survival (OS) was 49.4%, with a relapse-free survival (RFS) of 44.6%. In multivariate analysis, older patients, and those with high/very-high disease risk indices (DRI) were at higher risk for worse OS and higher non-relapse mortality (NRM). The study confirms that using PTCy and ATG (4.5 mg/kg), alongside CsA is safe and effective in preventing GVHD when using peripheral blood as the stem cell source in haploidentical hematopoietic cell transplantation (haplo-HCT).

Choosing Between Older Matched Sibling Donor and Younger Matched Unrelated Donor in Allogeneic Hematopoietic Cell Transplantation: Comparison of Clinical Outcomes in Acute Myeloid Leukemia and Myelodysplastic Syndrome.

The choice between an older matched sibling donor (MSD) and a younger matched unrelated donor (MUD) in allogeneic hematopoietic cell transplantation (HCT) remains a subject of ongoing debate. In this single-center retrospective study of 377 patients who received peripheral blood stem cell (PBSC) transplants for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS), we compared outcomes of 85 patients who received grafts from MSDs age >60 years and 292 patients who received grafts from MUDs age <30 years. Compared to recipients of MSD transplants, recipients of MUD transplants were younger and more likely to receive dual T cell depletion (TCD), a higher CD34+ cell dose, and a fresh graft. Recipients of MSD transplants were maintained on immunosuppressive therapy longer than those who received MUD grafts. We found no differences in overall survival, relapse-free survival, graft-versus-host disease (GVHD)-free and relapse-free survival, nonrelapse mortality, relapse, engraftment, graft failure, and acute GVHD between recipients of MSD grafts and recipients of MUD grafts. We report a higher 30-day incidence, but not 1-year incidence, of bloodstream infections among recipients of MUD transplants compared to subjects who received their grafts from a MSD. The incidence of moderate-severe chronic GVHD was higher in MSD graft recipients compared with MUD graft recipients in univariate analysis, but not in multivariate analysis. Although this difference could reflect the greater use of dual TCD, known to be associated with very low rates of chronic GVHD in MUD transplant recipients, the incidence of moderate-severe chronic GVHD was no different between MSD and MUD transplant recipients following propensity score matching, suggesting that other variables could be responsible. Taken together, our data suggest that in patients with AML or MDS who receive PBSC transplants, such factors as convenience, ease of access, and costs should be considered when selecting an older MSD over a younger MUD.