Grade III-IV Acute Graft-versus-host Disease Research Articles

Post-Transplant Cyclophosphamide, Abatacept and Short Course of Tacrolimus (CAST) for Graft-Versus-Host Disease Prevention Following Haploidentical Peripheral Blood Stem Cell Transplantation

Background: Haploidentical blood and marrow transplantation (BMT) substantially expands the pool of potential hematopoietic stem cell donors, including for minority groups. However, the outcomes of haploidentical transplantation remain inferior to matched unrelated donor (MUD) transplants when a standard post-transplant cyclophosphamide (PTCy)-based graft versus host disease (GvHD) prophylaxis regimen is employed in both settings. To address this issue, we sought to develop a more effective GvHD prevention regimen in haploidentical transplantation. While abatacept (Aba) seems to decrease the incidence of acute GvHD, PTCy is particularly effective in the prevention of chronic GvHD. Therefore, we designed a regimen that combines the merits of both agents and examined whether such approach can allow early withdrawal of tacrolimus (Tac). Methods: We enrolled 46 adult patients with hematological malignancies receiving haploidentical transplantation from a relative in a prospective single center pilot phase Ib-II clinical trial. Patients received non-myeloablative, reduced-intensity or myeloablative preparative regimens followed by G-CSF mobilized peripheral blood transplants and a combination of PTCy (50mg/kg on days +3 and +4), Aba (10mg/kg on days +5, +14 and +28) and Tac at a dose adjusted based on blood level. Tac taper was initiated on day +60 and completed by day +90. After treating 30 patients, the study was amended to administer an additional dose of Aba on day +56 based on the noted timing of acute GvHD development and Aba terminal ½ life. Patients received standard supportive care by institutional practice including G-CSF and anti-microbial prophylaxis. Serologically CMV positive patients also received letermovir prophylaxis. Results: Patient characteristics are summarized in table 1. Importantly, 19 out of 46 (41.3%) patients were from racial or ethnic minorities. The data cutoff date was July 29th, 2022. Three patients were excluded from this analysis due to short follow-up. For the remaining patients, median follow-up was 8.9 months. Median time to neutrophil engraftment was 18 days (13-30). One patient died before achieving platelet (plt) engraftment and 2 patients have not yet achieved plt engraftment. For the remaining 40 patients, median time to plt engraftment was 29 days (16-52). All patients achieved full donor chimerism at the time of count recovery. Tac was successfully tapered off as planned in all but 5 patients. Cumulative incidence of acute GvHD grades II-IV, III-IV and IV with death as competing event was 12.8%, 5.1% and 0%, respectively. One-year (y) cumulative incidence of moderate to severe chronic GvHD was 17.1%. All cases of acute GvHD except 1 grade II acute GvHD were observed in the first 30 patients. Cases of chronic GvHD included 2 cases of overlap syndrome. There was no case of steroid-refractory acute GvHD or GvHD-related death. One-y cumulative incidence of relapse (non-relapse mortality as competing event) was 8.3% (95% CI 0%-17.1%). KM estimates of 1-year relapse-free survival (RFS), overall survival (OS) and GRFS (composite end point of grade III-IV acute GvHD-, chronic GvHD requiring systemic therapy- and relapse-free survival) were 91.7% (95% CI 83%-100%), 90.6% (95% CI 80.9%-100%) and 71.8% (95% CI 57.2%-90%), respectively. None of the safety stopping rules was triggered. There was 1 case of thrombotic microangiopathy due to Tac and 2 cases of sinusoidal occlusive disease, 1 requiring treatment with defibrotide; all 3 patients recovered. There were 2 cases of respiratory failure of undetermined etiology. One-y cumulative incidence of non-relapse mortality (relapse as competing event) was 2.6% (95% CI 0%-7.8%). The incidence of CMV and EBV reactivation was 39.5% and 2.3%, respectively. There was no case of adenovirus or HHV-6 virus reactivation. BK viruria occurred in 27.9% of patients with limited symptomatology (1 patient required treatment with cidofovir). Immune reconstitution results are summarized in figure 1. Conclusion: CAST is a new GvHD prevention regimen that seems safe and effective, yielding excellent outcomes. CAST also allows early discontinuation of Tac. Outcomes with longer follow-up will be presented at the meeting. If the results are confirmed, CAST might be a step forward toward closing an important health disparity gap in BMT, equalizing the outcomes of haploidentical transplantation and MUD transplants. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

IPSS-Molecular but Not Individual Mutations Predicts Outcomes of Patients with Myelodysplastic Syndrome (MDS) after Allogeneic Hematopoietic Cell Transplantation (Allo-HCT): A Mayo Clinic Cohort

The decision to offer Allo-HCT in MDS relies on prognostic scoring models which include clonal cytogenetic (CG) abnormalities, blood counts (cytopenias), and % of marrow blasts (i.e. revised international prognostic scoring system, IPSS-R). Recently, an updated clinical-molecular prognostic model combining genomic profiling with hematologic and CG parameters, namely IPSS-Molecular (IPSS-M), showed better prognostic discrimination across all clinical endpoints and re-stratified almost one-half of patients (pts) vs. IPSS-R. Hence, we evaluated the impact of IPSS-M, CG risk group and individual mutations on Allo-HCT outcomes. The analysis included 191 consecutive MDS pts undergoing Allo-HCT who had available next generation sequencing (NGS) analysis performed at Mayo Clinic (at diagnosis (Dx, n=164 or prior to Allo-HCT, n=162) between 11/2015 and 1/2022. Median age at Allo-HCT was 64 (18-75) yrs, and 112 (58.6%) were male. At Dx, 126 (77%) pts had at least one pathogenic genetic alteration, including (>5% incidence) ASXL1 (28.0%), TP53 (18.9%), TET2 (14.6%), SRSF2(12.2%), U2FA1 (12.2%), DNMT3A (8.5%), BCOR (7.9%), RUNX1 (6.7%), and SF3B1 5.5%; a similar mutational pattern was present at Allo-HCT: ASXL1 (28%),TET2 (15.2%) U2AF1 (13.4%), TP53 (12.2%), SRSF2 (11%), RUNX1(9.8%), DNMT3A (7.3%), SETBP1 (7.3%), SF3B1 (6.7%), BCOR (6.7%), STAG2 (5.5%), and JAK2 (5.5%). Most pts (156, 81.7%) received at least 1 line of therapy, and 45 (23.6%) had >5% marrow blasts at Allo-HCT. The majority (134, 70%) received reduced intensity conditioning. Graft versus host disease (GVHD) prophylaxis consisted of methotrexate/tacrolimus in 138 (77.5%) and post-transplant cyclophosphamide in 40 (22.5%). HCT comorbidity index was >3 in 113 (59%). IPSS-M risk group was calculated and reclassified from IPSS-R into very low (1, 0.6%), low (24, 14.7%), moderate low (34, 20.9%), moderate high (41, 25.2%), high (29, 17.8%), very high (34, 20.9%), mainly for IPSS-R intermediate and high-risk groups (Fig. 1). Median F/U after Allo-HCT was 18.8 (0.4-76.8) months. The 100-day and 1-year non-relapse mortality (NRM) were 7.9% and 18.1%, respectively. The 2-year incidence of death and relapse were 40.1% (95% confidence intervals (CI) 33.5-48%) and 21.6% (95%CI 16.4-28.4%), respectively. Cumulative incidences of grade III-IV acute GVHD was 10% and 1-year cumulative incidence of extensive chronic GVHD was 12%. In multivariable analysis, IPSS-M predicted mortality [Hazard ratio (HR) (per 1 risk category) 1.21, 95%CI 1.00-1.47, p=0.049] and relapse (HR=1.47, 95%CI 1.13-1.92, p=0.004), but not NRM (HR 0.95, 95%CI 0.74-1.22). The 1-year mortality rates for very low/low, moderate-low, moderate-high, high/very high risks were 21%, 24%, 32%, and 37%, respectively (Fig. 1). Individual mutations had minimal independent association with outcome in the multivariable model. For mortality, only ASXL1 at Dx (HR 0.48, 95%CI 0.26-0.91, p=0.024) and SF3B1 at Allo-HCT (HR 2.51, 95%CI= 1.06-5.96, p=0.037) were significant. TP53 at Dx had a borderline association (HR 0.46, 95% CI= 0.942.69, p=0.086). Also, there was no significant association of individual mutation with relapse (including TP53 at Allo-HCT, HR 1.77, p=0.085). Only SF3B1 at Allo-HCT correlated with NRM (HR 3.16, 95%CI= 1.22-8.17, p=0.018). Conversely, CG risk group remained strongly associated with mortality (p=0.007) and relapse (p=0.003), particularly poor/very poor (P/VP) risk CG (Mortality: HR 2.46, 95%CI 1.44-4.19, p=0.001; Relapse: HR 3.46, 95%CI 1.70-7.05, p=0.0006). There was no association of CG risk with NRM. We demonstrate value of IPSS-M risk stratification in predicting outcomes after Allo-HCT for MDS, re-stratifying pts into more discrete prognostic groups that predict mortality and relapse risk. Hence, IPSS-M could inform post allo-HCT decision including future maintenance strategies to prevent relapse in high/very high IPSS-M. CG risk group (esp. P/VP risk), a core component of IPSS-M, independently contributes to outcome prediction both within the model and individually. Disease risk does not predict NRM, and individual mutations have limited association with outcome, suggesting allo-HCT may mitigate the poor prognostic impact of high-risk oncogenic mutations present at Dx, including TP53 and ASXL1. An updated analysis on mutational complexity will be shown at the meeting. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Conditioning Regimen Intensity and Donor Choice Do Not Impact Outcomes of Patients (pts) with Acute Myeloid Leukemia (AML) after Allogeneic Hematopoietic Cell Transplantation (Allo-HCT) in First Complete Remission (CR1): An EBMT Analysis

Allo-HCT is a curative treatment for fit pts with intermediate and adverse risk AML who achieve CR1. The presence of minimal residual disease (MRD) before allo-HCT has been shown to increase risk of relapse and decrease survival. Here, we describe outcomes of pts with AML who received allo-HCT in CR1 and the impact of MRD before allo-HCT on outcomes. We identified 1032 pts with AML who received allo-HCT in CR1 between 2015 and 2020 from the EBMT registry. The median age was 53.6 (range, 18.1-82.5) years and 526 (51%) were male. Most (94%) pts had de novo AML. FLT3-ITD and NPM1 mutations were detected in 46% and 44% of pts, respectively and high-risk cytogenetics were present in 20%. >1 course of induction therapy was required by 18% of pts to achieve CR1 and 39% were MRD positive at time of allo-HCT. The median time from diagnosis to allo-HCT was 4.9 months. Of pts with FTL3-wild type (FLT3-wt) disease, 33% were MRD negative and 22% were MRD positive at time of allo-HCT. In pts with FTL3-ITD mutation, 29% were MRD negative and 17% were MRD positive at time of allo-HCT. Donor type was matched sibling donor (MSD) in 29% of pts (n=297), matched unrelated donor (MUD) in 47% (n=481), mismatched unrelated donor (MMUD 9/10) in 8% (n=88), or haploidentical donor (haplo) in 16% (n=166). HCT-specific comorbidity index (HCT-CI) was >3 in 22% of pts (n=190). Myeloablative conditioning (MAC) was administered to 45% of pts (n=470), while reduced intensity conditioning (RIC) was used in 55% (n=562). The most common conditioning regimen was fludarabine/busulfan in MSD (n=148, 50%), MUD (n=272, 57%) and MMUD (n=38, 43%) recipients, while thiotepa/fludarabine/busulfan was the most used in haplo-HCT (n=99, 60%). Total body irradiation (TBI) was given to only 8% of pts (n=84), mainly in haplo-HCT (n=29). Most (n=1002, 98%) pts received calcineurin inhibitors (CNI), tacrolimus or cyclosporine A, for graft-versus-host disease (GVHD) prophylaxis in addition to mycophenolate mofetil (43%) or methotrexate (38%). Post-transplant cyclophosphamide was used in 18% (n=191) of pts, with 71% (n=136) having received haplo-HCT, and anti-thymocyte globulin was given to 67% (n=689). The median follow-up was 24 months. At day 60, the cumulative incidence of neutrophil engraftment was 99%. The cumulative incidence of grade III-IV acute GVHD (aGVHD) was 9% at day 180. At 2 years, the cumulative incidence of extensive chronic GVHD (cGVHD) was 17%. At 2 years, relapse incidence (RI), NRM, overall survival (OS), leukemia-free survival (LFS), and GVHD-free, relapse-free survival (GRFS) were 26%, 13%, 69%, 61%, and 48%, respectively. The main cause of death was primary disease in 55% of pts (n=157). Other causes of NRM were infections in 16% (n=45), and GVHD in 17% (n=47). In the multivariate analysis, compared to MSD, the use of MUD increased NRM (hazard ratio (HR) 1.86, p=0.02), GRFS (HR 1.28, p=0.039), aGVHD (HR 2.17, p<0.0001), and cGVHD (HR 1.36, p=0.044). The use of MMUD was associated with worse OS (HR 1.6, p=0.042) and higher risk of aGVHD (HR 2.11, p=0.003). Haplo-HCT was associated with higher incidence of aGVHD (HR 1.69, p=0.021) but lower risk of cGHVD (HR 0.63, p=0.033). Older age, lower performance status (PS), requiring >1 induction to achieve CR1, and FLT3-MRD positivity before allo-HCT were associated with worse LFS. Factors associated with lower OS were MMUD 9/10, older age, poor PS, >1 induction to achieve CR1, adverse cytogenetics, and FLT3-MRD positivity before transplant. In vivo TCD was associated with improved GRFS and lower risk of acute and cGVHD without increase of relapse. The use of RIC compared with MAC did not affect relapse, NRM or any other outcome. In conclusion, in pts with AML transplanted in CR1, those requiring >1 induction or with persistent FLT3-MRD positivity at time of allo-HCT had lower OS. Strategies to improve induction therapy, possibly through the addition of targeted agents, aiming to improve CR rates and deepening responses could potentially improve OS after allo-HCT. The use of RIC was associated with similar outcomes compared to MAC. This finding is particularly important for older pts or those with high HCT-CI scores unlikely to tolerate MAC. Survival after MSD allo-HCT is comparable to MUD and haplo, a finding that is in accordance with previous results for haplo and MUD as valid alternative donors in the absence of MSD. The use of MMUD was associated with lower OS compared to MSD and should be used as a last resort donor in this setting.

Epigenetic Priming with 5-Azacytidine Prior to Allogeneic Stem Cell Transplantation for Myeloid Malignancies with In Vivo T Cell Depletion: Results of a Phase II Trial

Background: Relapse is the main cause of death in patients who undergo allogeneic hematopoietic stem cell transplantation (HCT) for myeloid malignancies. Recent improvements in survival have been mainly due to reduction in non-relapse mortality (NRM). Acquired abnormalities of DNA methylation are frequent in myeloid malignancies and are particularly observed among patients with adverse risk features. Epigenetic priming with decitabine to induce DNA hypomethylation was investigated in a phase I trial for acute myeloid leukemia (AML) and has proven safe and feasible (Scandura et al Blood 2011). Applying the principle of chemotherapy-sensitization through hypomethylation in myeloid malignancy, we conducted a phase II trial (NCT02497404) of the epigenetic modulator -5-azacytidine given prior to a reduced intensity conditioning (RIC) regimen. Here we report the results of this trial. Methods: We designed an open label phase II study to determine the feasibility and efficacy of epigenetic priming with 5-Azacytidine prior to RIC for HCT with in-vivo T-cell depletion. Inclusion criteria were AML, myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (MPN) with an intermediate or poor risk profile by ELN and IPSS-R, respectively, and adequate organ function. Stem cell grafts were GCSF- mobilized peripheral blood stem cells from either a matched related donor (MRD) or matched unrelated donor (MUD), matched for HLA at loci A, B, C, DR, and DQ. The epigenetic priming regimen was 5-Azacytidine 75 mg/m2/daily X 5, given between days -11 to -7 (Dose reduction to 50 mg/m2/daily after 14 patients due to toxicity). The conditioning regimen consisted of Fludarabine 40 mg/m2/daily, days -6 to -3, and Melphalan 140 mg/m2, on day -3. Graft versus host disease (GVHD) - prophylaxis consisted of Alemtuzumab (total dose 60 mg for MUD and 30 mg for MRD), and Tacrolimus for 3-6 months post-transplant. The Primary objectives were overall survival (OS) and progression free survival (PFS) at 1 year. Secondary objectives were incidence of GVHD and NRM. Results: 39 adult patients with AML, MDS, and chronic neutrophilic leukemia (CNL) were enrolled prospectively between 2/2015 and 6/2018. The median age was 60 years (range, 26-74). The majority of patients had AML (33, 85%), or MDS (5, 13%). Nineteen AML patients (58%) had a poor risk karyotype. Nine cases (23%) had mutated TP53. The donor was MUD in 22 (44%), MRD in 17 (56%) of patients. Other patient characteristics are listed in Table 1. The median follow up for survivors is 6.7 years (5.8 - not reached). Thirty-eight patients engrafted neutrophils at a median of 13 days (9-16) and platelets at a median of 16 days (12-102). One patient was not evaluable due to early death on day 9. OS at 1 year was 64% (95% CI 51-81%) and 36% (95% CI 24-55%) at 4 years, (Figure 1). PFS at 1 year was 54% (95% CI 40-72%) and 33% (95% CI 21-52%) at 4 years. At 1 year, relapse was the cause of death in 21% (95% CI 18-22%) and NRM was 15% (95% CI 13-17%). At 4 years, relapse was the cause of death in 41% (95% CI 38-43%), while NRM reached 23% (95% CI 20-25%). The most common cause of NRM was infection in 5 patients (46%), followed by thrombotic microangiopathy and GVHD. The incidence of acute GVHD by day 100 was 29% (95% CI 13-43%) with grade III-IV acute GVHD found in 8% (95% CI 6-9%). The incidence of chronic GVHD at 1 year was estimated at 22% (95% CI 7.4-35%). No new cases of chronic GVHD were seen thereafter. The most common grade 3/4 toxicities were infections in 8 patients (21%) and renal failure (23%). We found 6/14 patients to have grade 3/4 renal toxicity with 2 requiring hemodialysis. After reducing the 5-azacytidine dose to 50 mg/m2/daily, we observed only 3/25 cases of grade 3/4 renal dysfunction. Conclusion: Preconditioning treatment with 5-azacytidine as epigenetic priming is tolerable with a toxicity profile overall similar to conditioning with fludarabine/melphalan. But the addition of azacytidine at 75 mg/m2/daily (total 5 doses) causes significant renal toxicity, which abates with dose reduction. The PFS in this very high-risk population with historically high relapse rates is promising. A larger number of patients is needed to further evaluate the efficacy of this approach. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Clinical Outcomes Following Allogeneic Hematopoietic Cell Transplantation with Omidubicel or Other Donor Sources in Patients with Hematologic Malignancies: Comparison of Clinical Trial Results to Center for International Blood and Marrow Transplant Research Database Controls

Background & objective: Omidubicel is an investigational advanced cell therapy manufactured from an appropriately HLA-matched single umbilical cord blood (UCB) unit that expands the number of stem cells while preserving stem cell function to optimize cell homing, engraftment, differentiation, and self-renewal. Allogeneic hematopoietic cell transplant (alloHCT) with omidubicel has demonstrated superiority to unmanipulated UCB transplant for patients with hematologic malignancies in a Phase III randomized trial (Horwitz ME, et al. Blood. 2021;138(6):1429-1440). The aim of the current real-world analysis was to compare the effectiveness of omidubicel versus other alloHCT donor sources used in clinical practice from the Center for International Blood and Marrow Transplant Research (CIBMTR) database of all alloHCTs performed in the United States in recent years. Methods: Data on patients who received omidubicel and unmanipulated UCB were drawn from the per-protocol (treated) population in the Phase III trial (NCT02730299). Data on patients who underwent myeloablative conditioning and first alloHCT for hematologic malignancies between 2017 and 2019 with haploidentical (with post-transplant cyclophosphamide), 8/8-matched unrelated (MUD), or 7/8-matched unrelated (MMUD) donors were obtained from the CIBMTR. Neutrophil engraftment (without chimerism), platelet engraftment, overall survival (OS), disease-free survival (DFS), non-relapse mortality (NRM), disease relapse (DR), and acute and chronic graft-versus-host disease (GvHD) were compared between groups with and without adjustment for baseline demographics and disease factors (age, gender, race, ethnicity, primary diagnosis, disease risk index, performance score, HCT comorbidity index, body weight, year of transplant and conditioning regimen). Analyses utilized Kaplan-Meier analyses, Cox proportional hazards models, and Fine-Gray models for outcomes with competing risks. Results: Fifty-two patients received omidubicel, 56 received unmanipulated UCB, and 807 patients received other donor sources. Omidubicel was associated with more rapid neutrophil recovery (median: 10 days) than all other donor sources (median 15-20 days; log-rank p-value <0.001). Omidubicel was associated with slower platelet engraftment than the haploidentical, MUD or MMUD donor sources and faster platelet engraftment than unmanipulated UCB (median: 35 days versus 19-26 days for haploidentical, MUD and MMUD, and 43 days for unmanipulated UCB; log-rank p-value <0.001). Results were similar in analyses accounting for death and relapse as competing risks and robust to adjustment for baseline demographic and disease factors (Table). OS was comparable across donor sources in unadjusted (Figure) and adjusted analyses (Table). DFS, NRM and DR were also comparable across donor sources. Rates of grade II-IV acute GvHD over the first 100 days post alloHCT were significantly higher for omidubicel (60% versus 32-43% for other sources, p-values from adjusted analyses <0.05 for all sources relative to omidubicel). However, rates of grade III-IV acute GvHD over the same time frame (15% for omidubicel versus 10-20% for other sources) and chronic GvHD over 12 months post alloHCT (33% for omidubicel versus 25-42% for other sources) were comparable across donor sources (p-values from adjusted analyses >0.05 for all sources relative to omidubicel). Conclusion: In this adjusted comparison to external CIBMTR controls receiving haploidentical or MUD/ MMUD donor sources, omidubicel was associated with earlier neutrophil engraftment, comparable OS, and comparable rates of acute GVHD grades III-IV and chronic GvHD. While this study used high-quality real-world data, harmonized inclusion criteria and outcome definitions, and adjustment for prognostic factors to mitigate risk of bias, the comparison of non-randomized treatment groups should be interpreted with caution. These results suggest that omidubicel may be an effective and important additional donor source, broadening the availability of transplantation for patients with hematologic malignancies. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Post-Transplantation Cyclophosphamide Combined with Tacrolimus and Low-Dose Post-Engraftment Anti-Thymoglobulin As Gvhd Prophylaxis for Patients Undergoing Peripheral Blood Stem Cell Transplantation from Haplo Donors: A Single Center Analysis

Post-transplantation cyclophosphamide (PT-Cy) use is a recent graft-versus-host disease (GVHD) prophylaxis strategy for patients undergoing allogeneic stem cell transplantation (allo-HSCT). PT-Cy combined with two immunosuppressants is now widely used after haplo-identical (haplo) and HLA-matched peripheral blood stem cell (PBSC) transplantations with promising GVHD and GVHD and relapse-free survival (GRFS) probabilities. Although appealing, these results may benefit from improvement notably outside matched sibling donor transplantation, and should be investigated in various ethnic populations. Therefore, we report our experience of GVHD prophylaxis regimen combining PT-Cy and tacrolimus with addition of post-engraftment low-dose anti-thymocyte globulin (ATG) in allogeneic stem cell transplantation from haplo-identical donors (Haplo). Fifty-three patients were included in the analysis. All patients received myeloablative or intensified sequential conditioning regimen. The median follow-up was 397 (range, 191~762) days. The cumulative incidences of 100-day grade II-IV acute GVHD was 9.4±4.1%, and no case of grade III-IV acute GVHD was documented. The cumulative incidences of 1-year chronic GVHD and moderate-to-severe chronic GVHD were 18.9±5.4% and 7.5±3.7%, respectively. The non-relapse mortality at day+100 and 1 year were 9.4±4.4% and 11.3±4.4%, respectively. The cumulative incidence of relapse at 1 year was 3.8±2.7%. The 1-year probability of DFS and OS were 84.5% (95%CI, 75.2~95.0%) and 88.7% (95% CI, 80.5~97.6%), respectively. The 1-year GRFS was estimated as 75.0% (95%CI, 64.1~87.8%). Our results suggested that a combination of PT-Cy, tacrolimus, and low-dose post-engraftment ATG was a promising GVHD prophylaxis with low incidence of acute GVHD in the haplo-transplantation setting. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Interventional Antibiotic Treatment Replacing Antibiotic Prophylaxis during Allogeneic Hematopoietic Stem Cell Transplantation Is Safe and Feasible: A Single-Center Analysis

Background: Patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) are at increased risk of infection-related mortality during the pre-engraftment period. Systemic antibiotic prophylaxis (SAP) is widely used during the period of neutropenia but is associated with disruption of the intestinal microbiome, an increased risk of Clostridium difficile infection (CDI) and colonization with multi-drug resistant (MDR) bacteria. Aims: We retrospectively assessed the safety and efficacy of a change in our center policy from SAP to an exclusively interventional antibiotic treatment (IAT) in adult patients undergoing allogeneic HSCT. Outcome measures were overall survival (OS) and non-relapse mortality (NRM) at 3 years, antibiotic administration, incidence of blood-stream infections (BSI) and incidence and severity of acute and chronic graft-versus-host disease (GVHD). Methods: Cefotaxime was used as standard of care prophylaxis during neutropenia after HSCT prior to January 2018. After a 12 months transition time during which both strategies were employed in parallel, SAP was replaced by an IAT strategy with meropenem being administered immediately by nursing staff in case of neutropenic fever or any other signs of infection, and subsequently deescalated to piperacillin/tazobactam (pip/taz) when appropriate. We compared 67 consecutive patients undergoing HSCT in 2017, all of whom received antibiotic prophylaxis (SAP cohort) with all patients in 2019 comprising the IAT cohort (n=68). Use of antibiotics is reported as number of daily doses per 100 care days (DDD/100CD) until discharge after HSCT. Results: Patient characteristics are summarized in table 1. Median age was 56 years, 82% of patients were grafted with peripheral blood stem cells (PBSC) for acute leukemia (74%) from a matched unrelated or related donor (MUD, 61%; MRD 17%). Patient characteristics were well balanced between the SAP and IAT cohorts, except those patients transplanted in 2019 were more likely to have an HCT-CI ≥ 3 (56% vs 36%, p=0.025) and receive reduced-intensity conditioning (62% vs 40%, p=0.025). In the SAP and IAT cohort, neutropenic fever was observed in 46% and 62% of patients (p=0.085). However, the cumulative incidence (CI) of BSI by day +100 post-HSCT was significantly higher in the IAT vs SAP cohort (40% vs 13%, p<0.001), which did not result in more patients admitted to the intensive care unit (13% vs 6%, p=ns) and did not translate into a higher CI of NRM at 3 years (10% vs 9%, p=ns). With a median follow-up of 1052 days, 3-year OS was 70% and 69% for the SAP and IAT cohort, resp. (p=ns, figure 1). CI of acute GVHD grade II-IV or chronic GVHD of any grade at 3 years was 34% (p=ns) and 45% (p=ns), resp., resulting in identical survival free of acute GVHD grade III-IV, chronic GVHD requiring systemic immunosuppressive therapy and relapse-free survival (GRFS) of 36% (p=ns) in both groups. We observed a tendency to a higher CI of severe chronic GVHD in the SAP cohort (27% vs 13%, p=0.08). There was no significant difference between the two cohorts in terms of newly detected colonization with MDR bacteria during conditioning and after HSCT (VRE 17%; ESBL 5%; 3/4 MRGN 5%; MRSA 0%) and the incidence of CDI was likewise equal in both cohorts (13%, p=ns). Compared to SAP, IAT resulted in significantly fewer days of antibiotic therapy (24 vs 18, p<0.001) and accordingly less administration of cefotaxime (12.8 vs 3.8 DDD/100CD), teicoplanin (26.2 vs 6.3 DDD/100CD), vancomycin (11.5 vs 8.3 DDD/100CD) and meropenem (23.1 vs 16.7 DDD/100CD). Solely use of pip/taz increased (14.3 vs 23.6 DDD/100CD), while the amount of imipenem remained unchanged (7.6 versus 7.8 DDD/100CD). Thus, we observed a significant 40% reduction of the median antibiotic consumption (p=0.0312) in 2019. In the multivariate analysis, only age > 60 years and a high or very high disease risk index were identified as negative prognostic factor for OS. Conclusion/Summary: Our single center experience in conducting HSCT without antibiotic prophylaxis but with strict guidelines for prompt antibiotic intervention demonstrated no disadvantage in OS and NRM, despite a higher CI of BSI. IAT resulted in considerably less consumption of cefotaxime, but also carbapenem and glycopeptide antibiotics. We conclude that the proposed procedure of IAT replacing SAP is safe and feasible. Larger patient numbers are needed to confirm a possible benefit of IAT on GVHD. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

ATG-Ptcy-CSA for Gvhd Prevention in Peripheral Blood Haploidentical Hematopoietic Cell Transplantation for Adults with Hematological Malignancies

INTRODUCTION The introduction of post-transplant cyclophosphamide (PTCY) for GVHD prevention can be considered a milestone in haploidentical hematopoietic cell transplantation (haplo-HCT). And secondary to its efficacy, the use of haplo-HCT with peripheral blood stem cell (PBSC) grafts has significantly increased in last decade. However the optimal immunosuppressive agents to combine with PTCY using peripheral blood stem cell (PBSC) sources is still a matter of debate, as in a retrospective analysis conducted by CIBMTR using PBSC grafts and PTCY-based GVHD prophylaxis in the haplo-HCT setting, was associated with higher rates of acute and chronic GVHD than with using bone marrow stem cell grafts. PTCY-based prophylaxis is considered a standard of care when haploidentical donors are selected. PTCY combined with anti-thymocyte globulin and cyclosporine (PTCY-ATG-CsA) became our institutional GVHD prophylaxis for peripheral blood (PB) haplo-HCT in 2015. The present analysis aims to share updated information about our experience using ATG-PTCY-CsA for GVHD prevention in PB haplo-HCT. METHODS Between October 2015 to December 2021, 157 consecutive adults underwent haplo-HCT at our institution and were included in the study. The GVHD prophylaxis was composed of rabbit-ATG (Thymoglobulin; Genzyme-Sanofi, Lyon, France), PTCy (50 mg/kg/day on days +3 to +4), and CsA (started on day +5 and titrated to therapeutic levels ranging between 200 and 400 ng/ml). One hundred twenty (76.4%) adults received a total dose of 4.5mg/kg of ATG (0.5 mg/kg on day -3, 2 mg/kg on day -2 and 2 mg/kg on day-1), and 37 (23.5%) received 2 mg/kg (0.5 mg/kg on day -2 and 1.5 mg/kg on day -1). T-cell replete PBSC grafts were infused on day 0 in all cases. Data was collected retrospectively and updated in March 2022. To perform regression analyses, post-transplant follow-up was censored at 2 years. RESULTS Of the 157 patients, the median age was 57 years (range: 43-66), and 67 (44%) were 60 years or older. Sixty-four (44%) patients were females. Acute myeloid leukemia was the most prevalent baseline diagnosis (n=79, 50.3%), and 38 (24.2%) patients received myeloablative conditioning (MAC) regimens. Forty-six (30%) adults had a KPS ≤80%, 46 (30%) had an HCT-CI score >3, and 34 (23.4%) had a high or very-high disease risk index (DRI). Fresh products were infused in 90 (57.32%) cases. A total of 152 patients achieved engraftment. The median time for neutrophil and platelet engraftment were 17 (IQR 19-15) and 22 days (IQR: 12-28). The cumulative incidence function (CIF) of bloodstream infection at day +28 was 51.6%. The day +180 CIF of CMV and EBV reactivations were 62.5% and 65.4%, respectively, and 5 (3.2%) patients had post-transplant lymphoproliferative disorder. The CIFs of grade II-IV and grade III-IV acute GVHD estimated at day +100 were 26.3% and 9.5%, and the CIF of moderate/severe cGVHD at 1 year was 19.9%. As reported in Table 1, the use of MAC regimens (HR 2.70), the administration of 2 mg/kg of ATG (HR 4.42, P=0.003) and the selection of donors older than 40 years (HR 3.35, P=0.011) increased the risk for grade III-IV aGVHD. The infusion of frozen products was not found to be predictor for GVHD. Nevertheless, a non-significant trend to lower grade II-IV aGVHD was documented in patients receiving frozen PBSC grafts (HR 0.54, P=0.060). The median follow-up in survivors was 32 months. Overall, 73 (46.5%) patients died, and 28 (17.3%) relapsed. The leading causes of death were infection and relapse. The median of days to discontinuation of the immunosuppression in survivors was 83 days (IQR: 69-119). As shown in Figure 1, the estimated 2-year OS, RFS, NRM, CIR, and GRFS were respectively: 49.4%, 44.6%, 36.6%, 18.8%, and 35.7%. The multivariate regression analysis reported n Table 1 showed that older patients and those with high and very-high DRI were at higher risk for worse OS and higher NRM. CONCLUSION Dual T-cell depletion using PTCy and ATG (total dose of 4.5mg/kg) combined with CsA is a safe drug combination for PB haplo-HCT. The use of this prophylaxis provided an effective GVHD prevention with acceptable relapse rates. Moreover, the selection of younger donors, and the use of a total dose of 4.5mg/kg of ATG increased the effectiveness of GVHD prevention. Further research is needed to decrease rates of NRM for patients undergoing haplo-HCT using this prophylaxis. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Phase I Study of Baricitinib Gvhd Prophylaxis in HLA-Matched, Peripheral Blood Allogeneic Hematopoietic Cell Transplant

Acute graft versus host disease (aGVHD) is a leading cause of non-relapse mortality after allogeneic peripheral blood hematopoietic cell transplant (PB-HCT). JAK inhibition has been shown to be an effective treatment for steroid refractory aGVHD. We performed a single arm, open label, phase I trial to evaluate the safety of a best-in-class balanced JAK1/2 inhibitor, baricitinib (Bari), for the prevention of aGVHD after HLA-matched, allogeneic PB-HCT (Choi et al. Leukemia2018; Kim et al. Leukemia, 2022). The study enrolled 24 subjects into two dosing cohorts (2mg and 4mg daily) from 2019 - 2022. The data cut-off for this analysis was June 1, 2022. The primary objectives were to determine the incidence of graft failure at 28 days post HCT and the cumulative incidence of grade III-IV acute GVHD by day 100. The secondary objective was to determine day 180 treatment related mortality. Subjects were treated with Bari 2mg or 4mg (n = 12/cohort) oral daily from days -3 to +100, followed by a taper. All subjects received standard of care GVHD prophylaxis with tacrolimus and mini-methotrexate +/- thymoglobulin (n=19) or post-transplant cyclophosphamide (pTCy) plus mycophenolate mofetil and tacrolimus (n=5). At data cut, the median follow up was 320 days (63-368 days). The median age was 57 (range 28-72), and diagnoses included AML (16), MDS (6), and ALL (2). All subjects with AML were required to be in CR/CRi and 8 were MRD positive by flow cytometry at the time of transplant. Ten recipients had PB-HCT from sibling donors and 14 had PB-HCT matched unrelated donors. Conditioning included myeloablative regimens (MAC, n=19) or reduced intensity (RIC, n=5). GVHD prophylaxis included tacrolimus /methotrexate for all subjects in the 2mg cohort and pTCy was used in 5 / 12 subjects in 4mg dosing cohort. Thymoglobulin was allowed for MUD recipients (n=5). No events of primary graft failure were observed. The median ANC engraftment was 12.5 days (range 12-21). The median platelet engraftment was 20 days (range 13-52). Treatment related mortality at day 180 was 8% (2/24). The cumulative incidence of grade III/IV aGVHD at day 100 was 4% (1/24, occurring in the 4mg cohort), while the overall incidence of grade III/IV aGVHD at any time was 12.5% (3/24) and two of these cases occurred after Bari discontinuation. The one case of grade III aGVHD prior to day 100 was a steroid-responsive lower GI GVHD that occurred at day 21 in the 4mg cohort and did not recur with taper of immune suppression and Bari. Grade II - IV aGVHD occurred in 33% (8/24, 4 in the 2mg cohort and 4 in the 4mg cohort). Two cases were steroid refractory (one in 2mg and one in 4mg cohorts). All cases of grade II aGVHD were responsive to steroids. We found no association between GVHD prophylaxis backbone regimen and incidence of aGVHD. 11 cases of chronic GVHD (3 mild and 8 moderate severity) have been reported. Of the moderate cGVHD cases, 4 developed in the 2mg cohort and 4 in the 4mg cohort. No unexpected grade 3/4 adverse events (AE) were observed. Thromboembolic disease was an AE of special interest. Four DVTs were observed: 1 in the 2mg cohort vs. 3 in 4mg cohort. All subjects in the 4mg cohort had pulmonary embolism occurring while off Bari, one occurring at 10 months post-transplant, one at day 141 and another at day 152. Of the evaluable cases at day 100, 14/15 (93%) receiving MAC vs. 4/5 (80%) receiving RIC conditioning achieved >95% bone marrow donor engraftment, whereas, 11/16 (69%) receiving MAC vs. 4/4 (100%) receiving RIC had mixed peripheral blood CD3 T-cell chimerism. Of those with mixed CD3 chimerism at day 100, 12 remain in remission and 3 have relapsed. The incidence of disease relapse at 1 year was 21%, with 2 relapses occurring in the 2mg cohort and 3 in the 4mg cohort. Of the 8 cases with MRD positivity at transplant, 2 relapsed within 3 months of transplant and both had AML. The 1-year overall survival was 70%. The one-year refined GVHD relapse free survival (GRFS) was 33%. In conclusion, Baricitinib is safe after HLA-matched, allogeneic PB-HCT with no episodes of primary graft failure and low rates of grade III/IV acute GVHD while on therapy. A follow up efficacy study to evaluate extended duration of the 2mg dose of Bari focused on AML patients receiving HLA matched transplants and myeloablative conditioning is planned. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

HLA-Haploidentical Vs Mismatched Unrelated Donor Transplants with Post-Transplant Cyclophosphamide-Based Gvhd Prophylaxis for AML and MDS: Is There a Winner?

Introduction: Finding a suitable donor is often influenced by race and ethnicity of the patient. Despite increased donor availability through registry, a proportion of patients does not find HLA-matched donors. In such situations, haploidentical donors or mismatched unrelated donors (MMUD) are commonly considered. Post-transplant cyclophosphamide (PTcy), given on days +3 and +4 after haploidentical donor transplants (HIDT), has significantly reduced rates of GVHD and improved outcomes. Given encouraging activity, we implemented use of PTcy in combination with tacrolimus and mycophenolate for GVHD prophylaxis in HLA-MMUD transplants and have reported promising results. This raises an important clinical question: Do outcomes of HLA-haploidentical or MMUD transplants differ when using PTcy-based GVHD prophylaxis? Does PTcy overcome adverse outcomes associated with HLA-MMUD similar to HLA-haploidentical donors? Methods: We retrospectively compared outcomes of 144 adult patients with acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS) who received PTcy, tacrolimus, and mycophenolate for GVHD prophylaxis and underwent either HIDT or HLA-MMUD transplants. Propensity score-based multivariable analyses (PSCA) were performed using age, KPS, HCT-CI, diagnosis, conditioning regimen, disease status at transplant, CMV serotype, and donor/recipient sex mismatch as variables to adjust confounding effects of patient characteristics between both groups. Results: Between January 2013 and December 2021, 89 patients received HIDT and 55 received MMUD transplants. Among MMUD, 89% (n=49) were 7/8 HLA-matched and 11% (n=6) were 6/8 HLA-matched. Median age of the population was 62 years, 22% were African American, 73% had AML, 20% received myeloablative conditioning regimen. All patients received peripheral blood stem cell transplants. CRS rate was higher in the HIDT group compared to MMUD (78% vs 38%, p<0.001). The median time of onset of CRS was 1-day post-transplant, and the median duration of CRS was 3 days. Median time to neutrophil engraftment was prolonged in the HIDT group (18 vs 15 days, p<0.001), while platelet engraftment was similar (23 vs 21 days, p=0.15). Graft failure rate was 3% in both groups. The cumulative incidence of grade III-IV acute GVHD at day 100 was similar (3.4% in HIDT vs 7.3% in MMUD, p=0.30), whereas chronic GVHD at 1 year was higher with HIDT compared to MMUD transplants (28% versus 14.2%, p=0.05). At a median follow up of 2.5 years, 1-year survival was 66.7% for HIDT and 69.5% for MMUD (p=0.46), 1-year relapse-free survival (RFS) was 58.9% for HIDT and 61.7% for MMUD (p=0.48), 1-year relapse was 18.3% for HIDT and 25% for MMUD (p=0.49), and 1-year non-relapse mortality (NRM) was 22.7% for HIDT and 13.2% for MMUD (p=0.11). Using PSCA, no difference in survival, RFS, relapse, and NRM was noted between both groups. Conclusion: Our study demonstrated that transplant outcomes did not differ between HLA-haploidentical and MMUD when PTcy was used for GVHD prophylaxis. PTcy can be safely used and provided promising results in HLA-MMUD transplants. In the absence of HLA-matched donors, either haploidentical or MMUD can be used. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Longitudinal Survival Outcomes in Allogeneic Stem Cell Transplantation: An Institutional Experience.

We analyzed data from 1943 consecutive patients who received allo-SCT. Patients were divided into groups (gps) based on the year (yr) of transplant. Primary endpoints were overall survival (OS), progression free survival (PFS), and GVHD-free relapse-free survival (GRFS). Secondary endpoints were the cumulative incidences of grade II-IV and grade III-IV acute GVHD (aGVHD), chronic GVHD (cGVHD), and non-relapse mortality (NRM). Our study found statistically significant improvements in OS, PFS, and GRFS. Five-year PFS among the groups increased from 24% to 48% over the years. Five-year OS increased from 25% to 53%. Five-year GRFS significantly increased from 6% to 14%, but remained relatively unchanged from 2004 to 2018. Cumulative incidences of grade II-IV aGVHD increased since 2009 (p &lt; 0.001). However, cumulative incidence of NRM decreased since 2004 (p &lt; 0.001). Our data show improved OS, PFS, and GRFS post allo-SCT over decades. This may be attributed to advances in supportive care and treatments focused on mitigation of GVHD and relapse.

Comparison of clinical outcomes between peripheral blood stem cells and peripheral blood stem cells plus bone marrow in myelodysplastic syndrome patients with haploidentical transplantation.

The comparison of haploidentical G-CSF-mobilized peripheral blood and bone marrow transplantation (HBMT) for patients with myelodysplastic syndrome (MDS) and haploidentical G-CSF-primed peripheral blood stem cell transplantation (HPBSCT) remains unclear. We performed a retrospective analysis using a propensity score method on 140 MDS patients who received HPBSCT (n = 46) or HBMT (n = 94) with BU/CY as a conditioning regimen prior to transplantation at our center between June 2016 and June 2021. HBMT recipients were associated with a reduced incidence of grade III-IV acute GVHD (17.22% vs. 30.57%, p = 0.019) within 100 days, reduced 2-year transplant-related mortality (TRM) (14.29% vs. 28.94%, p = 0.045) and superior 2-year overall survival (OS) (81.6% vs. 66.0%, p = 0.027), progression-free survival (PFS) (80.9% vs. 61.2%, p = 0.015), and GVHD relapse-free survival (GRFS) (64.6% vs. 53.3%, p = 0.062) compared with HPBSCT, but 2-year relapse incidence (RI) (5.96% vs. 9.39%, p = 0.445) was not affected. Multivariate analysis revealed that a GPB/GBM mixture was the independent factor for a reduced incidence of grade III-IV acute GVHD (p = 0.018) and TRM (p = 0.048), improved OS (p = 0.029), PFS (p = 0.019) and GRFS (p = 0.072). Collectively, the use of a GPB/GBM mixture as stem cell grafts for haplo-HSCT in patients with MDS appears to be an optimal choice.

Haploidentical Hematopoietic Cell Transplantation for Myelofibrosis in the Ruxolitinib Era

Haploidentical stem cell transplantation is a viable strategy in the absence of an HLA-identical donor, but in myelofibrosis (MF), concerns may rise due to the risk of graft failure. Considering that engraftment is a major issue in MF, we sought to highlight its impact on survival outcomes. In addition, we explored the impact of pretransplantation ruxolitinib administration as an independent variable on outcomes. Here we report the results of a retrospective, monocentric experience with T cell-replete haploidentical bone marrow transplantation with post-transplantation cyclophosphamide as graft-versus-host disease (GVHD) prophylaxis in 51 consecutive MF-affected patients. The median duration of follow-up was 47 months. All 51 patients received a double-alkylating conditioning regimen, and 21 patients (41%) received pretransplantation ruxolitinib. Thirty-seven of 49 evaluable patients (76%) achieved full donor chimerism with neutrophil engraftment, 8 of 49 (16%) experienced graft rejection, and 4 of 49 (8%) had primary poor graft function. Splenectomy was more frequent among patients who engrafted (P=.06). Graft rejection was the sole factor negatively impacting overall survival (hazard ratio [HR], 4.19; 95% confidence interval [CI], 1.37 to 12.80; P=.01) and the major determinant for nonrelapse mortality (HR, 10.31; 95% CI, 2.54 to 41.82; P=.001). The 24-month incidence of relapse was 19% and was negatively impacted by splenectomy (HR, 5.84; 95% CI, 1.28 to 26.72; P=.02). The cumulative incidence of grade II-IV acute GVHD was 27% (95% CI, 20% to 33%), and that of grade III-IV acute GVHD was 8% (95% CI, 4% to 12%). The 24-month cumulative incidence of all-grade chronic GVHD was 28% (95% CI, 21% to 35%). Our data show that T cell-replete haploidentical bone marrow transplantation following double-alkylating conditioning in patients with MF is associated with favorable rates of GVHD and an acceptable relapse risk; nevertheless, rejection is not negligible and is associated with significant mortality. Splenectomy, which favors engraftment, is predictive of a higher risk of relapse.

Conditioning Regimens in Allogeneic Hematopoietic Stem Cell Transplantation Do Not Fit All: Adjusting BuCy2 in Mexico to Improve Outcomes in Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS).

Background: Conditioning regimens are critical for allogeneic hematopoietic cell transplantation (allo-HCT). After unfavorable results using BuCy2 at the beginning of our HCT Program, a restructuring was made with the consequent development of a modified HCT method including a reduced conditioning regimen. The objective of this study was to describe the outcomes using Reduced BuCy2 (rBuCy2) in allo-HCT. Materials and Methods: Data from 38 consecutive patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) who underwent allo-HCT conditioned with rBuCy2 in a 21-year period were retrospectively analyzed. Results: Most patients were males (53%) and the median age was 35 years. The most common disease was myelodysplastic syndrome (55%). Toxicity grades III-IV were observed in 44%; and acute and chronic graft-versus-host disease were observed in 26% and 34%, respectively; the median follow-up was 26 months; 30-day non-relapse mortality (NRM) was 3%, and 1 and 2-year NRM were 8%. Ten-year overall survival (OS) was 60%, and 86%, for AML and MDS, respectively. Conclusion: Our rBuCy2 maintains a myeloablative effect, along with immunosuppression for fast engraftment and more importantly, this regimen reduces grades III-IV acute GVHD and NRM in allo-HCT and improves the OS and it appears to be an option for low and middle-income countries.

Thiotepa, busulfan and fludarabine conditioning-regimen is a promising approach for older adult patients with acute lymphoblastic leukemia treated with allogeneic stem cell transplantation.

For acute lymphoblastic leukemia (ALL) patients, total body irradiation (TBI)- based conditioning regimens are the first choice specially in young population. However, several studies have shown an equivalence in clinical outcomes with thiotepa-based conditioning regimen. We performed a retrospective study to evaluate the outcome of adult ALL patients who received allogeneic hematopoietic stem cell transplantation (allo-HCT) with a thiotepa-busulfan-fludarabine (TBF) myeloablative conditioning regimen with reduced toxicity. Fifty-five patients received a TBF regimen. The median age of the patients was 51 years (range, 17 to 72.4). Most patients had a diagnosis of B-ALL (93%) with 7% having T-ALL. Two - and 5-year overall survival was 73.2% and 64%, respectively. At 2 years, leukemia-free survival and GVHD-free, relapse-free survival were 59.5% and 57.6%, and at 5 years, 53.4% and 51.8%, respectively. The 5-year non-relapse mortality was 15%. The day 180 cumulative incidence (CI) of grade II-IV acute GVHD and grade III-IV acute GVHD were 38.2% and 5.5%, respectively. At 2 years, the CI of chronic GVHD and extensive chronic GVHD was 16.9% and 1.9%, respectively. Our study results do suggest that using TBF as the conditioning regimen in adult ALL patients is a promising option with acceptable toxicity.

ATG in HLA-Matched, Peripheral Blood, Hematopoietic Cell Transplantation in Acute Myeloid Leukemia and Myelodysplastic Syndrome: A Secondary Analysis of a CIBMTR Database

w?>Peripheral blood stem cells (PBSC) are the preferred grafts for hematopoietic cell transplantation (HCT), according to the CIBMTR. Donor recovery is faster with PBSC harvest, but PBSC is associated with higher chronic graft-versus-host disease (GVHD) and poorer quality of life. Anti-T-cell globulin (ATG) is polyclonal IgG from rabbits or horses immunized with human thymocytes or a human T-cell line, which may reduce GVHD in HCT and improve outcomes. The objective of this study was to analyze the impact of ATG in HLA-matched related (MRD) and matched (HLA 8/8) unrelated donor (MUD) HCT. We used a freely available CIBMTR database published online for secondary analyses. The database included patients ≥ 40 years old who have undergone their first PBSC MRD or MUD HCT for acute myeloid leukemia or myelodysplastic syndrome with or without ATG between 2008 and 2017. Patients who received posttransplant cyclophosphamide or alemtuzumab were excluded. Overall survival was not different with ATG (hazard ratio [HR] = 1.09; 95% confidence interval [CI], 1.00-1.19; P = .06) compared with no ATG. Relapse rate was higher with ATG (HR = 1.29; 95% CI, 1.17-1.43; P < .001) and non-relapse mortality was lower with ATG (HR = 0.84; 95% CI, 0.72-0.98; P = .03). Grades II-IV acute GVHD was significantly lower with ATG (HR = 0.77; 95% CI, 0.69-0.87; P < .001) but not grades III-IV acute GVHD (HR = 0.85; 95% CI, 0.69-1.04; P = .11). Both chronic GVHD (HR = 0.54; 95% CI, 0.48-0.60; P < .001) and moderate/severe chronic GVHD (HR = 0.45; 95% CI, 0.38-0.52; P < .001) were lower with ATG. There was an interaction between ATG and conditioning regimen for relapse rate and overall survival. Relapse rate was higher in those who received reduced-intensity (RIC) or non-myeloablative (NMA) conditioning regimens and ATG, compared with MAC ± ATG or RIC without ATG (interaction test, P = .003). Overall survival was also poorer with ATG and RIC or NMA conditioning regimens (interaction test, P = .03). Our results show that ATG can mitigate the more severe forms of chronic GVHD without impairing overall survival in HLA-matched HCT with PBSC grafts and myeloablative conditioning regimen. ATG should be standard in this population.© 2023 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Comparable survival outcomes with haploidentical stem cell transplantation and cord blood transplantation.

HLA-haploidentical stem cell transplantation using post-transplant cyclophosphamide (PTCy-haplo) and umbilical cord blood transplantation (UCBT) are alternative to HLA-matched stem cell transplantation. We conducted a matched-pair analysis of PTCy-haplo and UCBT using the Japanese registry data. We identified 136 patients aged between 16 and 69 years who received PTCy-haplo as their first transplantation for acute leukemia or myelodysplastic syndromes. Control group included 408 UCBT recipients selected to match the PTCy-haplo group. Overall and relapse-free survival probabilities at 2 years were comparable between the PTCy-haplo and UCBT groups: 55% vs. 53% for overall survival (p = 0.46), and 47% vs. 48% for relapse-free survival (p = 0.79), respectively. The cumulative incidence of relapse was significantly higher (43% vs. 29%, respectively, p = 0.006), while the cumulative incidence of non-relapse mortality (NRM) was significantly lower (9% vs. 23%, respectively, p < 0.001) in the PTCy-haplo group. The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) was lower in the PTCy-haplo group compared to the UCBT group (29% vs. 41%, respectively, p = 0.016), while those of grade III-IV acute GVHD and chronic GVHD were not statistically different between the two groups. Our results suggest that both PTCy-haplo and UCBT are viable alternatives to HLA-matched stem cell transplantation.

Post-Transplantation Cyclophosphamide Versus Tacrolimus and Methotrexate Graft-Versus-Host Disease Prophylaxis for HLA-Matched Donor Transplantation

The use of post-transplantation cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis is increasing in patients undergoing HLA-matched sibling (MSD) or unrelated (MUD) donor hematopoietic cell transplantation (HCT), but data about its comparative efficacy against the traditional GVHD prophylaxis are scarce. Two broad questions assessed in this study were (a) comparison of PTCy-based GVHD prophylaxis versus Tac/MTX (without ATG) in the MSD and (b) comparison of PTCy-based GVHD prophylaxis versus Tac/MTX (with ATG) in the MUD group. This retrospective single-center study analyzed the outcomes of 964 patients who received Tac/MTX (n=578) versus PTCy-based (n=386) GVHD prophylaxis. All MUD recipients in the Tac/MTX group also received ATG; thus separate analyses were conducted for MSD (n=412) and MUD (n=552) cohorts. In the MUD cohort, 306 patients received Tac/MTX/ATG and 246 received PTCy-based GVHD prophylaxis. In the MSD cohort, 272 received Tac/MTX and 140 received PTCy-based prophylaxis. Both PTCy groups included somewhat older patients than the Tac/MTX groups and more patients had myeloid malignancy (85%-90% versus 59%-64%, respectively). A majority of patients in all groups received myeloablative conditioning and peripheral blood graft. Both PTCy groups had a significantly delayed neutrophil engraftment, higher risk of hemorrhagic cystitis, and higher risk of bacterial infections than the Tac/MTX groups. The risks of viral infections and related deaths were significantly higher in Tac/MTX group in the MUD cohort. In multivariate analysis, the risk of grade III-IV acute GVHD was similar in PTCy and Tac/MTX groups in both MSD and MUD cohorts, but the risk of chronic GVHD was significantly lower with PTCy in the MSD cohort. PTCy was associated with a significantly lower risk of non-relapse mortality and better progression-free survival in the MUD. PTCy was associated with improved GVHD-free relapse-free survival in both MSD and MUD groups. Our data suggest a benefit of using PTCy-based GVHD prophylaxis in both MSD (versus Tac/MTX) and MUD (versus Tac/MTX/ATG) HCT.

A Multicenter Phase II, Double-Blind, Placebo-Controlled Trial of Maintenance Ixazomib After Allogeneic Transplantation for High-Risk Multiple Myeloma: Results of the Blood and Marrow Transplant Clinical Trials Network 1302 Trial

The role of allogeneic hematopoietic cell transplantation (allo-HCT) followed by maintenance therapy in high-risk multiple myeloma (MM) remains controversial. We evaluated the efficacy of ixazomib maintenance therapy after reduced-intensity conditioning allo-HCT from HLA-matched donors in patients with high-risk MM. The primary study endpoint was progression-free survival (PFS) postrandomization, treated as a time to event. Secondary endpoints were grade II-IV and grade II-IV acute graft-versus-host-disease (GVHD), chronic GVHD, best response, disease progression, nonrelapse mortality (NRM), overall survival (OS), toxicity, infection, and health-related quality of life. In this phase 2, double-blinded, prospective multicenter trial, we randomized patients with high-risk MM (ie, those with poor-risk cytogenetics, plasma cell leukemia, or relapsing within 24 months after autologous HCT) to ixazomib (3 mg on days 1, 8, and 15) or placebo after allo-HCT. The conditioning regimen included fludarabine/melphalan/bortezomib with tacrolimus plus methotrexate for GVHD. Fifty-seven patients were enrolled, of whom 52 (91.2%) underwent allo-HCT and 43 (82.7%) were randomized to ixazomib versus placebo. At 21 months postrandomization, the ixazomib and placebo groups had similar PFS (55.3% versus 59.1%; P=1.00) and OS (94.7% versus 86.4%; P=.17). The cumulative incidences of grade III-IV acute GVHD at 100 days (9.5% versus 0%) and chronic GVHD at 12 months (68.6% versus 63.6%) also were similar in the 2 groups. The secondary analysis showed that at 24 months post-allo-HCT, PFS and OS were 52% and 82%, respectively, with a corresponding NRM of 11.7%. These results demonstrate the safety and durable disease control with allo-HCT in high-risk MM patients. We could not adequately assess the efficacy of ixazomib maintenance because the trial terminated early owing to enrollment delays, but there was no indication of any impact on outcomes.

Comparison of Outcomes after Unrelated Double-Unit Cord Blood and Haploidentical Peripheral Blood Stem Cell Transplantation in Adults with Acute Myelogenous Leukemia: A Study on Behalf of Eurocord and the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Unmanipulated haploidentical hematopoietic stem cell transplantation (HCT) with post-transplantation cyclophosphamide as graft-versus-host disease (GVHD) prophylaxis (haplo-PTCY) and unrelated double-unit umbilical cord blood transplantation (dUCBT) are feasible options for treating patients with high-risk acute myelogenous leukemia (AML). This study compared outcomes after dUCBT and haplo-HCT using peripheral blood stem cells (PBSCs) in adult patients with AML in complete remission (CR) who underwent transplantation in European Society for Blood and Marrow Transplantation (EBMT)-affiliated centers. In a population of adults with de novo AML in first or second CR, we compared outcomes after dUCBT (n = 165) and after haplo-PTCY PBSC (n = 544) performed between January 2013 and December 2018. Patients receiving in vivo antithymocyte globulin, Campath, or ex vivo T cell depletion were excluded. The median follow-up was 33 months for the haplo-PTCY arm and 52 months for the dUCBT arm. No statistically significant differences were observed between the 2 arms in the rates of grade II-IV acute graft-versus-host disease (GVHD) (hazard ratio [HR], 1.31; P = .18), grade III-IV acute GVHD (HR, 1.17; P = .56), chronic GVHD (HR, .86; P = .48), relapse (HR, 1.07; P = .77), nonrelapse mortality (NRM) (HR, .94; P = .77), leukemia-free survival (LFS) (HR, .99; P = .95), or overall survival (OS) (HR, .99; P = .97). Favorable cytogenetic risk was the sole factor predictive of lower relapse incidence (RI). Younger age at transplantation was associated with lower NRM and higher LFS and OS. Both dUCBT and haplo-PTCY with PBSCs can be considered valid approaches for adult AML patients in CR. New strategies should be investigated in both settings to define the most appropriate conditioning regimen and potentially decrease RI and NRM through better immune reconstitution and optimal supportive care.