A phase I study of pevonedistat, azacitidine, and venetoclax in patients with relapsed/refractory acute myeloid leukemia.

Azacitidine/venetoclax is an active regimen in patients with newly diagnosed AML. However, primary or secondary resistance to azacitidine/venetoclax is an area of unmet need and overexpression of MCL-1 is suggested to be a potential resistance mechanism. Pevonedistat inhibits MCL-1 through activation of NOXA, and pevonedistat/azacitidine has previously shown activity in AML. To assess the tolerability and efficacy of adding pevonedistat to azacitidine/venetoclax in relapsed/refractory AML, we conducted a phase I multicenter openlabel study in 16 adults with relapsed/refractory AML. Patients were treated with azacitidine, venetoclax along with pevonedistat intravenously on days 1, 3 and 5 of each 28-day cycle at 10, 15 or 20 mg/m2 in successive cohorts in the dose escalation phase. The impact of treatment on protein neddylation as well as expression of pro-apoptotic BCL2 family members was assessed. The recommended phase II dose of pevonedistat was 20 mg/m2. Grade 3 or higher adverse events included neutropenia (31%), thrombocytopenia (13%), febrile neutropenia (19%), anemia (19%), hypertension (19%) and sepsis (19%). The overall response rate was 46.7% for the whole cohort including complete remission (CR) in 5 of 7 (71.4%) patients who were naïve to the hypomethylating agent/venetoclax. No measurable residual disease (MRD) was detected in 80.0% of the patients who achieved CR. The median time to best response was 50 (range: 23 - 77) days. Four patients were bridged to allogeneic stem cell transplantation. The combination of azacitidine, venetoclax and pevonedistat is safe and shows encouraging preliminary activity in patients with relapsed/refractory AML. (NCT04172844).

Haploidentical donor hematopoietic cell transplantation for myelodysplastic/myeloproliferative overlap neoplasms: results from a North American collaboration.

Haploidentical donors offer a potentially readily available donor, especially for non-White patients, for hematopoietic cell transplantation (HCT). In this North American collaboration, we retrospectively analyzed outcomes of first HCT using haploidentical donor and post-transplantation cyclophosphamide (PTCy) in myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) overlap neoplasms (MDS/MPN). We included 120 consecutive patients who underwent HCT using a haploidentical donor for MDS/MPN across 15 centers. Median age was 62.5 years and 38% were of non-White/Caucasian ethnicity. The median follow-up was 2.4 years. Graft failure was reported in seven of 120 (6%) patients. At 3 years, nonrelapse mortality (NRM) was 25% (95% confidence interval [CI]: 17-34), relapse 27% (95% CI: 18-36), grade 3-4 acute graftversus- host disease 12% (95% CI: 6-18), chronic graft-versus-host disease requiring systemic immunosuppression 14% (95% CI: 7-20), progression-free survival (PFS) 48% (95% CI: 39-59), and overall survival (OS) 56% (95% CI: 47-67). On multivariable analysis, NRM was statistically significantly associated with advancing age at HCT (per decade increment, subdistribution hazard ratio [sdHR] =3.28; 95% CI: 1.30-8.25); relapse with the presence of mutation in EZH2/RUNX1/SETBP1 (sdHR=2.61; 95% CI: 1.06-6.44); PFS with advancing age at HCT (per decade increment, HR=1.98, 95% CI: 1.13-3.45); and OS with advancing age at HCT (per decade increment, HR=2.01; 95% CI: 1.11-3.63) and splenomegaly at HCT/prior splenectomy (HR=2.20; 95% CI: 1.04-4.65). Haploidentical donors are a viable option for HCT in MDS/MPN, especially for those disproportionately represented in the unrelated donor registry. Hence, donor mismatch should not preclude HCT for patients with MDS/MPN, an otherwise incurable malignancy. In addition to patient age, disease-related factors including splenomegaly and high-risk mutations dominate outcomes following HCT.

Ruxolitinib resistance or intolerance in steroid-refractory acute graft-versus-host disease - a real-world outcomes analysis.

Ruxolitinib for steroid-refractory acute graft-versus-host disease (SR-aGVHD) results in resistance or intolerance in 1/5 of patients. Outcomes of such patients are undefined. We identified these patients in a multicentre review and reported outcomes. Ruxolitinib-resistant aGVHD was identified in 48/307 patients. Among patients receiving additional therapy, the overall response rate to next therapy was 36%. Median survival was 21 days. Ruxolitinib intolerance led to treatment discontinuation in 16/307 patients. Ten intolerant patients received additional therapy with 50% experiencing continued improvement of aGVHD. Median survival was 50 days in these patients. These data serve as a baseline for future SR-aGVHD studies.

Identification and targeting of novel CDK9 complexes in acute myeloid leukemia.

Aberrant activation of mTOR signaling in acute myeloid leukemia (AML) results in a survival advantage that promotes the malignant phenotype. To improve our understanding of factors that contribute to mammalian target of rapamycin (mTOR) signaling activation and identify novel therapeutic targets, we searched for unique interactors of mTOR complexes through proteomics analyses. We identify cyclin dependent kinase 9 (CDK9) as a novel binding partner of the mTOR complex scaffold protein, mLST8. Our studies demonstrate that CDK9 is present in distinct mTOR-like (CTOR) complexes in the cytoplasm and nucleus. In the nucleus, CDK9 binds to RAPTOR and mLST8, forming CTORC1, to promote transcription of genes important for leukemogenesis. In the cytoplasm, CDK9 binds to RICTOR, SIN1, and mLST8, forming CTORC2, and controls messenger RNA (mRNA) translation through phosphorylation of LARP1 and rpS6. Pharmacological targeting of CTORC complexes results in suppression of growth of primitive human AML progenitors in vitro and elicits strong antileukemic responses in AML xenografts in vivo.

Severity of Cytokine Release Syndrome and Its Association with Infections after T Cell-Replete Haploidentical Related Donor Transplantation.

An increased risk of infections has been described after T cell-replete haploidentical cell transplantation (haploHCT). Cytokine release syndrome (CRS) after haploHCT is a known phenomenon, but the impact of CRS severity on the risk of infections remains unexplored. We retrospectively evaluated 78 consecutive adult haploHCT recipients from 2012 to 2018 for the development of CRS (graded based on the criteria of Lee et al) and examined the incidence and mortality due to infections in correlation with CRS severity. In our study cohort, which was stratified into 3 groups by severity of CRS, 80% of the patients developed infections within 180 days of HCT. Significantly higher proportions of patients with CRS grade 2 (89%) and grade ≥3 (90%) than patients with CRS grade 0-1 (68%) had at least 1 infection in the first 100 days (P = .04). Bloodstream infections (BSIs) were seen more frequently in patients with CRS grade 2 and grade ≥3 in the first 6 months. Multivariable analysis for time to infection showed that CRS grade ≥3 was independently associated with an elevated risk of any infection compared with CRS grade 0-1 (hazard ratio [HR], 3.05; P = .007). CRS grade ≥3 was also associated with a higher hazard of viral (HR, 3.42; P = .04) and bacterial infections (HR, 2.83; P = .03) compared with CRS grade 0-1. After adjusting for time to neutrophil engraftment as a time-dependent covariate, CRS grade ≥3 still had a significant effect on viral infections (HR, 2.49; P = .03), but not on bacterial infections (HR, 1.32; P = .57). CRS grade was also a significant predictor for infection density (overall, bacterial, and viral). The incidence of infection-related mortality by day +100 was higher in patients with severe CRS. Severe CRS developing after post-transplantation cyclophosphamide-based haploHCT is independently associated with viral infections and an increased risk of bacterial infections, likely through delayed neutrophil engraftment.

Ixazomib for Chronic Graft-versus-Host Disease Prophylaxis following Allogeneic Hematopoietic Cell Transplantation.

Chronic graft-versus-host disease (cGVHD) is major cause of morbidity and mortality following allogeneic hematopoietic cell transplantation (HCT). Ixazomib is an oral, second-generation, proteasome inhibitor that has been shown in preclinical models to prevent GVHD. We conducted a phase I/II trial in 57 patients to evaluate the safety and efficacy of ixazomib administration for cGVHD prophylaxis in patients undergoing allogeneic HCT. Oral ixazomib was administered on a weekly basis for a total of 4 doses, beginning days +60 through +90, to recipients of matched related donor (MRD, n = 25) or matched unrelated donor (MUD, n = 26) allogeneic HCT in phase II portion of the study, once the recommended phase II dose of 4 mg was identified in phase I (n = 6). All patients received peripheral blood graft and standard GVHD prophylaxis of tacrolimus and methotrexate. Ixazomib administration was safe and well tolerated, with thrombocytopenia, leukopenia, gastrointestinal complaints, and fatigue the most common adverse events (>10%). In phase II (n = 51), the cumulative incidence of cGVHD at 1 year was 36% (95% confidence interval [CI], 19% to 54%) in the MRD cohort and 39% (95% CI, 21% to 56%) in the MUD cohort. One-year cumulative incidence of nonrelapse mortality (NRM) and relapse was 0% and 20% (95% CI, 8% to 36%) in the MRD cohort, respectively. In the MUD cohort, the respective NRM and relapse rates were 4% (0% to 16%) and 34% (17% to 52%). The outcomes on the study were compared post hoc with contemporaneous matched Center for International Blood and Marrow Transplant Research (CIBMTR) controls. This post hoc analysis showed no significant improvement in cGVHD rates in both the MRD (hazard ratio [HR] = 0.85, P = .64) or MUD cohorts (HR = 0.68, P = .26) on the study compared with CIBMTR controls. B cell activating factor plasma levels were significantly higher after ixazomib dosing in those who remained cGVHD free compared with those developed cGVHD. This study shows that the novel strategy of short-course oral ixazomib following allogeneic HCT is safe but did not demonstrate significant improvement in cGVHD incidence in recipients of MRD and MUD transplantation compared with matched CIBMTR controls. This study is registered at www.clinicaltrials.gov as NCT02250300.

Improving Outcomes of Acute Promyelocytic Leukemia in the Current Era: Analysis of the SEER Database.

BACKGROUND: Outcomes of acute promyelocytic leukemia (APL) have significantly improved with the availability of targeted agents. It remains unclear whether the population-level outcomes of APL have improved over time. METHODS: Using the SEER database, we identified patients aged ≥20 years with pathologically confirmed APL diagnosed in 2000 through 2014 and who were actively followed. Patients were stratified by diagnosis period into 3 groups (2000-2004, 2005-2009, and 2010-2014) to assess the temporal trends in overall survival (OS), cause-specific survival (CSS), and other outcomes. RESULTS: A total of 2,962 patients with a median age of 48 years (range, 20-96 years) were included. Hispanic patients constituted 21.5% of the cohort and the largest proportion (47.9%) of uninsured patients. The incidence of APL was 0.33 cases per 100,000 population per year. Incidence varied significantly by age, sex, race/ethnicity, and diagnosis period. Survival was significantly higher for patients diagnosed in 2010 through 2014 compared with those diagnosed in 2005 through 2009 and in 2000 through 2004 (4-year OS, 73.4% vs 65.6% vs 57.3%, respectively; 4-year CSS, 78.3% vs 70.8% vs 60.8%, respectively). Early mortality improved significantly over time (2000-2004, 25.3%; 2005-2009, 20.6%; 2010-2014, 17.1%) and was higher in men and Hispanic patients. According to multivariate analysis, diagnosis before 2010 and unmarried status were associated with a higher mortality risk. Uninsured patients had a significantly higher early mortality without a significant difference in post-30-day CSS. No significant changes were noted in risk of secondary malignancies. CONCLUSIONS: Population-level outcomes of APL have continued to improve over time. However, significant discrepancies in disease outcomes continue to exist, highlighting the need for more research.

Efficacy, Toxicity, and Infectious Complications in Ruxolitinib-Treated Patients with Corticosteroid-Refractory Graft-versus-Host Disease after Hematopoietic Cell Transplantation.

Corticosteroid-refractory graft-versus-host disease (SR-GVHD) remains a significant source of morbidity after allogeneic hematopoietic cell transplantation. No standard therapy exists in this setting; however, recent studies have demonstrated a very promising role for ruxolitinib, an oral Janus kinase 1/2 inhibitor. With increasing evidence of efficacy for SR-GVHD, limited data exist describing complications of ruxolitinib use, specifically infectious complications during use in SR-GVHD. In this study we report outcomes and infectious complications at our institution with ruxolitinib use. Overall, 43 patients were treated with ruxolitinib for SR-GVHD, 19 for acute SR-GVHD and 24 for chronic SR-GVHD. With respect to acute SR-GVHD, 15 patients had grade III acute GVHD and 4 patients had grade IV acute GVHD. At 28 days, a response rate of 84% was detected. With respect to chronic SR-GVHD, 16 patients had moderate refractory disease and 8 had severe refractory disease. At around 28 days, a 63% response rate was detected. Overall, 42% of patients (n = 18) treated with ruxolitinib had a documented infectious event. Infectious events were significantly more common among patients treated for acute SR-GVHD (P < .005). Among patients treated for acute SR-GVHD, both viral (n = 11) and bacterial (n = 10) events were frequently encountered. Cytomegalovirus reactivation was detected in 4 patients without organ involvement in any patient. Bacteremia was the most common bacterial event (n = 8), and 2 patients died after development of bacteremia. Only 5 of 24 patients treated with ruxolitinib for chronic SR-GVHD developed infectious complications after initiation of therapy. Nearly an even number of viral (n = 3) and bacterial (n = 4) were detected. This study supports the use of ruxolitinib in SR-GVHD, with impressive responses observed in both acute and chronic SR-GVHD. Infectious complications were particularly frequent among patients treated for acute SR-GVHD, and nearly all these patients were concurrently on high-dose steroids while on ruxolitinib. This study suggests careful monitoring for viral reactivation is required for patients initiated on ruxolitinib, supports the role of continuing prophylactic antimicrobial measures in ruxolitinib-treated GVHD patients, and raises the question of whether bacterial prophylaxis should be considered among patients initiated on ruxolitinib for acute SR-GVHD, particularly while on high-dose steroids.

Outcomes of Reduced-Intensity Conditioning Allogeneic Hematopoietic Cell Transplantation Performed in the Inpatient versus Outpatient Setting.

Allogeneic hematopoietic cell transplantation (allo-HCT) with reduced-intensity conditioning (RIC) is commonly performed as an inpatient procedure. The feasibility and outcomes of RIC allo-HCT in the outpatient setting is not known. We performed a single-center retrospective cohort study of patients aged ≥ 18years with hematologic malignancies who underwent RIC allo-HCT either in the inpatient or outpatient setting. Donor types included HLA-matched sibling and well-matched unrelated donors. The objectives were to compare the survival, complications, charges, and incidences of relapse, nonrelapse mortality (NRM), and acute and chronic graft-versus-host disease (GVHD) between the 2 groups. Between 2014 and 2017, 151 eligible patients were included, with 116 undergoing RIC allo-HCT in the inpatient setting and 35 patients undergoing RIC allo-HCT in the outpatient setting. Baseline characteristics were comparable between the 2 groups except for a higher proportion of patients with myeloma in the outpatient cohort (inpatient 15.5% versus outpatient 37.1%). The cumulative incidence of grades II to IV acute GVHD (inpatient 25.2% versus outpatient 25.7%), grades III to IV acute GVHD (inpatient 10.4% versus outpatient 8.5%), chronic GVHD (inpatient 38.3% versus outpatient 51.6%), NRM at 1 year (inpatient 10.8% versus outpatient 3.2%), and relapse (inpatient 24.8% versus outpatient 33.2%) did not significantly differ between the 2 cohorts. One-year progression-free survival (inpatient 64.4% versus outpatient 63.6%, P = .39) and overall survival (inpatient 73.8% versus outpatient 82.8%, P = .93) were also not significantly different between the 2 groups. The proportion of patients who developed neutropenic fever (inpatient 25.8% versus outpatient 8.5%, P = .03) and mucositis (inpatient 50.8% versus outpatient 8.5%, P < .001) and who required total parenteral nutrition (inpatient 20.6% versus outpatient 5.7%, P = .04) were more frequent in the inpatient cohort. About 51.5% of the outpatient cohort never required hospital admission in the first 100days. Outpatient HCT resulted in significantly lower charges than inpatient HCT in the first 100days (median charges: inpatient $339,621 versus outpatient $247,334; P < .001). On multivariate analysis the site of the HCT (outpatient versus inpatient) was not a significant predictor of either overall or progression-free survival. Outpatient RIC allo-HCT is feasible and safe with daily outpatient evaluation and aggressive supportive care resulting in outcomes comparable with those who received the transplant in the inpatient setting.

Merestinib blocks Mnk kinase activity in acute myeloid leukemia progenitors and exhibits antileukemic effects in vitro and in vivo.

Mitogen-activated protein kinase interacting protein kinases (Mnks) play important roles in the development and progression of acute myeloid leukemia (AML) by regulating eukaryotic translation initiation factor 4E (eIF4E) activation. Inhibiting Mnk1/2-induced phosphorylation of eIF4E may represent a unique approach for the treatment of AML. We provide evidence for antileukemic effects of merestinib, an orally bioavailable multikinase inhibitor with suppressive effects on Mnk activity. Our studies show that merestinib effectively blocks eIF4E phosphorylation in AML cells and suppresses primitive leukemic progenitors from AML patients in vitro and in an AML xenograft model in vivo. Our findings provide evidence for potent preclinical antileukemic properties of merestinib and support its clinical development for the treatment of patients with AML.

Predictive value of bronchiolitis obliterans syndrome stage 0p in chronic graft-versus-host disease of the lung.

Bronchiolitis obliterans syndrome (BOS) is a significant post-transplant complication with low survival. BOS stage 0p (BOS 0p) is a parameter detected on pulmonary function tests (PFTs) after lung transplantation to identify patients at risk to develop BOS. We performed a retrospective study on 442 patients who underwent allogeneic stem cell transplant from 2007 to 2011 to evaluate whether development of BOS 0p is a risk factor in this population for BOS. Patients who met criteria for BOS 0p were significantly more likely to develop BOS (hazard ratio [HR], 3.22; P < .001). BOS 0p was significantly associated with a history of lung disease pretransplant (HR, 2.48; P = .001) and chronic graft-versus-host disease (GVHD) outside the lung post-transplant (HR, 23; P < .001). Finally, BOS 0p criteria were adequately sensitive in predicting BOS (85%), with a high negative predictive value (98%). Our findings suggest a routine PFT screening strategy with the intent of detecting BOS 0p, especially among patients with prior lung disease and who developed chronic GVHD, could suitably identify an at-risk population for the development of BOS.

Double umbilical cord blood transplantation after novel myeloablative conditioning using a regimen of fludarabine, busulfan, and total lymphoid irradiation.

We conducted a pilot study evaluating double umbilical cord blood transplantation (dCBT) after myeloablative conditioning with fludarabine and busulfan 3.2 mg/kg i.v. × 4, followed by total lymphoid irradiation at 400 cGy (FluBu4/TLI) for any indicated hematological disorder for patients without a suitable donor. Twenty patients with predominantly high-risk disease underwent dCBT according to protocol. The regimen was well tolerated, with mucositis as the primary observed toxicity (n = 19). The cumulative incidence of neutrophil engraftment was 89% (95% confidence interval [CI], 64% to 97%), with a median time to recovery of 16 days (range, 12 to 31 days). All evaluable patients with neutrophil engraftment achieved complete donor chimerism by day 40. The cumulative incidence of grades III and IV acute graft-versus-host disease (GVHD) at day 100 was 10% (95% CI, 2% to 27%), and the cumulative incidence of chronic GVHD was 35% (95% CI, 16% to 55%) by the end of the study. At 1 year, the cumulative incidence of treatment-related mortality (TRM) was 35% (95% CI, 16% to 55%). The leading cause of nonrelapse mortality was acute GVHD (n = 4), followed by graft failure (n = 2) and chronic GVHD (n = 1). TRM was significantly associated with a pretransplantation hematopoietic cell transplantation-specific comorbidity index score ≥ 3 (P = .005). At 1 year, disease relapse occurred in 6 patients and overall survival was 40% (95% CI, 19% to 60%). We conclude that FluBu4/TLI is an adequate preparative regiment before dCBT, providing high engraftment rates and relatively early neutrophil recovery. The best survival outcomes were seen in patients without significant comorbidities before transplantation, and outcomes are comparable to previously published dCBT studies.

Premature cell senescence and T cell receptor-independent activation of CD8+ T cells in juvenile idiopathic arthritis.

OBJECTIVE: CD8+ T cells lacking CD28 were originally reported to be a characteristic feature of juvenile idiopathic arthritis (JIA), but the relevance of these unusual cells to this disease remains to be elucidated. Because of recent evidence that loss of CD28 cells is typical of terminally differentiated lymphocytes, the aim of this study was to examine functional subsets of CD8+ T cells in patients with JIA. METHODS: Blood and/or waste synovial fluid samples were collected from children with a definite diagnosis of JIA (n = 98). Deidentified peripheral blood (n = 33) and cord blood (n = 13) samples from healthy donors were also collected. CD8+ and CD4+ T cells were screened for novel receptors, and where indicated, bioassays were performed to determine the functional relevance of the identified receptor. RESULTS: JIA patients had a naive T cell compartment with shortened telomeres, and their entire T cell pool had reduced proliferative capacity. They had an overabundance of CD31+CD28(null) CD8+ T cells, which was a significant feature of oligoarticular JIA (n = 62) as compared to polyarticular JIA (n = 36). CD31+ CD28(null) CD8+ T cells had limited mitotic capacity and expressed high levels of the senescence antigens histone γH2AX and/or p16. Ligation of CD31, which was independent of the T cell receptor (TCR), sufficiently induced tyrosine phosphorylation, vesicle exocytosis, and production of interferon-γ and interleukin-10. CONCLUSION: These data provide the first evidence of cell senescence, as represented by CD31+CD28(null) CD8+ T cells, in the pathophysiology of JIA. Activation of these unusual cells in a TCR-independent manner suggests that they are maladaptive and could be potential targets for immunotherapy.

Outpatient Administration of CAR T-cell Therapies Using a Strategy of No Remote Monitoring and Early CRS Intervention.

Recent studies demonstrating the feasibility of outpatient chimeric antigen receptor modified (CAR) T-cell therapy administration are either restricted to CARs with 41BB costimulatory domains or employ intensive at-home monitoring. We report outcomes of outpatient administration of all commercially available CD19- and BCMA-directed CAR-T therapy using a strategy of no remote at-home monitoring and an early cytokine release syndrome (CRS) intervention strategy. Patients with hematologic malignancies who received CAR T-cell therapy in the outpatient setting during 2022-23 were included. Patients were seen daily in the cancer center day hospital for the first 7-10 days and then twice weekly through day 30. The primary endpoint was to determine 3-, 7- and 30-day post CAR T-cell infusion hospitalizations. Early CRS intervention involved administering tocilizumab as an outpatient for grade ≥1 CRS. 58 patients received outpatient CAR T-cell infusion (33 myeloma, 24 lymphoma and 1 acute lymphoblastic leukemia). Of these, 17 (41%), 16 (38%), and 9 (21%) patients were admitted between days 0-3, 4-7 and 8-30 post-CAR T-cell infusion, respectively. The most common reason for admission was CAR T-cell-related toxicities (33/42). Hospitalization was prevented in 15 out of 35 patients who received tocilizumab for CRS as an outpatient. The non-relapse mortality rates were 1.7% at 1 month and 3.4% at 6 months. In conclusion, we demonstrate that the administration of commercial CAR T-cell therapies in an outpatient setting is safe and feasible without intensive remote monitoring employing an early CRS intervention strategy.

Efficacy of Multiple SARS-CoV-2 Vaccine Doses in Patients with B Cell Hematologic Malignancies Receiving Chimeric Antigen Receptor T Cell Therapy: A Contemporary Cohort Analysis.

The mortality due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) approaches 40% in recipients of chimeric antigen receptor (CAR) T cell therapy (CAR-T). The efficacy of repeated vaccine doses, including bivalent boosters, remains unknown. We examined the efficacy of repeated vaccine doses among CAR-T recipients who received at least 2 or more vaccine doses after T cell infusion. This single-center retrospective study included adults age >18 years receiving CAR-T for relapsed/refractory (R/R) B cell hematologic malignancies targeting CD19, BCMA, or CD19 and CD20 between September 2018 through March 2022 and were alive beyond 2021 to receive incremental SARS-CoV-2 vaccine doses with available seroconversion data. Multivariable analyses were performed using the design-adjusted Cox regression and logistic regression approaches with stratification. In multivariable analysis, seroconversion rates were significantly greater with a total of 4 or more vaccine doses (odds ratio [OR], 8.22; P = .008). CAR-T recipients with other B cell hematologic malignancies had significantly lower seroconversion rates and diminished Ab titers compared to those with R/R multiple myeloma (OR, .07; P = .003). One patient died due to COVID-19 in this vaccinated study cohort, accounting for a COVID-19-attributable mortality rate of 1.7%. The results provide baseline vaccine response data in a contemporary cohort including patients with diverse group of SARS-COV2 variants and support the latest Centers for Disease Control and Prevention guidelines for repeated vaccinations directed against the prevalent variant of concern.

Severity and organ distribution of chronic graft-versus-host disease with posttransplant cyclophosphamide-based versus methotrexate/calcineurin inhibitor-based allogeneic hematopoietic cell transplantation.

The reduced risk of chronic graft-versus-host-disease (GVHD) with posttransplant cyclophosphamide (ptCy) in the setting of haploidentical related donor and more recently, with HLA-matched related and matched and mismatched unrelated donor allogeneic transplantation has been established. There is, however, paucity of data to show if ptCy impacts chronic GVHD pathogenesis, its phenotype and evolution after HCT regardless of the donor status. We examined the differences in chronic GVHD incidence and presentation in 314 consecutive patients after receiving their first allogeneic transplantation (HCT) using ptCy-based GVHD prophylaxis (ptCy-HCT; n = 120; including 95 with haploidentical related donor) versus conventional calcineurin inhibitor-based prophylaxis (CNI-MUD; n = 194) between 2012 and 2019. The 1-year cumulative incidence of all-grade chronic GVHD and moderate/severe chronic GVHD was 24% and 12%, respectively, after ptCy-HCT and 40% and 23% in the CNI-MUD recipients (p = 0.0003 and 0.007). Multivariable analysis confirmed that use of CNI-based GVHD prophylaxis and peripheral blood stem cell graft as the risk factors for chronic GVHD. The cumulative incidence of visceral (involving ≥1 of the following organs: liver, lungs, gastrointestinal tract, serous membranes) chronic GVHD was significantly higher with CNI-MUD vs. ptCy-HCT (27% vs. 15% at 1 year, p = 0.009). The incidence of moderate/severe visceral chronic GVHD was 20% in CNI-MUD group vs. 7.7% in the ptCy-HCT group at 1 year (p = 0.002). In addition, significantly fewer ptCy-HCT recipients developed severe chronic GVHD in ≥3 organs (0.8%) vs. 8.8% in the CNI-MUD group at 1-year posttransplant (p = 0.004). There was no significant different in relapse, non-relapse mortality, and relapse-free and overall survival between the two groups. Further investigation is needed to confirm that reduced risk and severity of chronic GVHD, less visceral organ distribution with ptCy-HCT leads to improved quality of life.

Haploidentical Donor Blood or Marrow Transplantation for Myelodysplastic/Myeloproliferative Overlap Neoplasms: Results from a North American Collaboration.

Haploidentical donors offer a potentially readily available donor, especially for non-White patients, for blood or marrow transplantation (BMT). In this collaboration across North America, we retrospectively analyzed outcomes of first BMT using haploidentical donor and posttransplantation cyclophosphamide (PTCy) in MDS/MPN-overlap neoplasms (MDS/MPN), an otherwise incurable hematological neoplasm. We included 120 patients, 38% of non-White/Caucasian ethnicity, across 15 centers with median age at BMT 62.5 years. The median follow-up is 2.4 years. Graft failure was reported in 6% patients. At 3-years, nonrelapse mortality (NRM) was 25%, relapse 27%, grade 3-4 acute graft versus host disease (GVHD) 12%, chronic GVHD requiring systemic immunosuppression 14%, progression-free survival (PFS) 48% and overall survival (OS) 56%. On multivariable analysis, statistically significant associations included older age at BMT (per decade increment) with NRM (sdHR 3.28, 95%CI 1.30-8.25), PFS (HR 1.98, 95% 1.13-3.45) and OS (HR 2.01, 95% CI 1.11-3.63), presence of mutation in EZH2/RUNX1/SETBP1 with relapse (sdHR 2.61, 95%CI 1.06-6.44), and splenomegaly at BMT/prior splenectomy with OS (HR 2.20, 95%CI 1.04-4.65). Haploidentical donors are a viable option for BMT in MDS/MPN, especially for those disproportionately represented in the unrelated donor registry. Disease-related factors including splenomegaly and high-risk mutations dominate outcomes following BMT.