Association between elevated white blood cell counts and thrombotic events in polycythemia vera: analysis from REVEAL

ABSTRACT

Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by clonal proliferation of hematopoietic progenitor cells and is associated with an increased risk of thrombotic events (TEs). Established risk factors for TEs in patients with PV include advanced age, TE history, and elevated hematocrit. Although an association of TE with elevated white blood cell (WBC) counts has been suggested by retrospective studies, this relationship needs further validation. The prospective observational study of patients with polycythemia vera in US clinical practices (REVEAL) study collected prospective clinical data from 2510 patients with PV with a median follow-up of 44.7 months (range, 2-59 months) from enrollment. Using time-dependent covariate Cox proportional hazards models, blood counts were individually modeled with sex, age, disease duration, TE history at enrollment (baseline covariates), and treatment (time-dependent covariate). Analysis of 2271 participants identified 142 TEs in 106 patients. Significant associations with initial TE occurrence during the study period were observed for hematocrit level >45% (hazard ratio [HR], 1.84; 95% confidence interval [95% CI], 1.234-2.749; P = .0028) and WBCs >11 × 109/L (HR, 2.35; 95% CI, 1.598-3.465; P < .0001). Elevated WBC count was significantly associated with initial TE occurrence in both low-risk and high-risk PV. When hematocrit was controlled at ≤45%, WBC count >12 × 109/L was significantly associated with TE occurrence (HR, 1.95; 95% CI, 1.066-3.554; P = .0300). The results support incorporation of WBC count into PV risk stratification and studies of treatment strategies, and indicate the importance of controlling both hematocrit and WBC count in disease management. This trial was registered at www.clinicaltrials.gov as #NCT02252159.

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.

Top advances of the year: Myeloproliferative neoplasms

The rapid pace of drug development in hematology has led to multiple approvals for myelofibrosis (MF) and polycythemia vera (PV) in recent years. Moreover, there are many innovative agents and combinations being explored for myeloproliferative neoplasms (MPNs). In the past year, there have been several advances in MF, PV, and essential thrombocythemia. In MF, investigational approaches are focusing on strategies to optimize inhibition of signal transduction (including JAK inhibition), modify epigenetics, enhance apoptosis, target DNA replication, transform host immunity, and/or alter the tumor microenvironment. In PV, ropeginterferon alfa-2b has been introduced to the market in the United States, and data continue to accumulate to support the safety and efficacy of this treatment. Hepcidin mimesis is also emerging as a novel way to treat erythrocytosis. In essential thrombocythemia, ropeginterferon alfa-2b is being evaluated, as are therapies to modify epigenetics and inhibit CALR. The enhanced focus on MPNs brings hope that our field can improve morbidity and mortality in this group of diseases.

Allogeneic hematopoietic cell transplantation for blastic plasmacytoid dendritic cell neoplasm: a CIBMTR analysis

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematological malignancy with a poor prognosis and considered incurable with conventional chemotherapy. Small observational studies reported allogeneic hematopoietic cell transplantation (allo-HCT) offers durable remissions in patients with BPDCN. We report an analysis of patients with BPDCN who received an allo-HCT, using data reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). We identified 164 patients with BPDCN from 78 centers who underwent allo-HCT between 2007 and 2018. The 5-year overall survival (OS), disease-free survival (DFS), relapse, and nonrelapse mortality (NRM) rates were 51.2% (95% confidence interval [CI], 42.5-59.8), 44.4% (95% CI, 36.2-52.8), 32.2% (95% CI, 24.7-40.3), and 23.3% (95% CI, 16.9-30.4), respectively. Disease relapse was the most common cause of death. On multivariate analyses, age of ≥60 years was predictive for inferior OS (hazard ratio [HR], 2.16; 95% CI, 1.35-3.46; P = .001), and higher NRM (HR, 2.19; 95% CI, 1.13-4.22; P = .02). Remission status at time of allo-HCT (CR2/primary induction failure/relapse vs CR1) was predictive of inferior OS (HR, 1.87; 95% CI, 1.14-3.06; P = .01) and DFS (HR, 1.75; 95% CI, 1.11-2.76; P = .02). Use of myeloablative conditioning with total body irradiation (MAC-TBI) was predictive of improved DFS and reduced relapse risk. Allo-HCT is effective in providing durable remissions and long-term survival in BPDCN. Younger age and allo-HCT in CR1 predicted for improved survival, whereas MAC-TBI predicted for less relapse and improved DFS. Novel strategies incorporating allo-HCT are needed to further improve outcomes.

Pharmacogenetic and clinical predictors of voriconazole concentration in hematopoietic stem cell transplant recipients receiving CYP2C19-guided dosing

CYP2C19-guided voriconazole dosing reduces pharmacokinetic variability, but many patients remain subtherapeutic. The aim of this study was to evaluate the effect of candidate genes and a novel CYP2C haplotype on voriconazole trough concentrations in patients receiving CYP2C19-guided dosing. This is a retrospective candidate gene study in allogeneic hematopoietic cell transplant (HCT) patients receiving CYP2C19-guided voriconazole dosing. Patients were genotyped for ABCB1, ABCG2, CYP2C9, CYP3A4, CYP3A5, and the CYP2C haplotype. Of 185 patients, 36% were subtherapeutic (of which 79% were normal or intermediate metabolizers). In all patients, CYP2C19 (p < 0.001), age (p = 0.018), and letermovir use (p = 0.001) were associated with voriconazole concentrations. In the subset receiving 200 mg daily (non-RM/UMs), CYP2C19 (p = 0.004) and ABCG2 (p = 0.015) were associated with voriconazole concentrations; CYP2C19 (p = 0.028) and letermovir use (p = 0.001) were associated with subtherapeutic status. CYP2C19 phenotype and letermovir use were significantly associated with subtherapeutic voriconazole concentrations and may be used to improve voriconazole precision dosing, while further research is needed to clarify the role of ABCG2 in voriconazole dosing.

Standardising acute myeloid leukaemia classification systems: a perspective from a panel of international experts

The existence of two acute myeloid leukaemia classification systems-one put forth by WHO and one by the International Consensus Classification in 2022-is concerning. Although both systems appropriately move towards genomic disease definitions and reduced emphasis on blast enumeration, there are consequential disagreements between the two systems on what constitutes a diagnosis of acute myeloid leukaemia. This fundamental problem threatens the ability of heath-care providers to diagnose acute myeloid leukaemia, communicate with patients and other health-care providers, and deliver appropriate and consistent management strategies for patients with the condition. Clinical trial eligibility, standardised response assessments, and eventual drug development and regulatory pathways might also be negatively affected by the discrepancies. In this Viewpoint, we review the merits and limitations of both classification systems and illustrate how the coexistence, as well as application of both systems is an undue challenge to patients, clinicians, hematopathologists, sponsors of research, and regulators. Lastly, we emphasise the urgency and propose a roadmap, by which the two divergent classification systems can be harmonised.

A simple prognostic system in patients with myelofibrosis undergoing allogeneic stem cell transplantation: a CIBMTR/EBMT analysis

To develop a prognostic model for patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) for myelofibrosis (MF), we examined the data of 623 patients undergoing allo-HCT between 2000 and 2016 in the United States (the Center for International Blood and Marrow Transplant Research [CIBMTR] cohort). A Cox multivariable model was used to identify factors prognostic of mortality. A weighted score using these factors was assigned to patients who received transplantation in Europe (the European Bone Marrow Transplant [EBMT] cohort; n = 623). Patient age >50 years (hazard ratio [HR], 1.39; 95% confidence interval [CI], 0.98-1.96), and HLA-matched unrelated donor (HR, 1.29; 95% CI, 0.98-1.7) were associated with an increased hazard of death and were assigned 1 point. Hemoglobin levels <100 g/L at time of transplantation (HR, 1.63; 95% CI, 1.2-2.19) and a mismatched unrelated donor (HR, 1.78; 95% CI, 1.25-2.52) were assigned 2 points. The 3-year overall survival (OS) in patients with a low (1-2 points), intermediate (3-4 points), and high score (5 points) were 69% (95% CI, 61-76), 51% (95% CI, 46-56.4), and 34% (95% CI, 21-49), respectively (P < .001). Increasing score was predictive of increased transplant-related mortality (TRM; P = .0017) but not of relapse (P = .12). The derived score was predictive of OS (P < .001) and TRM (P = .002) but not of relapse (P = .17) in the EBMT cohort as well. The proposed system was prognostic of survival in 2 large cohorts, CIBMTR and EBMT, and can easily be applied by clinicians consulting patients with MF about the transplantation outcomes.

Association between the choice of the conditioning regimen and outcomes of allogeneic hematopoietic cell transplantation for myelofibrosis

Allogeneic hematopoietic cell transplantation (allo-HCT) remains the only curative treatment for myelofibrosis. However, the optimal conditioning regimen either with reduced-intensity conditioning (RIC) or myeloablative conditioning (MAC) is not well known. Using the Center for International Blood and Marrow Transplant Research database, we identified adults aged ≥18 years with myelofibrosis undergoing allo-HCT between 2008-2019 and analyzed the outcomes separately in the RIC and MAC cohorts based on the conditioning regimens used. Among 872 eligible patients, 493 underwent allo-HCT using RIC (fludarabine/ busulfan n=166, fludarabine/melphalan n=327) and 379 using MAC (fludarabine/busulfan n=247, busulfan/cyclophosphamide n=132). In multivariable analysis with RIC, fludarabine/melphalan was associated with inferior overall survival (hazard ratio [HR]=1.80; 95% confidenec interval [CI]: 1.15-2.81; P=0.009), higher early non-relapse mortality (HR=1.81; 95% CI: 1.12-2.91; P=0.01) and higher acute graft-versus-host disease (GvHD) (grade 2-4 HR=1.45; 95% CI: 1.03-2.03; P=0.03; grade 3-4 HR=2.21; 95%CI: 1.28-3.83; P=0.004) compared to fludarabine/busulfan. In the MAC setting, busulfan/cyclophosphamide was associated with a higher acute GvHD (grade 2-4 HR=2.33; 95% CI: 1.67-3.25; P<0.001; grade 3-4 HR=2.31; 95% CI: 1.52-3.52; P<0.001) and inferior GvHD-free relapse-free survival (GRFS) (HR=1.94; 95% CI: 1.49-2.53; P<0.001) as compared to fludarabine/busulfan. Hence, our study suggests that fludarabine/busulfan is associated with better outcomes in RIC (better overall survival, lower early non-relapse mortality, lower acute GvHD) and MAC (lower acute GvHD and better GRFS) in myelofibrosis.

Impact of pre-transplant induction and consolidation cycles on AML allogeneic transplant outcomes: a CIBMTR analysis in 3113 AML patients

We investigated the impact of the number of induction/consolidation cycles on outcomes of 3113 adult AML patients who received allogeneic hematopoietic cell transplantation (allo-HCT) between 2008 and 2019. Patients received allo-HCT using myeloablative (MAC) or reduced-intensity (RIC) conditioning in first complete remission (CR) or with primary induction failure (PIF). Patients who received MAC allo-HCT in CR after 1 induction cycle had 1.3-fold better overall survival (OS) than 2 cycles to CR and 1.47-fold better than ≥3 cycles. OS after CR in 2 or ≥3 cycles was similar. Relapse risk was 1.65-fold greater in patients receiving ≥3 cycles to achieve CR. After RIC allo-HCT, the number of induction cycles to CR did not affect OS. Compared to CR in 1 cycle, relapse risk was 1.24-1.41-fold greater in patients receiving 2 or ≥3 cycles. For patients receiving only 1 cycle to CR, consolidation therapy prior to MAC allo-HCT was associated with improved OS vs. no consolidation therapy. Detectable MRD at the time of MAC allo-HCT did not impact outcomes while detectable MRD preceding RIC allo-HCT was associated with an increased risk of relapse. For allo-HCT in PIF, OS was significantly worse than allo-HCT in CR after 1-3 cycles.

A Phase I Trial of SYK Inhibition with Fostamatinib in the Prevention and Treatment of Chronic Graft-Versus-Host Disease

Despite the exciting advancement of novel therapies, chronic graft-versus-host disease (cGVHD) remains the most common cause of non-relapse mortality after allogeneic hematopoietic stem cell transplantation (HCT). Frontline treatment of cGVHD involves systemic steroids, which are associated with significant morbidities. We previously found that inhibition of spleen tyrosine kinase (SYK) with fostamatinib preferentially eradicated aberrantly activated B cells in both ex vivo studies of cGVHD patient B cells, as well as in vivo mouse studies. These and other preclinical studies implicated hyper-reactive B-cell receptor signaling and increased SYK expression in the pathogenesis of cGVHD and compelled this first in-human allogeneic HCT clinical trial. We investigated the safety and efficacy of the oral SYK inhibitor, fostamatinib, for both the prevention and treatment of cGVHD. The primary objective was to evaluate the safety of fostamatinib and determine its maximum tolerated dose in the post-HCT setting. Secondary objectives included assessing the efficacy of fostamatinib in preventing and treating cGVHD, as well as examining alterations in B-cell compartments with treatment. This was a single-institution phase I clinical trial that evaluated the use of fostamatinib in allogeneic HCT patients before the development of cGVHD or at the time of steroid-refractory cGVHD (SR-cGVHD). Patients received fostamatinib at one of three dose levels using a continual reassessment algorithm to determine the maximum tolerated dose. Multiparameter flow cytometry was used to evaluate changes in B cell subpopulations over the first year of treatment with fostamatinib. Nineteen patients were enrolled in this phase I trial, with 5 in the prophylaxis arm and 14 in the therapeutic arm. One patient (5%) required discontinuation of therapy for a dose-limiting toxicity. At a median follow-up of over 3 years, no patients had cancer relapse while on fostamatinib treatment, and recurrent malignancy was observed in 1 patient 2 years after the end of therapy. In the prophylaxis arm, 1 of 5 patients (20%) developed cGVHD while on fostamatinib. In the therapeutic arm, the overall response rate was 77%, with a complete response rate of 31%. The median duration of response was 19.3 months and the 12-month failure-free survival was 69% (95% confidence interval, 48-100). Patients were able to reduce their steroid dose by a median of 80%, with 73% remaining on a lower dose at 1 year compared to baseline. There was an early reduction in the proportion of IgD-CD38hi plasmablast-like cells with fostamatinib treatment, particularly in those SR-cGVHD patients who had an eventual response. B-cell reconstitution was not significantly impacted by fostamatinib therapy after allogeneic HCT. Fostamatinib featured a favorable safety profile in the post-HCT setting. Our data suggests an early efficacy signal that was associated with effects on expected cell targets in both the prophylaxis and treatment of cGVHD, providing rationale for a phase II investigation.

First-in-human study of JNJ-63709178, a CD123/CD3 targeting antibody, in relapsed/refractory acute myeloid leukemia

This study aimed to identify a recommended phase II dose and evaluate the safety, tolerability, pharmacokinetics/pharmacodynamics, and preliminary clinical activity of JNJ-63709178, a CD123/CD3 dual-targeting antibody, in patients with relapsed or refractory acute myeloid leukemia. Intravenous (i.v.) and subcutaneous (s.c.) administration of JNJ-63709178 were evaluated. The i.v. infusions were administered once every 2 weeks (cohorts 1-5 [n = 17]) or twice weekly (cohorts 6-11 [n = 36]). A twice-weekly s.c. dosing regimen with step-up dosing was also studied (s.c. cohorts 1-2 [n = 9]). Treatment-emergent adverse events (TEAEs) greater than or equal to grade 3 were observed in 11 (65%) patients in cohorts 1-5 and 33 (92%) patients in cohorts 6-11. At the highest i.v. dose (4.8 μg/kg), 5 (71%) patients discontinued treatment due to TEAEs. For s.c. administration (n = 9), eight (89%) patients experienced TEAEs greater than or equal to grade 3 and injection site reactions (≤ grade 3) emerged in all patients. At 4.8 μg/kg (i.v. and s.c.), the mean maximum serum concentrations were 30.3 and 3.59 ng/ml, respectively. Increases in multiple cytokines were observed following i.v. and s.c. administrations, and step-up dosing strategies did not mitigate cytokine production or improve the safety profile and led to limited duration of treatment. Minimal clinical activity was observed across all cohorts. The i.v. and s.c. dosing of JNJ-63709178 was associated with suboptimal drug exposure, unfavorable safety profiles, limited clinical activity, and inability to identify a recommended phase II dose.

Co-management strategies for acute myeloid leukemia patients in the community setting

The treatment landscape for acute myeloid leukemia (AML) has changed substantially in recent years. The introduction of newer therapies, including oral agents, less myelosuppressive agents, and parenteral regimens suitable for outpatient administration, has made it feasible for select patients to receive therapy in the outpatient setting and in community practices. Thorough patient evaluation (including molecular testing), planned supportive care (eg, transfusion support, antimicrobial prophylaxis), and vigilant patient monitoring (for tumor lysis syndrome and adverse events) by a multidisciplinary team are required for successful management of patients both in the community and at specialized leukemia centers. Some patients are unable or unwilling to travel to larger academic centers for treatment, and treatment of AML in the community setting may have potential advantages compared to less conveniently located academic/leukemia centers. This includes reduction of financial hardship for patients and their families and often better opportunities for family/caregiver support. Additionally, partnership between community practices and academic/leukemia centers is often crucial to optimizing AML management for many patients, as collaboration may facilitate access to additional expertise and trials, multidisciplinary teams for supportive care, easier transition to hematopoietic cell transplantation, and access to sophisticated molecular testing. In this review, we discuss AML treatment and management in the community setting, available therapies, and circumstances in which a referral to and co-management with an academic/leukemia center is more strongly recommended.

MPN-103 A Real-World Evaluation of the Association Between Elevated Blood Counts and Thrombotic Events in Polycythemia Vera: Analysis of Data From the REVEAL Study

CONTEXT

Polycythemia Vera (PV) leads to elevated peripheral blood counts (PBCs) and increased thromboembolic events (TE) risk. The conventional model used to determine TE-risk and treatment strategy includes advanced age and TE-history. Association between TE-risk and elevated hematocrit (HCT) is established; association with white-blood-cell count (WBC) or platelet count (PLT) have not been assessed consistently.

OBJECTIVE

Evaluate association between elevated PBCs and TE-risk.

DESIGN

Real-world Prospective Observational Study of Patients with Polycythemia Vera in US Clinical Practices (REVEAL; NCT02252159).

SETTING

Clinical practice.

PATIENTS

Included: ≥3 post-enrollment PBCs; excluded: post-enrollment TE without PBCs <6 months before that TE.

INTERVENTIONS

Noninterventional.

MAIN OUTCOME MEASURES

Association was assessed by the time-dependent covariate Cox-proportional hazards model. Time-to-first post-enrollment TE was modeled; for patients with no TE, time was censored at last visit. Each lab parameter was individually modeled with sex, age, disease duration, and TE-history at enrollment (baseline covariates) and treatment (time-dependent covariates). Thresholds included: HCT>45%, WBC>11×10⁹/L, PLT>400×10⁹/L. Alternative thresholds included: WBC<7, ≥7-<8.5; ≥8.5-<11, ≥11×10⁹/L, WBC>12×10⁹/L with controlled HCT≤45%, and PLT>600×10⁹/L.

RESULTS

Of 2510 enrolled, 2271 patients were included: median age, 67 years (range, 22-95); male, 54.1%; median disease duration, 4.1 years (range, 0-56.3), TE-history, 20.1%; receiving hydroxyurea, 52.6%; TEs, 4.7% (arterial, 1.3%; venous, 3.3%). HCT>45% vs ≤45% (HR=1.84 [95% CI, 1.234-2.749], P=0.0028), WBC>11 vs ≤11×10⁹/L (HR=2.35 [1.598-3.465], P<0.0001), and PLT>400 vs ≤400×10⁹/L (HR=1.60 [1.088-2.359], P=0.0170) were each associated with significantly increased TE-risk. WBC≥ 11 vs <7×10⁹/L was associated with the highest TE-risk (HR=2.61 [1.594-4.262], P=0.0001). TE-risk was increased for PLT>600 vs ≤600×10⁹/L, but not significantly (HR=1.37 [0.763-2.468], P=0.2913). WBC>12 vs ≤ 12×10⁹/L was significantly associated with increased TE-risk at HCT≤45% (HR=1.95 [1.066-3.554], P=0.0300). In all models, advanced age, female sex, and TE-history were associated with increased TE-risk.

CONCLUSIONS

The results demonstrate significant associations individually between elevated HCT, PLT, WBC (>11 and >12×10⁹/L), and increased TE-risk. Elevated WBC (>12×10⁹/L) is significantly associated with increased TE-risk when HCT is controlled, indicating that TE-risk may be reduced by controlling WBC as well as HCT. These data support incorporation of PBCs into risk stratification and treatment strategies for PV patients.

Financial Toxicity Intervention Improves Outcomes in Patients With Hematologic Malignancy

PURPOSE:

Patients with hematologic malignancies are extremely vulnerable to financial toxicity (FT) because of the high costs of treatment and health care utilization. This pilot study identified patients at high risk because of FT and attempted to improve clinical outcomes with comprehensive intervention.

METHODS:

All patients who presented to the Levine Cancer Institute's Leukemia Clinic between May 26, 2019, and March 10, 2020, were screened for inclusion by standardized two question previsit survey. Patients screening positive were enrolled in the comprehensive intervention that used nurse navigators, clinical pharmacists, and community pro bono financial planners. Primary outcomes were defined as improvement in mental and physical quality of life in all patients and improvement in overall survival in the high-risk disease group.

RESULTS:

One hundred seven patients completed comprehensive intervention. Patients experiencing FT had increased rates of noncompliance including to prescription (16.8%) and over-the-counter medications (15.9%). The intervention resulted in statistically significantly higher quality of life when measured by using Patient-Reported Outcomes Measurement Information System physical (12.5 ± 2.2 v 13.7 ± 1.8) and mental health scores (11.4 ± 2.2 v 12.4 ± 2.2; all P < .001). In patients with high-risk disease (as determined by using disease-specific scoring systems), risk of death in those receiving the intervention was 0.44 times the risk of death in those without the intervention after adjusting for race, and treatment with stem-cell transplant, oral chemotherapy, or immunotherapy (95% CI, 0.21 to 0.94; P = .034).

CONCLUSION:

Screening and intervention on FT for patients with hematologic malignancies is associated with increased quality of life and survival.

The mutational landscape in chronic myelomonocytic leukemia and its impact on allogeneic hematopoietic cell transplantation outcomes: a Center for Blood and Marrow Transplantation Research (CIBMTR) analysis

Somatic mutations are recognized as an important prognostic factor in chronic myelomonocytic leukemia (CMML). However, limited data are available regarding their impact on outcomes after allogeneic hematopoietic cell transplantation (HCT). In this registry analysis conducted in collaboration with the Center for International Blood and Marrow Transplantation Registry database/sample repository, we identified 313 adult patients with CMML (median age: 64 years, range, 28- 77) who underwent allogeneic HCT during 2001-2017 and had an available biospecimen in the form of a peripheral blood sample obtained prior to the start of conditioning. In multivariate analysis, a CMML-specific prognostic scoring system (CPSS) score of intermediate-2 (HR=1.46, P=0.049) or high (HR=3.22, P=0.0004) correlated significantly with overall survival. When the molecularly informed CPSS-Mol prognostic model was applied, a high CPSS-Mol score (HR=2 P=0.0079) correlated significantly with overall survival. The most common somatic mutations were in ASXL1 (62%), TET2 (35%), KRAS/NRAS (33% combined), and SRSF2 (31%). DNMT3A and TP53 mutations were associated with decreased overall survival (HR=1.70 [95% CI: 1.11-2.60], P=0.0147 and HR=2.72 [95% CI: 1.37-5.39], P=0.0042, respectively) while DNMT3A, JAK2, and TP53 mutations were associated with decreased disease-free survival (HR=1.66 [95% CI: 1.11-2.49], P=0.0138, HR=1.79 [95% CI: 1.06-3.03], P=0.0293, and HR=2.94 [95% CI: 1.50-5.79], P=0.0018, respectively). The only mutation associated with increased relapse was TP53 (HR=2.94, P=0.0201). Nonetheless, the impact of TP53 mutations specifically should be interpreted cautiously given their rarity in CMML. We calculated the goodness of fit measured by Harrell's C-index for both the CPSS and CPSS-Mol, which were very similar. In summary, via registry data we have determined the mutational landscape in patients with CMML who underwent allogeneic HCT, and demonstrated an association between CPSS-Mol and transplant outcomes although without major improvement in the risk prediction beyond that provided by the CPSS.

HLA informs risk predictions after haploidentical stem cell transplantation with posttransplantation cyclophosphamide

Hematopoietic cell transplantation from HLA-haploidentical related donors is increasingly used to treat hematologic cancers; however, characteristics of the optimal haploidentical donor have not been established. We studied the role of donor HLA mismatching in graft-versus-host disease (GVHD), disease recurrence, and survival after haploidentical donor transplantation with posttransplantation cyclophosphamide (PTCy) for 1434 acute leukemia or myelodysplastic syndrome patients reported to the Center for International Blood and Marrow Transplant Research. The impact of mismatching in the graft-versus-host vector for HLA-A, -B, -C, -DRB1, and -DQB1 alleles, the HLA-B leader, and HLA-DPB1 T-cell epitope (TCE) were studied using multivariable regression methods. Outcome was associated with HLA (mis)matches at individual loci rather than the total number of HLA mismatches. HLA-DRB1 mismatches were associated with lower risk of disease recurrence. HLA-DRB1 mismatching with HLA-DQB1 matching correlated with improved disease-free survival. HLA-B leader matching and HLA-DPB1 TCE-nonpermissive mismatching were each associated with improved overall survival. HLA-C matching lowered chronic GVHD risk, and the level of HLA-C expression correlated with transplant-related mortality. Matching status at the HLA-B leader and HLA-DRB1, -DQB1, and -DPB1 predicted disease-free survival, as did patient and donor cytomegalovirus serostatus, patient age, and comorbidity index. A web-based tool was developed to facilitate selection of the best haploidentical-related donor by calculating disease-free survival based on these characteristics. In conclusion, HLA factors influence the success of haploidentical transplantation with PTCy. HLA-DRB1 and -DPB1 mismatching and HLA-C, -B leader, and -DQB1 matching are favorable. Consideration of HLA factors may help to optimize the selection of haploidentical related donors.

Relapse and Disease-Free Survival in Patients With Myelodysplastic Syndrome Undergoing Allogeneic Hematopoietic Cell Transplantation Using Older Matched Sibling Donors vs Younger Matched Unrelated Donors

IMPORTANCE

Matched sibling donors (MSDs) are preferred for allogeneic hematopoietic cell transplantation (allo-HCT) in myelodysplastic syndrome even if they are older. However, whether older MSDs or younger human leukocyte antigen-matched unrelated donors (MUDs) are associated with better outcomes remains unclear.

OBJECTIVE

To investigate whether allo-HCT for myelodysplastic syndrome using younger MUDs would be associated with improved disease-free survival and less relapse compared with older MSDs.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study assessed data reported to the Center for International Blood and Marrow Transplant Research database from 1761 adults 50 years or older with myelodysplastic syndrome who underwent allo-HCT using an older MSD or younger MUD between January 1, 2011, and December 31, 2017, with a median follow-up of 48 months. Data analysis was performed from January 8, 2019, to December 30, 2020.

INTERVENTIONS/EXPOSURES

Allo-HCT from an older MSD (donor age ≥50 years) or a younger MUD (donor age ≤35 years).

MAIN OUTCOMES AND MEASURES

The primary outcome was disease-free survival. Secondary outcomes were overall survival, relapse, nonrelapse mortality, acute graft-vs-host disease (GVHD), chronic GVHD, and GVHD-free relapse-free survival.

RESULTS

Of 1761 patients (1162 [66%] male; median [range] age, 64.9 [50.2-77.6] years in the MSD cohort and 66.5 [50.4-80.9] years in MUD cohort), 646 underwent allo-HCT with an older MSD and 1115 with a younger MUD. In multivariable analysis, the rate of disease-free survival was significantly lower in allo-HCTs with older MSDs compared with younger MUDs (hazard ratio [HR], 1.17; 95% CI, 1.02-1.34; P = .02), whereas the difference in overall survival rate of allo-HCT with younger MUDs vs older MSDs was not statistically significant (HR, 1.13; 95% CI, 0.98-1.29; P = .07). Allo-HCT with older MSDs was associated with significantly higher relapse (HR, 1.62; 95% CI, 1.32-1.97; P < .001), lower nonrelapse mortality (HR, 0.76; 95% CI, 0.59-0.96; P = .02), lower acute GVHD (HR, 0.52; 95% CI, 0.42-0.65; P < .001), chronic GVHD (HR, 0.77; 95% CI, 0.64-0.92; P = .005), and a lower rate of GVHD-free relapse-free survival beyond 12 months after allo-HCT (HR, 1.42; 95% CI, 1.02-1.98; P = .04).

CONCLUSIONS AND RELEVANCE

This cohort study found higher disease-free survival and lower relapse for allo-HCT in myelodysplastic syndrome using younger MUDs compared with older MSDs. The risk of nonrelapse mortality and GVHD was lower with older MSDs. These results suggest that the use of younger MUDs should be considered in the donor selection algorithm for myelodysplastic syndrome, in which it is pivotal to minimize relapse given limited treatment options for managing relapsed disease.

Umbilical Cord Blood or HLA-Haploidentical Transplantation: Real-World Outcomes versus Randomized Trial Outcomes

Randomized clinical trials offer the highest-quality data for modifying clinical practice. Results of a phase III randomized trial of nonmyeloablative transplantation for adults with high-risk hematologic malignancies with 2 umbilical cord blood (UCB) units (n = 183) or HLA-haploidentical relative bone marrow (Haplo-BM; n = 154) revealed a 2-year progression-free survival (PFS) of 41% after Haplo-BM transplantation and 35% after 2-unit UCB transplantation (P = .41), with overall survival (OS) of 57% and 46%, respectively (P = .04). We sought to examine the generalizability of BMT CTN 1101 to a contemporaneous cohort beyond the trial's prespecified 2-year outcomes. All transplantations were performed between June 2012 and June 2018 in the United States. We hypothesized that the results of a rigorous phase III randomized trial would be generalizable. Changes in graft selection for HLA-haploidentical relative transplantation during the trial period allowed comparison of outcomes after transplantation with Haplo-BM with those after haploidentical peripheral blood (Haplo-PB). The trial's broad eligibility criteria were applied to the data source of the Center for International Blood and Marrow Transplant Research to select nontrial subjects. Extended follow-up of trial subjects was obtained from this data source. Three separate analyses were performed: (1) trial subjects beyond the trial's 2-year endpoint; (2) comparison of trial subjects with a contemporaneous cohort of nontrial subjects (195 2-unit UCB, 358 Haplo-BM, and 403 Haplo-PB); and (3) comparison of nontrial subjects by donor and graft type. Multivariate analyses were performed using Cox proportional hazards models for comparison of outcomes by treatment groups. With longer follow-up of the trial cohorts, 5-year PFS (37% versus 29%; P = .08) and OS (42% versus 36%; P = .06) were not significantly different between the treatment groups. We then compared the trial results with outcomes of comparable real-world transplantations. Five-year OS did not differ between trial and nontrial 2-unit UCB transplantations (36% versus 41%; P = .48) or between trial and nontrial Haplo-BM transplantations (42% versus 47%; P = .80), confirming generalizability. The randomized trial did not accrue as planned and therefore lacked the statistical power to detect a 15% difference in PFS. With substantially larger numbers of nontrial Haplo-BM transplantations, 5-year survival was higher after nontrial Haplo-BM compared with trial 2-unit UCB (47% versus 36%; P = .012). Nontrial patients who underwent Haplo-PB transplantation had higher 5-year survival (54%) compared with trial Haplo-BM (hazard ratio [HR], 0.76; P = .044) and nontrial Haplo-BM (HR, 0.78; P = .026). Similarly, survival was better after Haplo-PB compared with trial UCB (HR, 0.57; P < .0001) and nontrial UCB (HR, 0.63; P = .0002). When considering alternative donor low-intensity conditioning regimen transplantation, a haploidentical relative is preferred, and PB is the preferred graft source.

Outcomes of Allogeneic Hematopoietic Cell Transplantation in T-cell Prolymphocytic Leukemia: A Contemporary Analysis from the Center for International Blood and Marrow Transplant Research

T cell prolymphocytic leukemia (T-PLL) is a rare, aggressive malignancy with limited treatment options and poor long-term survival. Previous studies of allogeneic hematopoietic cell transplantation (alloHCT) for T-PLL are limited by small numbers, and descriptions of patient and transplantation characteristics and outcomes after alloHCT are sparse. In this study, we evaluated outcomes of alloHCT in patients with T-PLL and attempted to identify predictors of post-transplantation relapse and survival. We conducted an analysis of data using the Center for International Blood and Marrow Transplant Research database on 266 patients with T-PLL who underwent alloHCT between 2008 and 2018. The 4-year rates of overall survival (OS), disease-free survival (DFS), relapse, and treatment-related mortality (TRM) were 30.0% (95% confidence interval [CI], 23.8% to 36.5%), 25.7% (95% CI, 20% to 32%), 41.9% (95% CI, 35.5% to 48.4%), and 32.4% (95% CI, 26.4% to 38.6%), respectively. In multivariable analyses, 3 variables were associated with inferior OS: receipt of a myeloablative conditioning (MAC) regimen (hazard ratio [HR], 2.18; P < .0001), age >60 years (HR, 1.61; P = .0053), and suboptimal performance status, defined by Karnofsky Performance Status (KPS) <90 (HR, 1.53; P = .0073). Receipt of an MAC regimen also was associated with increased TRM (HR, 3.31; P < .0001), an elevated cumulative incidence of grade II-IV acute graft-versus-host disease (HR, 2.94; P = .0011), and inferior DFS (HR, 1.86; P = .0004). Conditioning intensity was not associated with relapse; however, stable disease/progression was correlated with increased risk of relapse (HR, 2.13; P = .0072). Both in vivo T cell depletion (TCD) as part of conditioning and KPS <90 were associated with worse TRM and inferior DFS. Receipt of total body irradiation had no significant effect on OS, DFS, or TRM. Our data show that reduced-intensity conditioning without in vivo TCD (ie, without antithymocyte globulin or alemtuzumab) before alloHCT was associated with long-term DFS in patients with T-PLL who were age ≤60 years or who had a KPS >90 or chemosensitive disease.

Allogeneic Transplantation to Treat Therapy-Related Myelodysplastic Syndrome and Acute Myelogenous Leukemia in Adults

Patients who develop therapy-related myeloid neoplasm, either myelodysplastic syndrome (t-MDS) or acute myelogenous leukemia (t-AML), have a poor prognosis. An earlier Center for International Blood and Marrow Transplant Research (CIBMTR) analysis of 868 allogeneic hematopoietic cell transplantations (allo-HCTs) performed between 1990 and 2004 showed a 5-year overall survival (OS) and disease-free survival (DFS) of 22% and 21%, respectively. Modern supportive care, graft-versus-host disease prophylaxis, and reduced-intensity conditioning (RIC) regimens have led to improved outcomes. Therefore, the CIBMTR analyzed 1531 allo-HCTs performed in adults with t-MDS (n = 759) or t-AML (n = 772) between and 2000 and 2014. The median age was 59 years (range, 18 to 74 years) for the patients with t-MDS and 52 years (range, 18 to 77 years) for those with t-AML. Twenty-four percent of patients with t-MDS and 11% of those with t-AML had undergone a previous autologous (auto-) HCT. A myeloablative conditioning (MAC) regimen was used in 49% of patients with t-MDS and 61% of patients with t-AML. Nonrelapse mortality at 5 years was 34% (95% confidence interval [CI], 30% to 37%) for patients with t-MDS and 34% (95% CI, 30% to 37%) for those with t-AML. Relapse rates at 5 years in the 2 groups were 46% (95% CI, 43% to 50%) and 43% (95% CI, 40% to 47%). Five-year OS and DFS were 27% (95% CI, 23% to 31%) and 19% (95% CI, 16% to 23%), respectively, for patients with t-MDS and 25% (95% CI, 22% to 28%) and 23% (95% CI, 20% to 26%), respectively, for those with t-AML. In multivariate analysis, OS and DFS were significantly better in young patients with low-risk t-MDS and those with t-AML undergoing HCT with MAC while in first complete remission, but worse for those with previous auto-HCT, higher-risk cytogenetics or Revised International Prognostic Scoring System score, and a partially matched unrelated donor. Relapse remains the major cause of treatment failure, with little improvement seen over the past 2 decades. These data mandate caution when recommending allo-HCT in these conditions and indicate the need for more effective antineoplastic approaches before and after allo-HCT.

Planned Granulocyte Colony-Stimulating Factor Adversely Impacts Survival after Allogeneic Hematopoietic Cell Transplantation Performed with Thymoglobulin for Myeloid Malignancy

The in vivo depletion of recipient and donor T lymphocytes using antithymocyte globulin (ATG; Thymoglobulin) is widely adopted in allogeneic hematopoietic stem cell transplantation (HCT) to reduce the incidence of both graft failure and graft-versus-host disease (GVHD). However, excess toxicity to donor lymphocytes may hamper immune reconstitution, compromising antitumor effects and increasing infection. Granulocyte-colony stimulating factor (G-CSF) administered early after HCT may increase ATG-mediated lymphotoxicity. This study aimed to investigate the effect of an interaction between ATG and post-transplantation granulocyte colony-stimulating factor (G-CSF) on allogeneic HCT outcomes, using the Center for International Blood and Marrow Transplant Research (CIBMTR) registry. We studied patients age ≥18 years with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) who received Thymoglobulin-containing preparative regimens for HLA-matched sibling/unrelated or mismatched unrelated donor HCT between 2010 and 2018. The effect of planned G-CSF that was started between pretransplantation day 3 and post-transplantation day 12 was studied in comparison with transplantations that did not include G-CSF. Cox regression models were built to identify risk factors associated with outcomes at 1 year after transplantation. A total of 874 patients met the study eligibility criteria, of whom 459 (53%) received planned G-CSF. HCT with planned G-CSF was associated with a significantly increased risk for nonrelapse mortality (NRM) (hazard ratio [HR] 2.03; P <.0001; 21% versus 12%) compared to HCT without G-CSF. The 6-month incidence of viral infection was higher with G-CSF (56% versus 47%; P = .007), with a particular increase in Epstein-Barr virus infections (19% versus 11%; P = .002). The observed higher NRM with planned G-CSF led to lower overall survival (HR, 1.52; P = .0005; 61% versus 72%). There was no difference in GVHD risk between the treatment groups. We performed 2 subgroup analyses showing that our findings held true in patients age ≥50 years and in centers where G-CSF was used in some, but not all, patients. In allogeneic peripheral blood HCT performed with Thymoglobulin for AML and MDS, G-CSF administered early post-transplantation resulted in a 2-fold increase in NRM and a 10% absolute decrement in survival. The use of planned G-CSF in the early post-transplantation period should be carefully considered on an individual patient basis, weighing any perceived benefits against these risks.

Fludarabine and Melphalan Compared with Reduced Doses of Busulfan and Fludarabine Improve Transplantation Outcomes in Older Patients with Myelodysplastic Syndromes

Reduced-intensity conditioning (RIC) regimens developed to extend the use of allogeneic hematopoietic stem cell transplantation (HSCT) to older patients have resulted in encouraging outcomes. We aimed to compare the 2 most commonly used RIC regimens, i.v. fludarabine with busulfan (FluBu) and fludarabine with melphalan (FluMel), in patients with myelodysplastic syndrome (MDS). Through the Center for International Blood and Marrow Transplant Research (CIBMTR), we identified 1045 MDS patients age ≥60 years who underwent first HSCT with a matched related or matched (8/8) unrelated donor using an RIC regimen. The CIBMTR's definition of RIC was used: a regimen that incorporated an i.v. busulfan total dose ≤7.2 mg/kg or a low-dose melphalan total dose ≤150 mg/m². The 2 groups, recipients of FluBu (n = 697) and recipients of FluMel (n = 448), were comparable in terms of disease- and transplantation-related characteristics except for the more frequent use of antithymocyte globulin or alemtuzumab in the FluBu group (39% versus 31%). The median age was 67 years in both groups. FluMel was associated with a reduced relapse incidence (RI) compared with FluBu, with a 1-year adjusted incidence of 26% versus 44% (P ≤ .0001). Transplantation-related mortality (TRM) was higher in the FluMel group (26% versus 16%; P ≤ .0001). Because the magnitude of improvement with FluMel in RI was greater than the improvement in TRM with FluBu, disease-free survival (DFS) was better at 1 year and beyond with FluMel compared with FluBu (48% versus 40% at 1 year [P = .02] and 35% versus 27% at 3 years [P = .01]). Overall survival (OS) was comparable in the 2 groups at 1 year (63% versus 61%; P = .4) but was significantly improved with FluMel compared with FluBu at 3 years (46% versus 39%; P = .03). Our results suggest that FluMel is associated with superior DFS compared with FluBu owing to reduced RI in older patients with MDS patients. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

HLA-haploidentical vs matched unrelated donor transplants with posttransplant cyclophosphamide-based prophylaxis

Posttransplant cyclophosphamide (PTCy) graft-versus-host disease (GVHD) prophylaxis has enabled haploidentical (Haplo) transplantation to be performed with results similar to those after matched unrelated donor (MUD) transplantation with traditional prophylaxis. The relative value of transplantation with MUD vs Haplo donors when both groups receive PTCy/calcineurin inhibitor/mycophenolate GVHD prophylaxis is not known. We compared outcomes after 2036 Haplo and 284 MUD transplantations with PTCy GVHD prophylaxis for acute leukemia or myelodysplastic syndrome in adults from 2011 through 2018. Cox regression models were built to compare outcomes between donor types. Recipients of myeloablative and reduced-intensity regimens were analyzed separately. Among recipients of reduced-intensity regimens, 2-year graft failure (3% vs 11%), acute grades 2 to 4 GVHD (hazards ratio [HR], 0.70; P = .022), acute grades 3 and 4 GVHD (HR, 0.41; P = .016), and nonrelapse mortality (HR, 0.43; P = .0008) were lower after MUD than with Haplo donor transplantation. Consequently, disease-free (HR, 0.74; P = .008; 55% vs 41%) and overall (HR, 0.65; P = .001; 67% vs 54%) survival were higher with MUD than with Haplo transplants. Among recipients of myeloablative regimens, day-100 platelet recovery (95% vs 88%) was higher and grades 3 and 4 acute (HR, 0.39; P = .07) and chronic GVHD (HR, 0.66; P = .05) were lower after MUD than with Haplo donor transplantation. There were no differences in graft failure, relapse, nonrelapse mortality, and disease-free and overall survival between donor types with myeloablative conditioning regimens. These data extend and confirm the importance of donor-recipient HLA matching for allogeneic transplantation. A MUD is the preferred donor, especially for transplantations with reduced-intensity conditioning regimens.

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.

Hemorrhage in patients with polycythemia vera receiving aspirin with an anticoagulant: a prospective, observational study

Polycythemia vera (PV) is associated with increased risk of thrombosis and hemorrhage. Aspirin, recommended for primary thromboprophylaxis, is often combined with anticoagulants during management of acute thrombotic events. The safety of dual antiplatelet and anticoagulant therapy is not established in PV. In a prospective, observational study, 2510 patients with PV were enrolled at 227 sites in the United States. Patients were monitored for the development of hemorrhage and thrombosis after enrollment. A total of 1602 patients with PV received aspirin with median (range) follow-up of 2.4 (0-3.6) years. The exposure-adjusted rate of all hemorrhages in patients receiving aspirin alone was 1.40 per 100 patient-years (95% confidence interval [CI]: 0.99-1.82). The combination of aspirin plus anticoagulant was associated with an incidence of hemorrhage of 6.75 per 100 patient-years (95% CI: 3.04-10.46). The risk of hemorrhage was significantly greater in patients receiving the combination of aspirin and anticoagulant compared with aspirin alone (total hemorrhages, hazard ratio [HR]: 5.83; 95% CI: 3.36-10.11; P.

Hematopoietic Cell Transplantation in the Treatment of Newly Diagnosed Adult Acute Myeloid Leukemia: An Evidence-Based Review from the American Society of Transplantation and Cellular Therapy

The role of hematopoietic cell transplantation (HCT) in the management of newly diagnosed adult acute myeloid leukemia (AML) is reviewed and critically evaluated in this evidence-based review. An AML expert panel, consisting of both transplant and nontransplant experts, was invited to develop clinically relevant frequently asked questions covering disease- and HCT-related topics. A systematic literature review was conducted to generate core recommendations that were graded based on the quality and strength of underlying evidence based on the standardized criteria established by the American Society of Transplantation and Cellular Therapy Steering Committee for evidence-based reviews. Allogeneic HCT offers a survival benefit in patients with intermediate- and high-risk AML and is currently a part of standard clinical care. We recommend the preferential use of myeloablative conditioning in eligible patients. A haploidentical related donor marrow graft is preferred over a cord blood unit in the absence of a fully HLA-matched donor. The evolving role of allogeneic HCT in the context of measurable residual disease monitoring and recent therapeutic advances in AML with regards to maintenance therapy after HCT are also discussed.

Comanagement Strategy Between Academic Institutions and Community Practices to Reduce Induction Mortality in Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) is a curable leukemia with > 90% survival in clinical trials. Population-based studies from Sweden and US SEER data have shown long-term survival rates of 62% and 65.7%, with the lower rate being from a higher percentage of early deaths.

Myeloablative Conditioning for Allogeneic Transplantation Results in Superior Disease-Free Survival for Acute Myelogenous Leukemia and Myelodysplastic Syndromes with Low/Intermediate but not High Disease Risk Index: A Center for International Blood and Marrow Transplant Research Study

Compared with reduced-intensity conditioning (RIC), myeloablative conditioning (MAC) is generally associated with lower relapse risk after allogeneic hematopoietic cell transplantation (HCT) for acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDS). However, disease-specific risk factors in AML/MDS can further inform when MAC and RIC may yield differential outcomes. We analyzed HCT outcomes stratified by the Disease Risk Index (DRI) in 4387 adults (age 40 to 65 years) to identify the impact of conditioning intensity. In the low/intermediate-risk DRI cohort, RIC was associated with lower nonrelapse mortality (NRM) (hazard ratio [HR], .74; 95% confidence interval [CI], .62 to .88; P < .001) but significantly greater relapse risk (HR, 1.54; 95% CI, 1.35 to 1.76; P < .001) and thus inferior disease-free survival (DFS) (HR, 1.19; 95% CI, 1.07 to 1.33; P = .001). In the high/very high-risk DRI cohort, RIC was associated with marginally lower NRM (HR, .83; 95% CI, .68 to 1.00; P = .051) and significantly higher relapse risk (HR, 1.23; 95% CI, 1.08 to 1.41; P = .002), leading to similar DFS using either RIC or MAC. These data support MAC over RIC as the preferred conditioning intensity for patients with AML/MDS with low/intermediate-risk DRI, but with a similar benefit as RIC in high/very high-risk DRI. Novel MAC regimens with less toxicity could benefit all patients, but more potent antineoplastic approaches are needed for the high/very-high risk DRI group.

Abstract 1920: Response to hypomethylating agents based on cytidine deaminase expression, genetic polymorphisms, and NPM1 mutation status in acute myeloid leukemia

Response to hypomethylating agents (HMAs) in patients (pts) with acute myeloid leukemia (AML) is variable. Data on biological predictors of response is limited. Cytidine deaminase (CDA) inactivates HMAs. Increased CDA activity may lead to HMA resistance. Using core pathway analysis, we identified nucleophosmin 1 (NPM1) indirectly influences CDA expression. We hypothesized that responses to HMAs occur in the setting of decreased CDA expression regulated by NPM1 and investigated the relationship between NPM1 status, CDA expression, single nucleotide polymorphisms (SNPs) in CDA, and HMA response in pts with AML.

AML pts with banked samples who received HMA-based therapy between 1/2014 to 12/2018 were reviewed. Responses following at least 2 cycles of HMA were categorized as responders (R) or non-responders (NR). Pt, disease, NPM1 status, and treatment characteristics were summarized. CDA gene and protein expression was examined in bone marrow and peripheral blood samples at diagnosis using qRT-PCR and CDA sandwich ELISA, respectively. CDA gene expression levels were normalized to the housekeeping gene, 18s, and the comparative CT method was used to assess expression. Comparisons based on response and NPM1 mutation status were performed using the Mann-Whitney U test. 17 SNPs previously shown to alter CDA activity were selected for analysis. SNPs were determined using real-time PCR with allele specific probes; longer insertions/deletions were identified by sanger sequencing. Univariate logistic regression analysis was performed to discern the association between SNPs in CDA and response to HMAs.

54 pts had available blood, marrow, or buccal samples available for analysis. 33 pts provided blood or marrow samples for gene and protein analysis prior to HMA. 22 pts (67%) were classified as R in this cohort. 35 pts had available buccal swabs for genotyping, and 28 pts (80%) were classified as R. Median OS was 21 months (mo) for all pts, 23 mo among R, and 18 mo in NR. CDA expression was significantly decreased in NPM1 wild type pts compared to NPM1 mutant pts (p=0.02) but did not differ in R compared to NR. No significant differences were identified in CDA protein expression based on NPM1 status or response. No SNPs were significantly associated with response.

Baseline CDA gene expression in bulk tumor cells was significantly lower in NPM1 wild type pts compared to NPM1 mutant pts but no different between pts responding to HMAs compared to NR. There was no clear correlation between CDA protein expression and NPM1 status or response. None of the CDA SNPs were predictive of response to HMAs. This analysis reveals feasibility of assessing CDA activity in this population. Our small sample size limits our ability to determine CDA activity as a biological predictor of response, and ongoing pt accrual will allow for further exploration of the role of CDA in HMA response.

Citation Format: Brittany Knick Ragon, Issam S. Hamadeh, C Greer Vestal, Alicia Hamilton, Mathew L. Smith, Danielle Boselli, Jing Ai, Thomas G. Knight, Michael R. Grunwald, Jonathan M. Gerber, Edward A. Copelan, Lawrence J. Druhan, Belinda R. Avalos, Nury M. Steuerwald, Jai N. Patel. Response to hypomethylating agents based on cytidine deaminase expression, genetic polymorphisms, and NPM1 mutation status in acute myeloid leukemia [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1920.

A Personalized Prediction Model for Outcomes after Allogeneic Hematopoietic Cell Transplant in Patients with Myelodysplastic Syndromes

Allogeneic hematopoietic stem cell transplantation (HCT) remains the only potentially curative option for myelodysplastic syndromes (MDS). Mortality after HCT is high, with deaths related to relapse or transplant-related complications. Thus, identifying patients who may or may not benefit from HCT is clinically important. We identified 1514 patients with MDS enrolled in the Center for International Blood and Marrow Transplant Research Registry and had their peripheral blood samples sequenced for the presence of 129 commonly mutated genes in myeloid malignancies. A random survival forest algorithm was used to build the model, and the accuracy of the proposed model was assessed by concordance index. The median age of the entire cohort was 59 years. The most commonly mutated genes were ASXL1(20%), TP53 (19%), DNMT3A (15%), and TET2 (12%). The algorithm identified the following variables prior to HCT that impacted overall survival: age, TP53 mutations, absolute neutrophils count, cytogenetics per International Prognostic Scoring System-Revised, Karnofsky performance status, conditioning regimen, donor age, WBC count, hemoglobin, diagnosis of therapy-related MDS, peripheral blast percentage, mutations in RAS pathway, JAK2 mutation, number of mutations/sample, ZRSR2, and CUX1 mutations. Different variables impacted the risk of relapse post-transplant. The new model can provide survival probability at different time points that are specific (personalized) for a given patient based on the clinical and mutational variables that are listed above. The outcomes' probability at different time points may aid physicians and patients in their decision regarding HCT.

Timing of allogeneic hematopoietic cell transplantation (alloHCT) for chronic myeloid leukemia (CML) patients

While TKI are the preferred first-line treatment for chronic phase (CP) CML, alloHCT remains an important consideration. The aim is to estimate residual life expectancy (RLE) for patients initially diagnosed with CP CML based on timing of alloHCT or continuation of TKI in various settings: CP1 CML, CP2 + [after transformation to accelerated phase (AP) or blast phase (BP)], AP, or BP. Non-transplant cohort included single-institution patients initiating TKI and switched TKI due to failure. CIBMTR transplant cohort included CML patients who underwent HLA sibling matched (MRD) or unrelated donor (MUD) alloHCT. AlloHCT appeared to shorten survival in CP1 CML with overall mortality hazard ratio (HR) for alloHCT of 2.4 (95% CI 1.2-4.9; p = .02). In BP CML, there was a trend toward higher survival with alloHCT; HR = 0.7 (0.5-1.1; p = .099). AlloHCT in CP2 + [HR = 2.0 (0.8-4.9), p = .13] and AP [HR = 1.1 (0.6-2.1); p = .80] is less clear and should be determined on a case-by-case basis.

Evaluation of CYP2C19 Genotype-Guided Voriconazole Prophylaxis After Allogeneic Hematopoietic Cell Transplant

There is a high risk of voriconazole failure in those with subtherapeutic drug concentrations, which is more common in CYP2C19 (cytochrome P450 2C19) rapid/ultrarapid metabolizers (RMs/UMs). We evaluated CYP2C19 genotype-guided voriconazole dosing on drug concentrations and clinical outcomes in adult allogeneic hematopoietic cell transplant recipients. Poor (PMs), intermediate (IMs), and normal metabolizers (NMs) received voriconazole 200 mg twice daily; RMs/UMs received 300 mg twice daily. Steady-state trough concentrations were obtained after 5 days, targeting 1.0-5.5 mg/L. Of 89 evaluable patients, 29% had subtherapeutic concentrations compared with 50% in historical controls (P < 0.001). Zero, 26%, 50%, and 16% of PMs, IMs, NMs, and RMs/UMs were subtherapeutic. Voriconazole success rate was 78% compared with 54% in historical controls (P < 0.001). No patients experienced an invasive fungal infection (IFI). Genotype-guided dosing resulted in $4,700 estimated per patient savings as compared with simulated controls. CYP2C19 genotype-guided voriconazole dosing reduced subtherapeutic drug concentrations and effectively prevented IFIs.

Maintenance Tyrosine Kinase Inhibitors Following Allogeneic Hematopoietic Stem Cell Transplantation for Chronic Myelogenous Leukemia: A Center for International Blood and Marrow Transplant Research Study

It remains unknown whether the administration of tyrosine kinase inhibitors (TKIs) targeting BCR-ABL1 after allogeneic hematopoietic cell transplantation (HCT) is associated with improved outcomes for patients with chronic myelogenous leukemia (CML). In this registry study, we analyzed clinical outcomes of 390 adult patients with CML who underwent transplantation between 2007 and 2014 and received maintenance TKI following HCT (n = 89) compared with no TKI maintenance (n = 301), as reported to the Center for International Blood and Marrow Transplant Research. All patients received TKI therapy before HCT. The majority of patients had a disease status of first chronic phase at HCT (n = 240; 62%). The study was conducted as a landmark analysis, excluding patients who died, relapsed, had chronic graft-versus-host disease, or were censored before day +100 following HCT. Of the 89 patients who received TKI maintenance, 77 (87%) received a single TKI and the other 12 (13%) received multiple sequential TKIs. The most common TKIs used for maintenance were dasatinib (n = 50), imatinib (n = 27), and nilotinib (n = 27). As measured from day +100, the adjusted estimates for 5-year relapse (maintenance, 35% versus no maintenance, 26%; P = .11), leukemia-free survival (maintenance, 42% versus no maintenance, 44%; P = .65), or overall survival (maintenance, 61% versus no maintenance, 57%; P = .61) did not differ significantly between patients receiving TKI maintenance or no maintenance. These results remained unchanged in multivariate analysis and were not modified by disease status before transplantation. In conclusion, our data from this day +100 landmark analysis do not demonstrate a significant impact of maintenance TKI therapy on clinical outcomes. The optimal approach to TKI administration in the post-transplantation setting in patients with CML remains undetermined.

Serum Flt3 ligand is a biomarker of progenitor cell mass and prognosis in acute myeloid leukemia

Fms-like tyrosine kinase 3 (Flt3) is expressed on progenitor cells and acute myeloid leukemia (AML) blasts. Fms-like tyrosine kinase 3 ligand (Flt3L) is detectable during homeostasis and increases in hypoplasia due to genetic defects or treatment with cytoreductive agents. Conversely, Flt3+ AML is associated with depletion of Flt3L to undetectable levels. After induction chemotherapy, Flt3L is restored in patients entering complete remission (CR) but remains depressed in those with refractory disease. Weekly sampling reveals marked differences in the kinetics of Flt3L response during the first 6 weeks of treatment, proportionate to the clearance of blasts and cellularity of the bone marrow. In the UK NCRI AML17 trial, Flt3L was measured at day 26 in a subgroup of 140 patients with Flt3 mutation randomized to the tyrosine kinase inhibitor lestaurtinib or placebo. In these patients, attainment of CR was associated with higher Flt3L at day 26 (Mann-Whitney UP < .0001). Day 26 Flt3L was also associated with survival; Flt3L ≤291 pg/mL was associated with inferior event-free survival (EFS), and Flt3L >1185 pg/mL was associated with higher overall survival (OS; P = .0119). The separation of EFS and OS curves increased when minimal residual disease (MRD) status was combined with Flt3L measurement, and Flt3L retained a near-significant association with survival after adjusting for MRD in a proportional hazards model. Serial measurement of Flt3L in patients who had received a hematopoietic stem cell transplant for AML illustrates the potential value of monitoring Flt3L to identify relapse. Measurement of Flt3L is a noninvasive test with the potential to inform clinical decisions in patients with AML.

Phase 1b study of the MDM2 inhibitor AMG 232 with or without trametinib in relapsed/refractory acute myeloid leukemia

This open-label, phase 1 study evaluated the safety, pharmacokinetics, and maximum tolerated dose of AMG 232, an investigational oral, selective mouse double minute 2 homolog inhibitor in relapsed/refractory acute myeloid leukemia (AML). AMG 232 was administered orally once daily for 7 days every 2 weeks (7 on/off) at 60, 120, 240, 360, 480, or 960 mg as monotherapy (arm 1) or at 60 mg with trametinib 2 mg (arm 2). Dose-limiting toxicities (DLTs), adverse events (AEs), pharmacokinetics, clinical and pharmacodynamic response, and expression of p53 target genes were assessed. All 36 patients received AMG 232. No DLTs occurred in arm 1, and 360 mg was the highest test dose; dose escalation was halted due to gastrointestinal AEs at higher doses. One of ten patients in arm 2 had a DLT (grade 3 fatigue); 60 mg was the highest dose tested with trametinib. Common treatment-related AEs (any grade) included nausea (58%), diarrhea (56%), vomiting (33%), and decreased appetite (25%). AMG 232 exhibited linear pharmacokinetics unaffected by coadministration with trametinib. Serum macrophage inhibitor cytokine-1 and bone marrow expression of BAX, PUMA, P21, and MDM2 increased during treatment. Of 30 evaluable patients, 1 achieved complete remission, 4 had morphologic leukemia-free state, and 1 had partial remission. Four of 13 (31%) TP53-wild-type patients and 0 of 3 (0%) TP53-mutant patients were responders. AMG 232 was associated with gastrointestinal AEs at higher doses but had acceptable pharmacokinetics, on-target effects, and promising clinical activity warranting further investigation in patients with relapsed/refractory AML. This trial was registered at www.clinicaltrials.gov as #NCT02016729.

Prognostic Score and Cytogenetic Risk Classification for Chronic Lymphocytic Leukemia Patients: Center for International Blood and Marrow Transplant Research Report

PURPOSE

To develop a prognostic model and cytogenetic risk classification for previously treated patients with chronic lymphocytic leukemia (CLL) undergoing reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (HCT).

EXPERIMENTAL DESIGN

We performed a retrospective analysis of outcomes of 606 patients with CLL who underwent RIC allogeneic HCT between 2008 and 2014 reported to the Center for International Blood and Marrow Transplant Research.

RESULTS

On the basis of multivariable models, disease status, comorbidity index, lymphocyte count, and white blood cell count at HCT were selected for the development of prognostic model. Using the prognostic score, we stratified patients into low-, intermediate-, high-, and very-high-risk [4-year progression-free survival (PFS) 58%, 42%, 33%, and 25%, respectively, P < 0.0001; 4-year overall survival (OS) 70%, 57%, 54%, and 38%, respectively, P < 0.0001]. We also evaluated karyotypic abnormalities together with del(17p) and found that del(17p) or ≥5 abnormalities showed inferior PFS. Using a multivariable model, we classified cytogenetic risk into low, intermediate, and high (P < 0.0001). When the prognostic score and cytogenetic risk were combined, patients with low prognostic score and low cytogenetic risk had prolonged PFS (61% at 4 years) and OS (75% at 4 years).

CONCLUSIONS

In this large cohort of patients with previously treated CLL who underwent RIC HCT, we developed a robust prognostic scoring system of HCT outcomes and a novel cytogenetic-based risk stratification system. These prognostic models can be used for counseling patients, comparing data across studies, and providing a benchmark for future interventions. For future study, we will further validate these models for patients receiving targeted therapies prior to HCT.

Symptom Burden and Blood Counts in Patients With Polycythemia Vera in the United States: An Analysis From the REVEAL Study

BACKGROUND

Approximately 50% of patients with polycythemia vera (PV) have PV-related symptoms at diagnosis; these symptoms might develop or worsen with time. Symptoms have been shown to negatively affect quality of life and interfere with daily activities. To our knowledge, an analysis to evaluate the relationship between blood count control and symptoms has not been published.

PATIENTS AND METHODS

The Prospective Observational Study of Patients with Polycythemia Vera in US Clinical Practices (REVEAL; NCT02252159) is a multicenter, noninterventional, nonrandomized prospective observational study of patients with PV in the United States. Patients included were required to have a complete blood count result within 30 days before completing the at-enrollment Myeloproliferative Neoplasm Self-Assessment Form Total Symptom Score (MPN-SAF TSS). Symptom severity was compared between those who had blood count control versus those who did not.

RESULTS

At the time of enrollment, 1714 patients (94.5%) were being managed with cytoreductive therapy; 468 patients (25.8%) had complete hematologic remission (CHR), 1614 patients (89.0%) had ≥1 controlled blood count, and 1122 patients (61.9%) had ≥2 controlled blood counts. Mean MPN-SAF TSSs were similar across patients in different blood count control groups. Fatigue was the most frequently reported symptom. The severity of individual symptoms, except those of pruritus and night sweats, was not affected by CHR or the number of blood counts that were controlled.

CONCLUSION

Symptom burden in patients with PV can persist despite control of blood counts, which suggests some discordance between laboratory values and symptom burden. Consequently, regular monitoring of symptom burden should be factored into the assessment of disease control.

Effect of CYP3A4, CYP3A5, and ABCB1 Polymorphisms on Intravenous Tacrolimus Exposure and Adverse Events in Adult Allogeneic Stem Cell Transplant Patients

Pharmacogenetics influences oral tacrolimus exposure; however, little data exist regarding i.v. tacrolimus. We investigated the impact of genetic polymorphisms in CYP3A4, CYP3A5, and ABCB1 on i.v. tacrolimus exposure and toxicity in adult patients receiving an allogeneic hematopoietic stem cell transplant for hematologic malignancies. Germline DNA was extracted from buccal swabs and genotyped for CYP3A4, CYP3A5, and ABCB1 polymorphisms. Continuous i.v. infusion of tacrolimus .03 mg/kg/day was initiated on day +5 post-transplant, and steady-state blood concentrations were measured 4days later. We evaluated the association between phenotypes and prevalence of nontherapeutic target concentrations (below or above 5 to 15 ng/mL) as well as tacrolimus-related toxicities. Of 63 patients, 28.6% achieved the target concentration; 71.4% were >15ng/mL, which was more common in CYP3A4 intermediate/normal metabolizers (compared with rapid) and those with at least 1 ABCB1 C2677T loss-of-function allele (P < .05). ABCB1 C2677T was significantly associated with concentrations >15ng/mL (odds ratio, 6.2; 95% confidence interval, 1.8 to 23.6; P = .004) and tacrolimus-related toxicities (odds ratio, 7.5; 95% confidence interval, 1.6 to 55.2; P = .02). ABCB1 C2677T and CYP3A4 are important determinants of i.v. tacrolimus exposure, whereas ABCB1 C2677T also impacts tacrolimus-related toxicities in stem cell transplants.

Patient-Reported Outcomes Data From REVEAL at the Time of Enrollment (Baseline): A Prospective Observational Study of Patients With Polycythemia Vera in the United States

BACKGROUND

Patients with polycythemia vera (PV) often experience symptoms that adversely affect their quality of life (QoL). The ongoing, prospective, observational REVEAL (Prospective Observational Study of Patients With Polycythemia Vera in US Clinical Practices) study was designed to collect contemporary data regarding burden of disease, clinical management, patient-reported outcomes (PROs), and health care resource utilization from adult patients with PV in the United States.

PATIENTS AND METHODS

Data on PROs were collected at enrollment using the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-SAF TSS; range, 0-100); the European Organization for Research and Treatment of Cancer-Core Quality of Life Questionnaire, version 3.0 (EORTC QLQ-C30; range, 0-100); and the Work Productivity and Activity Impairment Questionnaire-Specific Health Problem (WPAI-SHP; range, 0%-100%).

RESULTS

Among 2309 patients, mean (SD) disease duration was 5.8 (6.1) years and Charlson Comorbidity Index was 3.4 (0.8); 54.0% (1247/2309) were male. Mean (SD) MPN-SAF TSS was 18.8 (15.5). The most common symptoms were fatigue (80.1% [1844/2302]), early satiety (60.9% [1402/2302]), and inactivity (57.6% [1324/2302]). The most common severe symptoms were fatigue (16.8% [387/2302]), itching (13.4% [308/2302]), and inactivity (11.8% [271/2302]). The mean (SD) EORTC QLQ-C30 global health status/QoL score was 73.1 (23.2): mean functional subscale scores ranged from 80.5 (23.9) for cognitive functioning to 85.7 (24.6) for social functioning. The mean WPAI-SHP activity impairment score was 19.7% (n = 2300). Employed patients had mean WPAI-SHP scores for absenteeism, presenteeism, and overall work impairment of 3.2% (n = 810), 12.1% (n = 807), and 13.4% (n = 802), respectively.

CONCLUSION

These data confirm that many patients with PV experience symptoms, QoL impairments, and work productivity impairments that negatively affect their lives. Longitudinal data from REVEAL will be important for evaluating how PROs change over time in these patients.

Clinical and Disease Characteristics From REVEAL at Time of Enrollment (Baseline): Prospective Observational Study of Patients With Polycythemia Vera in the United States

REVEAL is the first large, prospective observational study aimed at examining the contemporary demographics, burden of disease, clinical management, patient-reported outcomes, and health care resource utilization in patients with polycythemia vera in the United States.

Assessment of Impact of HLA Type on Outcomes of Allogeneic Hematopoietic Stem Cell Transplantation for Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is a common hematologic malignancy with many highly effective therapies. Chemorefractory disease, often characterized by deletion of chromosome 17p, has historically been associated with very poor outcomes, leading to the application of allogeneic hematopoietic stem cell transplantation (allo-HCT) for medically fit patients. Although the use of allo-HCT has declined since the introduction of novel targeted therapy for the treatment of CLL, there remains significant interest in understanding factors that may influence the efficacy of allo-HCT, the only known curative treatment for CLL. The potential benefit of transplantation is most likely due to the presence of alloreactive donor T cells that mediate the graft-versus-leukemia (GVL) effect. The recognition of potentially tumor-specific antigens in the context of class I and II major histocompatibility complex on malignant B lymphocytes by donor T cells may be influenced by subtle differences in the highly polymorphic HLA locus. Given previous reports of specific HLA alleles impacting the incidence of CLL and the clinical outcomes of allo-HCT for CLL, we sought to study the overall survival and progression-free survival of a large cohort of patients with CLL who underwent allo-HCT from fully HLA-matched related and unrelated donors at Center for International Blood and Marrow Transplant Research transplantation centers. We found no statistically significant association of allo-HCT outcomes in CLL based on previously reported HLA combinations. Additional study is needed to further define the immunologic features that portend a more favorable GVL effect after allo-HCT for CLL.

Recent advances in hematopoietic cell transplantation in myelodysplastic syndrome

Myelodysplastic syndrome (MDS) is a heterogeneous group of malignant disorders of blood cell production occurring predominantly in elderly patients. While low intensity treatments are appropriate initially in most patients with favorable prognoses, hematopoietic cell transplantation (HCT) is the only curative therapy and is the best therapy for many higher risk patients. In patients who present with lower-risk disease, HCT may be considered at the time of meaningful disease progression. In patients receiving hypomethylating treatment, outcome of HCT is best when performed during response, and HCT is less effective when performed after resistance occurs. Advances over the last 2 decades have markedly improved safety and survival with HCT, and appropriate donors are now available for virtually every patient in whom HCT is indicated. The application of HCT in MDS has expanded significantly over the last few years and its use in MDS promises to continue to grow as results further improve.