How I reduce and treat posttransplant relapse of MDS.

ABSTRACT: Allogeneic hematopoietic stem cell transplantation (HSCT) is the only potentially curative option for patients with high-risk myelodysplastic syndromes (MDS). Advances in conditioning regimens and supportive measures have reduced treatment-related mortality and increased the role of transplantation, leading to more patients undergoing HSCT. However, posttransplant relapse of MDS remains a leading cause of morbidity and mortality for this procedure, necessitating expert management and ongoing results analysis. In this article, we review treatment options and our institutional approaches to managing MDS relapse after HSCT, using illustrative clinical cases that exemplify different clinical manifestations and management of relapse. We address areas of controversy relating to conditioning regimen intensity, chemotherapeutic bridging, and donor selection. In addition, we discuss future directions for advancing the field, including (1) the need for prospective clinical trials separating MDS from acute myeloid leukemia and focusing on posttransplant relapse, as well as (2) the validation of measurable residual disease methodologies to guide timely interventions.

Risk Prediction for Clonal Cytopenia: Multicenter Real-World Evidence.

Clonal cytopenia of undetermined significance (CCUS) represents a distinct disease entity characterized by myeloid-related somatic mutations with a variant allele fraction of ≥2% in individuals with unexplained cytopenia(s) but without a myeloid neoplasm (MN). Notably, CCUS carries a risk of progressing to MN, particularly in cases featuring high-risk mutations. Understanding CCUS requires dedicated studies to elucidate its risk factors and natural history. Our analysis of 357 CCUS patients investigated the interplay between clonality, cytopenia, and prognosis. Multivariate analysis identified 3 key adverse prognostic factors: the presence of splicing mutation(s) (score = 2 points), platelet count <100×109/L (score = 2.5), and ≥2 mutations (score = 3). Variable scores were based on the coefficients from the Cox proportional hazards model. This led to the development of the Clonal Cytopenia Risk Score (CCRS), which stratified patients into low- (score <2.5 points), intermediate- (score 2.5-<5), and high-risk (score ≥5) groups. The CCRS effectively predicted 2-year cumulative incidence of MN for low- (6.4%), intermediate- (14.1%), and high- (37.2%) risk groups, respectively, by Gray's test (P <.0001). We further validated the CCRS by applying it to an independent CCUS cohort of 104 patients, demonstrating a c-index of 0.64 (P =.005) in stratifying the cumulative incidence of MN. Our study underscores the importance of integrating clinical and molecular data to assess the risk of CCUS progression, making the CCRS a valuable tool that is practical and easily calculable. These findings are clinically relevant, shaping the management strategies for CCUS and informing future clinical trial designs.

Conditioning intensity and peritransplant flow cytometric MRD dynamics in adult AML.

In acute myeloid leukemia (AML), measurable residual disease (MRD) before or after allogeneic hematopoietic cell transplantation (HCT) is an established independent indicator of poor outcome. To address how peri-HCT MRD dynamics could refine risk assessment across different conditioning intensities, we analyzed 810 adults transplanted in first or second remission after myeloablative conditioning (MAC; n = 515) or non-MAC (n = 295) who underwent multiparameter flow cytometry-based MRD testing before as well as 20 to 40 days after allografting. Patients without pre- and post-HCT MRD (MRDneg/MRDneg) had the lowest risks of relapse and highest relapse-free survival (RFS) and overall survival (OS). Relative to those patients, outcomes for MRDpos/MRDpos and MRDneg/MRDpos patients were poor regardless of conditioning intensity. Outcomes for MRDpos/MRDneg patients were intermediate. Among 161 patients with MRD before HCT, MRD was cleared more commonly with a MAC (85 of 104; 81.7%) than non-MAC (33 of 57; 57.9%) regimen (P = .002). Although non-MAC regimens were less likely to clear MRD, if they did, the impact on outcome was greater. Thus, there was a significant interaction between conditioning intensity and "MRD conversion" for relapse (P = .020), RFS (P = .002), and OS (P = .001). Similar findings were obtained in the subset of 590 patients receiving HLA-matched allografts. C-statistic values were higher (indicating higher predictive accuracy) for peri-HCT MRD dynamics compared with the isolated use of pre-HCT MRD status or post-HCT MRD status for prediction of relapse, RFS, and OS. Across conditioning intensities, peri-HCT MRD dynamics improve risk assessment over isolated pre- or post-HCT MRD assessments in patients with AML.

Long-term survival can be achieved in a significant fraction of older patients with core binding factor acute myeloid leukemia treated with intensive chemotherapy.

Acute Myeloid Leukemia is mainly a disease of the elderly: however, the knowledge on the outcomes of treatment in core binding factor AML (CBFAML) in older population, is limited. We retrospectively collected data on 229 patients with CBF- AML followed long-term in the last two decades. A 5-year overall survival (OS) of 44.2% (95%CI, 39.9-47.5) and a 5-year event - free survival (EFS) of 32.9% (95%CI, 25.5-40.1) was observed. In a subgroup of >70-year patients who completed intensive therapy (induction + >3 courses of consolidation including autologous stem cell transplant: 10 patients) the median EFS was 11.8 months (95%CI, 9.4 - 15.2) and OS was 40.0% (95%CI, 36.4 - 44.1) at 5yr. In univariate analysis, age >70 (hazard ratio (HR) 1.78, [95%CI, 1.15 - 2.54], p=.008), failure to achieve remission following induction (HR, 8.96 [95%CI, 5.5 - 13.8], p=<.0001), no consolidation therapy (HR, 0.75 [95%CI, 0.47 - 1.84], p=.04) and less than 3 cycles of consolidation (HR, 1.48 [95%CI, 0.75 - 3.2], p=.0004), predicted poorer EFS. Our study shows that intensive therapy, in selected older CBF-AML patients, leads to longer survival. Achieving a CR seems to be the most important first step and at least 3 cycles of consolidation, an important second one. The analysis suggests that these patients should not be excluded from studies with intensive therapies.

NCCN Guidelines® Insights: Myelodysplastic Syndromes, Version 3.2022.

The NCCN Guidelines for Myelodysplastic Syndromes (MDS) provide recommendations for the evaluation, diagnosis, and management of patients with MDS based on a review of clinical evidence that has led to important advances in treatment or has yielded new information on biologic factors that may have prognostic significance in MDS. The multidisciplinary panel of MDS experts meets on an annual basis to update the recommendations. These NCCN Guidelines Insights focus on some of the updates for the 2022 version of the NCCN Guidelines, which include treatment recommendations both for lower-risk and higher-risk MDS, emerging therapies, supportive care recommendations, and genetic familial high-risk assessment for hereditary myeloid malignancy predisposition syndromes.

Prediction of Acute Graft versus Host Disease and Relapse by Endogenous Metabolomic Compounds in Patients Receiving Personalized Busulfan-Based Conditioning.

Busulfan-based conditioning is the most commonly used high-dose conditioning regimen for allogeneic hematopoietic cell transplant (HCT). The alkylating agent busulfan has a narrow therapeutic index, with busulfan doses personalized to a target plasma exposure (targeted busulfan). Using a global pharmacometabonomics approach, we sought to identify novel biomarkers of relapse or acute graft versus host disease (GVHD) in a cohort of 84 patients receiving targeted busulfan before allogeneic HCT. A total of 763 endogenous metabolomic compounds (EMCs) were quantitated in 230 longitudinal blood samples before, during, and shortly after intravenous busulfan administration. We performed both univariate linear regression and pathway enrichment analyses using global testing. The cysteine/methionine pathway and the glycine, serine, and threonine metabolism pathway were most associated with relapse. The latter be explained by the fact that glutathione S-transferases conjugate both busulfan and glutathione, which contains glycine as a component. The d-arginine and d-ornithine metabolism pathway and arginine and proline metabolism pathway were most associated with acute GVHD. None of these associations were significant after correcting for false discovery rate (FDR) with a strict cutoff of FDR-adjusted p < 0.1. Although larger studies are needed to substantiate these findings, the results show that EMCs may be used as predictive biomarkers in HCT patients.

Total body irradiation dose and risk of subsequent neoplasms following allogeneic hematopoietic cell transplantation.

We examined the impact of total body irradiation (TBI) dose and fractionation on risk of subsequent malignant neoplasms (SMNs) in the era of reduced-intensity and nonmyeloablative conditioning regimens for hematopoietic cell transplantation (HCT). Among 4905 1-year survivors of allogeneic HCT for hematologic malignancies (N = 4500) or nonmalignant disorders (N = 405) who received transplants between 1969 and 2014, we identified 581 SMNs (excluding squamous and basal cell of skin) in 499 individuals. With a median length of follow-up of 12.5 years, the cumulative incidence of SMNs by 30 years after HCT was 22.0%. Compared with age-, sex-, and calendar year-matched Surveillance, Epidemiology, and End Results (SEER) population rates, the standardized incidence ratio (SIR) of SMNs was increased 2.8-fold. The highest SIRs were for SMNs of bones (SIR, 28.8), oral cavity (SIR, 13.8), skin (SIR, 7.3), central nervous system (SIR, 6.0), and endocrine organs (SIR, 4.9). The highest excess absolute risks (EARs) were seen with breast cancer (EAR, 2.2) and cancers of the oral cavity (EAR, 1.5) and skin (EAR, 1.5) per 1000 person-years. The highest incidence of SMNs was in survivors exposed to unfractionated (600-1000 cGy) or high-dose fractionated (1440-1750 cGy) TBI. For patients receiving low-dose TBI, the incidence was comparable to myeloablative chemotherapy alone, although still twofold higher than in the general population. These data demonstrate a strong effect of TBI dose, dose fractionation, and risk of SMNs after HCT. The cumulative incidence of SMNs increases with follow-up time; thus, HCT survivors require lifetime monitoring for early detection and effective therapy of SMNs.

Survival, Nonrelapse Mortality, and Relapse-Related Mortality After Allogeneic Hematopoietic Cell Transplantation: Comparing 2003-2007 Versus 2013-2017 Cohorts.

Background: Allogeneic hematopoietic cell transplantation is indicated for refractory hematologic cancer and some nonmalignant disorders. Survival is limited by recurrent cancer and organ toxicity. Objective: To determine whether survival has improved over the past decade and note impediments to better outcomes. Design: The authors compared cohorts that had transplants during 2003 to 2007 versus 2013 to 2017. Survival outcome measures were analyzed, along with transplant-related complications. Setting: A center performing allogeneic transplant procedures. Participants: All recipients of a first allogeneic transplant during 2003 to 2007 and 2013 to 2017. Intervention: Patients received a conditioning regimen, infusion of donor hematopoietic cells, then immunosuppressive drugs and antimicrobial approaches to infection control. Measurements: Day-200 nonrelapse mortality (NRM), recurrence or progression of cancer, relapse-related mortality, and overall mortality, adjusted for comorbidity scores, source of donor cells, donor type, patient age, disease severity, conditioning regimen, patient and donor sex, and cytomegalovirus serostatus. Results: During the 2003-to-2007 and 2013-to-2017 periods, 1148 and 1131 patients, respectively, received their first transplant. Over the decade, decreases were seen in the adjusted hazards of day-200 NRM (hazard ratio [HR], 0.66 [95% CI, 0.48 to 0.89]), relapse of cancer (HR, 0.76 [CI, 0.61 to 0.94]), relapse-related mortality (HR, 0.69 [CI, 0.54 to 0.87]), and overall mortality (HR, 0.66 [CI, 0.56 to 0.78]). The degree of reduction in overall mortality was similar for patients who received myeloablative versus reduced-intensity conditioning, as well as for patients whose allograft came from a matched sibling versus an unrelated donor. Reductions were also seen in the frequency of jaundice, renal insufficiency, mechanical ventilation, high-level cytomegalovirus viremia, gram-negative bacteremia, invasive mold infection, acute and chronic graft-versus-host disease, and prednisone exposure. Limitation: Cohort studies cannot determine causality, and current disease severity criteria were not available for patients in the 2003-to-2007 cohort. Conclusion: Improvement in survival and reduction in complications were substantial after allogeneic transplant. Relapse of cancer remains the largest obstacle to better survival outcomes. Primary Funding Source: National Institutes of Health.

Individuals, Boundaries, and Graft-versus-Host Disease.

Hematopoietic cell transplantation generates new individuals, transplant chimeras, composed of 2 genetic partners-the patient and donor-derived cells-no longer restricted by their original genomes. Interactions of donor-derived and recipient cells occur prominently at the boundary of the recipient with a third partner, the microbiome, in particular skin and intestinal tract, leading to disruption of microbiome homeostasis. These interactions of donor and patient cells at the boundary set the stage for the development of graft-versus-host disease, an expression of the defense of individuality by recipient and donor. Establishment of tolerance and return of homeostasis at the boundary will allow for the survival of the new integrated, physiologic individual.

Early Mixed Lymphoid Donor/Host Chimerism is Associated with Improved Transplant Outcome in Patients with Primary or Secondary Myelofibrosis.

We investigated risk factors for the development of mixed chimerism in 131 patients who underwent transplantation for myelofibrosis and determined the impact of lymphoid (CD3+) and myeloid (CD33+) chimerism on transplant outcome. Disease risk included DIPSS plus categories low to high. The median patient age was 58 years. Patients were conditioned with high-intensity (myeloablative) or low/reduced-intensity (nonmyeloablative) regimens and received a transplant from a related or unrelated donor. Mixed CD3+ chimerism was observed earlier after HCT, whereas CD33+ chimerism occurred later. Mixed chimerism was more frequent with low-intensity regimens than with high- intensity regimens. Mixed CD3+ chimerism did not lead to graft failure and was associated with a reduced incidence of acute GVHD and improved overall survival (OS) and relapse-free survival, whereas mixed CD33+ chimerism was associated with an increased incidence of relapse and reduced OS and relapse-free survival, independent of the CD34+ cell dose transplanted. Thus, mixed CD3+ chimerism in patients with myelofibrosis had a favorable impact on transplantation outcome and does not require therapeutic interventions.

Targeted Sequencing Improves DIPSS-Plus Prognostic Scoring in Myelofibrosis Patients Undergoing Allogeneic Transplantation.

Primary myelofibrosis (MF) and secondary MF developing after polycythemia vera or essential thrombocythemia are clonal disorders of hematopoiesis. Currently the sole therapy offering the potential of cure is hematopoietic cell transplantation (HCT). Several risk classification systems including clinical, hematologic, and mutational parameters have been proposed. We analyzed the mutational landscape in addition to the Dynamic International Prognostic Scoring System (DIPSS)-plus in 55 patients with MF to determine the combined impact on post-HCT outcome. Mutations, analyzed in 75 genes, were most common in JAK2, CALR, ASXL1, TET2, GATA2, EZH2, U2AF1, and ETV6. Patients with ≥3 mutations in addition to JAK2 or CALR mutations had a higher post-transplantation relapse rate and nonrelapse mortality than patients with fewer mutations, independent of DIPSS-plus risk. The presence of higher numbers of mutations identified patients at the greatest risk of relapse within the highest overall risk group as determined by DIPSS-plus. These findings are consistent with molecular risk classifications for patients who do not undergo HCT and support the proposed transplantation risk classification incorporating mutational information.

Impact of clinical, cytogenetic, and molecular profiles on long-term survival after transplantation in patients with chronic myelomonocytic leukemia.

Chronic myelomonocytic leukemia (CMML) is a heterogeneous group of clonal hematopoietic malignancies with variable clinical and molecular features. We analyzed long-term results of allogeneic hematopoietic cell transplantation in patients with CMML and determined clinical and molecular risk factors associated with outcomes. Data from 129 patients, aged 7-74 (median 55) years, at various stages of the disease and transplanted from related or unrelated donors were analyzed. Using a panel of 75 genes somatic mutations present before hematopoietic cell transplantation were identified In 52 patients. The progression-free survival rate at 10 years was 29%. The major cause of death was relapse (32%), which was significantly associated with adverse cytogenetics (hazard ratio, 3.77; P=0.0002), CMML Prognostic Scoring System (hazard ratio, 14.3, P=0.01), and MD Anderson prognostic scores (hazard ratio, 9.4; P=0.005). Mortality was associated with high-risk cytogenetics (hazard ratio, 1.88; P=0.01) and high Hematopoietic Cell Transplantation Comorbidity Index (score ≥4: hazard ratio, 1.99; P=0.01). High overall mutation burden (≥10 mutations: hazard ratio, 3.4; P=0.02), and ≥4 mutated epigenetic regulatory genes (hazard ratio 5.4; P=0.003) were linked to relapse. Unsupervised clustering of the correlation matrix revealed distinct high-risk groups with unique associations of mutations and clinical features. CMML with a high mutation burden appeared to be distinct from high-risk groups defined by complex cytogenetics. New transplant strategies must be developed to target specific disease subgroups, stratified by molecular profiling and clinical risk factors.

Impact of Body Mass Index on Outcomes of Hematopoietic Stem Cell Transplantation in Adults.

This retrospective analysis of 2503 adult (age ≥20 years) allogeneic hematopoietic cell transplantation (HCT) recipients assessed the effect of body mass index (BMI) on transplantation outcomes. The median patient age was 51.7years. Patients with both nonmalignant and malignant diagnoses were included. Patients received either a myeloablative (52%) or a reduced-intensity (48%) conditioning regimen. Donors were either related (42%) or unrelated (58%). Cord blood recipients were excluded. Granulocyte colony-stimulating factor-mobilized peripheral blood cells were the stem cell source in 86% of transplantations. Graft-versus-host disease prophylaxis included at least 2 immunosuppressive agents, 1 of which was a calcineurin inhibitor. Patient groups were categorized as underweight, normal weight, overweight, obese, or very obese based on BMI. Endpoints included day +100 mortality, overall mortality, nonrelapse mortality (NRM), and relapse. Changes in nutritional status, based on laboratory parameters, were also examined. Underweight patients had significantly lower early and overall survival and greater NRM. Very obese patients had increased NRM, which was associated with the intensity of conditioning regimen. With long-term follow-up, increasing NRM was associated with both underweight and obese patients compared with normal-weight individuals. Changes in serum protein and albumin levels did not correlate with BMI. Although enteral nutrition is now recommended for some undernourished patients, the efficacy of enteral or parenteral nutrition has not been well studied. For obese patients, there are no guidelines regarding weight loss before transplantation, and acute weight loss in the pretransplantation period may be detrimental.

Allogeneic Hematopoietic Cell Transplantation in Patients Aged 50Years or Older with Severe Aplastic Anemia.

We report on 499 patients with severe aplastic anemia aged ≥ 50years who underwent hematopoietic cell transplantation (HCT) from HLA-matched sibling (n = 275, 55%) or HLA-matched (8/8) unrelated donors (n = 187, 37%) between 2005 and 2016. The median age at HCT was 57.8 years; 16% of patients were 65 to 77years old. Multivariable analysis confirmed higher mortality risks for patients with performance score less than 90% (hazard ratio [HR], 1.41; 95% confidence interval [CI], 1.03 to 1.92; P = .03) and after unrelated donor transplantation (HR, 1.47; 95% CI, 1 to 2.16; P = .05). The 3-year probabilities of survival for patients with performance scores of 90 to 100 and less than 90 after HLA-matched sibling transplant were 66% (range, 57% to 75%) and 57% (range, 47% to 76%), respectively. The corresponding probabilities after HLA-matched unrelated donor transplantation were 57% (range, 48% to 67%) and 48% (range, 36% to 59%). Age at transplantation was not associated with survival, but grades II to IV acute graft-versus-host disease (GVHD) risks were higher for patients aged 65years or older (subdistribution HR [sHR], 1.7; 95% confidence interval, 1.07 to 2.72; P = .026). Chronic GVHD was lower with the GVHD prophylaxis regimens calcineurin inhibitor (CNI) + methotrexate (sHR, .52; 95% CI, .33 to .81; P = .004) and CNI alone or with other agents (sHR, .27; 95% CI, .14 to .53; P < .001) compared with CNI + mycophenolate. Although donor availability is modifiable only to a limited extent, choice of GVHD prophylaxis and selection of patients with good performance scores are key for improved outcomes.

Allogeneic hematopoietic stem cell transplantation for MDS and CMML: recommendations from an international expert panel.

An international expert panel, active within the European Society for Blood and Marrow Transplantation, European LeukemiaNet, Blood and Marrow Transplant Clinical Trial Group, and the International Myelodysplastic Syndromes Foundation developed recommendations for allogeneic hematopoietic stem cell transplantation (HSCT) in myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML). Disease risks scored according to the revised International Prognostic Scoring System (IPSS-R) and presence of comorbidity graded according to the HCT Comorbidity Index (HCT-CI) were recognized as relevant clinical variables for HSCT eligibility. Fit patients with higher-risk IPSS-R and those with lower-risk IPSS-R with poor-risk genetic features, profound cytopenias, and high transfusion burden are candidates for HSCT. Patients with a very high MDS transplantation risk score, based on combination of advanced age, high HCT-CI, very poor-risk cytogenetic and molecular features, and high IPSS-R score have a low chance of cure with standard HSCT and consideration should be given to treating these patients in investigational studies. Cytoreductive therapy prior to HSCT is advised for patients with ≥10% bone marrow myeloblasts. Evidence from prospective randomized clinical trials does not provide support for specific recommendations on the optimal high intensity conditioning regimen. For patients with contraindications to high-intensity preparative regimens, reduced intensity conditioning should be considered. Optimal timing of HSCT requires careful evaluation of the available effective nontransplant strategies. Prophylactic donor lymphocyte infusion (DLI) strategies are recommended in patients at high risk of relapse after HSCT. Immune modulation by DLI strategies or second HSCT is advised if relapse occurs beyond 6 months after HSCT.

Total body irradiation dose escalation decreases risk of progression and graft rejection after hematopoietic cell transplantation for myelodysplastic syndromes or myeloproliferative neoplasms.

A non-myeloablative regimen of fludarabine and 200 cGy total body irradiation combined with post-grafting immunosuppression with mycophenolate mofetil and a calcineurin inhibitor facilitates allogeneic hematopoietic cell transplantation from HLA-matched related or unrelated donors in older patients and/or those with comorbidities. However, outcomes of prior studies have been disappointing in patients with myelodysplastic syndromes or myeloproliferative neoplasms due to high incidences of progression or graft failure (together termed hematopoietic cell transplantation-failure). We hypothesized that escalating the total body irradiation dose may improve the outcomes and subsequently performed a phase II total body irradiation dose-escalation trial. Patients with median age 66 years were enrolled in two arms to receive non-myeloablative conditioning followed by hematopoietic cell transplantation with total body irradiation dose escalation for excessive hematopoietic cell transplantation-failure: Arm A: myeloproliferative neoplasm/myelodysplastic syndrome low risk (n=36); and Arm B: myelodysplastic syndrome high-risk/chronic myelomonocytic leukemia (n=41). Total body irradiation dose levels were: Level-1 (300 cGy), Level-2 (400 cGy), or Level-3 (450 cGy). Patients received intravenous fludarabine 30 mg/m2 for three days. Total body irradiation was administered on day 0 followed by infusion of peripheral blood stem cells from HLA-matched related (n=30) or unrelated (n=47) donors. Post-grafting immunosuppression with mycophenolate mofetil and cyclosporine was administered. The primary end point was day 200 hematopoietic cell transplant failure, with the objective of reducing the incidence to <20%. The primary end point was reached on Arm A at dose Level-1 (300 cGy total body irradiation) with a cumulative incidence of day 200 hematopoietic cell transplant failure of 11%, and on Arm B at dose Level-3 (450 cGy) with a cumulative incidence of day 200 hematopoietic cell transplant failure of 9%. Increasing the total body irradiation dose leads to a higher success rate with non-myeloablative conditioning by reducing relapse and rejection. Further studies are necessary to decrease non-relapse mortality, especially among patients with high-risk disease. Trial registered under clinicaltrials.gov identifier: NCT00397813.

Transplant Decisions in Patients with Myelofibrosis: Should Mutations Be the Judge?

The prognosis of myeloproliferative neoplasms, including primary myelofibrosis (PMF), polycythemia vera, and essential thrombocythemia varies considerably, between these disorders as well as within each diagnosis. Molecular studies have identified "driver mutations" in JAK2, MPL1, and CALR and additional somatic DNA mutations, including ASXL1, EZH2, IDH1/2, and SRSF2, that affect prognosis differentially. Patients with mutations in CALR (type1) have a better outlook than patients with mutations in JAK2 or MPL, whereas patients without any of the driver mutations (triple negative) have the shortest life expectancy. Mutations in ASXL1, EZH2, and SRSF2 may be associated with shortened survival, and IDH mutations carry a higher risk of leukemic transformation. The combination and number of mutations are more important than a given single mutation. Mutations also appear to impact the outcome of hematopoietic cell transplantation (HCT), currently the only treatment with curative potential. Based on available data, the best post-HCT outcome is observed with CALR mutations. Triple negativity has a negative impact. The data on JAK2 are controversial. Mutations in ASXL1 or IDH1/2 reduce the probability of progression-free survival after HCT, although the impact of ASXL1 differs between patients with primary and secondary myelofibrosis. Although it is not clear to what extent HCT can overcome the risks associated with a given mutational pattern, at present, early HCT should be considered in triple-negative patients and patients with PMF who harbor mutations in ASXL1. Mutations in EZH2, SRSF2, or IDH, particularly if combined with other mutations, should also lead to consideration of HCT. Further studies are needed to validate the present observations and determine the impact of additional mutations that have been identified.

Hematopoietic Cell Transplantation for Myelofibrosis: the Dynamic International Prognostic Scoring System Plus Risk Predicts Post-Transplant Outcomes.

Hematopoietic cell transplantation (HCT) provides potentially curative treatment for patients with myelofibrosis (MF). HCT outcomes are associated with the Dynamic International Prognostic Scoring System (DIPSS) risk scores. In the present study we analyzed results in 233 patients to determine if the DIPSS plus classification, which adds cytogenetics, thrombocytopenia, and RBC transfusion dependence as risk factors, would better predict post-HCT outcomes than the original DIPSS. Multivariate analysis showed that each risk parameter incorporated into the DIPPS plus model contributed to its predictive power of overall mortality, relapse-free survival, and nonrelapse mortality. The 5-year overall survival (OS), relapse, and treatment-related mortality (TRM) rates for patients with low/intermediate-1 risk MF were 78%, 5%, and 20%, respectively. The 5-year OS, relapse, and TRM rates for patients with high-risk MF were 35%, 28%, and 40%, respectively. The HCT-specific comorbidity index of 3 or greater was associated with higher nonrelapse and overall mortality and reduced relapse-free survival. The relapse incidence was significantly increased in older patients (HR, 3.02; P = .0007). With a median follow-up of 8 years 124 patients (53%) were surviving. The components of the DIPSS plus classification still have prognostic relevance after adjustment by the DIPSS classification. This information should enhance our ability to advise patients when making decisions regarding timing of transplant.

Transplant Conditioning with Treosulfan/Fludarabine with or without Total Body Irradiation: A Randomized Phase II Trial in Patients with Myelodysplastic Syndrome and Acute Myeloid Leukemia.

In this prospective, randomized, phase II "pick the winner" trial we assessed the efficacy of transplant conditioning with treosulfan/fludarabine ± 2 Gy total body irradiation (TBI) in reducing post-transplant relapse in 100 patients, aged 2 to 70 years (median, 57), with myelodysplastic syndrome (MDS)/chronic myelomonocytic leukemia (n = 51) or acute myeloid leukemia (AML; n = 49). Patients received i.v. treosulfan, 14 g/m2/day on days -6 to -4 and i.v. fludarabine, 30 mg/m2/day on days -6 to -2, alone or combined with 2 Gy TBI (day 0). Donors were related (n = 43) or unrelated (n = 57). When a planned interim analysis showed superior progression-free survival in the TBI arm (P = .04), all subsequent patients received TBI. With a follow-up of 12 to 40 months (median, 20), the 1-year overall survival was 80% for the TBI arm and 69% for the non-TBI arm. The 1-year cumulative incidence of relapse was 22% and 34%, respectively (P = .06). Among patients with low-risk disease the 1-year relapse incidence was 15% and 31% (P = .20) and for patients with high-risk disease, 26% and 36% (P = .18), respectively. Among MDS patients the 1-year relapse incidence was 27% versus 33% (P = .49) and among AML patients 16% versus 35% (P = .05), respectively. The largest difference was among patients with unfavorable cytogenetics, with 1-year relapse incidences of 31% and 63% (P = .18), respectively. Nonrelapse mortality in this high-risk patient population was 9% at 6 months and did not differ between arms. Thus, treosulfan/fludarabine/low-dose TBI provided effective conditioning for allogeneic hematopoietic cell transplantation in high-risk patients up to 70 years of age. The addition of TBI had a more profound effect in patients with AML than in those with MDS. High-risk disease features were associated with a lower overall success rate. Further studies are warranted.