Prognostic stratification in venetoclax-based acute myeloid leukemia treatments: the molecular prognostic risk signature tested in a real-world setting.

Not available.

Chromosome 9p trisomy increases stem cells clonogenic potential and fosters T-cell exhaustion in JAK2-mutant myeloproliferative neoplasms.

JAK2V617F is the most recurrent genetic mutation in Philadelphia-negative chronic Myeloproliferative Neoplasms (MPNs). Since the JAK2 locus is located on Chromosome 9, we hypothesized that Chromosome 9 copy number abnormalities may be a disease modifier in JAK2V617F-mutant MPN patients. In this study, we identified a subset of MPN patients with partial or complete Chromosome 9 trisomy (+9p patients), who differ from JAK2V617F-homozygous MPN patients as they carry three JAK2 alleles as well as three copies of all neighboring gene loci, including CD274, encoding immunosuppressive Programmed death-ligand 1 (PD-L1) protein. Investigation of the clonal hierarchy revealed that the JAK2V617F occurs first, followed by +9p. Functionally, CD34+ cells from +9p MPN patients demonstrated increased clonogenicity, generating a greater number of primitive colonies, due to high OCT4 and NANOG expression, with knock-down of these genes leading to a genotype-specific decrease in colony numbers. Moreover, our analysis revealed increased PD-L1 surface expression in malignant monocytes from +9p patients, while analysis of the T cell compartment unveiled elevated levels of exhausted cytotoxic T cells. Overall, here we identify a distinct novel subgroup of MPN patients, who feature a synergistic interplay between +9p and JAK2V617F that shapes immune escape characteristics and increased stemness in CD34+ cells.

Proposals for Revised International Working Group-European LeukemiaNet Criteria for Anemia Response in Myelofibrosis.

With emerging new drugs in myelofibrosis (MF), a robust and harmonized framework for defining the severity of anemia and response to treatment will enhance clinical investigation and facilitate inter-study comparisons. Accordingly, the lead authors on the 2013 edition of the International Working Group-European LeukemiaNet (IWG-ELN) response criteria in MF were summoned to revise their document with the intent to i) account for gender-specific differences in determining hemoglobin levels for eligibility criteria, ii) revise definition of transfusion-dependent anemia (TDA) based on current restrictive transfusion practices, and iii) provide a structurally simple and easy to apply response criteria that are sensitive enough to detect efficacy signals (minor response) and also account for major responses. The initial draft of the 2024 IWG-ELN proposed criteria was subsequently circulated around a wider group of international experts and their feedback incorporated. The proposed articles include new definitions for TDA (≥3 units in the 12 weeks prior to study enrollment) and hemoglobin thresholds for eligibility criteria (<10 g/dL for women and <11 g/dL for men). The revised document also provides separate (TDA vs. non-TDA) and graded (major vs. minor response) response criteria while preserving the requirement for a 12-week period of screening and observation on treatment.

Targeting exhausted cytotoxic T cells through CTLA-4 inhibition promotes elimination of neoplastic cells in human myelofibrosis xenografts.

Myeloproliferative neoplasms represent a group of clonal hematopoietic disorders of which myelofibrosis (MF) is the most aggressive. In the context of myeloid neoplasms, there is a growing recognition of the dysregulation of immune response and T-cell function as significant contributors to disease progression and immune evasion. We investigated cytotoxic T-cell exhaustion in MF to restore immune response against malignant cells. Increased expression of inhibitory receptors like CTLA-4 was observed on cytotoxic T cells from MF patients together with a reduced secretion of IFNɣ and TNFɑ. CTLA-4 ligands CD80 and CD86 were increased on MF granulocytes and monocytes highlighting a possible role for myeloid cells in suppressing T-cell activation in MF patients. Unlike healthy donors, the activation of cytotoxic T cells from MF patients was attenuated in the presence of myeloid cells and restored when T cells were cultured alone or treated with anti-CTLA-4. Moreover, anti-CTLA-4 treatment promoted elimination of neoplastic monocytes and granulocytes in a co-culture system with cytotoxic T cells. To test CTLA-4 inhibition in vivo, patient-derived xenografts were generated by transplanting MF CD34+ cells and by infusing homologous T cells in NSGS mice. CTLA-4 blockade reduced human myeloid chimerism and led to T-cell expansion in spleen and bone marrow. Overall, these findings shed light on T-cell dysfunction in MF and suggest that CTLA-4 blockade can boost the cytotoxic T cell-mediated immune response against tumor cells.

Clinical impact of mutated JAK2 allele burden reduction in polycythemia vera and essential thrombocythemia.

The variant allele frequency (VAF) of driver mutations (JAK2, CALR) in myeloproliferative neoplasms is associated with features of advanced disease and complications. Ruxolitinib and interferon were reported to variably reduce the mutant VAF, but the long-term impact of molecular responses (MR) remains debated. We prospectively measured changes in JAK2 and CALR VAF in 77 patients with polycythemia vera and essential thrombocythemia, treated with ruxolitinib for a median of 8 years, and assessed correlation with complete clinical and hematological response (CCHR) and outcomes. At last observation time, JAK2 VAF reduced overall from a median of 68% (range, 20%-99%) to 3.5% (0%-98%). A profound and durable MR (DMR; defined as a VAF stably ≤2%), including complete MR in 8%, was achieved in 20% of the patients, a partial MR (PMR; VAF reduction >50% of the baseline level) in 25%, and 56% had no molecular response (NMR). A CCHR was reached by 69% overall, independently of any degree of MR achieved; conversely, a DMR correlated with longer duration of CCHR and, most importantly, with reduced rate of progression to myelofibrosis and with longer myelofibrosis-free, event-free and progression-free survival. Achievement of PMR also had some favorable impact on outcomes, compared to NMR. A baseline JAK2 VAF <50%, and a VAF reduction of ≥35% after 2 years of treatment, predicted for the achievement of DMR and reduced progression to myelofibrosis. Overall, these findings support the clinical value of achieving profound, durable MR and its consideration as surrogate endpoint in future clinical trials.

Validation and molecular integration of the RR6 model to predict survival after 6 months of therapy with ruxolitinib.

Not available.

ROP-ET: a prospective phase III trial investigating the efficacy and safety of ropeginterferon alfa-2b in essential thrombocythemia patients with limited treatment options.

Interferon-based therapies, such as ropeginterferon alfa-2b have emerged as promising disease-modifying agents for myeloproliferative neoplasms (MPNs), including essential thrombocythemia (ET). Current ET treatments aim to normalize hematological parameters and reduce the thrombotic risk, but they do not modify the natural history of the disease and hence, have no impact on disease progression. Ropeginterferon alfa-2b (trade name BESREMi®), a novel, monopegylated interferon alfa-2b with an extended administration interval, has demonstrated a robust and sustained efficacy in polycythemia vera (PV) patients. Given the similarities in disease pathophysiology and treatment goals, ropeginterferon alfa-2b holds promise as a treatment option for ET. The ROP-ET trial is a prospective, multicenter, single-arm phase III study that includes patients with ET who are intolerant or resistant to, and/or are ineligible for current therapies, such as hydroxyurea (HU), anagrelide (ANA), busulfan (BUS) and pipobroman, leaving these patients with limited treatment options. The primary endpoint is a composite response of hematologic parameters and disease-related symptoms, according to modified European LeukemiaNet (ELN) criteria. Secondary endpoints include improvements in symptoms and quality of life, molecular response and the safety profile of ropeginterferon alfa-2b. Over a 3-year period the trial assesses longer term outcomes, particularly the effects on allele burden and clinical outcomes, such as disease-related symptoms, vascular events and disease progression. No prospective clinical trial data exist for ropeginterferon alfa-2b in the planned ET study population and this study will provide new findings that may contribute to advancing the treatment landscape for ET patients with limited alternatives. TRIAL REGISTRATION: EU Clinical Trials Register; EudraCT, 2023-505160-12-00; Registered on October 30, 2023.

One thousand patients with essential thrombocythemia: the Florence-CRIMM experience.

We describe 1000 patients with essential thrombocythemia seen at the Center Research and Innovation of Myeloproliferative Neoplasms (CRIMM), Florence, Italy, between 1980 and 2023: median age 59 years (18-95), females 65%, JAK2/CALR/MPL-mutated 66%/19%/4%, triple-negative (TN) 11%. Extreme thrombocytosis (ExT, platelets ≥1000 × 109/L) in 16%, leukocytosis (leukocytes >11 × 109/L) in 16%, and at least one cardiovascular risk factor in 52% of cases. JAK2-mutated patients were older (median 62 years) and CALR-mutated and TN (53 years for both) younger (p < 0.001). Female gender clustered with TN (76%) and JAK2 (67%) vs CALR (46%) mutations (p < 0.001). ExT clustered with CALR (type-2 more than type-1), TN and MPL, and leukocytosis with JAK2 mutation (p < 0.001). In multivariable analysis, risk factors for arterial thrombosis-free survival were age ≥60 years (HR 2.0; p < 0.001) and JAK2 mutation (HR 1.3; p = 0.02) with borderline significance for male gender (p = 0.08) and cardiovascular risk factors (p = 0.08); for venous thrombosis-free survival, JAK2 mutation (HR 1.9; p = 0.03) with borderline significance for venous thrombosis history (p = 0.07); for overall survival, older age (p < 0.001), male gender (HR 1.9; p < 0.001), absolute neutrophil count (ANC) ≥ 8 × 109/L (HR 1.8; p = 0.01), absolute lymphocyte count (ALC) < 1.7 × 109/L (HR 1.2; p = 0.03); for myelofibrosis-free survival, CALR mutation (HR 2.7; p < 0.001, particularly for CALR type 1/1-like, HR 3.3) and MPL mutation (HR 3.9; p = 0.001); for leukemia-free survival, older age (p = 0.03). Cytoreductive therapy appeared to mitigate both venous (HR 0.3; p = 0.01) and arterial thrombosis (HR 4; p = 0.04); there was a trend for aspirin in preventing arterial thrombosis recurrence. The current study provides real-world observations in essential thrombocythemia, representing a valid source document for interpreting current literature and planning future studies.

Inherited polygenic effects on common hematological traits influence clonal selection on JAK2V617F and the development of myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPNs) are chronic cancers characterized by overproduction of mature blood cells. Their causative somatic mutations, for example, JAK2V617F, are common in the population, yet only a minority of carriers develop MPN. Here we show that the inherited polygenic loci that underlie common hematological traits influence JAK2V617F clonal expansion. We identify polygenic risk scores (PGSs) for monocyte count and plateletcrit as new risk factors for JAK2V617F positivity. PGSs for several hematological traits influenced the risk of different MPN subtypes, with low PGSs for two platelet traits also showing protective effects in JAK2V617F carriers, making them two to three times less likely to have essential thrombocythemia than carriers with high PGSs. We observed that extreme hematological PGSs may contribute to an MPN diagnosis in the absence of somatic driver mutations. Our study showcases how polygenic backgrounds underlying common hematological traits influence both clonal selection on somatic mutations and the subsequent phenotype of cancer.

CALR mutation burden in essential thrombocythemia and disease outcome.

ABSTRACT: Among 281 patients with essential thrombocythemia and calreticulin (CALR) mutation, we found a variant allele frequency of ≥60% to be associated with significantly shortened myelofibrosis-free survival, mostly apparent with CALR type-1 and CALR type-indeterminate mutations.

The prognostic contribution of CBL, NRAS, KRAS, RUNX1, and TP53 mutations to mutation-enhanced international prognostic score systems (MIPSS70/plus/plus v2.0) for primary myelofibrosis.

Contemporary risk models in primary myelofibrosis (PMF) include the mutation (MIPSS70) and mutation/karyotype enhanced (MIPSS70 plus/v2.0) international prognostic scoring systems. High molecular risk (HMR) mutations incorporated in one or both of these models include ASXL1, SRSF2, EZH2, IDH1/2, and U2AF1Q157; the current study examines additional prognostic contribution from more recently described HMR mutations, including CBL, NRAS, KRAS, RUNX1, and TP53. In a cohort of 363 informative cases (median age 58 years; 60% males), mutations included JAK2 61%, CALR 24%, MPL 6%, ASXL1 29%, SRSF2 10%, U2AF1Q157 5%, EZH2 10%, IDH1/2 4%, TP53 5%, CBL 5%, NRAS 7%, KRAS 4%, and RUNX1 4%. At a median follow-up of 4.6 years, 135 (37%) deaths and 42 (11.6%) leukemic transformations were recorded. Univariate analysis confirmed significant survival impact from the original MIPSS70/plus/v2.0 HMR mutations as well as CBL (HR 2.8; p < .001), NRAS (HR 2.4; p < .001), KRAS (HR 2.1; p = .01), and TP53 (HR 2.4; p = .004), but not RUNX1 mutations (HR 1.8; p = .08). Multivariate analysis (MVA) that included both the original and more recently described HMR mutations confirmed independent prognostic contribution from ASXL1 (HR 1.8; p = .007), SRSF2 (HR 4.3; p < .001), U2AF1Q157 (HR 2.9, p = .004), and EZH2 (HR 2.4; p < .001), but not from IDH1/2 (p = .3), TP53 (p = .2), CBL (p = .3), NRAS (p = .8) or KRAS (p = .2) mutations. The lack of additional prognostic value from CBL, NRAS, KRAS, RUNX1, and TP53 was further demonstrated in the setting of (i) MVA of mutations and karyotype, (ii) MVA of MIPSS70/plus/v2.0 composite scores and each one of the recently described HMR mutations, except TP53, and iii) modified MIPSS70/plus/plus v2.0 that included CBL, NRAS, KRAS, and TP53 as part of the HMR constituency, operationally referred to as "HMR+" category. Furthermore, "HMR+" enhancement of MIPSS70/plus/plus v2.0 did not result in improved model performance, as measured by C-statistics. We conclude that prognostic integrity of MIPSS70/plus/plus v2.0, as well as their genetic components, was sustained and their value not significantly upgraded by the inclusion of more recently described HMR mutations, including CBL, NRAS, KRAS, and RUNX1. Additional studies are needed to clarify the apparent additional prognostic value of TP53 mutation and its allelic state.

Functional relevance of circRNA aberrant expression in pediatric acute leukemia with KMT2A::AFF1 fusion.

ABSTRACT: Circular RNAs (circRNAs) are emerging molecular players in leukemogenesis and promising therapeutic targets. In KMT2A::AFF1 (MLL::AF4)-rearranged leukemia, an aggressive disease compared with other pediatric B-cell precursor (BCP) acute lymphoblastic leukemia (ALL), data about circRNAs are limited. Here, we disclose the circRNA landscape of infant patients with KMT2A::AFF1 translocated BCP-ALL showing dysregulated, mostly ectopically expressed, circRNAs in leukemia cells. Most of these circRNAs, apart from circHIPK3 and circZNF609, previously associated with oncogenic behavior in ALL, are still uncharacterized. An in vitro loss-of-function screening identified an oncogenic role of circFKBP5, circKLHL2, circNR3C1, and circPAN3 in KMT2A::AFF1 ALL, whose silencing affected cell proliferation and apoptosis. Further study in an extended cohort disclosed a significantly correlated expression of these oncogenic circRNAs and their putative involvement in common regulatory networks. Moreover, it showed that circAFF1 upregulation occurs in a subset of cases with HOXA KMT2A::AFF1 ALL. Collectively, functional analyses and patient data reveal oncogenic circRNA upregulation as a relevant mechanism that sustains the malignant cell phenotype in KMT2A::AFF1 ALL.

Ropeginterferon phase 2 randomized study in low-risk polycythemia vera: 5-year drug survival and efficacy outcomes.

In patients with low-risk polycythemia vera, exposure to low-dose Ropeginterferon alfa-2b (Ropeg) 100 µg every 2 weeks for 2 years was more effective than the standard treatment of therapeutic phlebotomy in maintaining target hematocrit (HCT) (< 45%) with a reduction in the need for phlebotomy without disease progression. In the present paper, we analyzed drug survival, defined as a surrogate measure of the efficacy, safety, adherence, and tolerability of Ropeg in patients followed up to 5 years. During the first 2 years, Ropeg and phlebotomy-only (Phl-O) were discontinued in 33% and 70% of patients, respectively, for lack of response (12 in the Ropeg arm vs. 34 in the Phl-O arm) or adverse events (6 vs. 0) and withdrawal of consent in (3 vs. 10). Thirty-six Ropeg responders continued the drug for up to 3 years, and the probability of drug survival after a median of 3.15 years was 59%. Notably, the primary composite endpoint was maintained in 97%, 94%, and 94% of patients still on drug at 3, 4, and 5 years, respectively, and 60% of cases were phlebotomy-free. Twenty-three of 63 Phl-O patients (37%) failed the primary endpoint and were crossed over to Ropeg; among the risk factors for this failure, the need for more than three bloodletting procedures in the first 6 months emerged as the most important determinant. In conclusion, to improve the effectiveness of Ropeg, we suggest increasing the dose and using it earlier driven by high phlebotomy need in the first 6 months post-diagnosis.

Effect of age and treatment on predictive value of measurable residual disease: implications for clinical management of adult patients with acute myeloid leukemia.

Measurable residual disease (MRD) is a powerful predictor of outcome in acute myeloid leukemia. In the early phases of treatment, MRD refines initial disease risk stratification and is used for the allocation to allogeneic transplant. Despite its well-established role, a relatively high fraction of patients eventually relapses albeit achieving MRDneg status. The aim of this work was to assess specifically the influence of baseline features and treatment intensity on the predictive value of an MRDneg status, particularly focusing on MRD2, measured after two consecutive chemotherapy cycles. Among baseline features, younger MRD2neg patients (<55 years) had a significantly longer disease-free survival (median not reached) compared to their older counterparts (median 25.0 months, P=0.013, hazard ratio=2.08). Treatment intensity, specifically the delivery of a high dose of cytarabine in induction or first consolidation, apparently had a pejorative effect on the outcome of MRD2neg patients compared to standard dose (P=0.048, hazard ratio=1.80), a finding also confirmed by the analysis of data extracted from the literature. The combination of age and treatment intensity allowed us to identify categories of patients, among those who reached a MRD2neg status, characterized by significantly different disease-free survival rate. Our data showed that variables such as age and intensity of treatment administered can influence the predictive value of MRD in patients with acute myeloid leukemia. In addition to underscoring the need for further improvement of MRD analysis, these findings call for a reasoned application of MRD data, as currently available, to modulate consolidation therapy on adequately estimated relapse rates.

A safety evaluation of ruxolitinib for the treatment of polycythemia vera.

INTRODUCTION: Polycythemia Vera (PV) is a chronic myeloproliferative neoplasm hallmarked by deregulated proliferation of hematopoietic stem cells leading to prevalent expansion of red cell mass, increased rate of vascular events, splenomegaly, disease-associated symptoms, and risk of evolution to secondary myelofibrosis and blast phase. PV is pathogenetically associated with autonomously persistent activation of JAK2, which causes overproduction of blood cells and an inflammatory condition responsible for the clinical manifestations of the disease. Extensively supported by preclinical studies, targeting JAK2-dependent signaling represents a rational therapeutic approach to PV, finally leading to the approval of ruxolitinib, a JAK1/2 inhibitor. AREAS COVERED (LITERATURE RESEARCH): We analyzed reports of phase 2 and phase 3 trials with ruxolitinib in PV and relevant literature dealing with efficacy and safety aspects, including most recent real-world reports. EXPERT OPINION: Ruxolitinib is the only JAK2 inhibitor approved for the treatment of PV with well-known efficacy for splenomegaly, symptoms, and potentially reduction of vascular events. The treatment regimen is notably manageable and safe, with the most prevalent side effects primarily encompassing myelosuppression, hyperlipidemia, non-melanoma skin cancer and infections, mainly reactivation of Herpes Zoster. These effects necessitate ongoing surveillance and proactive preventive measures.

The clinical experience of compassionate use program for avapritinib: implications for drug positioning in the therapeutic scenario of systemic mastocytosis.

In systemic mastocytosis, cytoreductive treatment is indicated for advanced systemic mastocytosis (AdvSM) variants. The treatment scenario is rapidly diversifying especially with the introduction of KIT tyrosine kinase inhibitors. Avapritinib is a second-generation potent and selective inhibitor of the mutant KIT D816V that, based on the results of pivotal clinical trials, was approved for the treatment of adults with AdvSM by the regulatory agencies US FDA and EMA. The present article reports the experience of treating SM patients with avapritinib in an Italian compassionate use program. The data from our case series confirm the drug as being active after multiple lines of treatment allowing rapid achievement of profound responses, making it also an effective bridging strategy to allogeneic transplant in eligible patients. However, the anticipated wider use of avapritinib in the near future will require careful monitoring of side effects, especially in heavily pretreated patients.

A globally applicable "triple A" risk model for essential thrombocythemia based on Age, Absolute neutrophil count, and Absolute lymphocyte count.

We examined the individual prognostic contribution of absolute neutrophil (ANC), lymphocyte (ALC), and monocyte (AMC) counts, on overall (OS), leukemia-free (LFS), and myelofibrosis-free (MFFS) survival in essential thrombocythemia (ET). Informative cases (N = 598; median age 59 years; females 62%) were retrospectively accrued from a Mayo Clinic database: JAK2 59%, CALR 27%, triple-negative 11%, and MPL 3%; international prognostic scoring system for ET (IPSET) risk high 21%, intermediate 42%, and low 37%; 7% (37/515) had abnormal karyotype and 10% (21/205) adverse mutations (SF3B1/SRSF2/U2AF1/TP53). At median 8.4 years, 163 (27%) deaths, 71 (12%) fibrotic, and 20 (3%) leukemic transformations were recorded. Multivariable analysis resulted in HR (95% CI) of 16.5 (9.9-27.4) for age > 70 years, 3.7 (2.3-6.0) for age 50-70 years, 2.4 (1.7-3.3) for ANC ≥8 × 109 /L, and 1.9 (1.4-2.6) for ALC <1.7 × 109 /L. The corresponding HR-based scores were 4, 2, 1, and 1, resulting in an new 4-tiered AgeAncAlc (AAA; triple A) risk model: high (5-6 points; median survival 8 years; HR 30.1, 95% CI 17.6-54), intermediate-2 (4 points; median 13.5 years; HR 12.7, 95% CI 7.1-23.0), intermediate-1 (2-3 points; median 20.7 years; HR 3.8, 95% CI 2.3-6.4) and low (0-1 points; median 47 years). The AAA model (Akaike Information Criterion [AIC] 621) performed better than IPSET (AIC 647) and was subsequently validated by an external University of Florence ET cohort (N = 485). None of the AAA variables predicted LFS while ALC <1.7 × 109 /L was associated with inferior MFFS (p = .01). Adverse mutations (p < .01) and karyotype (p < .01) displayed additional prognostic value without disqualifying the prognostic integrity of the AAA model. This study proposes a simple and globally applicable survival model for ET, which can be used as a platform for further molecular refinement. This study also suggests a potential role for immune-related biomarkers, as a prognostic tool in myeloproliferative neoplasms.

Incidence of blast phase in myelofibrosis according to anemia severity.

Myelofibrosis (MF) is a clonal malignancy frequently characterized by anemia and in 10%-20% of cases it can evolve into blast phase (BP). Anemia in MF is associated with reduced survival and -in primary MF- also with an increased probability of BP. Conventional treatments for anemia have limited effectiveness in MF. Within a dataset of 1752 MF subjects largely unexposed to ruxolitinib (RUX), BP incidence was 2.5% patients per year (p-y). This rate reached respectively 4.3% and 4.5% p-y in case of patients with common terminology criteria for adverse events (CTCAE) grade 3/4 and grade 2 anemia, respectively, that represented together 32% of the cohort. Among 273 MF cases treated with RUX, BP incidence was 2.89% p-y and it reached 4.86% p-y in subjects who started RUX with CTCAE grade 2 anemia (one third of total). Within patients with red blood cell transfusion-dependency at 6 months of RUX (21% of the exposed), BP rate was 4.2% p-y. Our study highlights a relevant incidence of BP in anemic MF patients, with a similar rate whether treated with or without RUX. These findings will help treating physicians to make decisions on the safety profile of innovative anemia treatments.