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.

Renal outcome in multiple myeloma patients with cast nephropathy: a retrospective analysis of potential predictive values on clinical and renal outcome.

OBJECTIVE: Cast nephropathy (CN) is the leading cause of acute kidney injury (AKI) in multiple myeloma (MM). Since it is sparsely documented why some patients with CN do achieve a renal response while others do not, we describe a single-center cohort of patients with multiple myeloma and biopsy-confirmed CN to evaluate potential markers of renal response. METHODS: The data was collected as a retrospective, single-center analysis of CN-patients treated at the Medical University Vienna between 01/01/2004 and 01/01/2022. Baseline parameters and clinical outcome was compared between renal responders and non-responders. RESULTS: Among 28 patients with CN, n = 23 were assessed for renal response (14 responders; 9 non-responders). Renal responders were younger (median age: 61 years; 77 years, p = 0.039), showed higher overall survival (153months; 58months, p = 0.044) and achieved hematologic response (≥PR) to first-line therapy (p = 0.029), and complete hematologic response (CR) at any time (p = 0.025) significantly more often. Further, we could show that rapid initiation of anti-myeloma therapy after initial presentation correlated significantly with renal response (median 9 days; 27 days, p = 0.016). Analyses of kidney biopsy specimens revealed that patients with a high IF/TA score showed end stage renal disease (dialysis ≥ 3 months) significantly more often (p = <0.001). DISCUSSION: In summary, our data suggests, that a rapid start with systemic hematologic treatment in patients with MM and CN is crucial and achieving an early hematologic response is important for renal recovery. Moreover, achieving a deep hematologic response and subsequent renal recovery improves clinical outcome as reflected by an overall survival benefit.

Ruxolitinib in patients with polycythemia vera resistant and/or intolerant to hydroxyurea: European observational study.

BACKGROUND: Hydroxyurea (HU) is a commonly used first-line treatment in patients with polycythemia vera (PV). However, approximately 15%-24% of PV patients report intolerance and resistance to HU. METHODS: This phase IV, European, real-world, observational study assessed the efficacy and safety of ruxolitinib in PV patients who were resistant and/or intolerant to HU, with a 24-month follow-up. The primary objective was to describe the profile and disease burden of PV patients. RESULTS: In the 350 enrolled patients, 70% were >60 years old. Most patients (59.4%) had received ≥1 phlebotomy in the 12 months prior to the first dose of ruxolitinib. Overall, 68.2% of patients achieved hematocrit control with 92.3% patients having hematocrit <45% and 35.4% achieved hematologic remission at month 24. 85.1% of patients had no phlebotomies during the study. Treatment-related adverse events were reported in 54.3% of patients and the most common event was anemia (22.6%). Of the 10 reported deaths, two were suspected to be study drug-related. CONCLUSION: This study demonstrates that ruxolitinib treatment in PV maintains durable hematocrit control with a decrease in the number of phlebotomies in the majority of patients and was generally well tolerated.

Change in Polycythemia Vera Treatment: Ropeginterferon Alfa-2b in Light of Current Trials

Ropeginterferon alfa-2b (RopegIFN) enables effective cytoreduction in polycythemia vera (PV). Recent analyses suggest that long-term RopegIFN therapy fulfills treatment goals important to patients with PV including good quality of life, the slowing of disease progression, and long event-free survival. Data support the use of RopegIFN in both early PV therapy and second-line and beyond.

Phenotypic characterization of disease-initiating stem cells in JAK2- or CALR-mutated myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPN) are characterized by uncontrolled expansion of myeloid cells, disease-related mutations in certain driver-genes including JAK2, CALR, and MPL, and a substantial risk to progress to secondary acute myeloid leukemia (sAML). Although behaving as stem cell neoplasms, little is known about disease-initiating stem cells in MPN. We established the phenotype of putative CD34+ /CD38- stem cells and CD34+ /CD38+ progenitor cells in MPN. A total of 111 patients with MPN suffering from polycythemia vera, essential thrombocythemia, or primary myelofibrosis (PMF) were examined. In almost all patients tested, CD34+ /CD38- stem cells expressed CD33, CD44, CD47, CD52, CD97, CD99, CD105, CD117, CD123, CD133, CD184, CD243, and CD274 (PD-L1). In patients with PMF, MPN stem cells often expressed CD25 and sometimes also CD26 in an aberrant manner. MPN stem cells did not exhibit substantial amounts of CD90, CD273 (PD-L2), CD279 (PD-1), CD366 (TIM-3), CD371 (CLL-1), or IL-1RAP. The phenotype of CD34+ /CD38- stem cells did not change profoundly during progression to sAML. The disease-initiating capacity of putative MPN stem cells was confirmed in NSGS mice. Whereas CD34+ /CD38- MPN cells engrafted in NSGS mice, no substantial engraftment was produced by CD34+ /CD38+ or CD34- cells. The JAK2-targeting drug fedratinib and the BRD4 degrader dBET6 induced apoptosis and suppressed proliferation in MPN stem cells. Together, MPN stem cells display a unique phenotype, including cytokine receptors, immune checkpoint molecules, and other clinically relevant target antigens. Phenotypic characterization of neoplastic stem cells in MPN and sAML should facilitate their enrichment and the development of stem cell-eradicating (curative) therapies.

Secreted mutant calreticulins as rogue cytokines in myeloproliferative neoplasms.

Mutant calreticulin (CALR) proteins resulting from a -1/+2 frameshifting mutation of the CALR exon 9 carry a novel C-terminal amino acid sequence and drive the development of myeloproliferative neoplasms (MPNs). Mutant CALRs were shown to interact with and activate the thrombopoietin receptor (TpoR/MPL) in the same cell. We report that mutant CALR proteins are secreted and can be found in patient plasma at levels up to 160 ng/mL, with a mean of 25.64 ng/mL. Plasma mutant CALR is found in complex with soluble transferrin receptor 1 (sTFR1) that acts as a carrier protein and increases mutant CALR half-life. Recombinant mutant CALR proteins bound and activated the TpoR in cell lines and primary megakaryocytic progenitors from patients with mutated CALR in which they drive thrombopoietin-independent colony formation. Importantly, the CALR-sTFR1 complex remains functional for TpoR activation. By bioluminescence resonance energy transfer assay, we show that mutant CALR proteins produced in 1 cell can specifically interact in trans with the TpoR on a target cell. In comparison with cells that only carry TpoR, cells that carry both TpoR and mutant CALR are hypersensitive to exogenous mutant CALR proteins and respond to levels of mutant CALR proteins similar to those in patient plasma. This is consistent with CALR-mutated cells that expose TpoR carrying immature N-linked sugars at the cell surface. Thus, secreted mutant CALR proteins will act more specifically on the MPN clone. In conclusion, a chaperone, CALR, can turn into a rogue cytokine through somatic mutation of its encoding gene.

Efficacy and safety of ruxolitinib in patients with myelofibrosis and low platelet count (50 × 109/L to <100 × 109/L) at baseline: the final analysis of EXPAND.

Background: Thrombocytopenia is a common feature of myelofibrosis (MF), a myeloproliferative neoplasm driven by dysregulated JAK/STAT signaling; however, pivotal trials assessing the efficacy of ruxolitinib (a JAK1/2 inhibitor) excluded MF patients with low platelet counts (<100 × 109/L). Objectives: Determination of the maximum safe starting dose (MSSD) of ruxolitinib was the primary endpoint, with long-term safety and efficacy as secondary and exploratory endpoints, respectively. Design: EXPAND (NCT01317875) was a phase 1b, open-label, ruxolitinib dose-finding study in patients with MF and low platelet counts (50 to <100 × 109/L). Methods: Patients were stratified according to baseline platelet count into stratum 1 (S1, 75 to <100 × 109/L) or stratum 2 (S2, 50 to <75 × 109/L). Previous analyses established the MSSD at 10 mg twice daily (bid); long-term results are reported here. Results: Of 69 enrolled patients, 38 received ruxolitinib at the MSSD (S1, n = 20; S2, n = 18) and are the focus of this analysis. The incidence of adverse events was consistent with the known safety profile of ruxolitinib, with thrombocytopenia (S1, 50%; S2, 78%) and anemia (S1, 55%; S2, 44%) the most frequently reported adverse events and no new or unexpected safety signals. Substantial clinical benefits were observed for patients in both strata: 50% (10/20) and 67% (12/18) of patients in S1 and S2, respectively, achieved a spleen response (defined as ⩾50% reduction in spleen length from baseline) at any time during the study. Conclusion: The final safety and efficacy results from EXPAND support the use of a 10 mg bid starting dose of ruxolitinib in patients with MF and platelet counts 50 to <100 × 109/L. Registration: ClinicalTrials.gov NCT01317875.

The cancer survival index-A prognostic score integrating psychosocial and biological factors in patients diagnosed with cancer or haematologic malignancies.

OBJECTIVE: We aimed to investigate whether (1) psychological and social indicators influence survival in patients diagnosed with cancer or haematologic malignancies when important biological aspects are controlled for, (2) psychological, social and biological indicators can be utilised to design one collated index for survival, usable in clinical practice to identify patients at risk of shorter survival and to improve personalised healthcare provision. METHODS: In this cross-sectional study, 2263 patients with cancer or haematologic malignancies participated. We analysed 15 biological, psychological and social indicators as risk factors for survival with a Cox proportional hazards model. Indicators significantly associated with survival were combined to compute models for the identification of patient groups with different risks of death. The training sample contained 1122 patients. Validation samples included the remaining 1141 patients, the total sample, as well as groups with different cancer entities. RESULTS: Five indicators were found to significantly impact survival: Cancer site (HR: 3.56), metastatic disease (HR: 1.88), symptoms of depression (HR: 1.34), female sex (HR: 0.73) and anaemia (HR: 0.48). Combining these indicators to a model, we developed the Cancer Survival Index, identifying three distinct groups of patients with estimated survival times of 47.2 months, 141 months and 198.2 months (p < 0.001). Post hoc analysis of the influence of depression on survival showed a mediating effect of the following four factors, related to both depression and survival: previous psychiatric conditions, employment status, metastatic disease and haemoglobin levels. CONCLUSIONS: Psychosocial and biological factors impact survival in various malignancies and can be utilised jointly to compute an index for estimating the survival of each patient individually-the Cancer Survival Index.

Appropriate management of polycythaemia vera with cytoreductive drug therapy: European LeukemiaNet 2021 recommendations.

Polycythaemia vera is associated with a reduced quality of life, a high rate of vascular events, and an intrinsic risk of disease evolution. The results of several randomised trials for the treatment of this disorder are now available, and both a new ropegylated formulation of interferon alfa-2b (ropeginterferon alfa-2b; 2018) and ruxolitinib (2015) have been approved in Europe. European LeukemiaNet (ELN) investigators have therefore deemed it appropriate to provide recommendations for the use of these drugs in clinical practice. An expert panel of 14 senior haematologists from ELN centres that had actively participated in previous ELN projects or relevant randomised trials, chaired by a member of the ELN Steering Committee, developed a list of clinical questions, and a methodologist established three patient, intervention, comparator, outcome (PICO) questions and systematically reviewed the evidence. Recommendations were approved by six Delphi consensus rounds and two virtual meetings (on Jan 26, 2021, and June 24, 2021). The expert panel recommended that patients with polycythaemia vera who are younger than 60 years and have not had previous thrombotic events should start cytoreductive drug therapy if at least one of the following criteria are fulfilled: strictly defined intolerance to phlebotomy, symptomatic progressive splenomegaly, persistent leukocytosis (>15 × 109 white blood cells per L), progressive leukocytosis (at least 100% increase if baseline count is <10 × 109 cells per L or at least 50% increase if baseline count is >10 × 109 cells per L), extreme thrombocytosis (>1500 × 109 platelets per L), inadequate haematocrit control requiring phlebotomies, persistently high cardiovascular risk, and persistently high symptom burden. Recombinant interferon alfa, either in the form of ropeginterferon alfa-2b or pegylated interferon alfa-2a, is the recommended cytoreductive treatment for these patients. The expert panel suggested that either interferon alfa or ruxolitinib should be considered for patients who are being treated with hydroxyurea but require a therapy change.

PD-L1 overexpression correlates with JAK2-V617F mutational burden and is associated with 9p uniparental disomy in myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPN) are chronic stem cell disorders characterized by enhanced proliferation of myeloid cells, immune deregulation, and drug resistance. JAK2 somatic mutations drive the disease in 50-60% and CALR mutations in 25-30% of cases. Published data suggest that JAK2-V617F-mutated MPN cells express the resistance-related checkpoint PD-L1. By applying RNA-sequencing on granulocytes of 113 MPN patients, we demonstrate that PD-L1 expression is highest among polycythemia vera patients and that PD-L1 expression correlates with JAK2-V617F mutational burden (R = 0.52; p < .0001). Single nucleotide polymorphism (SNP) arrays showed that chromosome 9p uniparental disomy (UPD) covers both PD-L1 and JAK2 in all MPN patients examined. MPN cells in JAK2-V617F-positive patients expressed higher levels of PD-L1 if 9p UPD was present compared to when it was absent (p < .0001). Moreover, haplotype-based association analyses provided evidence for germline genetic factors at PD-L1 locus contributing to MPN susceptibility independently of the previously described GGCC risk haplotype. We also found that PD-L1 is highly expressed on putative CD34+ CD38- disease-initiating neoplastic stem cells (NSC) in both JAK2 and CALR-mutated MPN. PD-L1 overexpression decreased upon exposure to JAK2 blockers and BRD4-targeting agents, suggesting a role for JAK2-STAT5-signaling and BRD4 in PD-L1 expression. Whether targeting of PD-L1 can overcome NSC resistance in MPN remains to be elucidated in forthcoming studies.

Inflammation-Based Scores as a Common Tool for Prognostic Assessment in Heart Failure or Cancer.

Background: Inflammation-based scores are widely tested in cancer and have been evaluated in cardiovascular diseases including heart failure. Objectives: We investigated the impact of established inflammation-based scores on disease severity and survival in patients with stable heart failure with reduced ejection fraction (HFrEF) paralleling results to an intra-institutional cohort of treatment naïve cancer patients. Methods: HFrEF and cancer patients were prospectively enrolled. The neutrophil-to-lymphocyte-ratio (NLR), the monocyte-to-lymphocyte-ratio (MLR), the platelet-to-lymphocyte-ratio (PLR), and the prognostic nutritional index (PNI) at index day were calculated. Association of scores with disease severity and impact on overall survival was determined. Interaction analysis was performed for the different populations. Results: Between 2011 and 2017, a total of 818 patients (443 HFrEF and 375 cancer patients) were enrolled. In HFrEF, there was a strong association between all scores and disease severity reflected by NT-proBNP and NYHA class (p ≤ 0.001 for all). In oncologic patients, association with tumor stage was significant for the PNI only (p = 0.035). In both disease entities, all scores were associated with all-cause mortality (p ≤ 0.014 for all scores). Kaplan-Meier analysis confirmed the discriminatory power of all scores in the HFrEF and the oncologic study population, respectively (log-rank p ≤ 0.026 for all scores). A significant interaction with disease (HFrEF vs. cancer) was observed for PNI (p interaction = 0.013) or PLR (p interaction = 0.005), respectively, with higher increase in risk per inflammatory score increment for HFrEF. Conclusion: In crude models, the inflammatory scores NLR, MLR, PLR, and PNI are associated with severity of disease in HFrEF and with survival in HFrEF similarly to cancer patients. For PNI and PLR, the association with increase in risk per increment was even stronger in HFrEF than in malignant disease.

Efficacy and safety of a novel dosing strategy for ruxolitinib in the treatment of patients with myelofibrosis and anemia: the REALISE phase 2 study.

Anemia is a frequent manifestation of myelofibrosis (MF) and there is an unmet need for effective treatments in anemic MF patients. The REALISE phase 2 study (NCT02966353) evaluated the efficacy and safety of a novel ruxolitinib dosing strategy with a reduced starting dose with delayed up-titration in anemic MF patients. Fifty-one patients with primary MF (66.7%), post-essential thrombocythemia MF (21.6%), or post-polycythemia vera MF (11.8%) with palpable splenomegaly and hemoglobin <10 g/dl were included. Median age was 67 (45-88) years, 41.2% were female, and 18% were transfusion-dependent. Patients received 10 mg ruxolitinib b.i.d. for the first 12 weeks, then up-titrations of up to 25 mg b.i.d. were permitted, based on efficacy and platelet counts. Overall, 70% of patients achieved a ≥50% reduction in palpable spleen length at any time during the study. The most frequent adverse events leading to dose interruption/adjustment were thrombocytopenia (17.6%) and anemia (11.8%). Patients who had a dose increase had greater spleen size and higher white blood cell counts at baseline. Median hemoglobin levels remained stable and transfusion requirements did not increase compared with baseline. These results reinforce the notion that it is unnecessary to delay or withhold ruxolitinib because of co-existent or treatment-emergent anemia.

Germline genetic factors influence the outcome of interferon-α therapy in polycythemia vera.

Interferon-α (IFN-α)-based treatments can induce hematologic and molecular responses (HRs and MRs, respectively) in polycythemia vera (PV); however, patients do not respond equally. Germline genetic factors have been implicated in differential drug responses. We addressed the effect of common germline polymorphisms on HR and MR after treatment of PV in the PROUD-PV and CONTINUATION-PV studies in a total of 122 patients who received ropeginterferon alfa-2b. Genome-wide association studies using longitudinal data on HR and MR over a 36-month follow-up did not reveal any associations at the level of genome-wide statistical significance. Furthermore, we performed targeted association analyses at the interferon lambda 4 (IFNL4) locus, well known for its role in hepatitis C viral clearance and recently reported to influence HR during treatment of myeloproliferative neoplasms. We did not observe any association of IFNL4 polymorphisms with HR in our study cohort; however, we demonstrated a statistically significant effect of the functionally causative IFNL4 diplotype (haplotype pair, including the protein-coding variants rs368234815/rs117648444) on MR (P = 3.91 × 10-4; odds ratio, 10.80; 95% confidence interval, 2.39-69.97) as reflected in differential JAK2V617F mutational burden changes according to IFNL4 diplotype status. Stratification of patients with PV based on IFNL4 functionality may allow for optimizing patient management during IFN-α-based therapy.

Austrian recommendations for the management of essential thrombocythemia.

According to the World Health Organization (WHO) classification, essential (primary) thrombocythemia (ET) is one of several Bcr-Abl negative chronic myeloproliferative neoplasms (MPN). The classical term MPN covers the subcategories of MPN: ET, polycythemia vera (PV), primary myelofibrosis (PMF), and prefibrotic PMF (pPMF). ET is marked by clonal proliferation of hematopoietic stem cells, leading to a chronic overproduction of platelets. At the molecular level a JAK2 (Janus Kinase 2), calreticulin, or MPL mutation is found in the majority of patients. Typical ongoing complications of the disease include thrombosis and hemorrhage. Primary and secondary prevention of these complications can be achieved with platelet function inhibitors and various cytoreductive drugs including anagrelide, hydroxyurea and interferon. After a long follow up, in a minority of ET patients the disease transforms into post-ET myelofibrosis or secondary leukemia. Overall, life expectancy with ET is only slightly decreased.

Impact of platelets on major thrombosis in patients with a normal white blood cell count in essential thrombocythemia.

OBJECTIVES: Cell counts have a significant impact on the complex mechanism of thrombosis in patients with essential thrombocythemia (ET). We recently demonstrated a considerable impact of white blood cell (WBC) counts on thrombotic risk in patients with optimized platelet counts by analysing a large anagrelide registry. In contrast, the current analysis of the registry aimed to estimate the influence of platelet counts on thrombotic risk in patients with optimized WBC counts. METHODS: Cox regression analysis and Kaplan-Meier plot were applied on all patients in the registry with optimized WBC counts. RESULTS: By using the calculated cut-off of 593 G/L for platelets, Cox regression analysis revealed a clear influence of elevated platelet counts on the occurrence of a major thrombotic event (P < .001). A Kaplan-Meier plot revealed a markedly shorter time to a major thrombotic event for patients with platelet counts above the cut-off (P < .001). CONCLUSIONS: The data show clear impact of platelet lowering on the thrombotic risk in ET patients with normal WBC counts. Therefore, selective platelet lowering with anagrelide appears sufficient for thrombotic risk reduction in WHO-diagnosed ET patients lacking leukocytosis.

Hereditary α tryptasemia is a valid genetic biomarker for severe mediator-related symptoms in mastocytosis.

Mastocytosis is a hematopoietic neoplasm characterized by expansion of KIT D816V-mutated clonal mast cells in various organs and severe or even life-threatening anaphylactic reactions. Recently, hereditary α-tryptasemia (HαT) has been described as a common genetic trait with increased copy numbers of the α-tryptase encoding gene, TPSAB1, and associated with an increased basal serum tryptase level and a risk of mast cell activation. The purpose of our study was to elucidate the clinical relevance of HαT in patients with mastocytosis. TPSAB1 germline copy number variants were assessed by digital polymerase chain reaction in 180 mastocytosis patients, 180 sex-matched control subjects, 720 patients with other myeloid neoplasms, and 61 additional mastocytosis patients of an independent validation cohort. α-Tryptase encoding TPSAB1 copy number gains, compatible with HαT, were identified in 17.2% of mastocytosis patients and 4.4% of the control population (P < .001). Patients with HαT exhibited higher tryptase levels than patients without HαT (median tryptase in HαT+ cases: 49.6 ng/mL vs HαT- cases: 34.5 ng/mL, P = .004) independent of the mast cell burden. Hymenoptera venom hypersensitivity reactions and severe cardiovascular mediator-related symptoms/anaphylaxis were by far more frequently observed in mastocytosis patients with HαT than in those without HαT. Results were confirmed in an independent validation cohort. The high prevalence of HαT in mastocytosis hints at a potential pathogenic role of germline α-tryptase encoding TPSAB1 copy number gains in disease evolution. Together, our data suggest that HαT is a novel emerging robust biomarker in mastocytosis that is useful for determining the individual patient´s risk of developing severe anaphylaxis.