Ruxolitinib is a potent Janus kinase (JAK)1/JAK2 inhibitor that has demonstrated rapid reductions in splenomegaly and marked improvement in disease-related symptoms and quality of life in patients ...with myelofibrosis (MF). The present analysis reports the 3-year follow-up (median, 151 weeks) of the efficacy and safety of Controlled Myelofibrosis Study With Oral Janus-associated Kinase (JAK) Inhibitor Treatment-II (the COMFORT-II Trial), comparing ruxolitinib with the best available therapy (BAT) in 219 patients with intermediate-2 and high-risk MF. In the ruxolitinib arm, with continued therapy, spleen volume reductions of ≥35% by magnetic resonance imaging (equivalent to approximately 50% reduction by palpation) were sustained for at least 144 weeks, with the probability of 50% (95% confidence interval CI, 36-63) among patients achieving such degree of response. At the time of this analysis, 45% of the patients randomized to ruxolitinib remained on treatment. Ruxolitinib continues to be well tolerated. Anemia and thrombocytopenia were the main toxicities, but they were generally manageable, improved over time, and rarely led to treatment discontinuation (1% and 3.6% of patients, respectively). No single nonhematologic adverse event led to definitive ruxolitinib discontinuation in more than 1 patient. Additionally, patients randomized to ruxolitinib showed longer overall survival than those randomized to BAT (hazard ratio, 0.48; 95% CI, 0.28-0.85; log-rank test, P = .009). This trial was registered at clinicaltrials.gov as #NCT00934544.
Key Points
Evaluation of Anagrelide (Xagrid
) Efficacy and Long-term Safety, a phase IV, prospective, non-interventional study performed in 13 European countries enrolled high-risk essential thrombocythemia ...patients treated with cytoreductive therapy. The primary objectives were safety and pregnancy outcomes. Of 3721 registered patients, 3649 received cytoreductive therapy. At registration, 3611 were receiving: anagrelide (Xagrid
) (n=804), other cytoreductive therapy (n=2666), or anagrelide + other cytoreductive therapy (n=141). The median age was 56
70 years for anagrelide
other cytoreductive therapy. Event rates (patients with events/100 patient-years) were 1.62
2.06 for total thrombosis and 0.15
0.53 for venous thrombosis. Anagrelide was more commonly associated with hemorrhage (0.89
0.43), especially with anti-aggregatory therapy (1.35
0.33) and myelofibrosis (1.04
0.30). Other cytoreductive therapies were more associated with acute leukemia (0.28
0.07) and other malignancies (1.29
0.44).
multivariate analyses identified increased risk for thrombosis with prior thrombohemorrhagic events, age ≥65, cardiovascular risk factors, or hypertension. Risk factors for transformation were prior thrombohemorrhagic events, age ≥65, time since diagnosis, and platelet count increase. Safety analysis reflected published data, and no new safety concerns for anagrelide were found. Live births occurred in 41/54 pregnancies (76%).
Myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN) are hematologically diverse stem cell malignancies sharing phenotypic features of both myelodysplastic syndromes and ...myeloproliferative neoplasms. There are currently no standard treatment recommendations for most adult patients with MDS/MPN. To optimize efforts to improve the management and disease outcomes, it is essential to identify meaningful clinical and biologic end points and standardized response criteria for clinical trials. The dual dysplastic and proliferative features in these stem cell malignancies define their uniqueness and challenges. We propose response assessment guidelines to harmonize future clinical trials with the principal objective of establishing suitable treatment algorithms. An international panel comprising laboratory and clinical experts in MDS/MPN was established involving 3 independent academic MDS/MPN workshops (March 2013, December 2013, and June 2014). These recommendations are the result of this collaborative project sponsored by the MDS Foundation.
Interferon-α (IFN-α) is a nonleukemogenic treatment of polycythemia vera (PV) able to induce cytogenetic remissions. Its use is limited by toxicity, leading to treatment discontinuation in ...approximately 20% of patients. We completed a phase 2 multicenter study of pegylated IFN-α-2a in 40 PV patients. Objectives included evaluation of efficacy, safety, and monitoring of residual disease using JAK2V617F quantification (%V617F). Median follow-up was 31.4 months. At 12 months, all 37 evaluable patients had hematologic response, including 94.6% complete responses (CRs). Only 3 patients (8%) had stopped treatment. After the first year, 35 patients remained in hematologic CR, including 5 who had stopped pegylated IFN-α-2a. Sequential samples for %V617F monitoring, available in 29 patients, showed %V617F decrease in 26 (89.6%). Median %V617F decreased from 45% before pegylated IFN-α-2a to 22.5%, 17.5%, 5%, and 3% after 12, 18, 24, and 36 months, respectively. Molecular CR (JAK2V617F undetectable) was achieved in 7 patients, lasting from 6+ to 18+ months, and persisted after pegylated IFN-α-2a discontinuation in 5. No vascular event was recorded. These results show that pegylated IFN-α-2a yields high rates of hematologic and molecular response in PV with limited toxicity, and could even eliminate the JAK2 mutated clone in selected cases. Available at www.clinicaltrials.gov as #NCT00241241.
Ruxolitinib, a Janus kinase (JAK) 1 and 2 inhibitor, was shown to have a clinical benefit in patients with polycythemia vera in a phase 2 study. We conducted a phase 3 open-label study to evaluate ...the efficacy and safety of ruxolitinib versus standard therapy in patients with polycythemia vera who had an inadequate response to or had unacceptable side effects from hydroxyurea.
We randomly assigned phlebotomy-dependent patients with splenomegaly, in a 1:1 ratio, to receive ruxolitinib (110 patients) or standard therapy (112 patients). The primary end point was both hematocrit control through week 32 and at least a 35% reduction in spleen volume at week 32, as assessed by means of imaging.
The primary end point was achieved in 21% of the patients in the ruxolitinib group versus 1% of those in the standard-therapy group (P<0.001). Hematocrit control was achieved in 60% of patients receiving ruxolitinib and 20% of those receiving standard therapy; 38% and 1% of patients in the two groups, respectively, had at least a 35% reduction in spleen volume. A complete hematologic remission was achieved in 24% of patients in the ruxolitinib group and 9% of those in the standard-therapy group (P=0.003); 49% versus 5% had at least a 50% reduction in the total symptom score at week 32. In the ruxolitinib group, grade 3 or 4 anemia occurred in 2% of patients, and grade 3 or 4 thrombocytopenia occurred in 5%; the corresponding percentages in the standard-therapy group were 0% and 4%. Herpes zoster infection was reported in 6% of patients in the ruxolitinib group and 0% of those in the standard-therapy group (grade 1 or 2 in all cases). Thromboembolic events occurred in one patient receiving ruxolitinib and in six patients receiving standard therapy.
In patients who had an inadequate response to or had unacceptable side effects from hydroxyurea, ruxolitinib was superior to standard therapy in controlling the hematocrit, reducing the spleen volume, and improving symptoms associated with polycythemia vera. (Funded by Incyte and others; RESPONSE ClinicalTrials.gov number, NCT01243944.).
Introduction
The pathogenesis of myeloproliferative neoplasms (MPNs) is closely related to the acquisition of specific molecular alterations in JAK2, MPL, or CALR genes, the presence of which ...represent major diagnostic criteria in the WHO classification. The CALR exon 9 insertions and deletions are very heterogeneous, and their detection mainly relies on polymerase chain reaction (PCR) fragment length analysis.
Methods
We report on the rare nonclassical profiles that we observed among the 1382 patients analyzed by PCR fragment length analysis. In difficult cases, we tested germline DNA and performed NGS analysis.
Results
We faced some troubling results because of the presence of several unexpected peaks. Our investigations showed that they resulted from a mix of isolated or double somatic mutations combined with germline alterations which could be misleading for a correct diagnosis. The precise interpretation of such difficult cases is mandatory as a misinterpretation could lead to the prescription of cytoreductive drugs to nondiseased persons or to an absence of treatment in true MPN patients.
Conclusion
Our observations showed that every mutation should be verified by direct Sanger sequencing, and we show that sometimes it may be necessary to study germline DNA and to complement with NGS analysis to precisely interpret the molecular alterations.
Myelofibrosis is a chronic myeloproliferative neoplasm characterised by splenomegaly, cytopenias, bone marrow fibrosis, and debilitating symptoms including fatigue, weight loss, and bone pain. ...Mutations in Janus kinase-2 (JAK2) occur in approximately 50% of patients. The only approved JAK2 inhibitor for myelofibrosis is the dual JAK1 and JAK2 inhibitor, ruxolitinib. 58-71% of patients treated with ruxolitinib in clinical trials so far have not achieved the primary endpoint of 35% or more reduction in spleen volume from baseline assessed by MRI or CT. Furthermore, more than 50% of patients discontinue ruxolitinib treatment after 3-5 years. On the basis of this unmet need, we investigated the efficacy and safety of fedratinib, a JAK2-selective inhibitor, in patients with ruxolitinib-resistant or ruxolitinib-intolerant myelofibrosis.
This single-arm, open-label, non-randomised, phase 2, multicentre study, done at 31 sites in nine countries, enrolled adult patients with a current diagnosis of intermediate or high-risk primary myelofibrosis, post-polycythaemia vera myelofibrosis, or post-essential thrombocythaemia myelofibrosis, found to be ruxolitinib resistant or intolerant after at least 14 days of treatment. Other main inclusion criteria were palpable splenomegaly (≥5 cm below the left costal margin), Eastern Cooperative Oncology Group performance status of 2 or less, and life expectancy of 6 months or less. Patients received oral fedratinib at a starting dose of 400 mg once per day, for six consecutive 28-day cycles. The primary endpoint was spleen response (defined as the proportion of patients with a ≥35% reduction in spleen volume as determined by blinded CT and MRI at a central imaging laboratory). We did the primary analysis in the per-protocol population only (patients treated with fedratinib, for whom a baseline and at least one post-baseline spleen volume measurement was available) and the safety analysis in all patients receiving at least one dose of fedratinib. This trial was registered with ClinicalTrials.gov, number NCT01523171.
Between May 8, 2012, and Aug 29, 2013, 97 patients were enrolled and received at least one dose of fedratinib. Of 83 assessable patients, 46 (55%, 95% CI 44-66) achieved a spleen response. Common grade 3-4 adverse events included anaemia (37 38% of 97 patients) and thrombocytopenia (21 22% of 97), with 18 (19%) patients discontinuing due to adverse events. Seven (7%) patients died during the study, but none of the deaths was drug related. Suspected cases of Wernicke's encephalopathy in other fedratinib trials led to study termination.
This phase 2 study met its primary endpoint, suggesting that patients with ruxolitinib-resistant or ruxolitinib-intolerant myelofibrosis might achieve significant clinical benefit with fedratinib, albeit at the cost of some potential toxicity, which requires further evaluation. Fedratinib development in this setting is currently being assessed.
Sanofi.
Available therapies for myelofibrosis can exacerbate cytopenias and are not indicated for patients with severe thrombocytopenia. Pacritinib, which inhibits both JAK2 and FLT3, induced spleen ...responses with limited myelosuppression in phase 1/2 trials. We aimed to assess the efficacy and safety of pacritinib versus best available therapy in patients with myelofibrosis irrespective of baseline cytopenias.
This international, multicentre, randomised, phase 3 trial (PERSIST-1) was done at 67 sites in 12 countries. Patients with higher-risk myelofibrosis (with no exclusions for baseline anaemia or thrombocytopenia) were randomly assigned (2:1) to receive oral pacritinib 400 mg once daily or best available therapy (BAT) excluding JAK2 inhibitors until disease progression or unacceptable toxicity. Randomisation was stratified by risk category, platelet count, and region. Treatment assignments were known to investigators, site personnel, patients, clinical monitors, and pharmacovigilance personnel. The primary endpoint was spleen volume reduction (SVR) of 35% or more from baseline to week 24 in the intention-to-treat population as assessed by blinded, centrally reviewed MRI or CT. We did safety analyses in all randomised patients who received either treatment. Here we present the final data. This trial is registered with ClinicalTrials.gov, number NCT01773187.
Between Jan 8, 2013, and Aug 1, 2014, 327 patients were randomly assigned to pacritinib (n=220) or BAT (n=107). Median follow-up was 23·2 months (IQR 14·8-28·7). At week 24, the primary endpoint of SVR of 35% or more was achieved by 42 (19%) patients in the pacritinib group versus five (5%) patients in the BAT group (p=0·0003). 90 patients in the BAT group crossed over to receive pacritinib at a median of 6·3 months (IQR 5·8-6·7). The most common grade 3-4 adverse events through week 24 were anaemia (n=37 17%), thrombocytopenia (n=26 12%), and diarrhoea (n=11 5%) in the pacritinib group, and anaemia (n=16 15%), thrombocytopenia (n=12 11%), dyspnoea (n=3 3%), and hypotension (n=3 3%) in the BAT group. The most common serious adverse events that occurred through week 24 were anaemia (10 5%), cardiac failure (5 2%), pyrexia (4 2%), and pneumonia (4 2%) with pacritinib, and anaemia (5 5%), sepsis (2 2%), and dyspnoea (2 2%) with BAT. Deaths due to adverse events were observed in 27 (12%) patients in the pacritinib group and 14 (13%) patients in the BAT group throughout the duration of the study.
Pacritinib therapy was well tolerated and induced significant and sustained SVR and symptom reduction, even in patients with severe baseline cytopenias. Pacritinib could be a treatment option for patients with myelofibrosis, including those with baseline cytopenias for whom options are particularly limited.
CTI BioPharma Corp.
Myelofibrosis (MF) is a clonal hematologic malignancy with progressive bone marrow fibrosis. Clinical manifestations of MF include splenomegaly, constitutional symptoms, and anemia, whose ...pathogenesis is multifactorial and largely due to ineffective erythropoiesis and is clinically associated with poor quality of life and reduced overall survival. The only curative treatment for MF is allogenic stem cell transplantation; however, few patients are eligible. Disease management strategies for MF-related anemia have limited effectiveness, and Janus kinase (JAK) inhibitors may induce or worsen related anemia. Thus, there is a significant unmet need for the treatment of patients with MF-related anemia. This review summarizes current and emerging treatments for anemia in MF, including luspatercept and KER-050 (transforming growth factor-β ligand traps), momelotinib and pacritinib (JAK inhibitors), pelabresib (a bromodomain extra-terminal domain inhibitor), PRM-151 (an antifibrotic agent), imetelstat (a telomerase inhibitor), and navitoclax (a BCL-2/BCL-xL inhibitor). Therapeutic combinations with ruxolitinib may offer another treatment approach.
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•Myelofibrosis (MF) is a hematologic malignancy with progressive bone marrow fibrosis.•Ineffective erythropoiesis contributes to MF-related anemia, a hallmark of MF.•Treatments for MF-related anemia have limited efficacy and durability of response.•Data from trials of novel therapies for MF-related anemia have had positive results.
Transformation of Philadelphia (Ph)–negative myeloproliferative neoplasms (MPNs) to myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) is associated with poor response to chemotherapy and ...short survival. Fifty-four patients with Ph-negative MPN (including 21 essential thrombocythemia ET, 21 polycythemia vera PV, 7 primary myelofibrosis, and 5 unclassified MPN) who had progressed to AML (n = 26) or MDS (n = 28) were treated with azacitidine in a patient-named program. Overall response rate was 52% (24% complete response CR, 11% partial response PR, 8% marrow CR or CR with incomplete recovery of cytopenias, 9% hematologic improvement) and median response duration was 9 months. Prognostic factors were for overall response the underlying MPN (71% vs 33% responses in ET and PV, respectively; P = .016); prognostic factors for CR achievement were the underlying MPN (14% CR for PV vs 43% for ET; P = .040) and World Health Organization classification at transformation (36% vs 12% CR in MDS and AML, respectively, P = .038). Recurrence of chronic phase features of the initial MPN was observed in 39% of the responders. Median overall survival was 11 months. Azacitidine gives encouraging results in Ph-negative MPN having progressed to AML or MDS, but response duration is short, and consolidation treatments have to be evaluated.
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