Meaningful Symptomatic Change in Patients With Myelofibrosis From the SIMPLIFY Studies.

OBJECTIVES: Patients with myelofibrosis develop symptoms due to bone marrow fibrosis, systemic inflammation, and/or organomegaly. Alleviating symptoms improves overall quality of life. Clinical trials have historically defined symptom response as a reduction of at least 50% in Total Symptom Score at week 24 compared with baseline. Whether 50% constitutes a meaningful benefit has not been established. This study determined the meaningful change threshold (MCT) for 2 momelotinib phase III trials, SIMPLIFY-1 and SIMPLIFY-2. METHODS: The absolute and percentage MCT was determined using anchor-based methods applied to the modified Myeloproliferative Neoplasm Symptom Assessment Form v2.0 and Patient Global Impression of Change. MCTs were applied retrospectively to determine responder rates. Generalized estimating equations estimated the treatment-related difference in likelihood of improvement. RESULTS: In SIMPLIFY-1, a Janus kinase inhibitor-naive population, the MCT was 8 points. In SIMPLIFY-2, a previously Janus kinase inhibitor-treated population, the MCT was 6 points. A 32% MCT was determined in both studies, showing that the historic 50% reduction threshold may be a conservative choice. In SIMPLIFY-1, a similar proportion of patients achieved responder status with 24 weeks of momelotinib or ruxolitinib therapy based on the absolute MCT (39% vs 41%, respectively). In SIMPLIFY-2, a significantly greater proportion of patients treated with momelotinib achieved responder states compared with best available therapy based on absolute and percent change MCTs. CONCLUSIONS: This study demonstrates that momelotinib provided clinically meaningful symptom benefit for patients with myelofibrosis and provides insight into the appropriateness of the symptom change threshold used in historical studies.

Safety and efficacy of zinpentraxin alfa as monotherapy or in combination with ruxolitinib in myelofibrosis: stage I of a phase II trial.

Pentraxin 2 (PTX-2; serum amyloid P component), a circulating endogenous regulator of the inflammatory response to tissue injury and fibrosis, is reduced in patients with myelofibrosis (MF). Zinpentraxin alfa (RO7490677, PRM-151) is a recombinant form of PTX-2 that has shown preclinical antifibrotic activity and no dose-limiting toxicities in phase I trials. We report results from stage 1 of a phase II trial of zinpentraxin alfa in patients with intermediate-1/2 or high-risk MF. Patients (n=27) received intravenous zinpentraxin α weekly (QW) or every 4 weeks (Q4W), as monotherapy or an additional therapy for patients on stable-dose ruxolitinib. The primary endpoint was overall response rate (ORR; investigatorassessed) adapted from International Working Group-Myeloproliferative Neoplasms Research and Treatment criteria. Secondary endpoints included modified Myeloproliferative Neoplasm-Symptom Assessment Form Total Symptom Score (MPN-SAF TSS) change, bone marrow (BM) MF grade reduction, pharmacokinetics, and safety. ORR at week 24 was 33% (n=9/27) and varied across individual cohorts (QW: 38% [3/8]; Q4W: 14% [1/7]; QW+ruxolitinib: 33% [2/6]; Q4W+ruxolitinib: 50% [3/6]). Five of 18 evaluable patients (28%) experienced a ≥50% reduction in MPN-SAF TSS, and six of 17 evaluable patients (35%) had a ≥1 grade improvement from baseline in BM fibrosis at week 24. Most treatment-emergent adverse events (AE) were grade 1-2, most commonly fatigue. Among others, anemia and thrombocytopenia were infrequent (n=3 and n=1, respectively). Treatment-related serious AE occurred in four patients (15%). Overall, zinpentraxin alfa showed evidence of clinical activity and tolerable safety as monotherapy and in combination with ruxolitinib in this open-label, non-randomized trial (clinicaltrials gov. Identifier: NCT01981850).

VEXAS syndrome: A review of bone marrow aspirate and biopsies reporting myeloid and erythroid precursor vacuolation.

Myeloid and erythroid precursor vacuolation is a common dysplastic finding associated with myeloid malignancies, toxins, drug, and nutritional deficiencies. It has been described as a core morphologic feature in VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. We sought to determine the number of cases attributable to VEXAS syndrome in bone marrow biopsies and aspirates (BAMB) reporting myeloid precursor vacuolation. We reviewed 1318 individual BAMB reports from January 2020 to July 2021 where "vacuole(s)," "vacuolation," or "vacuolated" was reported. Bone marrow biopsies with vacuolation confined to blasts or those completed as routine workup prior to stem cell transplant or post induction chemotherapy for AML (acute myeloid leukemia) were excluded. Myeloid and erythroid precursor vacuolation was noted in 219 reports representing 210 patients. The most common etiology was myelodysplastic syndrome (MDS) (38.6%), AML (16.7%), lymphoproliferative disorders and multiple myeloma (7.6%), drug or toxin exposure (5.2%) myeloproliferative neoplasm (MPN) or MPN/MDS overlap syndrome (4.3%). VEXAS syndrome was determined to be the etiology in 2.9% of patients. Two additional cases of VEXAS syndrome with bone marrow biopsies reported in the specified time frame did not explicitly report myeloid or erythroid precursor vacuolation but were identified based on clinical suspicion and repeat BAMB review. Myeloid and erythroid precursor vacuolation is a dysplastic feature attributable to VEXAS syndrome in at least 2.9% of cases. Standardized reporting of vacuolization, triaging of molecular sequencing and optimal treatment of this disorder are critical issues facing those seeing patients with suspected VEXAS syndrome.

Comparing the safety and efficacy of ruxolitinib in patients with Dynamic International Prognostic Scoring System low-, intermediate-1-, intermediate-2-, and high-risk myelofibrosis in JUMP, a Phase 3b, expanded-access study.

Ruxolitinib, a potent Janus kinase 1/2 inhibitor, has demonstrated durable improvements in patients with myelofibrosis. In this analysis of the Phase 3b JUMP study, which included patients aged ≥18 years with a diagnosis of primary or secondary myelofibrosis, we assessed the safety and efficacy of ruxolitinib in patients stratified by Dynamic International Prognostic Scoring System (DIPSS) risk categories. Baseline characteristic data were available to assess DIPSS status for 1844 of the 2233 enrolled patients; 60, 835, 755, and 194 in the low-, intermediate (Int)-1-, Int-2-, and high-risk groups, respectively. Ruxolitinib was generally well tolerated across all risk groups, with an adverse-event (AE) profile consistent with previous reports. The most common hematologic AEs were thrombocytopenia and anemia, with highest rates of Grade ≥3 events in high-risk patients. Approximately, 73% of patients experienced ≥50% reductions in palpable spleen length at any point in the ≤24-month treatment period, with highest rates in lower-risk categories (low, 82.1%; Int-1, 79.3%; Int-2, 67.1%; high risk, 61.6%). Median time to spleen length reduction was 5.1 weeks and was shortest in lower-risk patients. Across measures, 40%-57% of patients showed clinically meaningful symptom improvements, which were observed from 4 weeks after treatment initiation and maintained throughout the study. Overall survival (OS) was 92% at Week 72 and 75% at Week 240 (4.6 years). Median OS was longer for Int-2-risk than high-risk patients (253.6 vs. 147.3 weeks), but not evaluable in low-/Int-1-risk patients. By Week 240, progression-free survival (PFS) and leukemia-free survival (LFS) rates were higher in lower-risk patients (PFS: low, 90%; Int-1, 82%; Int-2, 46%; high risk, 15%; LFS: low, 92%; Int-1, 86%; Int-2, 58%; high risk, 19%). Clinical benefit was seen across risk groups, with more rapid improvements in lower risk patients. Overall, this analysis indicates that ruxolitinib benefits lower-risk DIPSS patients in addition to higher risk.

Primary analysis of JUMP, a phase 3b, expanded-access study evaluating the safety and efficacy of ruxolitinib in patients with myelofibrosis, including those with low platelet counts.

Ruxolitinib is a potent Janus kinase (JAK) 1/JAK2 inhibitor approved for the treatment of myelofibrosis (MF). Ruxolitinib was assessed in JUMP, a large (N = 2233), phase 3b, expanded-access study in MF in countries without access to ruxolitinib outside a clinical trial, which included patients with low platelet counts (<100 × 109 /l) and patients without splenomegaly - populations that have not been extensively studied. The most common adverse events (AEs) were anaemia and thrombocytopenia, but they rarely led to discontinuation (overall, 5·4%; low-platelet cohort, 12·3%). As expected, rates of worsening thrombocytopenia were higher in the low-platelet cohort (all grades, 73·2% vs. 53·5% overall); rates of anaemia were similar (all grades, 52·9% vs. 59·5%). Non-haematologic AEs, including infections, were mainly grade 1/2. Overall, ruxolitinib led to meaningful reductions in spleen length and symptoms, including in patients with low platelet counts, and symptom improvements in patients without splenomegaly. In this trial, the largest study of ruxolitinib in patients with MF to date, the safety profile was consistent with previous reports, with no new safety concerns identified. This study confirms findings from the COMFORT studies and supports the use of ruxolitinib in patients with platelet counts of 50-100 × 109 /l. (ClinicalTrials.gov identifier NCT01493414).

Primary analysis of a phase II open-label trial of INCB039110, a selective JAK1 inhibitor, in patients with myelofibrosis.

Combined Janus kinase 1 (JAK1) and JAK2 inhibition therapy effectively reduces splenomegaly and symptom burden related to myelofibrosis but is associated with dose-dependent anemia and thrombocytopenia. In this open-label phase II study, we evaluated the efficacy and safety of three dose levels of INCB039110, a potent and selective oral JAK1 inhibitor, in patients with intermediate- or high-risk myelofibrosis and a platelet count ≥50×109/L. Of 10, 45, and 32 patients enrolled in the 100 mg twice-daily, 200 mg twice-daily, and 600 mg once-daily cohorts, respectively, 50.0%, 64.4%, and 68.8% completed week 24. A ≥50% reduction in total symptom score was achieved by 35.7% and 28.6% of patients in the 200 mg twice-daily cohort and 32.3% and 35.5% in the 600 mg once-daily cohort at week 12 (primary end point) and 24, respectively. By contrast, two patients (20%) in the 100 mg twice-daily cohort had ≥50% total symptom score reduction at weeks 12 and 24. For the 200 mg twice-daily and 600 mg once-daily cohorts, the median spleen volume reductions at week 12 were 14.2% and 17.4%, respectively. Furthermore, 21/39 (53.8%) patients who required red blood cell transfusions during the 12 weeks preceding treatment initiation achieved a ≥50% reduction in the number of red blood cell units transfused during study weeks 1-24. Only one patient discontinued for grade 3 thrombocytopenia. Non-hematologic adverse events were largely grade 1 or 2; the most common was fatigue. Treatment with INCB039110 resulted in clinically meaningful symptom relief, modest spleen volume reduction, and limited myelosuppression.

The impact of myeloproliferative neoplasms (MPNs) on patient quality of life and productivity: results from the international MPN Landmark survey.

Myelofibrosis (MF), polycythemia vera (PV), and essential thrombocythemia (ET) are myeloproliferative neoplasms (MPNs) associated with high disease burden, reduced quality of life (QOL), and shortened survival. To assess how MPNs affect patients, we conducted a global MPN Landmark survey. This online survey of patients with MPNs and physicians was conducted in Australia, Canada, Germany, Japan, Italy, and the United Kingdom. The survey measured MPN-related symptoms and the impact of MPNs on QOL and the ability to work as well as disease-management strategies. Overall, 219 physicians and 699 patients (MF, n = 174; PV, n = 223; ET, n = 302) completed the survey; 90% of patients experienced MPN-related symptoms. The most frequent and severe symptom was fatigue. Most patients experienced a reduction in QOL, including those with low symptom burden or low-risk scores. A substantial proportion of patients reported impairment at work and in overall activity. Interestingly, physician feedback and blood counts were the most important indicators of treatment success among patients, with improvements in symptoms and QOL being less important. Regarding disease management, our study revealed a lack of alignment between physician and patient perceptions relating to communication and disease management, with patients often having different treatment goals than physicians. Overall, our study suggested that therapies that reduce symptom burden and improve QOL in patients with MPNs are crucial in minimizing disease impact on patient daily lives. Additionally, our findings showed a need for improved patient-physician communication, standardized monitoring of symptoms, and agreement on treatment goals.

Safety and efficacy of ruxolitinib in an open-label, multicenter, single-arm phase 3b expanded-access study in patients with myelofibrosis: a snapshot of 1144 patients in the JUMP trial.

JUMP is a phase 3b expanded-access trial for patients without access to ruxolitinib outside of a clinical study; it is the largest clinical trial to date in patients with myelofibrosis who have been treated with ruxolitinib. Here, we present safety and efficacy findings from an analysis of 1144 patients with intermediate- or high-risk myelofibrosis, as well as a separate analysis of 163 patients with intermediate-1-risk myelofibrosis - a population of patients not included in the phase 3 COMFORT studies. Consistent with ruxolitinib's mechanism of action, the most common hematologic adverse events were anemia and thrombocytopenia, but these led to treatment discontinuation in only a few cases. The most common non-hematologic adverse events were primarily grade 1/2 and included diarrhea, pyrexia, fatigue, and asthenia. The rates of infections were low and primarily grade 1/2, and no new or unexpected infections were observed. The majority of patients achieved a ≥50% reduction from baseline in palpable spleen length. Improvements in symptoms were rapid, with approximately half of all patients experiencing clinically significant improvements, as assessed by various quality-of-life questionnaires. The safety and efficacy profile in intermediate-1-risk patients was consistent with that in the overall JUMP population and with that previously reported in intermediate-2- and high-risk patients. Overall, ruxolitinib provided clinically meaningful reductions in spleen length and symptoms in patients with myelofibrosis, including those with intermediate-1-risk disease, with a safety and efficacy profile consistent with that observed in the phase 3 COMFORT studies. This trial was registered as NCT01493414 at ClinicalTrials.gov.

Safety and efficacy of fedratinib in patients with myelofibrosis previously treated with ruxolitinib: primary analysis of FREEDOM trial.

The phase 3b FREEDOM trial (ClinicalTrials.gov: NCT03755518) evaluates efficacy/safety of fedratinib in intermediate- or high-risk myelofibrosis patients with platelet count ≥50 × 109/L, previously treated with ruxolitinib. The trial design included protocol specified strategies to mitigate the risk for gastrointestinal (GI) adverse events (AEs), thiamine supplementation, and encephalopathy surveillance. Due to COVID-19, accrual was cut short with 38 patients enrolled. In the efficacy evaluable population (n = 35), nine (25.7%; 95% confidence interval 12.5-43.3) patients achieved primary endpoint of ≥35% spleen volume reduction (SVR) at end of cycle (EOC) 6; and 22 (62.9%) patients showed best overall response of ≥35% SVR up to end of treatment. Sixteen (44.4%) patients showed ≥50% reduction in total symptom score at EOC6 (n = 36). Compared to previously reported JAKARTA-2 trial, rates of GI AEs were lower, and no patient developed encephalopathy. Overall, FREEDOM study showed clinically relevant spleen and symptom responses with fedratinib, and effective mitigation of GI AEs.

Upfront allogeneic transplantation versus JAK inhibitor therapy for patients with myelofibrosis: a North American collaborative study.

Allogeneic hematopoietic cell transplantation (HCT) is the only curative therapy for myelofibrosis (MF) and is recommended for patients with higher risk disease. However, there is a risk of early mortality, and optimal timing is unknown. JAK inhibitor (JAKi) therapy may offer durable improvement in symptoms, splenomegaly and quality of life. The aim of this multicentre, retrospective observational study was to compare outcomes of patients aged 70 years or below with MF in chronic phase who received upfront JAKi therapy vs. upfront HCT in dynamic international prognostic scoring system (DIPSS)-stratified categories. For the whole study cohort, median overall survival (OS) was longer for patients who received a JAKi vs. upfront HCT, 69 (95% CI 57-89) vs. 42 (95% CI 20-not reached, NR) months, respectively (p = 0.01). In patients with intermediate-2 and high-risk disease, median OS was 55 (95% CI 36-73) months with JAKi vs. 36 (95% CI 20-NR) months for HCT (p = 0.27). An upfront HCT strategy was associated with early mortality and difference in median OS was not observed in any risk group by 5 years of follow-up. Within the limitations of a retrospective observational study, we did not observe any benefit of a universal upfront HCT approach for higher-risk MF.

Symptomatic benefit of momelotinib in patients with myelofibrosis: Results from the SIMPLIFY phase III studies.

BACKGROUND: Myelofibrosis (MF)-associated constitutional symptoms can severely impact health-related quality of life. Clinical trials in MF traditionally measure symptom response to treatment as a landmark endpoint of total symptom score (TSS) reduction ≥50% from baseline. However, this dichotomous assessment provides a limited view of clinically relevant symptomatic changes. Herein we evaluated longitudinal change from baseline in TSS over the continuous 24-week period and individual symptom scores to obtain a more comprehensive understanding of symptom benefits experienced by patients with MF receiving therapy. METHODS: Longitudinal symptom change was evaluated using mixed-effect model repeated measure (MMRM) methodology with individual item-level analyses to complement the interpretation of the landmark symptom results in the completed phase III SIMPLIFY studies of momelotinib in MF. MMRM compared mean change in TSS from baseline with Week 24 using data from all patient visits. Generalized estimating equations were used to estimate item-level odds ratios using multiple predictive imputations for missing data. RESULTS: Momelotinib and ruxolitinib groups reported similar overall symptom improvements, with a TSS difference of <1.5 points between groups for each post-baseline visit in SIMPLIFY-1. In SIMPLIFY-2, the improvement in TSS observed in momelotinib-treated patients was consistent with that observed in SIMPLIFY-1, whereas progressive TSS deterioration was observed with control. Item-level scores were heterogeneous in both studies. A similar and greater proportion of momelotinib-treated patients were categorized as "improved" or "stable" compared with control in SIMPLIFY-1 and SIMPLIFY-2, respectively. Odds ratios for between-group comparison ranged from 0.75 to 1.21 in SIMPLIFY-1, demonstrating similarity in likelihood of symptom improvement. In SIMPLIFY-2, the likelihood of symptom improvement in each item was higher in the momelotinib arm. CONCLUSIONS: These findings suggest that momelotinib provides clinically relevant symptom benefits in the JAK inhibitor-naïve and JAK inhibitor-exposed settings.

Patient-reported Outcomes and Quality of Life in Anemic and Symptomatic Patients With Myelofibrosis: Results From the MOMENTUM Study.

Myelofibrosis (MF) is a chronic myeloproliferative neoplasm that typically manifests with debilitating symptoms that progressively worsen, negatively impacting patients' quality of life. Fatigue is a multifactorial and burdensome MF-related symptom due to its severity, persistence, and prevalence, with anemia a contributing factor and major unmet need. Clinical trials of the Janus kinase (JAK)1/JAK2/activin A receptor type 1 inhibitor momelotinib have shown consistent anemia benefits, in addition to improvements in MF-related symptoms. The phase 3 MOMENTUM trial in symptomatic and anemic patients met its primary end point, with a greater proportion having a Myelofibrosis Symptom Assessment Form (MFSAF) Total Symptom Score (TSS) reduction ≥50% at week 24 with momelotinib versus danazol. To support the positive primary end point result, we conducted longitudinal, responder, and time-to-event analyses of patient-reported outcomes from MOMENTUM, as measured by the MFSAF, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), and Patient-Reported Outcomes Measurement Information System (PROMIS) assessments. These analyses demonstrated rapid and durable response benefits with momelotinib, with achievement of first TSS response by day 29 and continued improvement over time. Improvements favored momelotinib versus danazol for each MFSAF individual item, and greater improvements were observed for disease- and cancer-related fatigue and physical functioning at week 24, with significant results for multiple items/domains across the 3 assessments. These findings are consistent in demonstrating that momelotinib provides substantial symptom benefit.

Analysis of predictors of response to ruxolitinib in patients with myelofibrosis in the phase 3b expanded-access JUMP study.

Data from the large, prospective, multinational, phase 3b JUMP study were analyzed to identify factors predictive of spleen and symptom responses in myelofibrosis patients receiving ruxolitinib. Factors associated with higher spleen response rates included International Prognostic Scoring System (IPSS) low/intermediate-1 risk vs intermediate-2/high risk (43.1% vs 30.6%; adjusted OR [aOR] 0.65 [95% CI 0.44-0.95]), ruxolitinib as first- vs second- or later-line therapy (40.2% vs 31.5%; aOR 0.53 [95% CI 0.38-0.75]), and a ruxolitinib total daily dose at Week 12 of >20 mg/day vs ≤20 mg/day (41.3% vs 30.4%; aOR 0.47 [95% CI 0.33-0.68]). No association was seen between baseline characteristics or total daily dose at Week 12 and symptom response. Ruxolitinib led to higher spleen response rates in patients with lower IPSS risk, and when used earlier in treatment. Higher doses of ruxolitinib were associated with higher spleen response rates, but not with symptom improvement.Trial registrationINC424 for patients with primary myelofibrosis, post polycythemia myelofibrosis or post-essential thrombocythemia myelofibrosis (JUMP).2010-024473-39; NCT01493414Date of registration: 16 December 2011https://www.clinicaltrialsregister.eu/ctr-search/search?query=2010-024473-39https://clinicaltrials.gov/ct2/show/NCT01493414.

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.

Improved survival in red blood cell transfusion dependent patients with primary myelofibrosis (PMF) receiving iron chelation therapy.

Many patients with primary myelofibrosis (PMF) become red blood cell (RBC) transfusion dependent (TD), risking iron overload (IOL). Iron chelation therapy (ICT) may decrease the risk of haemosiderosis associated organ dysfunction, though its benefit in PMF is undefined. To assess the effect of TD and ICT on survival in PMF, we retrospectively reviewed 41 patients. Clinical data were collected from the database and by chart review. The median age at PMF diagnosis was 64 (range 43-86) years. Median white blood cell (WBC) count at diagnosis was 7.6 (range 1.2-70.9) x 10(9)/L; haemoglobin 104 (62-145) G/L; platelets 300 (38-2088) x 10(9)/L. Lille, Strasser, Mayo and International Prognostic System (IPS) scores were: low risk, n = 15, 8, 11, 3; intermediate, n = 15, 19, 9, 16; high, n = 5, 11, 5, 7; respectively. Primary PMF treatment was: supportive care, n = 23; hydroxyurea, n = 10; immunomodulatory, n = 4; splenectomy, n = 2. Sixteen patients were RBC transfusion independent (TI) and 25 TD; of these 10 received ICT for a median of 18.3 (0.1-117) months. Pre-ICT ferritin levels were a median of 2318 (range 263-8400) and at follow up 1571 (1005-3211 microg/L (p = 0.01). In an analysis of TD patients, factors significant for overall survival (OS) were: WBC count at diagnosis (p = 0.002); monocyte count (p = 0.0001); Mayo score (p = 0.05); IPS (p = 0.02); number of RBC units (NRBCU) transfused (p = 0.02) and ICT (p = 0.003). In a multivariate analysis, significant factors were: NRBCU (p = 0.001) and ICT (p = 0.0001). Five year OS for TI, TD-ICT and TD-NO ICT were: 100, 89 and 34%, respectively (p = 0.003). The hazard ratio (HR) for receiving >20 RBCU was 7.6 (95% Confidence Intervals [CI] 1.2-49.3) and for ICT was 0.15 (0.03-0.77). In conclusion, 61% of PMF patients developed RBC-TD which portended inferior OS; however patients receiving ICT had comparatively improved OS, suggesting a clinical benefit. Prospective studies of IOL and the impact of ICT in PMF are warranted.

No Differences in Outcomes Between JAK2 V617F-Positive Patients with Variant Allele Fraction < 2% Versus 2-10%: A 6-Year Province-wide Retrospective Analysis.

INTRODUCTION: JAK2 V617F mutation is one of the major criteria in the diagnosis of myeloproliferative neoplasms (MPN) and its variant allele fraction (VAF) determines the disease phenotype and outcomes. This study aimed to define characteristics and outcomes of patients with JAK2 V617F VAF < 2% compared to patients with VAF 2%-10%. PATIENTS AND METHODS: We included 5079 patients with JAK2 V617F tested during 2010-2015 and identified 216 patients (4.3%) with JAK2 V617F VAF < 10%. Twenty-seven patients were excluded because of missing follow-up data. RESULTS: A total of 189 patients were included for final analysis (89 patients with VAF < 2% and 100 patients with VAF 2%-10%). Patients with JAK2 V617F 2%-10% VAF had a significantly higher rate of splenomegaly, higher platelet counts, and more MPN diagnoses than the group with VAF < 2%. Ten patients (10.0%) with VAF 2%-10% and 24 patients (27.0%) with VAF < 2% had normal blood count and no thrombosis. There were no differences between the groups in all outcomes, including thrombotic complications (18.0% in both groups), progression to hematologic or solid cancers, and death. Patients without hematologic diagnosis had similar thrombotic incidence (16.7% in VAF < 2% vs. 20.0% in VAF 2%-10%). CONCLUSION: Patients with JAK2 V617F mutation VAF < 2% have similar survival and thrombotic incidence as patients with VAF 2%-10%. Patients with low VAF should be monitored in the same manner as patients with higher VAF with the same diagnoses to prevent morbidity and mortality. Patients without hematologic diagnosis may benefit from thrombotic risk reduction strategies such as optimization of cardiovascular risk factors.

Patterns of Ruxolitinib Therapy Failure and Its Management in Myelofibrosis: Perspectives of the Canadian Myeloproliferative Neoplasm Group.

Ruxolitinib improves splenomegaly and other disease-related symptoms in patients with myelofibrosis, but over time, many patients lose this benefit. It is difficult to determine whether this is due to resistance or intolerance to the drug; thus, we have used the more inclusive term of ruxolitinib failure. The survival of patients with myelofibrosis after ruxolitinib failure is poor but varies significantly by the pattern of the failure, underlining the need for a clinically appropriate classification. In this review, we propose diagnostic guidance for early recognition of the pattern of ruxolitinib failure and we recommend treatment options. The most frequent patterns of ruxolitinib failure are loss or failure to obtain a significant reduction in splenomegaly or symptom response, and the development or persistence of clinically significant cytopenias. Ruxolitinib dose modification and other ancillary therapies are sometimes helpful, and splenectomy is a palliative option in selected cases. Stem-cell transplantation is the only curative option for these patterns of failure, but its restricted applicability due to toxicity highlights the importance of ongoing clinical trials in this area. Recent approval of fedratinib by the US Food and Drug Administration provides an alternative option for patients with suboptimal or loss of spleen response. The transformation of myelofibrosis to accelerated or blast phase is an infrequent form of failure with an extremely poor prognosis, whereby patients who are ineligible for transplantation have limited treatment options.

Safety and efficacy findings from the open-label, multicenter, phase 3b, expanded treatment protocol study of ruxolitinib for treatment of patients with polycythemia vera who are resistant/intolerant to hydroxyurea and for whom no alternative treatments are available.

Ruxolitinib was recently approved for the treatment of patients with polycythemia vera who are resistant/intolerant to hydroxyurea based on data from the RESPONSE studies. This phase 3b, Expanded Treatment Protocol study (NCT02292446) of ruxolitinib for hydroxyurea-resistant/intolerant patients with polycythemia vera (N = 161: median exposure = 25.1 weeks) further evaluated the safety of ruxolitinib. Adverse events (AEs) led to dose adjustment/interruption in 37.9% of patients and study drug discontinuation in 8.7% of patients. The most common hematologic AEs included anemia and thrombocytosis; while headache and diarrhea were the most frequent nonhematologic AEs. At week 24, 45.3% of patients achieved hematocrit control; hematologic remission was seen in 18% of patients. At least, 50% of reduction in spleen length was achieved in 86.7% of patients from baseline at any time. The observed safety profile of ruxolitinib was consistent and the efficacy results were similar to the observed values in the RESPONSE studies.