Best Available Therapy Research Articles

Ruxolitinib reduces JAK2 p.V617F allele burden in patients with polycythemia vera enrolled in the RESPONSE study

In patients with polycythemia vera (PV), an elevated JAK2 p.V617F allele burden is associated with indicators of more severe disease (e.g., leukocytosis, splenomegaly, and increased thrombosis risk); however, correlations between allele burden reductions and clinical benefit in patients with PV have not been extensively evaluated in a randomized trial. This exploratory analysis from the multicenter, open-label, phase 3 Randomized Study of Efficacy and Safety in Polycythemia Vera With JAK Inhibitor INCB018424 Versus Best Supportive Care trial evaluated the long-term effect of ruxolitinib treatment on JAK2 p.V617F allele burden in patients with PV. Evaluable JAK2 p.V617F-positive patients randomized to ruxolitinib (n = 107) or best available therapy (BAT) who crossed over to ruxolitinib at week 32 (n = 97) had consistent JAK2 p.V617F allele burden reductions throughout the study. At all time points measured (up to weeks 208 [ruxolitinib-randomized] and 176 [ruxolitinib crossover]), mean changes from baseline over time in JAK2 p.V617F allele burden ranged from −12.2 to −40.0% (ruxolitinib-randomized) and −6.3 to −17.8% (ruxolitinib crossover). Complete or partial molecular response was observed in 3 patients (ruxolitinib-randomized, n = 2; ruxolitinib crossover, n = 1) and 54 patients (ruxolitinib-randomized, n = 33; ruxolitinib crossover, n = 20; BAT, n = 1), respectively. Among patients treated with interferon as BAT (n = 13), the mean maximal reduction in allele burden from baseline was 25.6% after crossover to ruxolitinib versus 6.6% before crossover. Collectively, the data from this exploratory analysis suggest that ruxolitinib treatment for up to 4 years provides progressive reductions in JAK2 p.V617F allele burden in patients with PV who are resistant to or intolerant of hydroxyurea. The relationship between allele burden changes and clinical outcomes in patients with PV remains unclear.

Pacritinib versus best available therapy for the treatment of myelofibrosis irrespective of baseline cytopenias (PERSIST-1): an international, randomised, phase 3 trial

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.

Results of the Persist-2 Phase 3 Study of Pacritinib (PAC) Versus Best Available Therapy (BAT), Including Ruxolitinib (RUX), in Patients (pts) with Myelofibrosis (MF) and Platelet Counts

Results of the Persist-2 Phase 3 Study of Pacritinib (PAC) Versus Best Available Therapy (BAT), Including Ruxolitinib (RUX), in Patients (pts) with Myelofibrosis (MF) and Platelet Counts <100,000/µl

Correlation Between Treatment Outcomes, Baseline Characteristics and Molecular Responses in the Majic Study Which Compared Ruxolitinib to Best Available Therapy in Essential Thrombocythemia

MAJIC is a phase II trial of Ruxolitinib (RUX) vs Best Available Therapy (BAT) in essential thrombocythemia (ET) patients with resistance/intolerance to Hydroxycarbamide (HC) per European LeukemiaNet (ELN) criteria. Primary outcome was rate of complete hematological response (CHR) within 1 year (ELN criteria); secondary outcomes included partial HR, safety, thrombosis, hemorrhage, progression free survival (including transformation), molecular response (MR), symptom & quality of life (QOL) assessment. We present new data concerning molecular, symptom & clinical responses. Patients were stratified by JAK2V617F status, patient-reported symptoms & QOL determined using EQ5D, MDASI & MPN Symptom Assessment Form (MPN10), & compared using linear mixed models of post-baseline scores through month 12 adjusting for baseline; response was defined as ≥50% reduction in MPN10 total symptom score (TSS). JAK2/CALR/MPL allele burdens were assessed at baseline & 4 monthly. 110 patients were eligible for the modified ITT analysis, 58 (52%) & 52 (48%) in RUX & BAT arms respectively, comprising 44 males, 66 females, mean age 64.2ys, & resistant (24.5%), intolerant (51.8%) or both (22.7%) to HC. CHR was achieved in 27 (46.6%) of RUX patients vs 23 (44.2%) BAT patients (χ2 test p= 0.81). PHR occurred in 26 (44.8%) & 27 (51.9%) of RUX & BAT treated respectively. Grade 3 or 4 anemia occurred in 19% & 0% for RUX arm vs 0% (both grades) for BAT arm, grade 3 or 4 thrombocytopenia in 5.2% & 1.7% of RUX vs 0% (both grades) of BAT patients respectively. Grade 3 or 4 infections occurred in 10.3% of RUX patients vs 3.6% BAT arm. 9 RUX treated patients had 10 thrombotic events & 1 RUX patient a hemorrhage; vs 5 thrombotic & 5 hemorrhagic events in BAT patients (adjusted following central review). Transformations to post-ET MF occurred in 8 RUX vs 3 BAT treated patients, 1 RUX patient developed AML. 2 non-treatment related deaths occurred in each arm. Mean MPN-10 TSS & individual symptoms of early satiety & itching during the first 12 months were all significantly lower for RUX vs BAT (all p Allele burden during study & MRs (per ELN-IWG criteria Barosi Blood 2013) are shown in Table 1. Assays for JAK2 V617F were performed independently in 3 centres using qPCR (Guy9s), TSCA NGS (Oxford) & amplicon-based NGS (Salisbury) & revealed Mean (range): JAK2 (Guy9s): 33.2 (0.1-94.6), N=52; JAK2 (Oxford): 38.0 (0.5-92.2), N=52; JAK2 (Sal): 38.3 (0-90.0), N=50 (limited to JAK2 positive only). With Interclass Correlation Coefficient as follows ICC (Guy9s v Oxford): 0.92 (95% CI 0.86-0.95) ICC (Guy9s v Sal): 0.92 (95% CI 0.86-0.95) ICC (Oxford v Sal): 0.997 (95% CI 0.994-0.998). Notably MRs (n=5) only occurred with RUX treatment. There was no pattern of MR or progression with C/PHR or transformation, but 1 patient who transformed to PET MF had a complete MR. In a separate analysis baseline symptoms & QOL were not associated with JAK2, CALR, nor MPL status. Within RUX, baseline symptoms & QOL did not predict MR; however, fatigue, early satiety & abdominal discomfort (all p Three non pre-specified multivariate analyses were performed to assess baseline factors influencing CHR (modelled for: treatment received, HC resistance or intolerance, white cell count, platelets, Hb & JAK2/CALR status); occurrence of ≥ grade 3 anemia or thrombocytopenia (modelled for: Hb (≥ 100g/dl) JAK2/CALR status); & transformation to PET-MF (modelled for: treatment, Hb ≤100g/dl). Only baseline Hb ≤100g/dl was significant for grade 3+ anemia (OR [95% CI]=0.17 [0.04, 0.72]), & PET-MF only occurred in patients with baseline WBC This updated analysis shows that HC resistant/intolerant ET is clinically & molecularly diverse. We confirm that these patients are at high risk of thrombosis & transformation as suggested in prior retrospective studies. Molecular responses were limited to RUX & for the first time we demonstrate such responses may correlate with symptom improvement but not always with progression events. Disclosures Harrison:Shire: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Incyte Corporation: Honoraria, Speakers Bureau; Baxaltra: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau. Mead:Novartis: Honoraria, Research Funding, Speakers Bureau. Aliman:Novartis: Other: Institutional funding and grant for international conference. . Chen:Novartis: Other: Advisory Board. Coppell:Novartis: Other: Travel, accommodation and conference attendance. Knapper:ONO pharmaceuticals: Research Funding; Novartis: Honoraria, Other: Travel and expenses for international conferences. Ali:Novartis: Honoraria, Other: Conference sponsorship, advisory board meetings. Hamblin:Novartis: Other: Advisory Board. Dueck:Bayer: Honoraria. Cross:Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau. Mesa:Celgene: Research Funding; Promedior: Research Funding; CTI: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Galena: Consultancy; Ariad: Consultancy; Novartis: Consultancy. McMullin:Novartis: Honoraria, Speakers Bureau.

Relationship of JAK2V617F Allelic Burden (AB) to Demographics, Disease Characteristics, and Response to Therapy in Persist-1, a Randomized Phase III Study of Pacritinib (PAC) Versus Best Available Therapy (BAT) in Patients (pts) with Primary and Secondary Myelofibrosis (MF)

Background: The majority of pts with MF present with a mutation in exon 14 of the JAK2 gene (JAK2V617F). Studies have suggested that in pts with MF and this mutation, a lower AB is associated with a myelodepletive phenotype and shortened survival (Tefferi, Leukemia 2008; Guglielmelli Blood 2009; reviewed in Vannucchi, Ther Adv Hematol 2011). For example, in a Cox proportional hazard model for factors predictive of overall survival (OS) in pts with primary MF, a JAK2V617F AB of <25% was associated with a shortened OS (p=0.002; Guglielmelli, Blood 2009). In the phase III trials of ruxolitinib (RUX) therapy in JAK inhibitor-naïve MF, RUX-treated pts had a median decrease in AB of 16% (maximal) in COMFORT-I followed up to 216 weeks and 7% in COMFORT-II at 48 weeks. The median AB at the start of therapy was not reported for COMFORT-I and in COMFORT-II was 84.5% (Cervantes, Blood 2013; Deininger, Blood2015).Methods: In this communication, we report on clinical correlates of quantitative baseline JAK2 mutational status and the effect of treatment on JAK2V617Fmutational burden in the PERSIST-1 trial. This trial enrolled JAK inhibitor-naïve pts with primary or secondary MF without restrictions on baseline platelet counts, randomized 2:1 between PAC and BAT (excluding JAK2 inhibitors) arms. Stratifications included Dynamic International Prognostic Scoring System (DIPSS) risk category, and baseline platelet counts (<50,000/μL, 50,000-100,000/μL, >100,000/μL). Following the 24-week primary analysis, crossover was allowed by physician/pt choice and 90/107 BAT-treated pts (84%) crossed over to receive PAC. Baseline characteristics have been previously reported (Mesa, ASCO 2016) and included 203/327 (62%) pts with Primary MF, 42 (13%) with post-essential thrombocythemia MF and 81 (25%) with post-polycythemia vera MF. 320 of 327 pts had informative PCR testing for JAK2V617F. We report the baseline characteristics of pts with high (≥50%) AB of JAK2V617F, low (<50%) AB of JAK2V617Fand those without a detectable mutation at baseline (<0.1%), as well as the effect of PAC and BAT on AB and correlation with outcome measures.Results: 131 (40.9%) had AB >50% (high AB), 115 (35.9%) had an AB ≥0.1% and ≤50% (low AB), and 74 (23.1%) had AB <0.1% (wild-type JAK2). Median AB values were 80.3% for the high AB group and 30.3% for the low AB group. Baseline characteristics that were significantly different between high and low AB pts are shown in the Table. No differences were noted in the DIPSS risk category or baseline percentage of blasts between pts with low or high AB. There were a higher percentage of pts with a lower AB in the PAC arm (64% vs. 48%; p=0.01). PAC therapy resulted in a median decrement in AB at Week 24 of −15.8% vs −7.9% for pts in the BAT arm (Figure). The median greatest reduction from baseline in AB in PAC-treated pts was −31.6%. Decrease in AB was strongly correlated with spleen volume reduction (p=0.003) and trended towards correlation with improvement in total symptom score (p=0.07) in PAC-treated, but not in BAT-treated pts. Overall survival was shorter in PAC-treated pts with a minimal AB reduction vs pts with greater decreases in AB.Conclusions: In the PERSIST-1 trial, pts with a JAK2V617FAB of <50% had substantially different disease and demographic characteristics when compared with those pts with a >50% AB despite similar distribution of DIPSS scores. In this trial, reduction in AB associated with PAC, but not BAT correlated with clinical benefit. [Display omitted] [Display omitted] DisclosuresVannucchi:Novartis: Consultancy, Research Funding, Speakers Bureau; Baxalta: Speakers Bureau; Shire: Speakers Bureau. Mead:Baxalta: Consultancy, Honoraria. Perkins:Novartis Oncology: Consultancy, Honoraria; Bristol-Myers Squibb: Other: Travel, Accommodations, Expenses. Mayer:CTI BioPharma Corp.: Other: Travel, Accommodations, Expenses, Research Funding. Schouten:Sanofi: Consultancy; Novartis: Consultancy. Farber:Alexion: Equity Ownership; Celgene: Honoraria, Research Funding, Speakers Bureau; Genentech: Research Funding, Speakers Bureau; Acerta: Research Funding; Gilead: Research Funding, Speakers Bureau; TG Therapeutics: Research Funding; Seattle Genetics: Speakers Bureau; Pharmacyclics: Speakers Bureau. Kiladjian:Novartis: Honoraria, Research Funding; AOP Orphan: Consultancy, Research Funding. Nangalia:Novartis: Consultancy, Other: Travel, Accommodations, Expenses. Dean:CTI BioPharma Corp.: Employment, Equity Ownership. Zhou:CTI BioPharma Corp.: Employment, Equity Ownership. Singer:CTI BioPharma Corp.: Employment, Equity Ownership, Other: Leadership . Mesa:Novartis: Consultancy, Honoraria; Incyte: Research Funding; Gilead: Research Funding; CTI BioPharma: Research Funding; Celgene: Research Funding; Genetech: Research Funding; Promedior: Research Funding. Harrison:Novartis: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; CTI BioPharma: Consultancy, Honoraria, Speakers Bureau; Baxter: Consultancy, Honoraria; Shire: Speakers Bureau; Gilead: Speakers Bureau; Incyte: Speakers Bureau.

A Pooled Overall Survival (OS) Analysis of 5-Year Data from the COMFORT-I and COMFORT-II Trials of Ruxolitinib for the Treatment of Myelofibrosis (MF)

A Pooled Overall Survival (OS) Analysis of 5-Year Data from the COMFORT-I and COMFORT-II Trials of Ruxolitinib for the Treatment of Myelofibrosis (MF)

A Review of Ruxolitinib for the Treatment of Myelofibrosis: A Critique of the Evidence.

As part of the National Institute for Health and Care Excellence's (NICE) Single Technology Appraisal (STA) process, ruxolitinib was assessed to determine the clinical and cost effectiveness of its use in the treatment of disease-related splenomegaly or symptoms in adults with myelofibrosis. Ruxolitinib had previously been assessed as part of the STA process and was not recommended in NICE guidance issued in June 2013 (TA289). A review of TA289 was commissioned following the availability of new longer-term survival data; a price discount patient access scheme (PAS) was also introduced. The Centre for Reviews and Dissemination (CRD) and Centre for Health Economics (CHE) Technology Appraisal Group at the University of York was commissioned to act as the independent Evidence Review Group (ERG). This article provides a summary of the manufacturer or sponsor of the technology's (referred to as the company) submission, the ERG review and the resulting NICE guidance issued in March 2016. The main clinical effectiveness data were derived from two good-quality multicentre randomised controlled trials (RCTs): COMFORT-II compared ruxolitinib with best available therapy (BAT) and COMFORT-I compared ruxolitinib with placebo. Both RCTs demonstrated a statistically significant reduction in splenomegaly and its associated symptoms in intermediate-2 and high-risk myelofibrosis patients. Overall survival was statistically significantly improved with ruxolitinib compared with BAT at 3.5years of follow-up in the COMFORT-II trial (hazard ratio 0.58, 95% CI 0.36-0.93). Grade 3-4 adverse events were more frequent in the ruxolitinib group than in the BAT group; 42% compared with 25%. Evidence relating to patients with lower-risk disease or low platelet counts (50-100×109/L) was less robust. The company's economic model was well-presented and had an appropriate model structure. The base-case incremental cost-effectiveness ratio (ICER) was estimated to be around £45,000 per quality-adjusted life-year (QALY) gained (including the PAS discount). Extensive sensitivity and scenario analyses were presented, demonstrating that the estimated ICER was robust to a range of input values and assumptions made in the model. Alternative scenarios presented by the ERG showed only modest increases in the estimated ICER, primarily as a result of including an element of drug wastage within the model. Alternative scenarios resulted in estimated ICERs ranging from around £45,000 to £49,000 per QALY gained (including the PAS discount). At the first appraisal meeting, the NICE Appraisal Committee concluded that ruxolitinib was clinically effective and was a cost effective use of National Health Service (NHS) resources for patients with high-risk myelofibrosis who meet NICE's end-of-life criteria. Following the consultation, the company offered a revised PAS, resulting in a revised base-case ICER of £31,229 per QALY gained. The company also presented new evidence on the cost effectiveness of ruxolitinib in intermediate-2 and high-risk subgroups and a revised version of the model. The NICE Appraisal Committee considered the new evidence and recommended ruxolitinib for the treatment of patients with intermediate-2-risk disease as well as patients with high-risk disease, based on International Prognostic Scoring System (IPSS) prognostic factors.

Pacritinib (PAC) vs best available therapy (BAT) in myelofibrosis (MF): Long-term follow-up of patient-reported outcomes (PROs) in the phase III PERSIST-1 trial.

7067Background: MF is a life-threatening hematologic malignancy that can markedly impact patient (pt) quality of life. PERSIST-1 compared PAC vs BAT, excluding JAK2 inhibitors, in pts with MF, rega...

Pacritinib (PAC) vs best available therapy (BAT) in myelofibrosis (MF): Outcomes in patients (pts) with baseline (BL) thrombocytopenia.

7011Background: Many pts with MF present with cytopenias, which are often progressive, and effective treatment (Tx) options that do not induce myelosuppression are limited. PAC, an oral kinase inhi...

Pacritinib (PAC) vs best available therapy (BAT) in myelofibrosis (MF): 60 week follow-up of the phase III PERSIST-1 trial.

7065Background: Effective treatment (Tx) options for patients (pts) with MF that do not induce myelosuppression are limited. PAC, an oral kinase inhibitor with specificity for JAK2, FLT3, IRAK1, an...

What Is Best Available Therapy (BAT) for the Treatment of Carbapenem-Resistant (CR) Gram-Negative Infections in the United States?

What Is Best Available Therapy (BAT) for the Treatment of Carbapenem-Resistant (CR) Gram-Negative Infections in the United States?

Analysis of Outcomes By Patient Subgroups in Patients with Myelofibrosis Treated with Pacritinib Vs Best Available Therapy (BAT) in the Phase III Persist-1 Trial

Introduction: There are few effective treatment options available for patients (pts) with myelofibrosis (MF). Pts with thrombocytopenia, a risk factor for shorter overall survival, have poorer prognosis (Gangat, J Clin Oncol 2010). Pacritinib is a kinase inhibitor with specificity for JAK2, FLT3, IRAK1, and CFSR1 and has demonstrated minimal myelosuppression in clinical trials (Hart, Leukemia 2011; Komrokji, Blood 2015; Mesa, ASCO 2015). In the phase III open-label PERSIST-1 trial, a significantly greater proportion of pts treated with pacritinib achieved spleen volume reductions (SVR) ≥35% vs BAT (ITT: 19.1% vs 4.7%, p=0.0003; pts evaluable at baseline and Week 24: 25.0% vs 5.9%, p=0.0001; Mesa, ASCO 2015). This analysis examines pt responses across subgroups.Methods: Pts naive to treatment with JAK inhibitors were randomized 2:1 to receive oral pacritinib 400 mg once daily or BAT. Stratification factors included DIPSS risk status and baseline platelet count. Pts were eligible who had DIPSS Intermediate (Int)-1, Int-2, or High risk disease; absolute neutrophil count >500/µL; palpable splenomegaly ≥5 cm; and baseline Total Symptom Score (TSS) ≥13 using the Modified MPN Symptom Assessment Form Total Symptom Score (MPN-SAF TSS and TSS 2.0). There was no restriction on baseline platelets or hemoglobin (Hgb) levels. The primary endpoint was the proportion of pts achieving SVR ≥35% at Week 24 by centrally-reviewed MRI or CT and the secondary endpoint was the proportion of pts achieving ≥50% reduction in TSS from baseline at Week 24 using 6 symptoms from the MPN-SAF TSS. Pt responses were analyzed by baseline risk factors for MF including platelet counts (<50,000/µL vs ≥ 50,000/µL and <100,000/µL vs ≥100,000/µL), sex, age (≥65 y vs <65 y), JAK2V617F mutation status (positive vs negative), baseline MF diagnosis (primary MF [PMF] vs secondary MF), reticulin and collagen fibrosis staging (> 1 vs ≤1), TSS (≥20 vs <20), white blood cell count (>25×109/L vs ≤25×109/L), peripheral blasts (≥5% vs <5%), Hgb (<10 g/dL vs ≥10 g/dL), transfusion dependency by Gale criteria (Y vs N), time from diagnosis (<12 mos vs ≥12 mos), ECOG PS (2-3 vs 0-1), and bone pain (>3 vs ≤3). In multivariate logistic regressions, the odds of SVR ≥35% and TSS reduction ≥50% at Week 24 were modeled as a function of prognostic factors for MF and adjusted for treatment (pacritinib vs BAT). Results for the 6 symptoms common to both TSS versions are reported.Results: 327 pts were enrolled and randomized (pacritinib: 220, BAT: 107). Overall, 62% of pts had PMF; 32% had baseline platelets <100,000/µL and 16% had <50,000/µL; 75% were positive for JAK2V617F. After a median follow-up of 8.4 months, treatment with pacritinib resulted in consistent rates of SVR across subgroups (Figure 1). When comparing vs BAT, the greatest differences in SVR ≥35% rates between treatment arms were observed in pts with baseline platelets <50,000/μL (+22.9% vs BAT), JAK2V617F-negative pts (+23.0% vs BAT) and those aged <65 y (+21.2% vs BAT). Improvements in TSS (TSS and TSS 2.0 reduction ≥50%) were also consistent for pts receiving pacritinib (Figure 2). By multivariate analysis, SVR ≥35% was significantly correlated only with ECOG PS ≥2 (odds ratio [OR]=2.97, p=0.030) and TSS reduction ≥50% was significantly correlated only with bone pain >3 (OR=0.35, p=0.004).Conclusions: Treatment with pacritinib resulted in consistent rates of SVR ≥35% and TSS reduction ≥50% irrespective of baseline characteristics. Comparisons vs BAT were favorable for all patient subpopulations examined for both endpoints. These results support the use of pacritinib across all intermediate- or high risk MF pt subgroups analyzed. [Display omitted] [Display omitted] DisclosuresVannucchi:Shire: Speakers Bureau; Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees. Off Label Use: This abstract discusses off-label use of pacritinib. Mesa:Gilead: Research Funding; NS Pharma: Research Funding; Incyte Corporation: Research Funding; Genentech: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Promedior: Research Funding; Pfizer: Research Funding; CTI Biopharma: Research Funding. Cervantes:Novartis: Consultancy, Speakers Bureau; Sanofi-Aventis: Consultancy; CTI-Baxter: Consultancy, Speakers Bureau. Prasad:BIOGEN IDEC: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Speakers Bureau. Elinder:Celgene: Consultancy. Recher:Sunesis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Chugai: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. te Boekhorst:CTI Biopharma: Consultancy; Novartis: Consultancy. Somervaille:Novartis Pharmaceuticals Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees. Dean:CTI Biopharma: Employment, Equity Ownership. Harrison:Shire: Speakers Bureau; Gilead: Honoraria; CTI Biopharma: Consultancy, Honoraria, Speakers Bureau; Sanofi: Honoraria, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau.

Long-Term Efficacy and Safety in COMFORT-II, a Phase 3 Study Comparing Ruxolitinib with Best Available Therapy for the Treatment of Myelofibrosis: 5-Year Final Study Results

Long-Term Efficacy and Safety in COMFORT-II, a Phase 3 Study Comparing Ruxolitinib with Best Available Therapy for the Treatment of Myelofibrosis: 5-Year Final Study Results

The Effect of Ruxolitinib on White Blood Cell Counts in Patients with Polycythemia Vera: Results from the RESPONSE Trial

Background: Age, prior thrombotic events, and an elevated hematocrit are established risk factors for increased risk of thrombosis in patients with polycythemia vera (PV). Evidence also suggests that elevated white blood cell (WBC) counts ≥ 11×109/L are a significant independent risk factor for thrombosis in patients with PV (P =0.02; Barbui T, et al. Blood. 2015; 126:560-561). Therefore, this analysis was conducted to evaluate the impact of ruxolitinib (Rux) and best available therapy (BAT) treatment on WBC counts among patients with Baseline WBC counts ≥ 11×109/L in the RESPONSE trial. RESPONSE is a global, multicenter, open-label phase 3 trial investigating Rux and BAT in patients with PV who are resistant to or intolerant of hydroxyurea (HU). In the RESPONSE trial, Rux was associated with durable improvements in hematocrit control without phlebotomy compared with BAT as well as reductions in WBC counts.Methods: Changes from Baseline in WBC counts in the Rux arm (n=110), BAT arm (n=112), and HU subgroup of the BAT arm (n=66) were evaluated as part of an exploratory analysis using the RESPONSE 80-Week analysis dataset. Patient subgroups with Baseline WBC counts ≥ 11×109/L and < 11×109/L were analyzed for changes in WBC counts at Weeks 12, 32, and 80. For patients with Baseline WBC counts ≥ 11×109/L, the proportion of patients who achieved a decrease in WBC counts to ≤ 10×109/L or a ≥50% reduction at Week 12 and Week 32, respectively, was summarized; time to achieve the decrease was analyzed by Kaplan-Meier method.Results: Baseline mean WBC counts were generally similar among patients in the Rux arm, BAT arm, and HU subgroup (17.6×109/L, 19.0×109/L, and 17.4×109/L, respectively). The proportion of patients with Baseline WBC counts ≥ 11×109/L was also similar among the Rux arm, BAT arm, and HU subgroup (75%, 71%, and 70%, respectively). In patients with Baseline WBC counts ≥ 11×109/L, patients treated with Rux had greater mean reductions in WBC counts compared with the BAT arm and HU subgroups, and these reductions were maintained over time; mean changes from Baseline in WBC values at Week 12/Week 32 (×109/L) were -7.7/-7.2 for Rux, -3.2/-4.2 for BAT, and -1.2/-2.2 for HU. In patients with lower Baseline WBC counts, mean values remained stable over time. The change from Baseline to Week 12 for individual patients with Baseline WBC counts ≥ 11×109/L is shown in Figure 1. In patients with Baseline WBC counts ≥ 11×109/L, worsening WBC counts were observed in 10.8% of patients in the Rux arm vs 35.4% in the BAT arm (P =0.0002) and 47.8% in the HU subgroup (P <0.0001). In this same subgroup with elevated WBC counts, a greater proportion of patients in the Rux arm achieved WBC counts ≤ 10×109/L or a ≥50% reduction compared with the BAT arm or HU subgroup (Week 12: Rux, 41% vs BAT, 19% vs HU, 13%; Week 32: Rux, 45% vs BAT, 22% vs HU, 9%); median time to this reduction was 8 weeks in the Rux arm and was not reached in the BAT arm or HU subgroup.Conclusion: Rux treatment resulted in better control of WBC counts compared to BAT in patients with PV. These changes in the Rux arm occurred early after study initiation (within a median of 8 weeks) and were durable over time. Although RESPONSE was not powered to assess the impact of Rux on thromboembolic events, the lower rate of thromboembolic events observed in the Rux arm vs the BAT arm (1.8 vs 8.2 per 100 patient-years of exposure) is consistent with the observed effects of Rux on hematocrit, WBC counts, and C-reactive protein levels, which are all associated with thromboembolic risk. [Display omitted] DisclosuresMiller:Incyte Corporation: Honoraria, Research Funding. Kiladjian:Novartis: Other: Travel grant; Research Funding paid to institution (Hôpital Saint-Louis et Université Paris Diderot); Incyte Corporation: Consultancy; Novartis: Consultancy. Naim:Incyte Corporation: Employment, Equity Ownership. Sun:Incyte Corporation: Employment, Equity Ownership. Gadbaw:Novartis Pharmaceuticals Corporation: Employment, Equity Ownership. Vannucchi:Baxalta: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Shire: Speakers Bureau.

Mutational Profile of Patients with Polycythemia Vera Treated with Ruxolitinib in the Phase III Controlled Response Study

Background. The JAK1/2 inhibitor ruxolitinib (RUX) demonstrated clinical benefit compared with best available therapy (BAT) in patients (pts) with polycythemia vera (PV) in a phase 3 study (RESPONSE TRIAL) (NEJM 2015; 372:426). A reduction of JAK2 V617F allele burden of 12.1% from baseline at week (w)32 was observed in pts receiving ruxolitinib compared to BAT (1.2%). Conversely, no information was available about other mutations that may occur in some PV pts.Aim. To analyze the molecular landscape of PV pts enrolled in the RESPONSE trial specifically as regarded subclonal mutations.Methods: In the RESPONSE study, PV pts with intolerance or refractoriness to hydroxyurea, showing an enlarged spleen volume (SV) >450 ml and phlebotomy requirement, were randomized (1:1) to receive RUX (n = 110) or BAT (n = 112). After institutional approval and informed written consent, samples for genotyping were available in 150 cases (67.5% of total, 75 each RUX and BAT). Mutations in 22 genes (JAK1, JAK2, JAK3, EZH2, ASXL1, TET2, IDH1, IDH2, CBL, SRSF2, DNMT3A, NFE2, SOCS1, SOCS2, SOCS3, SH2B3, STAT1, STAT3, STAT5A, STAT5B, SF3B1, U2AF1) were analyzed in blood DNA at baseline and at the latest available sample by deep sequencing with Ion Torrent-PGM. CALR mutations were analyzed by capillary electrophoresis. JAK2 V617F allele burden was confirmed by RT-qPCR assays.Results. 149/150 patients had informative sequencing results (RUX, n = 74 and BAT, n = 75). Mutation frequency at baseline in RUX pts was: JAK2 V617F 97.3% (mean allele burden=83.7±20.0%); JAK2Exon12 1.3%; other mutations in JAK2 5.4%; JAK3 1.3%; ASXL1 4.0%; TET2 20.3%; EZH2 4.0%; CBL 1.3%; SH2B3 2.0%; SOCS1 2.7%; NFE2 2.7%; STAT5A 1.3%. No somatic variants were detected in CALR, JAK1, SRSF2, IDH1, IDH2, SOCS2, SOCS3, DNMT3, STAT1, STAT5B, SF3B1, U2AF1. These frequencies were comparable in BAT arm. One patient was un-mutated in all assessed genes. 28.4% and 8.1% of RUX and 32.0% and 8.0% in BAT pts had 1 and >2 subclonal mutations, respectively. The proportion of PV pts harboring at least 1 mutation in either ASXL1, EZH2, SRSF2, IDH1/2, was significantly lower (8.1% in RUX and 10.6% in BAT) compared to reference series of primary myelofibrosis pts (31%) as it was for those having >2 HMR mutations (0.0 in RESPONSE vs 7.4% in PMF) (Leukemia 2014;28:1804)The median duration of treatment corresponding to the latest available sample for analysis was 82.8w; at that time, 43 pts (58.1%) randomized to RUX achieved a JAK2 V617F allele burden reduction ≥10%, of which 15 (20.3%) had >50% reduction. Among the latter pts, the median allele burden was 83.7% at baseline, 84.9%, 55.1% and 44.3% at 1, 2, and 3 years. Three patients attained an allele burden below 5% (from 65.1%, 17.3% and 83.7% at baseline to 3.2%, 0.5% and 1.4%, respectively, at latest follow up).Of the 27 pts harboring subclonal mutations at baseline, 12 (44.4%) presented a reduction of mutational allele burden ≥10%: 4 in JAK2 (other than JAK2 V617F/exon 12 mutations), 4 in TET2, 3 in ASXL1 and 1 each in JAK3, EZH2 and SH2B3. In 10 of the 12 pts, comparable decreases in JAK2 V617F allele burden were observed, suggesting reduction of a single clone expressing both mutations. Conversely, in 5 pts (18.5%) the allele burden of a baseline TET2 clone at increased by ≥10% (range: 10-37%); of these, one had concurrent reduction of JAK2 V617F burden from 17.3 to 0.5, thereby suggesting two independent clones.Eight pts (29.6%) acquired new mutations: 3 in TET2, 3 in U2AF1, 1 in DNMT3A and 1 in IDH1. Among these, 4 pts had achieved a reduction ≥10% of JAK2 V617F allele burden (18.4%, 25.4%, 30.5% and 39.4%, respectively). Three pts (4.0%) progressed during treatment (2 myelofibrosis,1 acute leukemia); no novel acquired mutation in the 22 genes was observed in these pts. All 3 pts were homozygous for V617F (92.3%, 72.7% and 59.0%) and did not show appreciable changes of allele burden during treatment.Conclusions. The current study identifies mutations and mutational combinations at baseline and during follow up in a representative cohort of pts enrolled in RESPONSE trial and treated with Ruxolitinib. We observed progressive reduction of JAK2 V617F allele burden that in some cases was associated with concurrent reduction of subclonal mutations. Conversely, emergency of novel clones as observed in some pts, whose significance might be clarified by ongoing analysis of hydroxyurea and phlebotomy treated patients that will be presented at the meeting. DisclosuresMahtab:Novartis Pharma AG: Employment. Rodriguez:Novartis Pharma: Employment. Vannucchi:Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Shire: Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees.

Continued Treatment with Ruxolitinib Provides Additional Hematocrit Control and Spleen Volume Responses in Patients with PV Treated in the RESPONSE Study

Continued Treatment with Ruxolitinib Provides Additional Hematocrit Control and Spleen Volume Responses in Patients with PV Treated in the RESPONSE Study

Relationship Between Patient-Reported Outcomes (PROs) and Health-Related Quality of Life (HRQoL) and Efficacy in Patients with Myelofibrosis in the Phase III Persist-1 Trial of Pacritinib Vs. Best Available Therapy (BAT)

Introduction: Myelofibrosis (MF) is a life-threatening hematologic malignancy characterized by splenomegaly and debilitating symptoms including fatigue, abdominal pain, night sweats, bone pain, pruritus, and unintentional weight loss. The myeloproliferative neoplasm symptom assessment form (MPN-SAF) is a PRO tool designed to measure MF-related symptom burden and was developed and validated at Mayo Clinic. It was modified (MPN-SAF total symptom score [TSS] and TSS 2.0) for use in the PERSIST-1 and PERSIST-2 phase 3 trials. For PERSIST-1, when examining the 6 common symptoms in both TSS versions (tiredness, night sweats, early satiety, itchiness, bone pain, and abdominal pain), pacritinib-treated patients (pts) had significant improvements in TSS overall and in individual symptoms vs BAT; Pt Global Impression of Change (PGIC) was also significantly improved for pts receiving pacritinib. Improvements in EORTC-QLQ-C30 scales were noted in the pacritinib arm (Mesa, EHA 2015). The proportion of pts achieving spleen volume reduction (SVR) ≥35% at Week 24 was significantly greater with pacritinib vs BAT (ITT: 19.1% vs 4.7%, p=0.0003; evaluable at baseline and Week 24: 25.0% vs 5.9%; p=0.0001). This analysis examines relationships between TSS improvement and changes in splenomegaly and HRQoL outcomes.Methods: Pts who received no prior JAK inhibitor therapy were randomized 2:1 to oral pacritinib 400 mg once daily or BAT. Pts were stratified by DIPSS risk (Int-1/Int-2 vs High) and platelet count (<50,000/μL vs 50,000/μL to <100,000/μL vs ≥100,000/μL). Pts must have had a baseline total TSS ≥13 using MPN-SAF TSS 2.0. Each symptom is rated on a scale from 0 (absent) to 10 (worst imaginable) using MPN-SAF TSS and TSS 2.0. Results for the 6 symptoms common to both TSS versions are reported. Additional PROs used for assessment of HRQoL included EORTC QLQ-C30 and EQ-5D-5L. In multivariate logistic regressions, odds of TSS reduction ≥50% at Week 24 were modeled as a function of Week 24 SVR ≥35%, spleen length reduction (SLR) ≥ 50%, PGIC, improvement in each EORTC scale, and improvement in EQ-5D-5L Overall Health State (OHS) and in each dimension individually while adjusting for treatment (pacritinib vs BAT). Correlations were examined in all pts and by baseline platelet counts (<50,000/μL, <100,000/μL, and ≥100,000/μL).Results: A total of 327 pts were enrolled (PAC: 220, BAT: 107). 62% of pts had primary MF, 32% had baseline platelets <100,000/μL, and 16% had baseline platelets <50,000/μL. TSS reduction ≥50% was found to be associated with SVR ≥35% and improvement in splenomegaly (SLR ≥50%). In the total pt population, there was a significant association between TSS reduction and SVR (odds ratio [OR]=2.60, p=0.016). In all pts, there was a significant association between TSS reduction and improvements in OHS as measured by EQ-5D-5L (OR=2.30, p=0.013). TSS reductions were also marginally associated with improvements in the QLQ-C30 Global Health Scale (GHS)/QoL Scale (OR=1.92, p=0.050) and, though not statistically significant, there was a trend of improvement in perceived overall health as measured by PGIC (OR=2.16, p=0.118). TSS reductions were further examined in pts grouped by baseline platelet count. Improvement in EQ-5D-5L OHS was marginally associated with TSS reductions in pts with platelets <50,000/μL (OR=6.03, p=0.057). For pts with platelets <100,000/μL, reductions in TSS were significantly associated with reductions in splenomegaly (SLR ≥50%; OR=9.53, p=0.004), and improvements in the QLQ-C30 GHS/QoL domain (OR=4.03, p=0.022) as well as the EQ-5D-5L OHS (OR=5.49, p=0.008). A significant association between TSS reductions and SVR ≥35% was observed in pts with platelets ≥100,000/μL (OR=3.99, p=0.005). In all pts, improvements in Fatigue as measured by QLQ-C30 were significantly associated with TSS reductions (OR=2.20, p=0.019) as well as in pts with baseline platelets <50,000/μL (OR=17.88, p=0.008) and <100,000/μL (OR=10.18, p<0.001).Conclusions: In the total pt population, TSS reduction was associated with improvements in spleen response and perceived overall health. This trend was also observed in pts with low baseline platelet counts. Additionally, TSS reduction was significantly associated with improvements in fatigue, a major contributor to poor HRQoL in pts with MF. This reinforces the clinical relevance of measuring TSS using a validated instrument as an endpoint in MF trials. DisclosuresMesa:NS Pharma: Research Funding; Pfizer: Research Funding; Gilead: Research Funding; Incyte Corporation: Research Funding; CTI Biopharma: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Genentech: Research Funding; Promedior: Research Funding. Off Label Use: This abstract discusses off-label use of pacritinib. Harrison:Shire: Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau; Gilead: Honoraria; CTI Biopharma: Consultancy, Honoraria, Speakers Bureau; Sanofi: Honoraria, Speakers Bureau. Cervantes:Novartis: Consultancy, Speakers Bureau; Sanofi-Aventis: Consultancy; CTI-Baxter: Consultancy, Speakers Bureau. Dean:CTI Biopharma: Employment, Equity Ownership. Wang:CTI Biopharma: Employment, Equity Ownership. Yang:Baxalta: Employment, Other: Stock. Vannucchi:Shire: Speakers Bureau; Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees.

Demographics, Baseline Characteristics, and Disease Symptom Burden in RESPONSE-2: A Randomized, Phase 3 Study of Ruxolitinib in Polycythemia Vera Patients (pts) Who Are Resistant to or Intolerant of Hydroxyurea (HU)

BACKGROUND: Polycythemia vera (PV) is characterized by increased red cell mass often associated with elevated leukocyte and platelet counts, splenomegaly and significant symptom burden. In the RESPONSE study, which only enrolled PV patients with splenomegaly, ruxolitinib (Rux) demonstrated superior improvements in hematocrit (HCT) control and reductions in spleen volume compared with best available therapy (BAT) in pts who were resistant to or intolerant of HU. Supportive data included clinically meaningful improvements in PV-related symptom burden and quality of life (QOL) measures. Here, we describe the baseline (BL) characteristics and symptom burden of PV pts resistant to or intolerant of HU enrolled in the RESPONSE-2 study, which unlike RESPONSE, enrolled PV patients with a nonpalpable spleen.METHODS: RESPONSE-2 is an open-label, randomized (1:1), multicenter, phase 3 study evaluating the efficacy and safety of Rux vs BAT in PV pts who are HU-resistant/-intolerant, require phlebotomy (PBT), and have no palpable spleen. Pts' BL symptom burden, BL QOL and BL pt-reported outcomes (PRO) were assessed by using 10-items modified Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-SAF TSS), the Pruritus Symptom Impact Scale (PSIS), European QOL Questionnaire (EQ-5D-5L), and Work Productivity and Activity Impairment: Polycythemia Vera V2.0 (WPAI: PV).RESULTS: A total of 149 pts were enrolled. BL demographic data from both arms combined are summarized in the Table. Forty percent of the patients were resistant whereas 60% were intolerant of HU treatment. Other than HU, prior treatments included interferons (15.4%), alkylating agents (8.1%), alkyl sulfonates (2.7%), pyrimidine analogs (0.7%), and other antineoplastic agents (1.0%). Ninety-seven percent of pts had at least 1 PBT within 16 weeks (wks) prior to screening and 72% had ≥ 2 PBT within 24 wks prior to screening. Past medical histories included hypertension (49%), pruritus (23%) and fatigue (9%). BL demographics of pts in RESPONSE-2 were generally comparable with previous PV studies (Table). Despite using frequent phlebotomy and cytoreductive agents during the screening period prior to randomization, 55% and 52% of pts had WBC counts greater than 10 × 109/L and platelet counts greater than 400 × 109/L, respectively, suggesting inadequately controlled disease even while receiving therapy. Additionally, pts had significant symptom burden at BL as measured by the MPN-SAF with fatigue (3.6) and pruritus (3.4) (Table). As measured by EQ-5D-5L scale, 26% and 19% of pts reported moderate to extreme pain/discomfort and depression, respectively. In WPAI outcomes, 40 of 149 pts reported missing work due to PV accounting for 14.3% of their working time.SUMMARY/CONCLUSION: Demographic and BL data from the RESPONSE-2 study highlight the significant unmet medical need in this inadequately controlled HU-resistant/-intolerant PV population. As expected, pts in RESPONSE-2 reported lower scores for symptoms associated with splenomegaly (early satiety, 1.8 vs 2.0; abdominal discomfort, 1.7 vs 2.0) as compared with RESPONSE population. In comparison to PV pts with splenomegaly in the RESPONSE trial, pts without splenomegaly in the RESPONSE-2 trial have a distinct but comparable disease burden with marked fatigue and pruritus.Table 1Baseline demographics and symptoms (n = 149)Age, median (range), years66.0 (26.0, 87.0)Time since diagnosis of PV, median, months80.7Male, %57.7Female, %42.3ECOG performance status, % 0 172.5 26.8Hematocrit (%), median,(n=149)43.0n (%) < 40 ≥ 40 to ≤ 45 > 452 (1.3) 146 (98.0) 1 (0.7)WBC count (x 109/L), median (n=149)10.6n (%) ≤ 10 > 10 and ≤ 15 > 1567 (45.0) 43 (28.9) 39 (26.2)PLT count (x 109/L), median (n=148)420.0n (%) < 100 ≥ 100 and < 400 ≥ 400 to < 600 ≥ 6002 (1.3) 68 (45.6) 38 (25.5) 40 (26.8)JAK2 mutation, n (%) (n=149) Positive Negative Unknown143 (96.0) 4 (2.7) 2 (1.3)MPN-SAF Symptom (n)Mean (SD)Total score (n=145)2.0 (1.67)Fatigue (n=146)3.6 (2.72)Early satiety (n=145)1.8 (2.47)Abdominal discomfort (n=143)1.7 (2.44)Inactivity (n=142)2.1 (2.77)Concentration problem (n=146)2.3 (2.75)Night sweats (n=145)2.2 (3.07)Pruritus (n=145)3.4 (3.37)Bone pain (n=144)2.1 (2.89)Fever (n=144)0.2 (0.92)Weight loss (n=142)0.7 (1.72) DisclosuresPassamonti:Novartis: Consultancy. Cavo:JANSSEN, CELGENE, AMGEN: Consultancy. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Other: Research Funding paid to institution (University of Florence), Research Funding; Shire: Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees. Bensasson:Novartis: Employment. Khan:Novartis: Employment. Mounedji:Novartis: Employment.

Long-Term Follow-up in Interferon-Alpha Treated Polycythemia Vera Patients - a Single Center Analysis

▪Introduction: Interferon-alpha (IFNα) has been successfully used to treat myeloproliferative neoplasms (MPN) for 30 years, although never officially registered for this indication. Studies with new pegylated interferons are underway to finally achieve IFNα registration for MPN.Aims: The aim of this retrospective analysis was to investigate the long-term survival of polycythemia vera (PV) patients that received IFNα while being treated at the outpatient clinic of the Medical University of Vienna, a center that has been treating MPN with IFNα since 1984, and to compare it to patients that received best available therapy (BAT). All treatments were based on international recommendations and standardized center specific guidelines.Methods: The medical histories of patients diagnosed with PV according to the PVSG- or WHO-criteria were investigated and information on the course of the disease and on cytoreductive treatment was collected. For a patient to be included in the analysis, IFNα (conventional or pegylated IFNα2a, -2b, or IFNα2c, or lymphoblastoid IFNα) had to be given for at least 365 days, or, in patients who were followed for more than 10 years, for at least 10% of the observation period after the diagnosis of PV. IFNα-patients who did not fulfill these criteria were not included. The IFNα-patients were compared to patients who received BAT consisting of other cytoreductive agents and/or phlebotomy. A portion of IFNα-patients also received other cytoreductive agents. The patients were then divided into three risk groups based on a previously published score based on age at diagnosis (<57, 57-66, ≥67), venous thromboembolism at baseline and leukocyte counts at diagnosis ≥15 G/L (Fig. 1A). Kaplan-Meier plots were used to compute overall, fibrosis- and AML-free survival.Results: Of 129 patients, 67 received IFNα, 62 BAT (22 received no cytoreductive therapy). Median duration of IFNα treatment was 1981 days. Overall survival was generally better in patients treated with IFNα in all three risk groups. While the difference in the intermediate risk group did not reach significance (Fig. 1C), the survival benefit in the low risk group narrowly missed significance (p=0.127, Fig. 1B). More importantly, IFN-patients in the highest risk group lived significantly longer than patients receiving BAT (p=0.005, Fig. 1D). Median age in all three risk groups did not differ between the two groups, ruling out age as a possible confounder. Also, there were no other relevant differences between any of the groups. Although fibrosis-free survival differed in the low and intermediate risk group, no significant differences were observed. There was no benefit in leukemia-free survival in this analysis.Discussion: This study supports the theory that IFNα can have a beneficial impact not only on symptoms and blood counts of PV-patients, but also on the long-term outcome in regard of overall survival, even in high risk patients. However, due to the retrospective nature of this study, the low case number in some subgroups and the lack of information on the fitness of the individual patients, our results can only serve as an impulse on future studies investigating the long-term outcome of IFNα-patients in MPN. [Display omitted] DisclosuresOff Label Use: Interferon-alpha, use in myeloproliferative neoplasms. Gisslinger:AOP ORPHAN: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen Cilag: Honoraria, Speakers Bureau; Geron: Consultancy; Sanofi Aventis: Consultancy.

Pacritinib Bests Available Therapies for Myelofibrosis.

Abstract In a phase III trial, the JAK2 inhibitor pacritinib outperformed best-available therapy for patients with myelofibrosis.