Abstract: Interferon‐α2 reduces elevated blood cell counts and splenomegaly in patients with myeloproliferative neoplasms ( MPN ) and may restore polyclonal hematopoiesis. Its use is limited by inflammation‐mediated toxicity, leading to treatment discontinuation in 10‐30% of patients. Ruxolitinib, a potent anti‐inflammatory agent, has demonstrated benefit in myelofibrosis ( MF ) and polycythemia vera ( PV ) patients. Combination therapy ( CT ) with these two agents may be more efficacious than monotherapy with either, potentially improving tolerability of interferon‐α2 as well. We report the preliminary results from a phase II study of CT with pegylated interferon‐α2 and ruxolitinib in 50 MPN patients ( PV , n = 32; low‐/intermediate‐1‐risk MF , n = 18), the majority (n = 47) being resistant and/or intolerant to interferon‐α2 monotherapy. Objectives included remission (2013 revised criteria encompassing histologic, hematologic, and clinical responses), complete hematologic response ( CHR ), molecular response, and toxicity. Follow‐up was 12 months. Partial remission ( PR ) and sustained CHR were achieved in 9% and 44% of PV patients, respectively. In MF patients, complete or partial remission was achieved in 39%, and sustained CHR in 58%. The median JAK 2 V617F allele burden declined significantly in both groups. Hematologic toxicity was the most common adverse event and was managed by dose reduction. Thirty‐seven serious adverse events were recorded in 23 patients; the discontinuation rate was 20%. We conclude that CT with interferon‐α2 and ruxolitinib is efficacious in patients with low‐/intermediate‐1‐risk MF and, to a lesser extent, in patients with PV . These preliminary results encourage phase III studies as well as a study with CT in newly diagnosed MPN patients.

Abstract: Background: The Philadelphia-negative, chronic myeloproliferative neoplasms (MPN) include essential thrombocythemia (ET), polycythemia vera (PV) and primary myelofibrosis (MF) (PMF). Chronic inflammation and a deregulated immune system are considered important for clonal evolution and disease progression. Ruxolitinib is a potent anti-inflammatory agent and has shown great benefit in MPN patients (pts), reducing spleen size and inflammation-mediated symptoms, thereby improving quality of life (QoL). Interferon-alpha2 (IFNa2) has been used successfully for decades in the treatment of MPN. However, 10-20% of pts are intolerant to IFNa2, yet others show limited response. Since concurrent inflammation might attenuate the efficacy of IFNa2 therapy, a combination therapy (CT) with the two agents may be more efficacious than monotherapy, likely reducing the inflammation-mediated adverse effects of IFNa2 as well. The purpose of this COMBI-trial is to evaluate the safety and efficacy of CT with IFNa2 and ruxolitinib. Patients and Methods: At the time of data cutoff, a total of 30 pts ≥18 years with prefibrotic or hyperproliferative PMF (n=7), PV (n=20) or post-PV MF (PPV-MF) (n=3) with or without prior treatment with IFNa2 and without serious comorbidity were enrolled. Evidence of active disease was required. Initial therapy was IFNa2 45 μg x 1 sc/week (Pegasys®) or 35 μg x 1 sc/week (PegIntron®) + ruxolitinib (Jakavi®) 20 mg x 2/day. Efficacy was evaluated by internationally accepted clinicohematological response criteria, with the modification that splenomegaly was assessed by palpation instead of imaging, by week 2 and 1, 3, 6 and 9 months. In addition, JAK2V617F-allele burden was monitored. Adverse events (AE) including serious AE (SAE) were recorded. Results: Median treatment duration was 24.4 weeks (range, 3.4 weeks-43.3 weeks). Twenty-seven pts were previously treated with IFNa2 (n=18 intolerant, n=5 unresponsive, n=4 both). Three pts were treatment-naïve. Twenty-seven pts (90%) remained on CT; 3 pts discontinued treatment due to an AE. One patient died from transformation to AML shortly after initiation of CT and was not included in this interim analysis. Marked improvements in pruritus, night sweats, and fatigue were recorded within the first 2-3 days in the large majority of pts and in all within 4 weeks. Palpable splenomegaly in 7 pts at baseline was significantly reduced by week 2. Hct control without phlebotomy was achieved by week 4 in 78 % of pts (7 of 9), who at baseline had an elevated hct. Only 3 pts required a total of 3 phlebotomies after initiation of CT. In Figure 1 median hct levels at 0, 1, 3, 6 months are shown. Overall, complete response (CR) was achieved as best response in 19 pts (63.3%) and partial response (PR) or major response in 8 pts (26.7%). Only 3 pts (10%) had no response (NR) to treatment. Among PV pts, 15 (75%) achieved CR (week 2, n=6; 1 month, n=6; 3 months, n=3). The other 5 PV pts achieved PR (week 2, n=3; 1 month, n=2). In PMF pts, CR (n=2) or major response (n=2) was achieved in 4 pts (57.1%) by week 2 or 1 month, and NR in 3 pts (42.8%). Among PPV-MF pts, 2 pts (66.7%) achieved CR and 1 patient (33,3%) PR by week 2. Furthermore, JAK2V617F% declined significantly as depicted in Figure 2 (JAK2V617F% over time for each patient) and 3 (median JAK2V617F% at 0, 3, 6 months). Anemia (n=15, 2 grade 3), granulocytopenia (n=13, 2 grade 3) or thrombocytopenia (n=6, 1 grade 3) were the most common AEs and were managed by dose reduction. One patient with PPV-MF (leuko- and thrombocytosis) developed pancytopenia within the first 2 weeks on CT, necessitating pausing medication for 〉 2 weeks. Eleven SAEs requiring hospitalization were recorded in 9 pts: pneumonia (n=3), fever (n=2), lipotymia, hematemesis, phlebitis, herpes zoster, angina pectoris and arterial hypertension, 1 patient each. Conclusion: CT with IFNa2 and ruxolitinib is highly efficacious and safein pts with PV or hyperproliferative MF,who were unresponsive or intolerant to monotherapy with IFNa2. Complete clinicohematological responses were achieved in the majority of pts in concert with a reduction in the JAK2V617F-allele burden. In general, the treatment was well tolerated. The preliminary results from this study are highly promising, encouraging a prospective study with CT in newly diagnosed pts. Additional follow-up data will be presented including QoL assessment and the impact of concurrent treatment with statins. Figure 1. Figure 1. Figure 2. Figure 2. Figure 3. Figure 3. Disclosures Off Label Use: The combination therapy with ruxolitinib (JAK1-2 inhibitor) and interferon-alpha is off-label in MPNs. The concept is dual myelosuppressive action and dual clonal suppression in addition to the anti-inflammatory properties of ruxolitinib.. Bjørn:Novartis Oncology: Research Funding. Bjerrum:Bristoll Myers Squibb, Novartis and Pfizer: Other: educational activities. El Fassi:Novartis Denmark: Honoraria, Other: Have conducted an educational session for Novartis Denmark, regarding MPNs and ruxolitinib, for this a honorarium was received.. Nielsen:Novartis: Research Funding. Pallisgaard:Roche: Other: travel grant; Amgen: Membership on an entity's Board of Directors or advisory committees, Other: travel grant, Speakers Bureau; Novartis: Other: travel grant, Research Funding, Speakers Bureau; Qiagen: Membership on an entity's Board of Directors or advisory committees; Bristol Meyer Squibb: Speakers Bureau. Hasselbalch:Novartis: Research Funding.

Abstract: Background: To investigate the role of genomics in determining response and resistance to front line treatment in MPN, we performed somatic mutational profiling of the DALIAH trial, a randomized controlled phase III trial of interferon versus hydroxyurea in newly diagnosed MPN patients. Methods: We performed genomic analyses on 202 pre-treatment primary MPN samples obtained from patients enrolled on the DALIAH trial (NCT01387763) and 135 samples obtained after 24 months of treatment. Genomic profiling comprised targeted next generation sequencing (NGS) of 100 genes, selected on the basis of their known or suspected involvement in the pathogenesis of myeloid malignancies, and 1609 informative single nucleotide polymorphisms (SNPs) on chromosome 9p. Clinicohematological response was determined by central review using ELN 2009 (ET, PV and pre-MF) and EUMNET 2005 (PMF) criteria. We evaluated the association of somatic mutations with clinical parameters and with attainment of clinicohematological complete response (CR) at 24 months. Results: Prior to treatment, 191 of 202 (95%) patients had somatic mutations, including 93% with canonical MPN phenotypic drivers: JAK2 (74%), CALR (14%), and MPL (5%). Among those with JAK2 mutations 37% had JAK2 copy-neutral loss of heterozygosity (JAK2 CN-LOH). Patients with PV were more likely to have JAK2 CN-LOH (p = 0.0001) as compared with patients with other MPN subtypes. At baseline, patients with JAK2 CN-LOH had significantly higher hemoglobin (p = 0.0001), higher white blood cell count (WBC, p = 0.002) and lower platelet count (p=0.0001) than patients without JAK2 CN-LOH. Mutations in TET2 (24%), DNMT3A (16%), and ASXL1 (10%) were the most frequent co-occurring non-MPN phenotypic driver mutations and they occurred across all MPN subtypes. In addition, 5% of patients had spliceosome gene mutations, and 6% had mutations in genes involved in RAS/MAPK signaling. Patients with TET2, DNMT3A or ASXL1 mutations were significantly older than patients without these mutations (p= 0.0001) and there was a significant association between the presence of a TET2, DNMT3A or ASXL1 mutation and prior stroke (p = 0.004). There were no other significant associations between somatic mutation status and baseline clinical characteristics. The probability of attaining clinicohematological CR at 24 months was independent of baseline somatic mutations. Among patients with JAK2 mutations who remained on interferon treatment at 24 months, those with CR had a greater reduction in mean variant allele fraction (VAF) (28% to 8%, p 〈 0.0001) than those who did not achieve CR (34% to 23%, p=0.03). In contrast, the mutant CALR VAF did not significantly decline in either those achieving CR with interferon treatment (16% to 12%, p=0.38) or those not achieving CR (20% to 16%, p=0.35). In patients with JAK2 mutations treated with hydroxyurea, CR at 24 months was associated with a change in VAF (mean 24% to 13%, p=0.04). Among patients who remained on treatment for 2 years, 44 mutations in 35 patients were newly detected or expanded on serial sampling. DNMT3A mutations were the most frequently acquired, accounting for 41% of new mutations. ASXL1, TET2, PPM1D, TP53, IDH2, and CBL mutations were also recurrently acquired. 97% of patients who acquired new mutations were JAK2-mutant. Among those with acquired DNMT3A mutations, 85% were treated with interferon, and 23% had CR at 24 months. Among those that acquired non-DNMT3A mutations, 38% were treated with interferon and 47% had CR at 24 months. The VAF of newly detected mutations was low (median 1.5%), and half of the patients with newly acquired mutations had at least 50% reduction in JAK2V617F VAF, suggesting that new mutations could either have arisen independently or be subclonal to the dominant JAK2-mutant clone. Conclusions: Using sequential genomic analyses of a phase III clinical trial of interferon versus hydroxyurea in MPN patients, we found mutation-specific and treatment-specific patterns of response. We uncovered distinct patterns of response to interferon in JAK2-mutant MPN as compared with CALR-mutant MPN. We found that DNMT3A mutations were the most frequent acquired mutations at 24 months and that these were enriched in patients treated with interferon. In aggregate, these results provide insights into molecular response and resistance to interferon and inform the clinical use of interferon in MPN patients. Disclosures Hansen: Alexion: Research Funding. Neuberg:Pharmacyclics: Research Funding; Madrigal Pharmaceuticals: Equity Ownership; Celgene: Research Funding. Hasselbalch:Novartis: Research Funding; AOP Orphan Pharmaceuticals: Other: Data monitoring board. Lindsley:Jazz Pharmaceuticals: Research Funding; Takeda Pharmaceuticals: Consultancy; Medlmmune: Research Funding. Mullally:Janssen: Research Funding.

Abstract: Although somatic mutations influence the pathogenesis, phenotype, and outcome of myeloproliferative neoplasms (MPNs), little is known about their impact on molecular response to cytoreductive treatment. We performed targeted next-generation sequencing (NGS) on 202 pretreatment samples obtained from patients with MPN enrolled in the DALIAH trial (A Study of Low Dose Interferon Alpha Versus Hydroxyurea in Treatment of Chronic Myeloid Neoplasms; #NCT01387763), a randomized controlled phase 3 clinical trial, and 135 samples obtained after 24 months of therapy with recombinant interferon-alpha (IFNα) or hydroxyurea. The primary aim was to evaluate the association between complete clinicohematologic response (CHR) at 24 months and molecular response through sequential assessment of 120 genes using NGS. Among JAK2-mutated patients treated with IFNα, those with CHR had a greater reduction in the JAK2 variant allele frequency (median, 0.29 to 0.07; P & lt; .0001) compared with those not achieving CHR (median, 0.27 to 0.14; P & lt; .0001). In contrast, the CALR variant allele frequency did not significantly decline in those achieving CHR or in those not achieving CHR. Treatment-emergent mutations in DNMT3A were observed more commonly in patients treated with IFNα compared with hydroxyurea (P = .04). Furthermore, treatment-emergent DNMT3A mutations were significantly enriched in IFNα–treated patients not attaining CHR (P = .02). A mutation in TET2, DNMT3A, or ASXL1 was significantly associated with prior stroke (age-adjusted odds ratio, 5.29; 95% confidence interval, 1.59-17.54; P = .007), as was a mutation in TET2 alone (age-adjusted odds ratio, 3.03; 95% confidence interval, 1.03-9.01; P = .044). At 24 months, we found mutation-specific response patterns to IFNα: (1) JAK2- and CALR-mutated MPN exhibited distinct molecular responses; and (2) DNMT3A-mutated clones/subclones emerged on treatment.

Abstract: Background Recombinant Interferon Alpha-2a (r-IFNα) is a potent immunomodulating agent, which has been used off-label for the treatment of polycythemia vera (PV) for more than three decades and has been demonstrated to induce high rates of clinical, hematological and molecular responses. Only few studies have compared efficacy and safety of r-IFNα vs. hydroxyurea (HU), which is considered first line therapy for PV patients 〉 60 years in most parts of the world. However, recent studies have provided encouraging results for the treatment of PV with r-IFNα compared to HU irrespective of age (R. Hoffmann 2016; H. Gisslinger 2018). Aims To examine the difference in efficacy and safety of low-dose r-IFNα in PV patients ≤ 60 or 〉 60 years of age compared to HU 〉 60 years of age. Methods Ninety newly diagnosed or previously phlebotomized PV patients only (WHO 2008) were enrolled in the DALIAH trial (NCT01387763). All patients provided written informed consent. Patients ≤ 60 years were randomized (I:I) to r-IFNα-2a (Pegasys®) or to r-IFNα-2b (PegIntron®) whereas patients 〉 60 years were randomized (I:I:I) to either r-IFNα-2a, r-IFNα-2b or to HU. The starting dose of r-IFNα-2a and r-IFNα-2b was 45 or 35 µg/week, respectively. The HU dose was 500 to 2000 mg/day. Patients randomized to r-IFNα who presented with major thrombosis or platelets 〉 1500 109/L received HU from inclusion and until normalization of the platelet count. Efficacy assessment consisted of the clinicohematological and the molecular response rates by intention to treat analysis (ITT) using the European Leukemia Net (ELN) 2009 criteria. JAK2V617F analysis was performed by qPCR. Groups were compared by Fisher's Exact Test. Results Three-year analysis was available in all but five patients (n=85) at time of abstract submission (Table 1). The analysis was performed after a median of 36 months (range: 33-39 months). The median treatment dose was 684 mg/day (IQR: 131 - 942) for HU, 51 μg/week (IQR: 30-90 μg/week) and 54 μg/week (IQR: 30-66 μg/week) for r-IFNα-2a age ≤ 60 and 〉 60, respectively, and 41 μg/week (IQR: 29-45 μg/week) and 36 μg/week (IQR: 31-37 μg/week) for r-IFNα-2b age ≤ 60 and 〉 60. The overall clinicohematological response rate (ORR) was 68% (13/19) for HU, 42% (14/33) for r-IFNα ≤ 60 years and 39% (13/33) for r-IFNα 〉 60 years. The partial clinicohematological response rate (PHR) and the complete clinicohematological response rate (CHR) was 53% (10/19) and 16% (3/19) for HU, 9% (3/33) and 33% (11/33) for r-IFNα ≤ 60 years and 9% (3/33) and 30% (10/33) for r-IFNα 〉 60 years. Neither the ORR, CHR nor the PHR was significantly different between the three groups. Maintenance of CHR from first occurrence to data analysis after 36 months was 11% (2/19) for HU, 21% (7/33) for r-IFNα ≤ 60 years and 18% (6/33) for r-IFNα 〉 60 years. Forty-seven JAK2V617F positive patients were available for molecular response analysis after 36 months of therapy. A partial molecular response (PMR) was detected in 21% (4/19) of HU treated patients and in 24% (7/29) of r-IFNα treated patients ≤ 60 years and 18% (6/33) of r-IFNα 〉 60 years. Notably, 7% (2/29) of the r-IFNα treated patients ≤ 60 years obtained a complete molecular response (CMR). The median JAK2V617F reduction from baseline was 38% (IQR: 31-63%) for HU, 79% (IQR: 59-92%) for r-IFNα ≤ 60 years and 73% (IQR: 49-97%) for r-IFNα 〉 60 years. There was no statistically significant difference in the PMR between groups. Discontinuation of treatment for any reason after 36 months of therapy was 21% (4/19) for HU, 52% (17/33) for r-IFNα ≤ 60 years and 45% (15/33) for r-IFNα 〉 60 years. Toxicity related discontinuation was 5% (1/19) for HU and 30% (10/33) for both r-IFNα ≤ 60 and 〉 60 years. Grade 3-4 AEs occurred in 32% (6/19) of HU treated patients, 27% (9/33) in r-IFNα treated patients ≤ 60 years and in 42% (14/33) r-IFNα treated patients 〉 60 years. SAEs were reported in 21% (4/19) for HU, 9% (3/33) for r-IFNα ≤ 60 years and 24% (8/33) for r-IFNα 〉 60 years. The numbers of grade 3-4 AEs as well as SAEs were comparable between groups. Conclusion After 36 months of therapy CHR was non-significantly higher in PV patients treated with r-IFNα compared to HU by ITT, irrespective of age. Also, maintenance of CHR was longer for r-IFNα. However, ORR was non-significantly higher for HU. PMR was almost similar between the three groups but the median JAK2V617F reduction was greater for r-IFNα. Toxicity related discontinuation from study therapy was higher for r-IFNα compared to HU. Disclosures Stentoft: Bristol-Myers Squibb: Research Funding; Merck Sharp & Dohme: Research Funding. Hasselbalch:Novartis: Research Funding.

Abstract: We report the final 2-year end-of-study results from the first clinical trial investigating combination treatment with ruxolitinib and low-dose pegylated interferon-α2 (PEG-IFNα2). The study included 32 patients with polycythemia vera and 18 with primary or secondary myelofibrosis; 46 patients were previously intolerant of or refractory to PEGIFNα2. The primary outcome was efficacy, based on hematologic parameters, quality of life measurements, and JAK2 V617F allele burden. We used the 2013 European LeukemiaNet and International Working Group- Myeloproliferative Neoplasms Research and Treatment response criteria, including response in symptoms, splenomegaly, peripheral blood counts, and bone marrow. Of 32 patients with polycythemia vera, ten (31%) achieved a remission which was a complete remission in three (9%) cases. Of 18 patients with myelofibrosis, eight (44%) achieved a remission; five (28%) were complete remissions. The cumulative incidence of peripheral blood count remission was 0.85 and 0.75 for patients with polycythemia vera and myelofibrosis, respectively. The Myeloproliferative Neoplasm Symptom Assessment Form total symptom score decreased from 22 [95% confidence interval (95% CI):, 16-29] at baseline to 15 (95% CI: 10-22) after 2 years. The median JAK2 V617F allele burden decreased from 47% (95% CI: 33-61%) to 12% (95% CI: 6-22%), and 41% of patients achieved a molecular response. The drop-out rate was 6% among patients with polycythemia vera and 32% among those with myelofibrosis. Of 36 patients previously intolerant of PEG-IFNα2, 31 (86%) completed the study, and 24 (67%) of these received PEG-IFNα2 throughout the study. In conclusion, combination treatment improved cell counts, reduced bone marrow cellularity and fibrosis, decreased JAK2 V617F burden, and reduced symptom burden with acceptable toxicity in several patients with polycythemia vera or myelofibrosis. #EudraCT2013-003295-12.

Abstract: Insulin resistance in skeletal muscle in type 2 diabetes (T2D) is characterized by more pronounced metabolic and molecular defects than in obesity per se. There is increasing evidence that adipose tissue dysfunction contributes to obesity-induced insulin resistance in skeletal muscle. Here, we used an unbiased approach to examine if adipose tissue dysfunction is exaggerated in T2D and linked to diabetes-related mechanisms of insulin resistance in skeletal muscle. Transcriptional profiling and biological pathways analysis were performed in subcutaneous adipose tissue (SAT) and skeletal muscle biopsies from 17 patients with T2D and 19 glucose-tolerant, age and weight-matched obese controls. Findings were validated by qRT-PCR and western blotting of selected genes and proteins. Patients with T2D were more insulin resistant and had lower plasma adiponectin than obese controls. Transcriptional profiling showed downregulation of genes involved in mitochondrial oxidative phosphorylation and the tricarboxylic-acid cycle and increased expression of extracellular matrix (ECM) genes in SAT in T2D, whereas genes involved in proteasomal degradation were upregulated in the skeletal muscle in T2D. qRT-PCR confirmed most of these findings and showed lower expression of adiponectin in SAT and higher expression of myostatin in muscle in T2D. Interestingly, muscle expression of proteasomal genes correlated positively with SAT expression of ECM genes but inversely with the expression of ADIPOQ in SAT and plasma adiponectin. Protein content of proteasomal subunits and major ubiquitin ligases were unaltered in the skeletal muscle of patients with T2D. A transcriptional signature of exaggerated adipose tissue dysfunction in T2D, compared with obesity alone, is linked to low plasma adiponectin and increased transcriptional activation of proteasomal degradation in skeletal muscle.