Silver, Richard T.

Abstract Background: Cytoreductive therapy with hydroxyurea (HU) has been considered first line therapy for patients with high risk polycythemia vera (PV) and essential thrombocythemia (ET) since the results of the PVSG-08 trial demonstrated thrombotic risk reduction (Fruchtman SM et al 1997) for PV and PT1 for ET (Harrison CN et al 2005). Although HU is well tolerated by most patients and has been shown to reduce thrombotic risk in this setting, concern regarding the leukemogenic potential of this oral ribonucleotide reductase inhibitor balanced by the observation of molecular responses with interferon-α (IFN-α) led us to compare the clinical response and tolerability of pegIFN-α (PEG) and HU in a global, randomized, phase III trial. Methods : MPD-RC 112 trial (NCT01258856) enrolled patients with high risk (age >60 years, history of thrombosis, extreme thrombocytosis, symptomatic splenomegaly, uncontrolled cardiovascular risk factors), newly diagnosed (<5 years), WHO defined ET/PV that were treatment naïve (HU <3 months) and randomized (1:1) to PEG or HU. The primary endpoint was complete hematologic response (CHR) rate by European LeukemiaNet (ELN) criteria between the arms after 12 months of therapy. A planned interim analysis based on intent-to-treat with testing boundaries for efficacy and futility was conducted after 75 patients were on study for 12 months. Response assessment by ELN criteria were conducted by blinded review by 4 investigators (JM, RAM, AY, RH). Intent-to-treat analysis was conducted for efficacy endpoints (HU n=39; PEG n=36). Safety analysis included all patients who received treatment (HU n=36; PEG n=36). Results: Patients: The MPD-RC 112 trial involved 24 centers in 6 countries; enrollment began 09/2011 and concluded 7/2016 prior to full accrual due to study drug availability with 168 patients enrolled (Table 1 for 75 patients in the interim analysis). There was no imbalance between arms with respect to history of thrombosis, erythromelalgia, diabetes, hypertension, but age was significantly older on HU. This remained true when analyzing by ET/PV disease strata with the exception of diabetes which was slightly imbalanced within the PV cohort (HU 5/23, 22%; PEG 0/21, 0%; p<0.05). Response: CHR and PHR were observed in 13 (33%) and 14 (36%) patients for an overall response rate (ORR) of 69% (27/39) for HU, and 10 (28%) and 19 (53%) for an ORR of 81% (29/36) for PEG (CHR comparison p=0.60 based on z-test which did not cross either testing boundary). 10 patients randomized to HU were not evaluable for 12-month response due to never initiating treatment (n=3) or early study discontinuation for AEs (n=1), patient withdrawal (n=5), or treatment non-compliance (n=1). 3 patients were not evaluable for response on PEG due to early study discontinuation for AEs (n=1), physician decision (n=1), or patient withdrawal (n=1). Excluding patients who never initiated treatment did not impact the primary endpoint comparison (HU 13/36, 36%; PEG 10/36, 28%; p=0.45). For ET, CHR and PHR were observed in 7 (44%) and 4 (25%) patient on HU, and 6 (40%) and 6 (40%) for PEG (CHR comparison p=0.83). For PV, CHR and PHR were observed in 6 (26%) and 10 (44%) patients on HU, and 4 (19%) and 13 (62%) for PEG (CHR comparison p=0.58). Normalization of spleen by palpation at 12 months was seen in 2/7 (29%) and 5/7 (71%) of the HU and PEG treated patients with palpable spleen at baseline, respectively. Among 38 PV patients, rate of phlebotomy use at 12 months was 0/18 (0%) vs 5/20 (20%) on HU and PEG (p=0.02). From baseline to best score through 12 months, 9/28 (32%) and 12/34 (35%) patients with data on HU and PEG, respectively, had a ≥50% reduction in MPN-SAF Total Symptom Score (p=0.79). Toxicity: No Grade 4 AEs occurred in either treatment arm. Overall, Grade 3 AEs occurred in 5/36 (14%) HU patients and 16/36 (44%) PEG patients (Grade 3 hematologic: 4/36 [11%] HU vs 8/36 [22%] PEG; Grade 3 non-hematologic: 5/36 [14%] HU vs 16/36 [44%] PEG). See Table 2 for Grade 3 AEs regardless of attribution occurring in >10% of patients in either arm. Conclusions: This interim analysis does not show a clear difference in primary endpoint of CHR between HU and PEG. A comparative analysis of the quality of life and symptom burden will provide further insight into the tolerability of these agents (Mesa et al ASH 2016). The final results of this pivotal trial will provide necessary data required to firmly establish the optimal first line therapy for patients with high risk ET/PV. Disclosures Mascarenhas: CTI Biopharma: Research Funding; Janssen: Research Funding; Promedior: Research Funding; Roche: Research Funding; Novartis: Other: DSMB , Research Funding; Incyte: Other: Clinical Trial Steereing Committee, Research Funding. Mesa:Celgene: Research Funding; Promedior: Research Funding; CTI: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Galena: Consultancy; Ariad: Consultancy; Novartis: Consultancy. Yacoub:Alexion: Honoraria; Seattle Genetics: Consultancy, Honoraria, Speakers Bureau; Incyte: Consultancy, Honoraria, Speakers Bureau. Harrison:Baxaltra: Consultancy, Honoraria, Speakers Bureau; Incyte Corporation: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Shire: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau. McMullin:Novartis: Honoraria, Speakers Bureau. Vannucchi:Novartis: Honoraria, Speakers Bureau. Kiladjian:Novartis: Honoraria, Research Funding; AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding. Mead:Novartis: Honoraria, Research Funding, Speakers Bureau. Kessler:Incyte: Honoraria. Ritchie:Celgene: Consultancy, Other: Travel, Accomodations, Expenses, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Novartis: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; Ariad: Speakers Bureau; Pfizer: Consultancy, Research Funding; Astellas Pharma: Research Funding; Bristol-Meyers Squibb: Research Funding; NS Pharma: Research Funding. Schlenk:Amgen: Research Funding; Pfizer: Honoraria, Research Funding.

Abstract Abstract 800 Background: Ruxolitinib (RUX), an oral JAK1/JAK2 inhibitor, reduced spleen volume (SV), improved myelofibrosis (MF)-associated symptoms and quality of life (QoL), and appeared to exhibit a survival advantage over placebo (PBO) in patients (pts) with MF regardless of JAK2V617F mutation status in the phase III COMFORT-I study. We describe long-term efficacy and safety of RUX from COMFORT-I, with 1 year of additional follow up beyond previously published data. Methods: Eligible pts (N=309) were randomized (1:1) to RUX or PBO. The primary analysis occurred when all pts completed 24 weeks (wks) and when half the pts completed 36 wks of treatment. All pts receiving PBO were eligible for crossover to RUX after the primary analysis; crossover before wk 24 was permitted if pts met protocol-defined criteria for worsening splenomegaly. The proportion of pts with ≥35% SV reduction at 24 wks (primary endpoint) and durability of SV response were assessed. Although symptom burden (measured daily using the modified MF Symptom Assessment Form v2.0) was only measured up to wk 24, QoL continued to be evaluated beyond wk 24 (every 24 wks) using the EORTC QoL Questionnaire-Core 30 (QLQ-C30). Overall survival (OS) was assessed according to original randomized treatment. Results: In this updated analysis, median follow-up of pts randomized to RUX was 102 wks. All pts receiving PBO completed crossover or discontinued within 3 months of the primary analysis. Of 134 pts randomized to RUX who remained on treatment after the primary data analysis, 100 continue on study. Mean SV reduction in pts randomized to RUX was 31.6% at wk 24 and has remained stable with additional follow up through wk 96 (Table). In pts who achieved a ≥35% SV reduction, response was durable, with a median response duration of 108 wks. RUX treatment was also associated with durable improvements in the Global Health Status/QoL (Table) and the 5 functional domains of the EORTC QLQ-C30. Twenty-seven (27) pts randomized to RUX and 41 pts randomized to PBO died, representing a continued OS benefit in favor of RUX (HR=0.58; 95% CI: 0.36, 0.95; P = 0.028; Fig 1) similar in magnitude to that previously reported. OS favored RUX across subgroups including starting dose as well as baseline risk status and hemoglobin (Hgb). Of 34 pts randomized to RUX who discontinued after the primary analysis, 4 discontinued for an adverse event (AE). In pts who continued on RUX, anemia and thrombocytopenia remained the most frequently reported AEs. New onset of grade 3 or 4 anemia and thrombocytopenia was reported in only 12 and 5 pts, respectively. One pt discontinued for anemia. Overall, among all pts randomized to RUX, Grade 3 and 4 anemia regardless of baseline Hgb was reported in 37.4% and 14.8% of pts, respectively. Similarly, Grade 3 and 4 thrombocytopenia was reported in 11.0% and 5.2% of pts, respectively. These rates were similar to those reported in the primary analysis. By wk 36, the proportion of pts receiving red blood cell transfusions decreased to the level seen with PBO and remained stable thereafter (Fig 2). Rates of nonhematologic AEs adjusted for increased follow-up duration remain similar to those seen at the time of the primary data analysis. No additional cases of acute myeloid leukemia (AML) in pts randomized to RUX were reported. Two pts originally randomized to PBO developed AML, 21 and 178 days after crossover to RUX. There continued to be no reports of a withdrawal syndrome after RUX discontinuation. Conclusions: RUX provides durable reductions in SV and improvements in QoL. Although all pts randomized to PBO crossed over to RUX shortly after the primary analysis, with 1 year of additional follow up, RUX continues to be associated with a survival advantage over PBO. RUX continues to be well tolerated; the AE profile with long-term treatment is consistent with that previously reported. The proportion of pts receiving transfusions decreased over time to rates similar to PBO, and there were no reports of a specific withdrawal syndrome or cytokine rebound phenomenon after RUX discontinuation. Disclosures: Verstovsek: Incyte Corporation: Research Funding. Mesa:Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding. Gotlib:Incyte: Consultancy, travel to congress Other. Levy:Incyte: Employment, Equity Ownership. Gupta:Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; YM Biosciences: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofiå]Aventis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Catalano:Incyte: Consultancy. Deininger:Bristol-Myers Squibb: Consultancy, Research Funding; Novartis: Consultancy; Ariad: Consultancy. Miller:Novartis: Consultancy, Research Funding, Speakers Bureau, development of educational presentations Other; Incyte: development of educational presentations, development of educational presentations Other. Talpaz:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; B.M.S.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Ariad: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Teva: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. Winton:Incyte: Consultancy, Honoraria. Arcasoy:Incyte: Research Funding. Lyons:Incyte: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Novartis: Research Funding; Telik: Research Funding. Paquette:Incyte: Consultancy. Vaddi:Incyte: Employment, Equity Ownership. Erickson-Viitanen:Incyte: Employment, Equity Ownership. Sun:Incyte Corporation: Employment, Equity Ownership. Sandor:Incyte Corporation: Employment, Equity Ownership. Kantarjian:Incyte: grant support Other.

Yacoub et al report excellent responses to pegylated interferon alfa-2a in patients with hydroxyurea-resistant/intolerant polycythemia vera or essential thrombocythemia.

SummaryMyelofibrosis (MF) patients can present with a wide spectrum of disease characteristics. We analysed the consistency of ruxolitinib efficacy across patient subgroups in the COntrolled MyeloFibrosis Study With ORal JAK Inhibitor Treatment (COMFORT‐I,) a double‐blind trial, where patients with intermediate‐2 or high‐risk MF were randomized to twice‐daily oral ruxolitinib (n = 155) or placebo (n = 154). Subgroups analysed included MF subtype (primary, post‐polycythaemia vera, post‐essential thrombocythaemia), age (≤65, > 65 years), International Prognostic Scoring System risk group, baseline Eastern Cooperative Oncology Group performance status (0, 1, ≥2), JAK2 V617F mutation (positive, negative), baseline haemoglobin level (≥100, <100 g/l), baseline platelet count (100–200 × 109/l, >200 × 109/l), baseline palpable spleen size (≤10, >10 cm), and baseline quartile of spleen volume and Total Symptom Score (TSS; Q1 = lowest, Q4 = highest). Mean percentage change from baseline to week 24 in spleen volume and TSS were calculated for ruxolitinib and placebo in each subgroup. Overall survival was estimated by Kaplan–Meier method according to original randomization group. In ruxolitinib‐treated patients, reductions in spleen volume and TSS and evidence of improved survival relative to placebo across subgroups were consistent with those seen in the COMFORT‐I population, confirming that ruxolitinib is an effective therapy for the spectrum of MF patients studied in COMFORT‐I.

Purpose To assess the effects of ruxolitinib on symptom burden and quality of life (QoL) and to evaluate the ability of the modified Myelofibrosis Symptom Assessment Form (MFSAF) v2.0 to measure meaningful changes in myelofibrosis-related symptoms in patients with myelofibrosis. Patients and Methods COMFORT-I (Controlled Myelofibrosis Study With Oral JAK Inhibitor Treatment–I) is a double-blind, placebo-controlled phase III study evaluating ruxolitinib in patients with intermediate-2 or high-risk myelofibrosis. Exploratory analyses were conducted on the following patient-reported outcomes (PROs) assessments: modified MFSAF v2.0 (individual symptoms and Total Symptom Score [TSS]), European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30), Patient Reported Outcomes Measurement Information System (PROMIS) Fatigue Scale, and Patient Global Impression of Change (PGIC). Results Patients receiving ruxolitinib experienced improvements in individual myelofibrosis-related symptoms, although patients receiving placebo experienced worsening (P < .001). The majority (91%) of ruxolitinib-treated patients designated as ≥ 50% TSS responders (≥ 50% TSS improvement) self-reported their condition as either “Much improved” or “Very much improved” on the PGIC. These patients achieved significant improvements in the EORTC QLQ-C30 functional domains and Global Health Status/QoL versus patients receiving placebo, who experienced worsening on these measures (P ≤ .0135). Ruxolitinib-treated patients with a lesser degree of symptom improvement (< 50% TSS responders) also achieved improvements over placebo on these measures. The degree of spleen volume reduction with ruxolitinib correlated with improvements in TSS, PGIC, PROMIS Fatigue Scale, and EORTC Global Health Status/QoL. Ruxolitinib-treated patients who achieved a ≥ 35% reduction in spleen volume experienced the greatest improvements in these PROs. Conclusion Ruxolitinib-treated patients achieved clinically meaningful improvements in myelofibrosis-related symptoms and QoL, but patients receiving placebo reported worsening of symptoms and other PROs.