Kuliczkowski, Kazimierz

Abstract Background Fedratinib (SAR302503) is a JAK2-selective inhibitor that has provided clinically meaningful reductions in MF-associated splenomegaly and symptoms in Phase I and II studies (J Clin Oncol 2011;29:789. Haematologica 2013;98:S1113). Here, we present efficacy and safety data from the Phase III JAKARTA study of fedratinib versus placebo in patients with MF (NCT01437787). Methods In this international double-blind, placebo-controlled, 3-arm study, patients aged ≥18 years with IPSS intermediate-2 or high-risk MF, platelet count ≥50 × 109/L, and splenomegaly were randomized (1:1:1) to receive placebo or fedratinib 400 mg or 500 mg, orally, once daily, in consecutive 4-week cycles. Patients who received placebo were eligible to cross-over to fedratinib (randomized 1:1 to 400 mg or 500 mg) following 6 cycles of treatment, or prior to Cycle 6 if the patient had disease progression. The primary endpoint was spleen response rate (RR) (≥35% reduction in spleen volume from baseline measured by MRI or CT at Week 24, and confirmed 4 weeks later). Secondary endpoints included symptom RR (≥50% reduction in total symptom score from baseline at Week 24, measured through a daily electronic eDiary using the modified Myelofibrosis Symptom Assessment Form [Cancer 2011;117:4869. Blood 2011;118:401]), and safety of fedratinib. Results A total of 289 patients were randomized: median age 65 years; 59% male; 63% primary MF; 48% high-risk MF; 67% JAK2V617F positive; 16% platelet count <100 × 109/L; median baseline spleen volume 2568 mL (range 316–8244); median baseline total symptom score 14.7 (0–57). Median (range) exposures for placebo, 400 mg and 500 mg groups were 24 (2–34), 30 (1–55) and 28 (1–60) weeks, respectively. Spleen RRs at Week 24 (placebo 1%; 400 mg 47%; 500 mg 49%), and confirmed at Week 28 (placebo 1%; 400 mg 36%; 500 mg 40%), were significantly (p<0.0001) higher in both fedratinib groups compared with placebo (Table). Nineteen patients had a spleen response at Week 24 not confirmed 4 weeks later (spleen reduction 25–35% [n=10]; image not available/evaluable [n=8]; image taken outside time window [n=1]). Spleen RRs by baseline platelet level are shown in the table. Patients treated with fedratinib had significantly (p<0.0001) greater improvements in MF symptoms compared with placebo (Table). The most common all grade non-hematologic treatment-emergent adverse event (TEAE) was diarrhea (16%, 66% and 56% of patients in the placebo, 400 mg and 500 mg groups, respectively). Grade 3/4 diarrhea was reported in 5% of patients in both the 400 mg and 500 mg dose groups. The most common hematologic TEAE was anemia (any grade 91%, 99% and 98%; Grade 3/4 25%, 43% and 60% in the placebo, 400 mg and 500 mg groups, respectively). Rates of Grade 3/4 thrombocytopenia were 9% (placebo), 17% (400 mg), and 27% (500 mg). Incidences of Grade 3/4 liver function tests (placebo/400 mg/500 mg) were: bilirubin, 2%/2%/1%; ALT, 0%/3%/3%; and AST, 1%/2%/2%. Overall treatment discontinuation rates up to 24 weeks of treatment were 25% (placebo), 22% (400 mg) and 32% (500 mg). Twenty-five patients died during the study (10, 5 and 10 in the placebo, 400 mg and 500 mg groups, respectively); the most common causes of death: disease progression (placebo [n=5]; 400 mg [n=3]; 500 mg [n=4]) and adverse events (placebo [n=4]; 400 mg [n=1]; 500 mg [n=4]). Conclusions In this Phase III, randomized, placebo-controlled, 3-arm study of 289 MF patients, treatment with fedratinib 400 mg or 500 mg once-daily demonstrated clinically meaningful and statistically significant reductions in splenic volume and MF-associated symptom burden versus placebo. Fedratinib had an acceptable safety profile, with the adverse events reported consistent with those observed in previous studies. This study was sponsored by Sanofi. Disclosures: Pardanani: Sanofi, Bristol Myers Squibb, PharmaMar and JW Pharma: Clinical trial support Other. Harrison:Novartis: Research Funding; Novartis, Sanofi, YM Bioscience, Celgene, SBio, Gilead: Honoraria; Novartis, Sanofi, Shire: Speakers Bureau; Novartis, Sanofi, YM Bioscience, SBio, Gilead: Membership on an entity’s Board of Directors or advisory committees. Cortes:Incyte, Sanofi: Consultancy; Incyte, Sanofi: Research Funding. Cervantes:Novartis: Speakers Bureau; Novartis and Sanofi: Membership on an entity’s Board of Directors or advisory committees. Mesa:Incyte, Genentech, Lilly, MS Pharma, Gilead: Research Funding. Jourdan:Sanofi: Honoraria. Vannucchi:Novartis: Membership on an entity’s Board of Directors or advisory committees. Drummond:Sanofi, Novartis, Celgene: Honoraria; TargeGen, Novartis: Speakers Bureau; Sanofi, Novartis, Celgene: Consultancy. Passamonti:Novartis, Celgene, Incyte, Sanofi, Roche: Honoraria. Neumann:Sanofi: Employment. Gao:Sanofi: Employment.

Abstract Introduction Fedratinib (SAR302503), a JAK2-selective inhibitor, has demonstrated clinical improvements in splenomegaly and constitutional symptoms in patients with MF in Phase I/II trials (J Clin Oncol 2011;29:789. Haematologica 2013;98:S1113). The aim of this primary analysis was to determine the effect of fedratinib on key MF symptom burden and global assessment of HRQoL in the JAKARTA trial (NCT01437787). Methods JAKARTA is a double-blind, placebo-controlled, international, 3-arm, Phase III study, in which patients ≥18 years of age with intermediate- or high-risk MF, platelet count ≥50 × 109/L, and splenomegaly were randomized (1:1:1) to receive placebo or fedratinib at a dose of 400 or 500 mg, orally, once daily, in consecutive 4-week cycles. Total symptom score (TSS), a key efficacy end point (TSS: averaged daily total score of 6 item measures over 1 week: night sweats, pruritus, abdominal discomfort, early satiety, pain under ribs on left side, and bone or muscle pain), was assessed through a daily electronic eDiary using the modified Myelofibrosis Symptom Assessment Form (MFSAF; Cancer 2011;117:4869. Blood 2011;118:401), with symptom response defined as a ≥50% reduction in TSS at the end of Cycle 6 (EOC6). HRQoL was assessed using the EuroQOL (EQ)-5D instrument that was completed at baseline and EOC6. Patient performance was assessed using the Eastern Cooperative Oncology Group Performance Scale (ECOG PS). Spleen volume was measured by MRI or CT at baseline and EOC6. Results In JAKARTA, a total of 289 patients were randomized: median age 65 years; 59% male; 63% primary MF; 48% high-risk MF; 67% JAK2V617F positive; 16% platelet count <100 × 109/L. The symptom evaluable population comprised 261 patients (placebo [n=82]; 400 mg [n=89]; 500 mg [n=90]). The mean (SD) baseline TSS was 14.6 (11.9), 17.6, (13.5), and 16.9 (11.9) in the placebo, 400 mg, and 500 mg groups, respectively. At Week 24 (EOC6), the proportion of patients with a symptom response was significantly higher (p<0.0001) in the 400 and 500 mg groups versus placebo (Table). Symptom responses with fedratinib were also higher than placebo in the subgroup of patients with baseline platelets <100 × 109/L (Table). For individual symptoms, the greatest improvements were seen for night sweats and early satiety (Table). Baseline HRQoL (EQ-5D, mean [SD]) was similar in the three groups (placebo: 62.5 [21.2]; 400 mg: 61.3 [22.2]; 500 mg: 60.1 [20.1]). Fedratinib treatment led to improvements in HRQoL from baseline to Week 24, whereas placebo treatment led to slight worsening of HRQoL (Table). At Week 24, the degree of improvement in TSS was greatest in patients with ≥35% reduction in spleen volume from baseline (Figure). Mean TSS improvement was correlated with improvement in HRQoL (TSS reductions were greater in EQ-5D improvers versus non-improvers), and ECOG PS (TSS reductions were greater in patients with ECOG PS 1 or 2 score improvement versus those with ECOG PS worsening). Conclusions Fedratinib treatment over 24 weeks led to significant improvements in MF symptoms versus placebo. Patients treated with fedratinib also experienced substantial improvements in HRQoL versus placebo. Symptom improvements were associated with spleen responses. This study was sponsored by Sanofi. Disclosures: Mesa: Incyte, Genentech, Lilly, MS Pharma, Gilead: Research Funding. Cortes:Incyte, Sanofi: Consultancy; Incyte, Sanofi: Research Funding. Cervantes:Novartis: Speakers Bureau; Novartis and Sanofi: Membership on an entity’s Board of Directors or advisory committees. Jourdan:Sanofi: Honoraria. Vannucchi:Novartis: Membership on an entity’s Board of Directors or advisory committees. Drummond:TargeGen, Novartis: Speakers Bureau; Sanofi, Novartis, Celgene: Honoraria; Sanofi, Novartis, Celgene: Consultancy. Passamonti:Novartis, Celgene, Incyte, Sanofi, Roche: Honoraria. Neumann:Sanofi: Employment. Joulain:Sanofi: Employment. Iqbal:Sanofi: Employment. Harrison:Novartis: Research Funding; Novartis, Sanofi, YM Bioscience, Celgene, SBio, Gilead: Honoraria; Novartis, Sanofi, Shire: Speakers Bureau; Novartis, Sanofi, YM Bioscience, SBio, Gilead: Membership on an entity’s Board of Directors or advisory committees.