Assessing the safety and efficacy of ruxolitinib in a multicenter, open-label study in Japanese patients with myelofibrosis

Norio Komatsu, Keita Kirito, Kazuya Shimoda, Takayuki Ishikawa, Kohshi Ohishi, Kazuma Ohyashiki, Naoto Takahashi, Hikaru Okada, Taro Amagasaki, Toshio Yonezu, Koichi Akashi

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13 Citations (Scopus)


Ruxolitinib is a potent JAK1/JAK2 inhibitor that has demonstrated durable improvements in splenomegaly, symptoms, and overall survival in controlled clinical trials in patients with myelofibrosis. The single-arm study reported here was initiated to collect further safety and efficacy data in Japanese patients with myelofibrosis and is the largest study of ruxolitinib in this population. The primary objective was to assess safety. Secondary endpoints included changes in spleen size and patient-reported outcomes. The primary analysis occurred when all patients (N = 51) completed 24 weeks or discontinued. Overall, 86.3% of patients completed treatment; 9.8% discontinued due to adverse events (AEs). Consistent with previous studies, the most common AEs were anemia (62.7%) and thrombocytopenia (29.4%). Furthermore, levels of select immunologic biomarkers remained stable, and no deaths occurred. At week 24, 30.0% of evaluable patients experienced ≥50% reductions from baseline in palpable spleen length; 26.0% had ≥35% reductions in spleen volume. Additionally, ruxolitinib led to clinically significant improvements in symptoms and quality of life. Overall, findings from this study indicate that ruxolitinib is safe and effective in Japanese patients with myelofibrosis, with these benefits extending to patients with intermediate-1–risk myelofibrosis and to those with low platelet counts.

Original languageEnglish
Pages (from-to)309-317
Number of pages9
JournalInternational journal of hematology
Issue number3
Publication statusPublished - Mar 1 2017

All Science Journal Classification (ASJC) codes

  • Hematology


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