Oral eltrombopag for up to three years is safe and well-tolerated in Japanese patients with previously treated chronic immune thrombocytopenia: an open-label, extension study

Shinya Katsutani, Yoshiaki Tomiyama, Akiro Kimura, Yoshitaka Miyakawa, Shinichiro Okamoto, Yasushi Okoshi, Haruhiko Ninomiya, Hiroshi Kosugi, Kazuyoshi Ishii, Yasuo Ikeda, Toshihiro Hattori, Koichi Katsura, Yuzuru Kanakura

Eltrombopag is an oral, nonpeptide, thrombopoietin receptor agonist approved for treatment of chronic immune thrombocytopenia (ITP). The safety, tolerability, and efficacy of eltrombopag for up to 3 years were evaluated in 19 Japanese patients with chronic ITP who had completed a prior 6-month study. Patients received eltrombopag once daily at the last dosage received in the prior study (12.5, 25, or 50 mg). Dose adjustments and treatment interruptions were permitted to maintain platelet counts of 50,000-200,000/μL. Primary evaluations were safety and tolerability of long-term eltrombopag treatment. The median duration of exposure was 27.5 months (range, 9.9-32.3). Adverse events were similar to those reported with short-term use of eltrombopag, and none led to treatment discontinuation. Nine serious adverse events were reported. Median platelet counts began to increase after 1 week of treatment and remained above 50,000/μL for most assessments. Bleeding episodes decreased from 63 % at baseline to 21 % after 2 weeks of treatment and remained below baseline for all assessments. Of 15 patients receiving concomitant baseline ITP medications, 10 permanently discontinued or achieved a sustained reduction of at least one treatment without requiring rescue treatment. Long-term treatment with eltrombopag was safe, well tolerated, and effective in Japanese patients with chronic ITP.