An open-label long-term phase III extension trial to evaluate the safety and efficacy of pregabalin in Japanese patients with fibromyalgia

Abstract

Objectives To assess the long-term safety and efficacy of pregabalin for the treatment of Japanese patients with fibromyalgia (FM).

Methods This 53-week, open-label extension study was conducted at 20 study sites in Japan in patients with FM who had completed a preceding 16-week, placebo-controlled, double-blind trial. Patients received pregabalin, starting at 150 mg/day and increasing to a maintenance dose of 300 or 450 mg/day. The primary endpoint was safety, and secondary endpoints included measures of pain, sleep, and physical functioning.

Results 106 patients entered the trial and received at least one dose of the study drug. The most common treatment-related adverse events were somnolence, dizziness, increased weight, and constipation. There were no treatment-related serious or severe adverse events. There were five (4.7 %) discontinuations due to adverse events, of which three (2.8 %) were considered related to the study drug. Most adverse events resolved over time and could be managed without dose reduction or treatment discontinuation. Improvements in secondary efficacy endpoints of pain, sleep, and physical functioning emerged early in the study and were maintained for the duration of treatment.

Conclusions These data indicate that the long-term treatment of Japanese FM patients with pregabalin may be both safe and effective.

Keywords::

• Clinical trial
• Fibromyalgia
• Japan
• Pain
• Safety

Acknowledgments

This study was funded by Pfizer Japan Inc. Medical writing support was provided by Joshua Fink PhD, of UBC Scientific Solutions, and funded by Pfizer Inc. We would like to acknowledge the contribution of the study’s principal investigators: Sadahiko Kameda (Kameda Internal Medicine), Yoshinobu Koyama (Aso Iizuka Hospital), Yoshifuji Matsumoto (Fujita Health University Nanakuri Sanatorium), Kenji Miki (Kobe Konan Yamate Clinic), Yasuhiko Munakata (Taihaku Sakura Hospital), Masato Murakami (Nihon University Itabashi Hospital), Shouhei Nagaoka (Yokohama Minami Kyosai Hospital), Shiro Nakayama (Nakayama Internal Rheumatism Allergic), Syuji Ohno (Ohno Clinic), Hiroshi Oka (Kasumigaseki Aban Clinic), Yoshinori Okubo (Okubo Clinic), Masanari Omata (Ohimachi Orthopaedic Clinic), Motohiro Oribe (Oribe Rheumatism Internist Clinic), Yuki Sekiguchi (Yokohama Motomachi Women’s Clinic LUNA), Eishi Shirasawa (Shirasawa Orthopedic Clinic), Takao Sugiyama (Shimoshizu National Hospital), Nobuo Takubo (Takubo Rheumatism Orthopedics Department), Fusazo Urano (Shinonoi General Hospital), Ryoichi Yamazaki (Yamazaki Orthopedic Clinic), and Masao Yukioka (Yukioka Hospital).

Conflict of interest

H. Ohta, M.O., and M.S. are employees of Pfizer Japan Inc. K.N. and H. Oka received a consultancy fee from Pfizer Japan Inc. for their participation in this study. C.U. declares no competing interests. K.N., H. Oka, and C.U. were not compensated for their work on this manuscript.