Presented at the 2012 AAPM Annual Meeting « Back

A Multicenter, Randomized, Double-Blind, Placebo-Controlled Switch Study to Evaluate the Safety, Tolerability, and Efficacy of Milnacipran in Patients with an Inadequate Response to Duloxetine for the Treatment of Fibromyalgia

Lucinda Bateman, MD, lbateman@pol.net¹, Allan Spera, PhD², Robert H. Palmer, MD², Joel M. Trugman, MD², Yuhua (Jennifer) Lin, MS², (1) The Fatigue Consultation Clinic, Salt Lake City, Utah, (2) Forest Research Institute, Jersey City, New Jersey

Introduction: This study evaluates the safety, tolerability, and efficacy of milnacipran following a direct switch from duloxetine in fibromyalgia patients with an inadequate response to duloxetine. Methods: Patients receiving duloxetine (60 mg/day) for ≥4 weeks at screening were eligible. After 2 weeks of open-label duloxetine 60 mg/day, patients with VAS pain scores ≥40 (0-100 mm) and dissatisfied with duloxetine were randomized to 4:1 to milnacipran 100 mg/day (n = 86) or placebo (n = 21) for 10 weeks. The primary efficacy parameter was the percentage of patients with ratings of "much improved" or "very much improved" on the Patient Global Impression of Change (PGIC). The secondary efficacy parameter was 1-week recall VAS pain score. Efficacy was analyzed using last observation carried forward. The study protocol was approved at each site by an IRB; all patients provided written, informed consent. Results: Among patients switched to milnacipran, 59.3% completed the double-blind treatment period; placebo patients had a completion rate of 52.4%. At Week 10, 32.9% of patients switched to milnacipran were PGIC responders and milnacipran patients had a mean decrease from baseline in VAS pain of 12.3 mm (23.8% of placebo patients were PGIC responders and the mean decrease from baseline in VAS pain was 1.3 mm). Treatment-emergent AEs in patients switched to milnacipran were similar to those reported in previous placebo-controlled trials. Conclusions: These results suggest that fibromyalgia patients who inadequately respond to duloxetine may benefit by switching to milnacipran. The direct switch from duloxetine to milnacipran was safe and well tolerated in this study.

Funding: This study was supported by Forest Research Institute, a subsidiary of Forest Laboratories, Inc. and Cypress Bioscience, Inc.