The results of a pair of double-blind, placebo-controlled Phase III clinical trials of milnacipran for the treatment of fibromyalgia were presented at the 2007 American College of Rheumatology meeting in Boston. Total daily dosages of 100 mg and 200 mg of milnacipran demonstrated statistically significant and clinically meaningful improvements in not only pain, but also other core symptoms of FM. In addition, they found that the therapeutic effects of milnacipran among responders in the six-month study were sustained for up to one year in a double-blind extension trial. The total number of participants for both studies was 2,084.
The approach utilized in these studies was somewhat different than that used in most clinical trials. The reasoning was that, although chronic widespread pain is the defining characteristic of fibromyalgia, patients typically experience a broad spectrum of other symptoms, including fatigue, cognitive dysfunction and reduced physical function. Therefore, milnacipran was evaluated using a “composite responder” approach. That means individual patients must see concurrent improvements of several FM symptoms – not just pain. Because of this, a composite responder analysis represents a more stringent assessment of therapeutic effect than the evaluation of individual symptoms. Milnacipran is the first treatment studied for FM to be evaluated using a composite responder approach.
Milnacipran is a unique dual-reuptake inhibitor, which preferentially blocks the reuptake of norepinephrine with higher potency than serotonin. (Norepinephrine and serotonin are both neurotransmitters and are known to play an essential role in regulating pain and mood.) Milnacipran has been used outside the U.S. for over 10 years and is approved for the treatment of depression in more than 32 countries. It is being developed in the U.S. for the treatment of fibromyalgia by Forest Laboratories, Inc. and its licensor Cypress Biosciences, Inc. They are currently planning to submit a New Drug Application to the FDA by the end of this year, requesting approval of milnacipran for the treatment of FM.
Published On: November 28, 2007