Lyrica Shows Durable Effect In Fibromyalgia

WASHINGTON, Nov. 16 -- In a majority of patients with fibromyalgia, Lyrica (pregabalin) maintains its painkilling effect for several months, a researcher reported here.

"This is the first study to report long-term pain relief for fibromyalgia," according to Leslie Crofford, M.D., of the University of Kentucky in Lexington, speaking at the American College of Rheumatology meeting here.

Explain to patients who ask that there is no approved treatment for fibromyalgia, although several drugs have been shown to have a short-term effect.

Note that this study suggests the effect of Lyrica (pregabalin) is more long-lived, although not all patients will have a response and not all will be able to tolerate the medication's side effects.

This study was published as an abstract and presented orally at a conference. These data and conclusions should be considered to be preliminary as they have not yet been reviewed and published in a peer-reviewed publication. Lyrica, manufactured by Pfizer, is approved for the treatment of such conditions as diabetic neuropathy and post-herpetic neuralgia, but earlier double-blind studies have suggested that it relieves pain associated with fibromyalgia, as well as improving quality of sleep and reducing fatigue, Dr. Crofford said.

But many drugs have shown a short-term benefit in fibromyalgia, commented Eric Ruderman, M.D., of Northwestern in Chicago, who was not involved in the study. "Lots of things look interesting in fibromyalgia in small studies, short studies, but they don't really last," he said.

It was for that reason, Dr. Crofford said, that she and colleagues undertook a six-month, two-phase clinical trial involving 1,051 participants, most of them women. On average, they had a pain score of 78 on a scale of 100 and had had fibromyalgia for more than seven years.

In the first phase, lasting six weeks, all patients self-titrated to a dose of Lyrica at which they felt comfortable, to a maximum of 600 mg/day. Patients were classified as responders if they had at least a 50% reduction in pain scores at their optimum dose and reported that they were "much" or "very much" improved.

At the end of the six weeks, 663 patients (or 63%) were classified as responders and 566 entered the 26-week, double-blind, placebo-controlled part of the trial, Dr. Crofford said. Of those, 279 stayed on Lyrica, and 287 were switched to placebo.

One in four placebo patients reported their pain worsened within seven days of beginning the double-blind part of the study, compared with 34 days for those who remained on Lyrica.
The time to loss of therapeutic effect was significantly longer for Lyrica patients, at P<0.001.
By the end of the double-blind study, 61% of placebo patients had lost therapeutic response, compared to 32% of those getting Lyrica.
The main adverse effects were mild or moderate dizziness (36%), somnolence (22%), sinusitis, arthralgia, and anxiety.

Dr. Crofford said that the roughly 40% of the original participants who didn't go on to the double-blind phase dropped out for three main reasons: they couldn't tolerate the drug, they were lost to follow-up, or they reported lack of efficacy.

Dr. Ruderman said the study will allow physicians treating patients with the condition to give some guidance as to how long they can expect a therapeutic effect. Durability of response, he noted, "is an incredibly important issue" for physicians and patients.

That said, he cautioned that the drug is not approved for fibromyalgia, "but nothing is."

Dr. Crofford and all co-authors disclosed a relationship with Pfizer. Three of the four co-authors disclosed that they were Pfizer employees.