By Pat Anson, Editor

Lyrica, a blockbuster drug widely prescribed to treat chronic pain in adults, works no better than a placebo in treating juveniles with fibromyalgia, according to the results of a new study released by Pfizer (PFE). Lyrica is Pfizer’s top selling drug with annual worldwide sales of over $5 billion.

The double-blind Phase IV trial was conducted to fulfill a post-marketing study required by the Food and Drug Administration after Lyrica was approved for the management of fibromyalgia in adults in 2007. The generic name of Lyrica is pregabalin, which was originally developed as an anti-epileptic drug.

“The primary endpoint of the study was not achieved as there was not a statistically significant difference between pregabalin and placebo in mean pain score,” Pfizer said in a statement.

A total of 107 adolescents (ages 12-17 years) were enrolled in the 15-week study at multiple centers across the U.S., Europe and Asia. It was the first large study on the efficacy and safety of Lyrica in juveniles with fibromyalgia.

The National Institutes of Health estimates that about 5 million Americans suffer from fibromyalgia, a poorly understood disorder characterized by deep tissue pain, fatigue, headaches, mood swings and insomnia.

In the study, Lyrica was administered twice daily, starting at 75 mg/day and then increasing to up to 450 mg/day, depending on the tolerability and response of the patient. The most common side effects in the study were dizziness, nausea, headache, increased weight and fatigue. Many other patients who take Lyrica complain of similar symptoms.

"Pfizer is committed to better understanding the full clinical profile of our approved medicines in pediatric and adolescent patients. This study advances the understanding of this patient population," said Steve Romano, MD, senior vice president of Global Medicines Development for Pfizer. "These results do not change the established benefit of Lyrica for its approved indications, including fibromyalgia in adults."

In addition to fibromyalgia, Lyrica is approved by the FDA to treat chronic pain associated with epilepsy, shingles, diabetic peripheral neuropathy, and spinal cord injury. The drug is also prescribed “off label” to treat lumbar spinal stenosis, the most common type of lower back pain in older adults.