Two Phase 4 clinical trials of Lyrica (pregabalin) in adolescent fibromyalgia patients failed to statistically improve mean pain scores, but showed good effects on a number of other measurements, suggesting that adolescents with fibromyalgia might benefit from this drug treatment.
The report, “Safety and efficacy of pregabalin in adolescents with fibromyalgia: a randomized, double-blind, placebo-controlled trial and a 6-month open-label extension study,“ published by researchers from the University of Cincinnati College of Medicine in the journal of Pediatric Rheumatology, suggests that more research is necessary to develop a drug treatment suitable for this age group of patients.
Lyrica is approved both in the U.S. and Europe for adults with fibromyalgia, but adolescents suffering from the condition are left without approved treatments. The clinical trials, sponsored by Pfizer, included adolescents ages 12 to 17 who were recruited to study centers across the U.S., India, Taiwan, and the Czech Republic.
The first trial (NCT01020474) explored how 15 weeks of treatment affected 80 youngsters randomized to receive either Lyrica or a placebo, and was followed by a six-month follow-up study (NCT01020526) involving participants from the first study. In the follow-up trial, all participants received Lyrica, as the trial intended to study treatment safety. The dose for all participants was optimized at study start, and doses ranged from 75 to 450 mg per day.
The trial’s main goal was a change in mean pain scores at the end of 15 weeks, measured with the use of daily pain diaries. While the study did not find an overall improvement on this point, other measures, including weekly measures of mean pain scores, showed that Lyrica lowered pain in 10 out of 15 weeks of the trial.
Also, the patient global impression of change, as well as parents’ global impression of change, were improved, and there was a tendency for improved sleep in adolescent patients receiving Lyrica, but the difference between the group receiving a placebo was not statistically significant.
One participant treated with Lyrica had two serious adverse events during the first study (gallstones and major depression), and another six, of whom three received Lyrica, had adverse events deemed less serious.
Researchers observed improvement in mean pain scores during the follow-up study, which tended to be somewhat larger in those who received Lyrica in the first study.
Adverse events were common, reported by 71.4 percent of participants, but only two stopped the treatment because of side effects. In total, six participants had one or more severe adverse effects. The most commonly reported side effects were dizziness, fatigue, headache, nausea, and stomach pain.
The side effects were similar to those observed in adult patients, and since the drug did have some positive effects, researchers hope the trial will inspire others who are searching for suitable treatments for adolescent fibromyalgia patients.