Pfizer's phase 4 study of Lyrica to treat adolescents with fibromyalgia fails to meet primary endpoint
Pfizer announced top-line results of a double-blind phase 4 study evaluating the safety and efficacy of Lyrica (pregabalin) capsules CV in adolescents (ages 12-17 years) with fibromyalgia (FM). 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. The treatment difference was 0.66 points, which reflects an improvement of 1.60 points from baseline for pregabalin-treated patients and 0.94 points for placebo (p=0.121). This study was conducted to fulfill a post-marketing commitment required by the US Food and Drug Administration (FDA) when Lyrica was approved for the management of fibromyalgia. The safety and efficacy of pregabalin in paediatric patients have not been established.
A total of 107 adolescent patients were enrolled in this phase 4, 15-week double-blind, randomised, placebo-controlled study from multiple centers across the US, Europe and Asia. This study is the first large pharmacological treatment study to be completed in this study population.
"Pfizer is committed to better understanding the full clinical profile of our approved medicines in paediatric and adolescent patients. This study advances the understanding of this patient population," says Steve Romano, MD, senior vice president and Head, Global Medicines Development for the Pfizer Global Innovative Pharmaceutical business. "Lyrica has more than 10 years of real world experience supporting the needs of patients and remains an important treatment choice for healthcare professionals. These results do not change the established benefit of Lyrica for its approved indications, including fibromyalgia in adults."
Study medication was administered twice daily. Dosing started at 75 mg/day and was optimised over a 3 week period, based on tolerability and response, to a dose of 75 mg/day, 150 mg/day, 300 mg/day or 450 mg/day, with the optimised dose maintained for the next 12 weeks.
The safety profile observed in this study is consistent with the known profile for Lyrica in prior fibromyalgia studies in adults, with the exception of mild nausea, which occurred at a higher rate in pregabalin-treated patients. The most common adverse events in this study in pregabalin treated patients were dizziness, nausea, headache, increased weight and fatigue.
Lyrica is currently approved for various indications in 139 countries and regions globally. Lyrica is approved for five indications in the US, of which four are in the therapeutic area of pain. These indications include neuropathic pain associated with diabetic peripheral neuropathy, post-herpetic neuralgia (pain after shingles), neuropathic pain associated with spinal cord injury, fibromyalgia and partial onset seizures in adults with epilepsy who take one or more drugs for seizures.
Lyrica’s ongoing clinical development programme is focussed on the significant unmet needs of patients with certain chronic pain conditions. Antiepileptic drugs (AEDs), including Lyrica, increase the risk of suicidal thoughts or behaviour in patients taking AEDs for any indication. There have been post-marketing reports of angioedema and hypersensitivity with Lyrica. Treatment with Lyrica may cause dizziness, somnolence, dry mouth, edema and blurred vision.
Other most common adverse reactions include weight gain, constipation, euphoric mood, balance disorder, increased appetite and thinking abnormal (primarily difficulty with concentration/attention).