Following years of regulatory hurdles, the FDA has approved Pozen's Treximet, which combines an anti-inflammatory with GlaxoSmithKline's Imitrex, for the acute treatment of migraine attacks with or without aura in adults. Pozen first sought FDA approval in 2005 and was asked to submit more data twice. GSK would pay Pozen $20 million when the drug is launched and the company would get a 6 per cent royalty on sales.
Treximet is the only migraine product designed to target multiple mechanisms of migraine by combining a triptan, a class of migraine-specific medicines pioneered by GSK, and an anti-inflammatory pain reliever in a single tablet. The product is expected to be available in US pharmacies by mid-May.
Treximet contains 85 mg sumatriptan, formulated with RT Technology, and 500 mg naproxen sodium. Sumatriptan is the active ingredient in Imitrex Tablets, available in 25 mg, 50 mg and 100 mg strengths. In clinical trials, Treximet provided a significantly greater percentage of patient's migraine pain relief at two hours compared to sumatriptan 85 mg or naproxen sodium 500 mg alone. In addition, Treximet provided more patients sustained migraine pain relief from two to 24 hours compared to the individual components.
"Migraine patients want their medicine to work early, and to continue to provide relief," said, Dr. Stephen Silberstein, professor of neurology and director of the Jefferson Headache Center at Thomas Jefferson University and an investigator who participated in clinical trials. "The FDA approval of Treximet is good news for migraine patients because clinical trials showed that Treximet produced sustained migraine pain relief for a significant number of patients." Further, Silberstein said, significantly fewer patients on Treximet required the use of a rescue medication to treat their migraine attack than those taking sumatriptan 85 mg.
The approval of Treximet was based on data from two identical double-blind, randomised, placebo-controlled, parallel-group, multicenter studies of more than 2,900 migraine sufferers.
Findings from these pivotal studies demonstrated that Treximet provided more patients migraine pain relief at two and four hours compared to sumatriptan 85 mg, naproxen sodium 500 mg or placebo alone. Importantly, in these studies, Treximet was effective at relieving the pain of a migraine attack and maintaining that relief from two to 24 hours. In addition, Treximet effectively relieved migraine associated symptoms - nausea and sensitivity to light and sound - compared to placebo. Treximet was also studied in a one-year open-label tolerability and safety study of 565 patients who treated nearly 24,500 migraine attacks with the active drug. Patients completing the one-year study treated an average of five migraine attacks per month with Treximet.
According to analysts' forecasts, the side effects that appear on the Treximet label would make it harder for the companies to market the drug. Treximet may cause an increased risk of serious cardiovascular thrombotic events, myocardial infarction, and stroke, which can be fatal. This risk may increase with duration of use, the company informed. Treximet was generally well-tolerated in these pivotal studies The most common treatment-related adverse events reported within 24 hours of taking Treximet were dizziness; nausea; somnolence; chest discomfort and chest pain; neck, throat and jaw pain, tightness and pressure; numbness/tingling; upset stomach; and dry mouth.
Pozen stock rose $3.58, or 34 per cent, to $14.11 in afternoon trading whereas shares of GlaxoSmithKline rose 33 cents to $42.54.