Positive results of the latest study of Zelrix® are giving hope to manufacturer NuPathe that the triptan patch treatment will be on the market soon. Zelrix is a novel way of taking sumatriptan (Imitrex®): it delivers the active ingredient through the skin via a transdermal patch. The patch, which was designed for migraineurs who experience nausea, allows sumatriptan to take effect without having to go through the gastrointestinal system.

The 12-month study was an open-label trial designed to assess long-term safety. Zelrix was well tolerated by the 183 enrolled patients. The most common adverse events all involved the application site and included itching (21.9% of patients), pain (21.3%) and hypersensitivity (6%). There was no observed increase in skin irritation with successive or cumulative patch usage.

Just under 14% of patients discontinued participation due to adverse events, primarily application site reactions. Only three patients reported a triptan adverse event with any treatment. These side effects can include tightness or a heavy feeling in the chest, tingling, numbness in the extremities, sensations of warmth or cold, tingling down the arms and pain, tightness, or pressure in the neck, throat and jaw.

In addition, the company reported that in 58% of migraines treated, patients reported relief from migraine pain within two hours of applying the patch, and were headache-free 24% of the time. Patients were nausea-free within two hours 79% of the time.

In a press release, Mark Pierce, MD, PhD, chief scientific officer of NuPathe, commented: “The safety and tolerability of Zelrix in this 12-month trial was consistent with the profile observed in the pivotal Phase III trial for Zelrix in which only a single migraine was treated. Additionally, the results demonstrate strong and consistent efficacy throughout the duration of the trial.”

Nupathe plans to submit a new drug application to the FDA in the fourth quarter of 2010.