Clinical Trial Results Are Promising
One of the most common problems with Migraine medications is that oral medications are often problematic and not optimally effective. There are three primary reasons for this:
- The Migraineur may be vomiting and not retaining much of the medication.
- Migraineurs also have a high incidence of gastric stasis, which can prevent the absorption of oral medications.
- Oral medications take too long to act.
For these reasons, alternative methods of delivery have been developed for some Migraine medications. We've seen Migraine abortives in subcutaneous injections (Imitrex, DHE) and nasal sprays (Imitrex, Zomig, Migranal).
More recently, we've seen newer, novel delivery systems being developed for Migraine abortive medications. Zelrix is a sumatriptan (generic Imitrex) transdermal delivery system, a "sumatriptan patch," currently in development.
This patch, however, is significantly different from other patches. This patch doesn't just sit on the skin and wait for the medication to be absorbed into your skin. NuPathe, the developer of Zelrix, calls it "SmartRelief." SmartRelief is a proprietary iontophoretic system combining modern electronics with state-of-the-art formulation and pharmaceutics technology. Iontophoresis is a non-invasive method for transporting a molecule through the skin by means of a mild electrical current. The electrical current carries the charged molecule from the patch across the skin. Once across, the drug is rapidly absorbed and distributed systemically.
Early studies of Zelrix showed that sumatriptan administration using this iontophoretic transdermal technology delivered medication with blood levels within the same range as nasal spray, tablet, and injectable sumatriptan.6
At the 14th International Headache Congress earlier this month, Phase III trial results for Zelrix were released. (Phase III trials are expanded controlled and uncontrolled trials after preliminary evidence suggesting effectiveness of the drug has been obtained. They're intended to gather additional information to evaluate the overall benefit-risk relationship of the drug and provide and adequate basis for physician labeling. They're the last phase of trials before applying for FDA approval.)
Trial Objectives: To evaluate the effectiveness and tolerability of Zelrix.
• randomized, double-blind, placebo controlled
• 530 patients treated at 37 sites in the US
• Participant age range: 18-65 years
• participants with IHS defined Migraine treated one moderate to severe migraine attack with Zelrix or a placebo patch
• assessments included:
- degree of freedom from pain
- degree of relief from photophobia, phonophobia, nausea
- sustained headache pain relief
- need to use rescue medication.
- Tolerability was evaluated by reports of adverse event reports, examining the skin when removing the patch, and the final study visit.
Zelrix met the primary efficacy endpoint of a statistically significant improvement compared to placebo for pain freedom at two hours after patch application (18 percent vs. 9 percent, p=0.0092). Additional pre-defined two hour efficacy endpoints included:
- Pain relief: 53 percent of patients treated with Zelrix compared with 29 percent for placebo (p