Twelve-Month Tolerability and Efficacy Study of NP101, the Sumatriptan Iontophoretic Transdermal System

Objective. To assess the long-term tolerability and efficacy of NP101, a novel transdermal sumatriptan patch being developed for the acute treatment of migraine. Background.-Nausea (with or without vomiting) and gastroparesis have been characterized as being among the most problematic challenges affecting migraine care today. Migraine-associated nausea can cause patients to delay or avoid taking oral medication with a resultant loss or reduction of therapeutic efficacy. Migraine-associated gastroparesis can impair absorption and reduce bioavailability of oral migraine medications and thereby reduce and delay therapeutic efficacy. The non-oral triptan formulations that have been used to overcome these challenges are associated with other shortcomings that can limit their use. Designed to overcome these shortcomings and treatment limitations imposed by gastrointestinal signs and symptoms, the NP101 patch avoids the need for oral administration, does not depend upon gastrointestinal absorption, and provides more consistent, predictable plasma concentrations than oral and intranasal formulations of sumatriptan and a lower maximum plasma concentration than sumatriptan injection. Methods.-Patients diagnosed with migraine who had participated in a randomized, double-blind, Phase III study of the NP101 patch were given the option to use NP101 to treat migraine episodes with moderate or severe headache pain for up to 12 months in this open-label trial. Results.-One hundred eighty-three patients applied 2089 study patches. The most common adverse events involved the patch application site (45% of patients). The only non-application-site adverse events reported in > 2% of patients were nausea (n = 6, 3.3%), upper respiratory tract infection (n = 6, 3.3%), and nasopharyngitis (n = 4, 2.2%). The incidence of triptanassociated adverse events was 1.6%. Across all visits for investigator assessments, the majority of patients (ranging from 74.7% at Month 1 to 92.2% at Month 9) were scored as having no erythema at patch application sites. For patient assessments, the percentage of patch placement sites scored as having no or minimal redness was 38.2% at the time of patch removal and 65.4% 24 hours after patch activation. Two hours after patch activation across all patch treatments over the 12-month study, 23.8% of initial acute migraine episodes were scored as being free from headache pain, 58.2% as having headache pain relief, 78.9% as nausea free, 60.1% as phonophobia free, 53.4% as photophobia free, and 20.7% as migraine free. No evidence of waning tolerability or efficacy was observed over the 12-month study period. Conclusion.-NP101, a transdermal sumatriptan formulation in development for the acute treatment of migraine, demonstrated tolerability and efficacy with successive uses over 12 months in this clinical trial.