LAS VEGAS, NVAn orally inhaled dihydroergotamine studied for the rescue treatment of acute migraine exhibited significant pain relief compared with placebo, according to the results of a pivotal phase 3 trial presented at PAINWeek 2012.

The efficacy of the acute treatment of migraine can be evaluated by the extent of rescue medication use (RMU) when headache symptoms persist or recur 2–24 hours after the initial abortive treatment. Shashidar Kori, MD, and colleagues from MAP Pharmaceuticals, Inc., Mountain View, CA, reported the results from two analyses of RMU in the acute treatment of migraine episodes. The frequency of RMU use was recorded during a randomized, placebo-controlled, double-blind trial of MAP0004, an investigational, orally inhaled dihydroergotamine (DHE).  In this Phase 3 trial, MAP0004 was shown to be superior to placebo for the acute treatment of migraine.  In addition to their ad-hoc analysis of RMU, the researchers also reported their subgroup analysis of patients with severe migraine pain at baseline during the double-blind period.

RMU was permitted in this study if migraine symptoms were not relieved by 2 hours after the study drug was administered. The post-hoc analysis included 794 patients randomized (1:1) to receive double-blind treatment with MAP0004 or placebo.

Patients receiving MAP0004 experienced statistically significant reduction of migraine symptoms compared with patients receiving placebo. RMU in the double-blind period was consistently lower with MAP0004 than with placebo at 2 hours (4.3% vs. 8.1%, P=0.0261); 4 hours (19.6% vs. 37.9%, P<0.0001); 24 hours (36% vs. 54%, P<0.0001); and 48 hours (42% vs. 59%, P <0.0001) after study drug administration. RMU was also significantly lower with MAP0004 than with placebo across demographic and baseline characteristics. Among patients who reported pain relief at 2 hours, MAP0004-treated patients had significantly lower RMU at 4, 24, and 48 hours than placebo-treated patients. In this study, RMU was significantly lower with MAP0004 than with placebo overall and across demographic and baseline characteristics.

In a second presentation, Dr. Kori and colleagues reported their post-hoc analysis of the efficacy of MAP0004 compared with placebo using Fisher’s exact test in the Phase 3 trial. Severe baseline migraine pain was reported in 366 of the 794 subjects. Subjects with severe migraine pain treated with MAP0004 experienced statistically significant pain relief compared with those treated with placebo (P<0.05) in as little as 10 minutes after receiving MAP0004 and at every subsequent prescheduled evaluation time point. Compared to subjects treated with a placebo, the treatment groups experienced significantly less pain (P<0.05) by 60 minutes, and at all subsequent time points following treatment. Sustained pain relief and sustained pain-free values, both between 2–24 hours and between 2–48 hours, were statistically significantly higher for MAP0004 relative to placebo. Among subjects with severe migraine, headache recurrence over 24 hours occurred in 6.2% of those treated with MAP0004, compared to 18% when treated with placebo.

Based on the results of this Phase 3 trial, the investigators concluded that MAP0004 was effective for the acute treatment of patients with severe migraine.