Biohaven Pharmaceutical has completed patient enrolment in its pivotal Phase III trial of rimegepant as a preventive treatment for migraine.

Rimegepant is the company’s lead oral calcitonin gene-related peptide (CGRP) receptor antagonist candidate. It has demonstrated efficacy and safety in three pivotal Phase III trials and a Phase IIb trial in the acute treatment of migraine.

More than 1,600 patients have been enrolled in the trial, with topline data expected to be available in the fourth quarter of this year.

The Phase III trial of rimegepant examines the efficacy and safety of the drug in adult subjects who have suffered from migraine for at least one year, and in those with a frequency of four to 14 migraine attacks of moderate to severe intensity per month over the three months before enrolment.

The primary outcome measure of the trial is the change from baseline at week 12 in the mean number of migraine days per month.

Secondary outcome measures include the achievement of at least a 50% reduction from baseline in mean monthly migraine days across the double-blind treatment phase and the mean number of rescue medication days per month.

Biohaven CEO Vlad Coric said: “Given rimegepant’s high affinity for the CGRP receptor and its relatively long half-life, we believe rimegepant may possess unique dual-therapy action with a potential ability to provide acute treatment of migraine attacks and preventive effects.

“To our knowledge, rimegepant is currently the only small molecule CGRP antagonist being developed for both the acute and preventive indications in the treatment of migraine.”

In the second quarter of this year, Biohaven submitted new drug applications (NDAs) to the FDA for the Zydis ODT and tablet formulations of rimegepant.

Last month, Biohaven commenced patient enrolment in a Phase II clinical trial of rimegepant to treat refractory trigeminal neuralgia.