Biohaven announced completion of enrollment in Study BHV3000-302, the company's second pivotal Phase 3 clinical trial examining the efficacy and safety of rimegepant in the acute treatment of migraine. The trial began shortly after the commencement of rimegepant's first efficacy trial, Study BHV3000-301, and the two trials enrolled simultaneously with the objective of announcing topline results for the migraine program in the first quarter of 2018. Together the two pivotal trials enrolled approximately 3,000 subjects, which is expected to support a robust assessment of the efficacy of rimegepant in the acute treatment of migraine as required by the FDA for registration. Biohaven continues to evaluate the long-term safety of rimegepant in a third trial, Study BHV3000-201.
Rimegepant is a second generation, oral, calcitonin gene related peptide (CGRP) receptor antagonist being developed for the acute treatment of migraine. Rimegepant is, to the company's knowledge, only one of two small molecule CGRP-receptor antagonists in late stage clinical development. Biohaven is conducting two double-blind, placebo-controlled Phase 3 clinical trials to evaluate the efficacy and safety of 75 mg of rimegepant. The co-primary endpoints of the studies are freedom from pain at two hours post-dosing and freedom from the patient's most bothersome symptom (nausea, photophobia or phonophobia) at two hours post-dosing. The company is also pursuing development of its third generation CGRP-receptor antagonist, BHV-3500, for the acute and preventative treatment of migraine.
"Completion of enrollment in this second migraine trial in only about four months underscores both the priority of the CGRP program within Biohaven and the very high unmet need for innovative therapies to better treat migraine attacks. Rimegepant was designed to be highly potent at the CGRP receptor and administered orally to allow convenient dosing by migraine sufferers when and where a migraine attack hits,” Vlad Coric, M.D., Chief Executive Officer at Biohaven, said. “We continue to efficiently advance our CGRP-receptor antagonist program as we strive to bring patients more therapeutic options in treating disabling migraines. I am pleased to report that we remain on track to receive topline results in these two Phase 3 trials in the first quarter of next year."
Acute attacks of migraine can differ in intensity and frequency, with many being highly disabling. More than 90% of migraine sufferers are unable to work or function normally during an attack. CGRP-receptor antagonists represent a novel class of drug candidates for the treatment of migraine and the first new class specific to the acute treatment of migraine in over 25 years. This unique and specific mode of action potentially offers an alternative to current agents. In addition, CGRP-receptor antagonists could be appropriate for those who have contraindications to the frequently used triptans, such as patients with underlying cardiovascular diseases.
In a previously completed Phase 2b clinical trial, the 75 mg dose of rimegepant was observed to have achieved a statistically significant improvement compared to placebo at two hours post-dosing on all four key migraine symptoms: pain, nausea, photophobia and phonophobia. Rimegepant-treated patients also experienced durable efficacy, achieving statistically higher rates of pain freedom at 24 and 48 hours post-dosing compared to placebo. Durability of treatment response is an important unmet need not fulfilled by current treatment options associated with headache recurrence.
Migraine is both a widespread and disabling neurological disease. The Migraine Research Foundation ranks migraine as the world's third most prevalent illness, affecting approximately 39 million people in the United States. Current treatment approaches, such as triptans, can be limited by headache recurrence within 24 hours after taking migraine medication, as well as cardiovascular contraindications and warnings.