Biohaven Pharmaceutical Holding Company Ltd. (NYSE: BHVN) Files An 8-K Regulation FD Disclosure
Item 7.01 Regulation FD Disclosure.

On December10, 2018, Biohaven Pharmaceutical Holding Company Ltd. (the “Company”) issued a press release announcing results from its ongoing rimegepant long-term safety study of rimegepant, an oral calcitonin gene-related peptide (CGRP) receptor antagonist. A copy of the press release is furnished herewith as Exhibit99.1 to this Current Report on Form8-K.

The information contained in this Item 7.01, including Exhibit99.1, is being “furnished” and shall not be deemed “filed” for purposes of Section18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liability of that section or Sections 11 and 12(a)(2)of the Securities Act of 1933, as amended (the “Securities Act”). The information in this Item 7.01, including Exhibit99.1, shall not be incorporated by reference into any registration statement or other document to the Securities Act or into any filing or other document to the Exchange Act, except as otherwise expressly stated in any such filing.

Item 8.01 Other Events.

On December10, 2018, the Company announced initial positive results from its ongoing long-term, open-label safety study of rimegepant, an oral CGRP receptor antagonist. Based upon this interim analysis (database cutoff of November21, 2018) of Study BHV3000-201 (NCT03266588 or “Study 201”) it appears that rimegepant may be safe and well tolerated with long-term dosing in patients with migraine. In this study, patients are allowed to treat migraine attacks of all severities (mild to severe) up to once daily for up to a full year. The interim results also include hepatic safety and tolerability data of rimegepant 75 mg in study participants based upon review of both adverse events and regularly scheduled liver function tests. Interim hepatic data were reviewed by an external independent panel of liver experts. The panel provided a consensus opinion based upon the Drug-Induced Liver Injury Network (DILIN) causality assessment. The panel did not assess any liver cases as probably related to study drug and there were no Hy’s Law cases identified. The panel concluded that there was no liver safety signal detected through the data analysis cut-off date, including in a subset of patients with near-daily dosing (> 15 doses/month). In aggregate, the panel noted that, compared to placebo arms of other migraine treatments, there was a very low incidence of overall elevations of liver laboratory abnormalities (1.0% incidence of serum ALT or AST > 3xULN). Subjects will continue to participate in Study 201 with additional data analyses to be submitted to the FDA in connection with the planned filing, including the required 120-day safety update.

The most common individual AEs (occurring > 5%) in Study 201 were upper respiratory tract infection and viral respiratory tract infection. There were low rates of discontinuation due to AEs in the treatment period (2.6%).

In addition to the interim safety analysis, preliminary open-label efficacy data from Study 201 suggest that rimegepant may be associated with a reduction in migraine days per month (30 days) compared to the observational lead-in period, suggesting a potential preventive effect. In an exploratory analysis, patients who experienced > 15 migraine days/month (N=172) during the standard of care observation period demonstrated a mean reduction of 4 headache days/month by 12 weeks of intermittent dosing with rimegepant. Approximately 40% of patients who had > 15 headache days/month during the observation period showed at least a 30% or more reduction in their monthly number of headache days by 12 weeks of treatment with rimegepant. Reduction from baseline in the mean number of headache days per month was observed beginning as early as the first month and continued in subsequent months of therapy. Biohaven initiated a double-blind, placebo-controlled trial examining regularly scheduled dosing of rimegepant 75mg for the preventive treatment of migraine in November2018.

Study 201 is a multicenter, open-label safety study with 1,780 U.S. adult patients treated at the time of the November21, 2018 interim data analysis cutoff. Eligible patients were required to have a history of two to 14 migraine attacks of moderate to severe intensity per month. Patients were allowed to take rimegepant 75 mg up to once per day for up to 52 weeks. There was not a limit on the number of attacks per month that could be treated. Approximately 473 patients have received near daily dosing (15 or more doses a month) of rimegepant 75 mg to date for a duration of 1-12 months.

Forward-Looking Statements

This report includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements involve substantial risks and uncertainties, including statements that are based on the current expectations and assumptions of the Company’s management. All statements, other than statements of historical facts, included in this report, including statements regarding rimegepant’s potential to be an improved treatment option for the acute treatment of migraine, rimegepant’s ultimate safety profile, and the potential for rimegepant to provide a preventive