Civamide Nasal Solution for Cluster Headache

Inclusion Criteria: * Written IRB-approved informed consent has been obtained and signed, within 12 months of entering into the Baseline Period (Day -3). * Male or female 18 years or older. * Subject has ≥2 year history of episodic cluster headache with at least 2 previous episodic cluster headache periods. * Cluster Headaches must meet the following International Headache Society Diagnostic Criteria : * Severe, unilateral, orbital, superorbital and/or temporal pain lasting 15 to 180 minutes untreated. * Headache is associated with at least one of the following which have to be present on the side of the pain: * Conjunctival injection * Lacrimation * Nasal Congestion * Rhinorrhea * Forehead and facial sweating * Miosis * Ptosis * Eyelid edema or * A sense of restlessness or agitation * The current episodic cluster headache period is expected to last at least 5 weeks but no more than 24 weeks from the time of entry into the Baseline Period (Day -3), based on the average duration of the subject's usual episodic cluster headache period. * At least one cluster headache (but no more than 8) daily on each of the three days of the Baseline Period (Days -3, -2, -1) immediately preceding Study Day 1. * The subject is in generally good health, other than history of episodic cluster headache. * The subject agrees not to begin any new concurrent medications or restricted medications during their participation in study. * All females of childbear…