Safety and Efficacy Study of Oral Senicapoc on Allergen Challenge in Atopic Asthmatic Subjects

Inclusion Criteria:

• History of asthma (as defined by the Global Initiative in Asthma definition or having been previously treated for asthma);
• Baseline (pre-bronchodilator) forced expiratory volume at one second (FEV1) ≥70% of predicted;
• Clinically acceptable medical history, physical examination, 12 lead ECG, vital signs, and clinical laboratory tests );
• Positive response on screening to skin prick test to either house dust mite, cat hair, or grass pollen;
• A positive inhaled methacholine challenge with a PC20 ≤ 8 mg/mL (within 6 months prior to Screening Visit 1);
• Screening allergen challenge demonstrates that the subject experiences both an early and late asthmatic response. The early asthmatic response must include a fall in FEV1 of equal to or more than 20% from the post saline value, on at least one occasion, between 5 and 30 minutes after the final concentration of allergen. The late asthmatic response must include a fall in FEV1 of equal to or more than 15% from the post saline value, on at least three occasions, two of which must be consecutive, between 4 and 10 hours after the final concentration of allergen;
• Non-smoker (refrained from any tobacco usage or any products containing nicotine for 6 months prior to Screening Visit 1);
• Able and willing to give written informed consent to participate in the study.

Exclusion Criteria:

• Any subject who has experienced any allergic reaction to a drug that suggests an increased potential for a hypersensitivity to senicapoc (e.g. clotrimazole);
• Previous ingestion of senicapoc (ICA-17043) prior to Screening Visit 1;
• Any condition that might interfere with the absorption, distribution, metabolism, and/or excretion of drugs;
• Respiratory tract infection or asthma exacerbation within 4 weeks of the first Screening Visit or within the period between Screening Visit 1 and Day 1 unless study physician believes lung function was unaffected (no greater than 10% decrease in baseline FEV1) by such event;
• Considering or scheduled to undergo any surgical procedure during the duration of the study;
• History of alcohol and/or drug abuse within 2 years prior to Screening Visit 1;
• Donation of blood (>450 mL) or significant loss of blood within 56 days prior to Screening Visit 1;
• Received any commercially licensed investigational product within 30 days prior to Screening Visit 1 or received any unlicensed investigational product within 90 days prior to Screening Visit 1;
• History of chronic hepatitis B or C, a positive test for hepatitis B surface antigen, hepatitis C antibody, a history of HIV infection, or demonstration of HIV antibodies;
• A positive qualitative urine drug test, a positive urine or breath alcohol test, or a positive urine cotinine or CO breath test at the first Screening visit or on Day 1;
• Use of oral or inhaled or intranasal corticosteroid, long acting beta agonists (e.g., salmeterol or formoterol), leukotriene receptor antagonists (e.g., zafirlukast or montelukast), theophylline, nedocromil sodium, cromolyn sodium, zileuton , or anti-cholinergic agents within the 28 days prior to the first Screening visit;
• Use of oral antihistamines within 1 week prior to the first Screening visit;
• Symptomatic with hay fever during any of the Screening Visits or Day 1;
• A >10 pack year cigarette history.