Inclusion Criteria:

• Able and willing to give written informed consent to participate in the study as HIPAA authorization;
• Clinically acceptable medical history, physical examination, 12 lead ECG, vital signs, and clinical laboratory tests
• History of physician-diagnosed asthma according to Global Initiative for Asthma, AND exercise-induced asthma/ bronchoconstriction;
• Current treatment for asthma with short-acting inhaled beta-2-agonist ONLY;
• Baseline FEV1 >65% of predicted at Screen Visit 1;
• A 20% or greater drop in FEV1 following exercise challenge on at least two separate occasions prior to enrollment;
• Non-smoker (refrained from any tobacco usage, or any products containing nicotine, for 6 months prior to Day 1);

Exclusion Criteria:

• Subject who has experienced any allergic reaction to a drug which, suggests an increased potential for a hypersensitivity to senicapoc (e.g., clotrimazole);
• Previous ingestion of senicapoc (ICA-17043)
• Pregnant or lactating female;
• Condition that might interfere with the absorption, distribution, metabolism, and/or excretion of drugs; subjects who have had any previous gastrointestinal surgery, except appendectomy or cholecystectomy (if performed more than 90 days prior to Screening Visit 1) or a history of clinically significant active cardiovascular, neurologic, endocrine, hepatic, or renal disorders;

• Infectious illness, e.g. acute bacterial, acute and chronic parasitic, fungal infection or viral infection within 6 weeks prior to Screening Visit

  1 or between Screening Visit 1 and Day 1 (Randomization).

• Treatment for conditions other than asthma with systemic corticosteroids within 1 month prior to Visit 1.
• Asthma exacerbation having necessitated treatment with inhaled corticosteroids within 6 weeks prior to study Screening Visit 1.
• History of severe asthma as defined by use of oral/injectable corticosteroids within the last 3 months and/or more than two bursts in the last year.
• Undergoing desensitization therapy unless on a maintenance dose for at least 3 months prior to entry and will continue as such throughout study participation.
• History of chronic pulmonary diseases other than asthma.
• Considering or scheduled to undergo any surgical procedure during the duration of the study;
• Ingestion of any investigational medication within 30 days prior to Screening Visit 1;
• A positive plasma alcohol, or urine cotinine test at Screening Visit 1;

• Use of the following asthma medications for the stated period prior to Screening Visit 1 and throughout the study:

  • Oral or parenteral corticosteroids within 3 months prior to Screening Visit 1
  • Inhaled corticosteroids (ICS) (e.g., budesonide, fluticasone propionate) within 1 month prior to Screening Visit 1
  • long acting beta agonists; leukotriene receptor antagonists; or anti-cholinergic agents (e.g. tiotropium)

within the 2 weeks prior to Screening Visit;

• Use of antihistamines within 3 days prior to Screening Visit 1;
• Has a >10 pack-year history of smoking;
• Hypertension at screen (BP > 150/90), if deemed by Investigator to be unfit to complete exercise challenge testing;
• Screen QTc > 450 msec or ECG not suitable for QT measurement (e.g., poorly defined termination of T-wave);
• After exercise challenge test, subject not recovering to at least 90% of baseline FEV1 following administration of short-acting beta-2-agonist.