Oral Ifetroban to Treat Aspirin Exacerbated Respiratory Disease (AERD)

Inclusion Criteria: 1. History of physician-diagnosed asthma 2. History of nasal polyposis 3. History of at least two reactions to oral aspirin or other nonselective cyclooxygenase inhibitor with features of lower airway involvement (cough, chest tightness, wheezing, dyspnea), or one reaction that was life-threatening and required hospitalization, or a diagnosis of AERD by a physician-conducted challenge to aspirin in the last five years before starting treatment. 4. Stable asthma (post-bronchodilator forced expiratory volume in 1 second (FEV1) of ≥ 60%, no glucocorticoid burst for at least two weeks prior to starting treatment, no hospitalizations or emergency room visits for asthma at least three months prior to starting treatment and not on a dose \>1000 µg fluticasone or equivalent daily). 5. ≥ 18 years of age 6. Exhibit symptomatic AERD within three weeks of starting treatment by demonstrating a score of at least 20 on the Sino-nasal Outcome Test (SNOT) - 22. Exclusion Criteria: 1. Current smoking, defined as daily tobacco smoking in the last six months and at least one instance of tobacco smoking in the last three months. 2. Current pregnancy or breastfeeding 3. Use of oral or systemic steroids (e.g. prednisone or equivalent) \> 20 mg daily in the last four weeks before starting treatment. 4. Daily use of long-acting antihistamines in the last two weeks before starting treatment. 5. Less than 12 months of allergy shots (maintenance dose of allergy shots are allowed if treatment duration exceeds 12 months). Less than 1 month of 5-lipoxygenase inhibitors (e.g. zileuton) and/or leukotriene receptor antagonists (e.g. montelukast). 6. Any use of nonsteroidal anti-inflammatory drugs (NSAIDs) or any drug that inhibits the cyclooxygenase enzyme in the last two weeks before starting treatment. 7. History of bleeding diathesis or use of anticoagulant or antiplatelet drugs in the last two weeks before starting treatment. 8. Any immunosuppressive treatment including but not limited to methotrexate, cyclosporine, mycophenolate, tacrolimus, gold, penicillamine, sulfasalazine, hydroxychloroquine, azathioprine, and cyclophosphamide in the last two weeks before starting treatment (maintenance dose of allergy shots are allowed if treatment duration exceeds 12 months). Biologics/immunotherapies such as Xolair or Nucala are permitted if duration exceeds three months. 9. Endoscopic sinus surgery / polypectomy within the past three months 10. Previously treated in a clinical trial with ifetroban within the past three months. 11. Previously treated with other investigational drugs within eight weeks or five half-lives, whichever is longer, before screening 12. Conditions/concomitant disease which make them unevaluable for the efficacy endpoints