This purpose of this clinical trial is to determine if a statin drug, Simvastatin, added to inhaled corticosteroids and bronchodilators can reduce systemic and airway inflammation, improve lung function and symptoms, and reduce acute exacerbations in patients with severe asthma who are already on controller inhaler therapy.

This proposed investigator-initiated, single-center, early Phase II, cross-over, randomized clinical trial, titled "Randomized Trial of Simvastatin for the Treatment of Severe Asthma", will be conducted at the University of California, Davis Medical Center (UCDMC) in Sacramento, CA. This trial will evaluate Simvastatin for treatment of asthma in subjects with severe asthma (as defined by the American Thoracic Society (ATS)), who are already taking inhaler controller therapy. The investigators plan to enroll 24 patients with severe allergic asthma.

The investigators hypothesize that treatment with Simvastatin 40 mg (administered once daily) will not only improve indicators of airway and systemic allergic/Th2 inflammation, but will also reduce acute exacerbations and improve lung function. All patients will be on standard controller therapy including appropriate doses of inhaled corticosteroids and long-acting bronchodilators.

See above.

Inclusion Criteria:

1. statin-naïve adults >18 years old with the ATS definition of severe asthma,
2. on ICS and LABA,
3. confirmation of allergic asthma (serum IgE >100 kU/L, positive radioallergosorbent test (RAST) panel, and/or peripheral blood absolute eosinophil count of ≥700/mm3),
4. clinically stable for 4 weeks.

Exclusion Criteria:

1. baseline FEV1 <30% predicted,
2. current smokers or ex-smokers with >5 pack-years of smoking history,
3. pregnant women, nursing/lactating mothers, or women of childbearing potential who are actively attempting to become pregnant,
4. nasal or sinus surgery or trauma within 3 months of study participation,
5. ischemic heart disease,
6. liver disease, and
7. the concurrent use of the following medications (amiodarone, verapamil, diltiazem, gemfibrozil, cyclosporine, antifungal azoles (itraconazole, ketoconazole, or voriconazole), and danazol.