Over the last two decades, the prevalence of asthma has dramatically increased in many parts of the world. Currently, there are no effective ways to prevent the development of nasal allergies and asthma, and there are no cures for these diseases. Sublingual immunotherapy (SLIT) may help reduce symptoms of allergy and asthma. The purpose of this study is to evaluate the safety and efficacy of a cockroach extract given sublingually to adults with perennial (year-round) nasal allergies, asthma, or both.~At study entry, participants will receive a dose of placebo and then up to five incremental doses of cockroach extract or placebo at 15-minute intervals while observed by the clinical research staff. Doses will continue to be given until a sign or symptom occurs that indicates the participant is having difficulty tolerating the drug, or until the maximum study dose is reached.~For the next 6 months, participants will take the maximum study dose of cockroach extract or placebo daily at home.~This study will consist of 8 study visits. Skin tests, breathing tests, and blood collection will occur at study screening and other visits during the study. At study entry, participants will be taught to use an EpiPen in the event of a severe allergic reaction at any time during the study. A physical and oral exam, breathing test, and blood collection will occur at study entry and all follow-up visits.
There is currently no effective way to prevent development of allergic rhinitis (nasal allergies) and asthma and no cure. Sublingual immunotherapy (SLIT), a type of therapy in which allergens are placed under the tongue, may be a way to control and possibly prevent allergic rhinitis and asthma. However, detailed research of this approach is limited. The purpose of this study is to evaluate the safety and efficacy of a sublingual cockroach extract given to adults with perennial allergic rhinitis, asthma, or both.