To evaluate the safety, tolerability and pharmacokinetics (PK) of MK0633 in adolescent mild-to-moderate asthma patients to permit further clinical investigation.

Inclusion Criteria:

• Patient is judged to be in good health, other than having mild to moderate asthma, based on medical history, physical examination, vital signs, and laboratory safety tests
• Patient has no clinically significant abnormality on electrocardiogram (ECG) performed at the prestudy (screening) visit and/or prior to administration of the initial dose of study drug
• Patient has at least 1 year of mild-to-moderate asthma
• Patient has been a nonsmoker for at least 6 months
• Patients of childbearing potential must agree to use a medically acceptable method of contraception during the study and for 90 days after the last dose of study drug
• Patients must be able to swallow tablets

Exclusion Criteria:

• Patient has a history of clinically significant endocrine, gastrointestinal, cardiovascular, hematological, hepatic, immunological, renal, respiratory, other than asthma, or genitourinary abnormalities or diseases
• Patient has required a visit to a hospital or emergency room due to an asthma exacerbation within 3 months of the prestudy visit
• Patient has unresolved signs and symptoms of an upper respiratory tract infection (URI) or has had had an upper respiratory tract infection within 3 weeks prior to the prestudy visit
• Patient has a history of stroke, chronic seizures, or major neurological disorder
• Patient has a history of neoplastic disease
• Use of theophylline, Singulair (montelukast), Xolair (omalizumab), Zyflo amd Zyflo CR (zileuton), oral corticosteroids and oral beta agonists are excluded approximately 2 weeks prior to administration of study drug and throughout the study
• Patient consumes alcoholic beverages