Study to Evaluate the Effectiveness and Safety of MK-1029 in the Treatment of Persistent Asthma That is Not Controlled With Montelukast (ML) in Adults (MK-1029-011 AM2)

Inclusion Criteria:

- not pregnant or breastfeeding and does not plan to become pregnant for the duration
of the study;

- symptoms of persistent asthma for at least one year;

- current use of asthma treatments: 1) "as-needed" inhaled SABAs (albuterol/salbutamol)
and no asthma controller for at least 4 weeks prior to Screening Visit OR 2) stable
dose of ICS, combination ICS/LABA and/or oral asthma controller(s) for at least 4
weeks prior to Screening Visit and able to tolerate discontinuing all controllers
while receiving ML;

- no history of smoking OR no smoking for at least 1 year, with a smoking history of no
more than 10 pack-years;

- able to maintain a constant day/night, awake/sleep cycle;

- agrees to not change habitual consumption of beverages or foods containing caffeine
throughout the study;

- Body Mass Index (BMI) of 15 kg/m^2 to 40 kg/m^2.

Exclusion Criteria:

- history of myocardial infarction, congestive heart failure, or uncontrolled cardiac
arrhythmia within 3 months prior to Screening Visit;

- hospitalized or hospitalization within 4 weeks prior to Screening Visit;

- intention of moving or anticipation of missing any study visits;

- any major surgical procedure(s) within 4 weeks prior to Screening Visit;

- participation in a clinical trial involving an investigational drug within 4 weeks
prior to Screening Visit;

- current regular use or a recent past abuse (within past 5 years) of alcohol (>14
drinks/week) or illicit drugs;

- donation of a unit of blood within 2 weeks prior to Screening Visit or intention of
donating a unit of blood during the study;

- evidence of another active pulmonary disorder such as bronchiectasis or COPD;

- treatment in an emergency room for asthma within 4 weeks prior to Screening Visit or
hospitalization for asthma within 2 months prior to Screening Visit;

- respiratory tract infection which required treatment with antibiotics within 2 months
prior to Screening Visit;

- evidence of active sinus disease within 1 week prior to Screening Visit;

- history of a psychiatric disorder, other than stable depression, within 3 months
prior to Screening Visit;

- history of human immunodeficiency virus (HIV);

- hypersensitivity or intolerance to inhaled beta-agonists and/or leukotriene
inhibitors or any of their ingredients, including lactose and galactose;

- unstable disease of the ophthalmologic, neurological, hepatic, renal, connective
tissue, genitourinary, gastrointestinal, cardiovascular or hematologic systems;

- cancer (except for successfully treated basal and squamous cell carcinomas of the
skin) or history of cancer within 5 years prior to Screening Visit;

- uncontrolled hypertension.