Efficacy and Safety of Navarixin (SCH 527123) in Participants With Allergen-Induced Asthma (P05363)

Evaluation of treatment in participants with mild asthma.

To evaluate the effect of navarixin (MK-527123, SCH 527123) treatment on allergen-induced late asthmatic response (LAR) in participants with mild asthma.

Eligibility Criteria:
Inclusion Criteria:

* Man or woman 18 to 65 years of age of any race.
* Has mild, stable, allergic asthma as defined by American Thoracic Society criteria.
* Has history of episodic wheezing and shortness of breath.
* Has Forced Expiratory Volume in 1 second (FEV1) of at least 70% of predicted at Screening and within 10% of preallergen screening value at both baselines.
* Has positive methacholine challenge at Screening. Methacholine challenges are considered positive if decreases of at least 20% in the FEV1 occur at a concentration of less than or equal to 16 mg/mL.
* Baseline methacholine PC20 (concentration that initiated a 20% fall in FEV1) must be within 1 doubling concentration of the preallergen screening PC20 to enter treatment.
* Has positive skin-prick test to common allergens (cat, dust mite, grass, pollen).
* Has a positive Early Asthmatic Response of \>=20% fall in FEV1 measured from the FEV1 immediately prior to challenge, and Late Asthmatic Response of \>=15% fall in FEV1 from the FEV1 measured immediately prior to challenge during Screening period.
* Has been free from asthma exacerbation for at least 4 weeks before Screening. An exacerbation is defined as an occurrence of any clinical deterioration of asthma that requires emergency treatment, hospitalization due to asthma, or treatment with additional medication, as judged by the clinical investigator.
* Has been free from relevant seasonal allergen exposure for at least 4 weeks before the study and be able to remain so for the duration of the study.
* Has a current nonsmoking status. If previous smokers, cumulative smoking history must be fewer than 10 pack-years (pack-year=20 cigarettes smoked daily for 1 year). Previous smokers must not have smoked within 1 year before Screening.
* Is willing to give written informed consent to participate in the study.
* Has the ability to comply with the dosing regimen, to adhere to the visit schedule, and to participate in all treatment procedures, including sputum induction.
* Female participant of childbearing potential must have a negative serum pregnancy tests (human chorionic gonadotropin; hCG) at Screening and must use a medically acceptable, highly effective, adequate form of birth control (ie, failure rate \<1% per year when used consistently and correctly) prior to Screening and agrees to continue using it while in the study (Screening and Treatment Periods). Medically acceptable, highly effective forms of birth control include hormonal implants, oral contraceptives, hormonal patches, intravaginal ring, medically acceptable prescribed intrauterine devices (IUDs), and a monogamous relationship with a male partner who has had a vasectomy. A female participant who is not of childbearing potential must have a medical record of being surgically sterile (eg, hysterectomy, tubal ligation), or be at least 1 year postmenopausal. Absence of menses for at least 1 year will indicate that a female is postmenopausal. A female participant should be encouraged to continue using a highly effective method of birth control for 30 days following the end of treatment.
* Participants, if male and sexually active with women of childbearing potential, must agree to use an adequate form of contraception for the duration of the study and to have sexual relations with only those women who use a highly effective birth control method.
* Clinical laboratory tests (complete blood count \[CBC\], blood chemistries, and urinalysis) must be within normal limits or clinically acceptable to the investigator/sponsor.

Exclusion Criteria:

* Has had a diagnosis of chronic obstructive pulmonary disease (COPD) or any other clinically relevant lung disease (eg, cystic fibrosis, pulmonary fibrosis, bronchiectasis) other than mild allergic asthma, or has a history of having been intubated.
* Has had a worsening of a respiratory tract infection within 4 weeks before Screening.
* Has had any clinically significant abnormality; history of clinically significant hypotensive episodes of fainting, dizziness, or lightheadedness; history or symptoms of cardiovascular disease; significant neurologic disease; or hematologic abnormality, including coagulopathy; or has a medication regimen or clinically relevant medical condition other than asthma that may interfere with the effect of study medication.
* Had a peripheral blood neutrophil (PBN) count of \<3 × 10\^9/L at the Screening Visit.
* Has an allergy/sensitivity to the study drug or its excipients.
* Is pregnant, breast-feeding, or intends to become pregnant during the study.
* Has used any investigational drug within 30 days or 5 half-lives of Screening.
* Is presently participating in any other clinical study.
* Is part of the staff personnel directly involved with this study
* Is a family member of the investigational study staff.
* Has received any treatment prohibited by the protocol (Table 3), or any medication that may interfere with the effect of the study medication more recently than the indicated washout period prior to Screening, or must continue to receive the prohibited treatment.