Evaluation of an Asthma Treatment Strategy Based on Exhaled Nitric Oxide Measurements in Adolescents

Over the past two decades, the prevalence of asthma has dramatically increased in many parts of the world. The current National Asthma Education and Prevention Program (NAEPP) identifies inhaled corticosteroids (ICS) as the preferred long-term control therapy for all forms of persistent asthma. However, there is still a significant proportion of patients with persistent asthma who are not receiving ICS therapy or do not follow their treatment plan. Individualized asthma treatment plans are needed. The use of biomarkers, in addition to NAEPP guidelines, may help enhance the level of asthma assessment, guide medication regimens, and improve overall asthma control. This study will determine whether NAEPP-recommended treatment, combined with eNO measurement, is more effective in reducing asthma symptoms than NAEPP-recommended treatment alone. ICAC-01 will last 46 weeks and will comprise 8 study visits.

ICAC-01 also includes a mechanistic sub-study (ICAC-02). Its primary objective is to determine whether "highly sensitized", compared to "weakly sensitized" asthmatic subjects have more severe asthma, as defined by the levels at randomization to the completion of ICAC-01. To address the primary objective of ICAC-02, the study will include all the participants enrolled in ICAC-01 with dust mite-, cockroach- and/or alternaria-specific IgE levels within certain parameters.

Inclusion criteria

• Clinical diagnosis of asthma made by a doctor over a year prior to study entry OR symptoms have been present more than a year if the diagnosis was made less than a year prior to study entry
• Have symptoms consistent with persistent asthma OR have evidence of uncontrolled disease. More information on this criterion can be found in the DAIT ICAC-01 protocol.
• Currently reside in a pre-selected area containing at least 20% of households below the U.S. government poverty level
• Do not smoke and have not used smokeless tobacco products in the year prior to study entry
• Able to perform eNO measurement procedures and spirometry at study screening
• Parent or guardian willing to provide informed consent, if applicable
• History of clinical varicella (chicken pox) or have received varicella vaccine
• Planning to stay in the area for the next 12 months
• Primary language is English. Spanish speakers may enroll at centers with Spanish-speaking staff.
• Parent or guardian primarily speaks English (or Spanish at centers with Spanish-speaking staff), for participants with parent or guardian providing informed consent
• Willing to allow the study physician to manage disease for the duration of the study
• Willing to change asthma medications in order to follow the protocol

Exclusion criteria

• Adherence to controller medication between Visits 1 and 2 is less than 25%. More information on this criterion can be found in the DAIT ICAC-01 protocol.
• Determined to have mild intermittent asthma at Visit 1
• Have had a life-threatening asthma exacerbation requiring intubation, mechanical ventilation, or resulting in a hypoxic seizure in the 5 years prior to study entry
• Have significant medical illnesses other than asthma. More information on this criterion can be found in the DAIT ICAC-01 protocol.
• Unable to use a metered-dose inhaler for administration of a beta-agonist rescue medication or a dry powder inhaler for the administration of asthma controller regimens
• Known hypersensitivity to any medications commonly used for the treatment of asthma
• Have not completed a home evaluation within 4 weeks of study screening
• Currently participating in another asthma-related drug or intervention study, or have participated in another asthma-related drug or intervention study in the month prior to study entry
• Does not sleep at least 4 nights per week in one home
• Lives with a foster parent (not applicable if patient is able to provide informed consent)
• Does not have access to a phone
• Requires certain medications. More information on this criterion can be found in the DAIT ICAC-01 protocol.
• Urine cotinine level above 100 ng/ml at study screening
• Pregnant or breastfeeding