Comparability and Standardization of Controlled Allergen Challenge Facilities

Allergen challenge facilities have been utilized for many years in clinical drug trials studying onset of action, proof of concept, duration of action, and efficacy. Each facility has somewhat different design characteristics and pollen dispersal technologies. Facilities are located in disparate geographic areas and have populations of participants who are sensitized to allergens unique to that area. Therefore, facilities have operated as single sites with little effort to evaluate facility comparability or to attempt standardization across facilities. The purpose of this study is to compare the two sites and assess whether the sites are able to achieve similar symptom scores.

When CACF have been designed with a high degree of rigor, quality assurance and validation testing, the exposure to controlled levels of pollen in such facilities as the Environmental Exposure Unit (EEU) and the Biogenics Research Chamber (BRC) will demonstrate comparable/standardized symptomatic responses. This will be demonstrable not only following pollen exposure but will also have similar reductions in symptoms following treatment with a Food and Drug Administration (FDA) approved medication known to be effective for the treatment of seasonal allergic rhinoconjunctivitis ( SAR); cetirizine 10mg. Because of quality assurance and validation testing completed at these facilities a priori, this comparability will be demonstrated despite their disparate geographical physical locations and the utilization of these facilities of somewhat different mechanical and technical materials and methods to achieve similar outcomes.

This multi-center study of SAR will enroll 50 participants at each site. These participants will be age 18-65, male and female, with a mixture of ethnic groups. The study will involve 3 Phases: Screening, Treatment Exposure Visit, and a cross-over Treatment Exposure Visit. In all stages, a CACF visit will be pivotal to determine participant eligibility for enrollment and response to therapy. The qualifying participants will receive a double-blinded, placebo-controlled, crossover intervention with cetirizine HCl 10mg.

All participants will give written informed consent prior to any study related procedures being performed. Participants who meet all inclusion/exclusion criteria during the screening process will be asked to return to the EEU for their first pollen exposure visit (Treatment Visit #1). At the Screening Visit participants will provide a full medical history and undergo a physical examination. They will have their height/weight and vitals measured and skin testing will be performed to confirm allergic response to a panel of common aeroallergens. Women of child bearing potential will undergo a urine pregnancy test to rule out pregnancy. Eligible participants will be invited back to the research centre for 4 pollen exposure visits at 2 of these visits participants will receive either cetirizine or placebo. All participants will receive placebo at some point throughout the study.

Eligibility Criteria:
Inclusion Criteria:

* history of rhinoconjunctivitis during ragweed season for a minimum of 2 years, including the previous 2 ragweed seasons.
* positive skin test to ragweed allergen.

Exclusion Criteria:

* participant is pregnant, lactating or actively trying to conceive.
* has a history of receiving immunotherapy containing short ragweed within the last 3 years.
* participant has current allergy symptoms.