Corixa allergy drug proves safe

The toll-like receptor 4 (TLR4) agonist, CRX-675, was given to participants intranasally prior to stimulation with ragweed allergen. Although the primary objective of this clinical trial was to evaluate the safety of CRX-675 given as a single intranasal dose, the efficacy of the drug was also measured.

A total number of 28 subjects were randomized to either a CRX-675 group receiving four escalating doses of the drug or a placebo group. Each subject in the study completed a series of direct nasal challenges with increasing concentrations of ragweed allergen to determine an allergen dose that would result in a 30% reduction in nasal volume (congestion) during the screening period of the study.

There were no serious or severe adverse events reported. The majority of the adverse events were mild and either considered unrelated to the drug being evaluated or resolved without intervention. The adverse event profile of CRX-675-treated subjects was similar to that of placebo-treated subjects. These results confirm that intranasal administration of CRX-675 is safe.

However, there were no consistent trends for improvement in nasal congestion post ragweed challenge for the CRX-675 treatment groups beyond those observed in the placebo group and no dose response relationship was detected.

Dr Steven Gillis, chairman and CEO at Corixa said: “Meaningful data regarding the potential efficacy of CRX-675 in the setting of allergic rhinitis will have to wait for results from additional planned studies that are designed to examine the safety and efficacy of intranasal CRX-675 administered multiple times in a treatment cycle. Such randomized, placebo controlled studies could begin either late in 2005 or in 2006.”