Effect of BN 52063, a specific PAF-acether antagonist, on bronchial provocation test to allergens in asthmatic patients. A preliminary study

Platelet Activating Factor, PAF-acether, elicits acute and more prolonged inflammatory responses in both experimental animals and man, and is recognised as a possible mediator of asthma. The effect of a specific PAF-acether antagonist, BN 52063, on the early asthmatic response to inhaled allergen was assessed in a randomised, double-blind, crossover study in eight atopic asthmatics, who received three days treatment with BN 52063 or placebo, separated by a one week washout. On the third day of treatment, subjects were challenged with nebulised house dust mite or pollen allergen. BN 52063 significantly antagonised early bronchoconstriction and showed a tendency to inhibit residual bronchial hyperreactivity, assessed six hours after allergen challenge by a provocation test to acetylcholine. No side effects were reported during active treatment. This is the first study in man demonstrating the efficacy of a specific PAF-acether antagonist on the immediate response to inhaled allergen challenge in asthmatics. The findings support the possible role of specific PAF-acether antagonists in the treatment of asthma.