A decrease in FEV(1) of at least 20% in response to inhalation of up to 10,000 bioequivalency allergy units (BAU) or allergy units (AU) per ml of a selected common aeroallergen (house dust mite, cat hair or grasses) or up to 150 Antigen E units per ml of short ragweed. Asthmatic patients must also demonstrate a late asthmatic response (defined as a 20% fall from the baseline established following completion of the early asthmatic response).