The present invention relates to a method for treating chronic obstructive pulmonary disease in a mammalian subject, which comprises administering an effective amount of a specific bicyclic compound of formula (I):and/or a tautomer thereof to a subject in need thereof.本發明係有關於哺乳類對象中用以治療慢性阻塞性肺疾之方法,其包括對需要該方法之對象,投予有效量之式(I)之特定雙環化合物及/或其互變異構物: