I started on Dupixent in 11/23 and it worked great until about 5/24....don't know whether I developed antibodies to it or eosinophilic pneumonia as my physician has not tested for that. Had a Dupixent holiday for about three weeks and started again. The major problem was that the congestion/secretions did not improve but seemed to be worse. I am going to request a serology test for antibodies. Of all the medications other than the "normal inhalers" I feel that Dupixent probably holds the most promise, but I do think that whether it is used for asthma or COPD the key is do you have Type II inflammation.