What is the miracle drug for COPD?

Could you elaborate on the so-called 'miracle drug' for COPD? Is there a specific medication or treatment that has been proven to significantly improve the symptoms and quality of life for patients suffering from Chronic Obstructive Pulmonary Disease? Are there any clinical trials or studies that support its effectiveness? Additionally, what are the potential side effects or risks associated with this treatment? Lastly, is it widely available and accessible to patients, or are there any barriers to obtaining it?