Clinical trials with new drugs for chronic obstructive pulmonary disease (COPD) have been performed. Viruses exacerbate COPD and bacteria may play a part in severe COPD; therefore, antibiotic and antiviral approaches have a sound rationale. Antiinflammatory approaches have been studied. Advances in understanding the molecular basis of other processes have resulted in novel drugs to target reactive oxidant species, mucus, proteases, fibrosis, cachexia, and muscle wasting, and accelerated aging. Studies with monoclonal antibodies have been disappointing, highlighting the tendency for infections and malignancies during treatment. Promising future directions are lung regeneration with retinoids and stem cells.