The RAPID trial is the single largest randomized placebo-controlled trial of alpha1-antitrypsin augmentation therapy completed to date. Ma et al. measured plasma desmosine levels in participants of this study and they presented the results of this very interesting study at the American Thoracic Society meeting 2015. In patients receiving alpha1-antitrypsin supplementation, plasma desmosine levels decreased significantly at 3 months and were further reduced at 1 year and 2 years compared to baseline desmosine levels. An increase in plasma desmosine levels was observed in the placebo group at 3 months and 1 year and 2 years compared to baseline levels. A significant treatment difference between groups (active arm versus placebo arm) was observed at every time point. Furthermore, plasma desmosine levels were inversely correlated with CT scan lung density decline. Ma et al. demonstrated with this study that plasma desmosine has great potential for use as a surrogate-endpoint in clinical trials to assess the effects of interventions on emphysema progression especially in alpha1-antitrypsin supplementation trials.