This study is a continuation of the placebo-controlled study CE1226_4001 (NCT00261833) to evaluate the efficacy and safety of Zemaira® intravenous (i.v). administration in subjects with emphysema due to alpha1-proteinase inhibitor deficiency. The long-term verification of a disease-modifying benefit of Zemaira® on the progression of emphysema will be assessed by volume-adjusted lung density, measured yearly by computed tomography (CT).