Belimumab Treatment of Emphysema Patients With Anti-GRP78 Autoantibodies

Specific Aim 1: To conduct a double-blind, Phase IIa trial, in which 18 former smokers with pulmonary emphysema (per chest CT scans), and circulating anti-GRP78 autoantibody levels \>mean normal values (by ELISA), will be randomized 2:1 to belimumab vs. placebo. Subjects will receive 8 infusions of either belimumab or placebo over a 6 month interval. Plasma anti-GRP78 will be measured pre-treatment, and at 1, 3, 5, and 7 months. The investigators hypothesize belimumab therapy will more effectively reduce anti-GRP78 IgG autoantibodies, the primary endpoint of this trial, compared to placebo. Specific Aim 2: To determine effects of the belimumab therapy on secondary endpoints (at the times detailed for Aim 1) that include levels of pneumococcal-binding antibodies (by ELISA), circulating B-cell numbers and phenotypes (by flow cytometry), and the rate and severity of adverse events (AE) at any time during treatment. The investigators hypothesize belimumab will have dose-related effects on B-cell numbers and their differentiation, while minimally reducing host defense antibodies, and will also have an acceptable AE profile.