Long Term Safety of Alpha1-Proteinase Inhibitor in Subjects With Alpha1 Antitrypsin Deficiency

This is a 2-year open-label extension of the double-blind, placebo-controlled GTi1201 study. The purpose of this study is to obtain an additional 2 years of safety data for intravenously administered Alpha-1 MP 60 mg/kg/week in subjects with AATD.

The study consists of a Screening Visit (the same visit as the End-of-Study Visit in the GTi1201 study for subjects who complete the GTi1201 study or is the same visit as the Early Discontinuation Visit for subjects meeting the early withdrawal criterion for forced expiratory volume in 1 second \[FEV1\] decline), a treatment period of 104 weeks (beginning immediately after screening \[on the same day as the Screening Visit\] but no sooner than 1 week after the last infusion of investigational product in the GTi1201 study), and an End-of-Study Visit.

Subjects meeting the entrance criteria of the extension study will begin receiving weekly intravenous (IV) infusions of Alpha-1 MP 60 mg/kg on the day of screening and will continue to receive weekly infusions for a total of 104 infusions.

Safety assessments will include adverse events, concomitant medications, complete physical examination (excluding breast and genitourinary examination), hematology, chemistry, urine cotinine, and pregnancy test. Efficacy assessments will include whole lung computed tomography density, quality-of-life assessment, carbon monoxide diffusing capacity, and pulmonary function tests. The occurrence of chronic obstructive pulmonary exacerbations, will also be evaluated as a safety and as an efficacy measurement.