New biologic: Alpha-1-proteinase inhibitor (human) for injection (Glassia): A new chronic augmentation and maintenance therapy for emphysema due to alpha-1-antitrypsin deficiency

Alpha-1-proteinase inhibitor (human) for injection is indicated for the treatment of chronic augmentation and maintenance therapy in adults with emphysema due to congenital deficiency of alpha-1-proteinase inhibitor (also commonly referred to as alpha-1-antitrypsin (AAT) deficiency). AAT deficiency is a chronic, autosomal, co-dominant hereditary disorder characterized by reduced levels of alpha-1-proteinase inhibitor in the blood and lungs. Alpha-1-proteinase inhibitor (human) is prepared from human plasma obtained from US-licensed plasma collection centers.

Efficacy. A phase 2/3 randomized, double blind, active controlled trial was conducted to compare intravenous Glassia to Prolastin (another FDA-approved alpha-1-proteinase inhibitor) in AAT-deficient patients. Patients were required to have lung disease related to alpha-1-proteinase inhibitor deficiency and "at-risk" alleles associated with alpha-1-proteinase inhibitor plasma levels <11 μM. Subjects already receiving alpha-1-proteinase inhibitor therapy were required to undergo a 5-week wash-out period. Patients were randomly assigned to receive either Glassia (n=33 patients) or Prolastin (n=17 patients) at a dose of 60 mg/kg intravenously per week for 12 consecutive weeks. From week 13 to 24, all subjects received open-label weekly infusions of Glassia at a dose of 60 mg/kg. Trough levels of functional and antigenic alpha-1-proteinase inhibitor were measured prior to treatment, at baseline, and throughout the study until week 24. Glassia was shown to be non-inferior to Prolastin. Furthermore, all subjects receiving Glassia had mean serum trough antigenic alpha-1-proteinase inhibitor levels >11 μM (levels above this are thought to be protective) during weeks 7 to 12. It is important to note; however, the clinical efficacy of Glassia in influencing the course of pulmonary emphysema or the frequency, duration, or severity of pulmonary exacerbations has not been demonstrated in a randomized, controlled clinical trial setting.

Safety. A total of 68 patients have received treatment with Glassia as part of 2 US-based clinical studies. The most common Glassia-related adverse reactions-occurring in >3% of patients in clinical studies-were headache (6%) and dizziness (3%). Since Glassia is derived from human plasma, its use may carry a risk of transmitting infectious agents (theoretically including the Creutzfeldt-Jakob disease agent) despite manufacturing steps designed to minimize the risk of viral transmission.