Feasibility of Aerosolized Alpha-1 Antitrypsin as a Therapeutic Option

Augmentation therapy with alpha 1-antitrypsin: present and future of production, formulation, and delivery

Alpha 1-antitrypsin is one of the first protein therapeutics introduced on the market - more than 30 years ago - and, to date, it is indicated only for the treatment of the severe forms of a genetic condition known as alpha-1 antitrypsin deficiency. The only approved preparations are derived from plasma, posing potential problems associated with its limited supply and high processing costs. Moreover, augmentation therapy with alpha 1-antitrypsin is still limited to intravenous infusions, a cumbersome regimen for patients. Here, we review the recent literature on its possible future developments, focusing on i) the recombinant alternatives to the plasma-derived protein, ii) novel formulations, and iii) novel administration routes. Regulatory issues and the still unclear noncanonical functions of alpha 1-antitrypsin - possibly associated with the glycosylation pattern found only in the plasma-derived protein - have hindered the introduction of new products. However, potentially new therapeutic indications other than the treatment of alpha-1 antitrypsin deficiency might open the way to new sources and new formulations.

Methods of Purification and Application Procedures of Alpha1 Antitrypsin: A Long-Lasting History

The aim of the present report is to review the literature addressing the methods developed for the purification of alpha1-antitrypsin (AAT) from the 1950s to the present. AAT is a glycoprotein whose main function is to protect tissues from human neutrophil elastase (HNE) and other proteases released by neutrophils during an inflammatory state. The lack of this inhibitor in human serum is responsible for the onset of alpha1-antitrypsin deficiency (AATD), which is a severe genetic disorder that affects lungs in adults and for which there is currently no cure. Being used, under special circumstances, as a medical treatment of AATD in the so-called "replacement" therapy (consisting in the intravenous infusion of the missing protein), AAT is a molecule with a lot of therapeutic importance. For this reason, interest in AAT purification from human plasma or its production in a recombinant version has grown considerably in recent years. This article retraces all technological advances that allowed the manufacturers to move from a few micrograms of partially purified AAT to several grams of highly purified protein. Moreover, the chronic augmentation and maintenance therapy in individuals with emphysema due to congenital AAT deficiency (current applications in the clinical setting) is also presented.