Orphan drug development in alpha-1 antitypsin deficiency

Alpha-1 antitrypsin deficiency (AATD, OMIM #613490) is a rare metabolic disorder affecting lungs and liver. The purpose of this study is to assess the impact of the US orphan drug act on AATD by providing a quantitative clinical-regulatory insight into the status of FDA orphan drug approvals and designations for compounds intended to treat AATD. This is across-sectional analysis of the FDA database for orphan drug designations. Primary endpoint: orphan drug approvals. Secondary endpoint: orphan drug designations by the FDA. Close of database was 16 July 2021. STROBE criteria were respected. Primary outcome: one compound, alpha-1-proteinase inhibitor (human) was approved as an orphan drug in 1987 with market exclusivity until 1994. Secondary outcome: sixteen compounds received FDA orphan drug designation including protein, anti-inflammatory, mucolytic, gene, or cell therapy. Drug development activities in AATD were comparable to other rare conditions and led to the FDA-approval of one compound, based on a relatively simple technological platform. The current unmet medical need to be addressed are extrapulmonary manifestations, in this case the AATD-associated liver disease. Orphan drug development is actually focusing on (1) diversified recombinant AAT production platforms, and (2) innovative gene therapies, which may encompass a more holistic therapeutic approach.