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Alpha-1 antitrypsin (AAT)

CSL Behring · Phase 3 active Biologic

Alpha-1 antitrypsin (AAT) is a protease inhibitor that replaces deficient endogenous AAT to prevent neutrophil elastase-mediated tissue destruction in the lungs and other organs.

Alpha-1 antitrypsin (AAT) is a protease inhibitor that replaces deficient endogenous AAT to prevent neutrophil elastase-mediated tissue destruction in the lungs and other organs. Used for Alpha-1 antitrypsin deficiency with emphysema, Alpha-1 antitrypsin deficiency with progressive lung disease, Alpha-1 antitrypsin deficiency-related liver disease.

At a glance

Generic nameAlpha-1 antitrypsin (AAT)
Also known asAlpha-1 proteinase inhibitor (A1-P1)
SponsorCSL Behring
Drug classProtease inhibitor / Protein replacement therapy
TargetNeutrophil elastase
ModalityBiologic
Therapeutic areaPulmonology / Genetic / Rare Disease
PhasePhase 3

Mechanism of action

AAT is a serine protease inhibitor naturally produced by the liver that protects tissues from degradation by neutrophil elastase released during inflammation. In alpha-1 antitrypsin deficiency, insufficient AAT levels allow unopposed elastase activity, leading to progressive lung and liver damage. Augmentation therapy with exogenous AAT restores protective capacity and slows disease progression.

Approved indications

Common side effects

Key clinical trials

Primary sources

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SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

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