ABSTRACT
BACKGROUND & AIMS: Homozygous ZZ alpha-1 antitrypsin (AAT) deficiency produces mutant AAT (Z-AAT) proteins in hepatocytes, leading to progressive liver fibrosis. We evaluated the safety and efficacy of an investigational RNA interference therapeutic, fazirsiran, that degrades Z-AAT mRNA, reducing deleterious protein synthesis. METHODS: This ongoing, phase 2 study randomized 40 patients to subcutaneous placebo or fazirsiran 25/100/200 mg. The primary endpoint was percentage change in serum Z-AAT concentration from baseline to Week 16. Patients with fibrosis on baseline liver biopsy received treatment on Day 1, Week 4, and then every 12 weeks, and had a second liver biopsy at or after Weeks 48, 72, or 96. Patients without fibrosis received two doses on Day 1 and Week 4. RESULTS: At Week 16, least-squares mean percent declines in serum Z-AAT concentration were -61%, -83% and -94% with fazirsiran 25/100/200 mg, respectively, versus placebo (all P< .0001). Efficacy was sustained through Week 52. At post-dose liver biopsy, fazirsiran reduced median liver Z-AAT concentration by 93% compared with an increase of 26% with placebo. All fazirsiran-treated patients had histological reduction from baseline in hepatic globule burden. Portal inflammation improved in 5/12 and 0/8 patients with baseline score >0 in the fazirsiran and placebo groups, respectively. Histological METAVIR score improved by >1 point in 7/14 and 3/8 patients with fibrosis >F0 at baseline in the fazirsiran and placebo groups, respectively. No adverse events led to discontinuation and pulmonary function tests remained stable. CONCLUSIONS: Fazirsiran reduced serum and liver concentrations of Z-AAT in a dose dependent manner and reduced hepatic globule burden (NCT03945292).
ABSTRACT
Alpha-1 antitrypsin deficiency (AATD) is one of the most common genetic diseases and is caused by mutations in the SERPINA1 gene. The homozygous Pi*Z variant is responsible for the majority of the classic severe form of alpha-1 antitrypsin deficiency, which is characterized by markedly decreased levels of serum alpha-1 antitrypsin (AAT) with a strong predisposition to lung and liver disease. The diagnosis and early treatment of AATD-associated liver disease are challenges in clinical practice. In this review, the authors aim to summarize the current evidence of the non-invasive methods in the assessment of liver fibrosis, as well as to elucidate the main therapeutic strategies under investigation that may emerge in the near future.
A deficiência de alfa-1 antitripsina é uma das doenças genéticas mais comuns e é causada por mutações no gene SERPINA1. A mutação Pi*Z em homozigotia é responsável pela maioria dos casos de apresentação clássica da deficiência de alfa-1-antripsina, que se caracteriza por uma diminuição significativa dos níveis séricos desta proteína com forte predisposição ao desenvolvimento de doença pulmonar e hepática. O diagnóstico precoce e tratamento da doença hepática representam importantes desafios na prática clínica. Nesta revisão, os autores têm como objetivo resumir a evidência atual dos métodos não invasivos na avaliação da fibrose hepática, bem como, elucidar as principais estratégias terapêuticas atualmente sob investigação e que poderão emergir num futuro próximo.
