The FALCON program: Two phase 2b randomized, double-blind, placebo-controlled studies to assess the efficacy and safety of pegbelfermin in the treatment of patients with nonalcoholic steatohepatitis and bridging fibrosis or compensated cirrhosis

Background: Nonalcoholic steatohepatitis (NASH) is the progressive form of nonalcoholic fatty liver disease (NAFLD); no approved therapies for NASH currently exist. Pegbelfermin (PGBF), a human fibroblast growth factor 21 analog, has metabolic effects that may provide benefit for patients with NASH.

Design: The FALCON 1 and 2 studies are phase 2b, multicenter, double-blind, placebo-controlled, randomized trials to assess safety and efficacy of PGBF treatment in patients who have histologically-confirmed NASH with stage 3 liver fibrosis (FALCON 1; NCT03486899) or compensated cirrhosis (FALCON 2; NCT03486912). In both studies, randomized patients receive once weekly subcutaneous injections of PGBF (10, 20, or 40 mg) or placebo during a 48-week treatment period and are then followed for an additional 4 weeks.

Endpoints: The primary efficacy endpoint for FALCON 1 is the proportion of patients who achieve ≥1 stage improvement in fibrosis (by NASH CRN fibrosis score) without NASH worsening or NASH improvement (≥2 point decrease in NAFLD Activity Score) without fibrosis worsening at Week 24. For FALCON 2, the primary efficacy endpoint is ≥1 stage improvement in fibrosis without NASH worsening at Week 48. Key safety endpoints for both studies include incidence and frequency of adverse events, bone mineral density and immunogenicity.

Summary: Previous clinical trial data show that PGBF can reduce hepatic fat and improve metabolic factors and biomarkers of hepatic injury and fibrosis. The FALCON studies aim to evaluate PGBF treatment specifically in patients with NASH and advanced fibrosis, who are at greatest risk of poor clinical outcomes over time.