A Phase 3 Trial of Pirfenidone in Patients with Idiopathic Pulmonary Fibrosis (ASCEND)

Two earlier pirfenidone trials (CAPACITY 1 and 2) had mixed results. ASCEND was designed to definitively test pirfenidone in IPF with FVC decline as the primary endpoint.

Multicenter RCT (n=555) comparing pirfenidone 2403 mg/day vs. placebo in patients with IPF over 52 weeks.

Pirfenidone reduced the proportion of patients with ≥10% decline in FVC or death by 47.9% vs placebo (16.5% vs 31.8%, p<0.001). Pirfenidone also reduced 6-minute walk distance decline and progression-free survival. All-cause mortality was numerically lower but not statistically significant.

Pirfenidone significantly slows FVC decline in IPF and is FDA-approved for this indication. It is one of two antifibrotic agents (along with nintedanib) that are standard of care for IPF.

Mortality benefit was not statistically significant in this trial alone (pooled analysis with CAPACITY trials showed mortality benefit). GI side effects (nausea, dyspepsia) are common.