Endeavor BioMedicines announced that both the U.S. Food and Drug Administration (FDA) and the European Commission (EC) have granted Orphan Drug Designation to its investigational therapy taladegib (ENV-101) for the treatment of idiopathic pulmonary fibrosis (IPF). The clinical-stage biotechnology company is currently enrolling patients in the Phase 2b WHISTLE-PF clinical trial, with enrollment expected to be completed in 2026.
"Receiving Orphan Drug Designation for taladegib in both the United States and European Union underscores the significant unmet medical need for patients with IPF," said Lisa Lancaster, M.D., Chief Medical Officer at Endeavor BioMedicines. "We are encouraged by the potential of taladegib to reverse the course of disease across multiple measures of IPF, which is a major step forward from current standard-of-care."
Regulatory Benefits and Market Exclusivity
The FDA grants Orphan Drug Designation to drugs intended for treating rare diseases affecting fewer than 200,000 people in the U.S. This designation provides sponsors financial incentives to support clinical development and the potential for up to seven years of market exclusivity if the drug receives approval for the designated orphan indication.
In the European Union, Orphan Drug Designation is granted by the EC based on a positive opinion from the European Medicines Agency's Committee for Orphan Medicinal Products. The designation applies to drugs for rare, life-threatening diseases with a prevalence of not more than five in 10,000 in the EU. Benefits include eligibility for protocol assistance, exemptions or reductions in certain regulatory fees, and 10 years of marketing exclusivity upon approval.
WHISTLE-PF Trial Design and Objectives
The Phase 2b WHISTLE-PF (Wound-remodeling Hedgehog-Inhibitor ILD Study Testing Lung Function Endpoints-PF) clinical trial is a global, randomized, placebo-controlled study evaluating taladegib's therapeutic potential in individuals with IPF (NCT06422884). The trial will evaluate the efficacy of a range of taladegib doses through 24 weeks of treatment, characterize the investigational compound's safety and tolerability, and assess its effect on patient-reported outcomes.
The study will also measure effects on lung function, lung capacity, and lung fibrosis as assessed by chest high-resolution computed tomography.
Mechanism of Action and Disease Background
Taladegib is a Hedgehog (Hh) signaling pathway inhibitor that works by binding to and inhibiting a key receptor in the Hh pathway. This mechanism stops the abnormal accumulation of myofibroblasts that cause fibrosis, potentially resolving the excessive wound-healing process seen in pulmonary fibrosis and improving lung volume and function.
IPF is a chronic, progressive lung disease that affects more than 150,000 adults in the United States. Although the exact cause of IPF is unknown, various environmental factors can deliver repeated injuries to lung cells that trigger abnormal wound-healing processes and life-threatening lung scarring. The disease has limited treatment options and a very poor prognosis, with an average life expectancy of three to five years after diagnosis.
