Endeavor BioMedicines' IPF drug meets Phase 2b primary endpoint

Endeavor BioMedicines announced that its Phase 2b WHISTLE-PF trial of taladegib met its primary endpoint, demonstrating statistically significant improvements in lung function and reduced lung fibrosis in patients with idiopathic pulmonary fibrosis (IPF). IPF is a progressive, fatal disease affecting over 150,000 U.S. adults, with current therapies only slowing decline. Taladegib, which targets the Hedgehog signaling pathway, showed potential to reverse disease progression.

Results of the WHISTLE-PF trial

• ▪Endeavor BioMedicines reported that taladegib exhibited a tolerability profile consistent with previous studies of taladegib, with serious adverse events balanced between the placebo and taladegib arms of the WHISTLE-PF trial
• ▪Endeavor BioMedicines announced on October 8, 2026, that its Phase 2b WHISTLE-PF trial of taladegib met its primary endpoint, showing statistically significant improvement in percent predicted forced vital capacity compared to placebo
• ▪Patients treated with taladegib in the WHISTLE-PF trial showed statistically significant improvements compared to placebo in total lung capacity, percent quantitative total interstitial lung disease, and percent quantitative lung fibrosis

Design of the WHISTLE-PF trial

• ▪Endeavor BioMedicines' Phase 2b WHISTLE-PF trial evaluated taladegib over 24 weeks in 213 patients with idiopathic pulmonary fibrosis across 74 sites in 14 countries
• ▪In the WHISTLE-PF trial, 73% of the 213 enrolled patients with idiopathic pulmonary fibrosis continued using background standard-of-care therapies during the study

Regulatory designations for taladegib

• ▪The European Medicines Agency granted PRIority MEdicines designation to taladegib, making it the first and only investigational idiopathic pulmonary fibrosis therapy to receive this designation
• ▪Taladegib has received Orphan Drug Designation from the U.S. Food and Drug Administration and the European Medicines Agency's Committee for Orphan Medicinal Products

Overview of idiopathic pulmonary fibrosis

• ▪Idiopathic pulmonary fibrosis is a chronic, progressive lung disease characterized by life-threatening lung scarring that affects more than 150,000 adults in the United States
• ▪Idiopathic pulmonary fibrosis has limited treatment options and a poor prognosis, with an average life expectancy of only three to five years after diagnosis
• ▪Current standard-of-care therapies for idiopathic pulmonary fibrosis slow the decline of lung function but do not halt or reverse disease progression

Taladegib development

• ▪Taladegib, also known as ENV-101, blocks the Hedgehog signaling pathway, a cellular wound-healing pathway abnormally activated in fibrotic lung diseases, by inhibiting a key receptor to eliminate aberrant scarring and improve lung volume and function
• ▪Chief Medical Officer Lisa Lancaster said Endeavor BioMedicines plans to present the WHISTLE-PF trial data at a future medical meeting and discuss Phase 3 plans for taladegib with global regulatory authorities