AC Immune SA (NASDAQ: ACIU) announced an amendment to its 2018 license and collaboration agreement with Eli Lilly and Company for developing tau aggregation inhibitor small molecules targeting Alzheimer's disease and other neurodegenerative diseases.

Under the amended agreement, AC Immune will receive CHF10 million upfront and a milestone payment when Phase 1 dosing begins. The company remains eligible for development, regulatory and commercial milestones exceeding CHF1.7 billion, plus tiered royalty payments in the low double digits.

The collaboration will focus on developing new lead tau Morphomer candidates and potential backup compounds. AC Immune plans to initiate Investigational New Drug-enabling studies in the first half of 2026.

The Morphomer tau candidates were selected for their ability to enter the brain when administered orally and for their binding to pathological tau protein conformations. AC Immune states it has generated preclinical data suggesting the compounds may inhibit aggregation and seeding across pathological and disease stages.

"The progress in this collaboration highlights the important breakthroughs we have made with Morphomer small molecules for intracellular targeting of Tau," said Dr. Andrea Pfeifer, CEO of AC Immune.

AC Immune is a clinical-stage biopharmaceutical company developing precision therapeutics for neurodegenerative diseases. The company's technology platforms include SupraAntigen and Morphomer, with candidates currently in Phase 2 and Phase 3 development.