PRTA

Prothena saw significant progress in 2025 clinical pipeline with 2 partner programs advancing to Phase III. Roche advanced prasinezumab to Phase III PARAISO trial for Parkinson's disease. Novo Nordisk advanced coramitug to Phase III CLEOPATTRA trial for ATTR-CM. Collaborations with BMS progressed with Phase II TargetTau-1 trial and Fast Track designation. Introduced CYTOPE technology for intracellular targeting. 2026 priorities include capturing value from partnerships, share redemption program, and advancing preclinical portfolio.

2026 net cash used in operating and investing activities expected to be between $50M - $55M. Potential aggregate clinical milestone payments up to $105M in 2026 from coramitug and PRX019.

Not applicable as focus is on R&D and partnerships rather than traditional product segment financials

Risks associated with forward-looking statements including actual results differing from expectations, as per press release and SEC filings.

Q: With primary completion dates for partnered program trials not until 2029, walk through key milestones in 2026-2027.

A: Expect to share CYTOPE activities, data from BMS tau program in H1 2027, and 2 Phase III readouts in 2029.

Q: Elaborate on PRX012 transferrin receptor tech.

A: Transferrin-based approach offers potential improvement in amyloid removal and ARIA-E profile.

Q: Plans for PRX019 Phase I study.

A: Phase I to complete in 2026, data to be shared with BMS.

Q: Data needed for CYTOPE platform partnership.

A: Exciting in vivo data from TDP-43 CYTOPE program, broad therapeutic area applications.