Prothena (PRTA) Cantor Global Healthcare Conference 2025 summary

Recent corporate developments

• Underwent significant restructuring in 2025, reducing headcount to align with partnership obligations and future opportunities.

• Focused on shareholder-accretive actions, including plans for distributable reserves and potential share repurchase.

• Maintains $300 million in cash at year-end, with 2026 guidance to be provided in the next quarterly call.

• Operational clarity achieved by concentrating resources on advancing partnered programs and seeking new partnerships for unpartnered assets.

Pipeline and clinical milestones

• Prasinezumab for Parkinson’s disease advancing to phase 3 with Roche, based on consistent phase 2 results and ongoing data sharing.

• Coramitug for ATTR cardiomyopathy moving to phase 3 with Novo Nordisk, with a differentiated mechanism targeting misfolded TTR.

• PRX012, an anti-Abeta Alzheimer’s candidate, showed robust amyloid reduction but higher ARIA rates; exploring transferrin-based approaches to mitigate risk.

• X19 in phase 1 for neurodegeneration, with Bristol Myers Squibb to decide on phase 2 advancement in 2026.

• Tau phase 2 readout expected in 2027, with primary endpoint of tau PET.

Financial outlook and partnership economics

• Up to $105 million in clinical milestones anticipated in 2026, mainly from coramitug and X19 programs.

• Roche partnership for prasinezumab includes up to $755 million in milestones and high double-digit teen royalties, with $135 million received to date.

• Novo Nordisk deal for coramitug valued at $1.23 billion in milestones, with $100 million received and next milestone estimated at $50 million.

• Remaining milestone payments and royalties are not included in current cash guidance.