Prothena (PRTA) Cantor Global Healthcare Conference 2025 summary

Recent corporate developments

• Underwent restructuring after a phase 3 readout, reducing headcount to align with partnership obligations and future opportunities.

• Focused on shareholder-friendly actions, including plans for share repurchase supported by the creation of distributable reserves.

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

• Operational clarity achieved by concentrating resources on near-term value creation and partnership programs.

• Actively seeking to partner out unpartnered programs to maximize value.

Pipeline and clinical milestones

• Prasinezumab for Parkinson’s disease is advancing to phase 3 with Roche, based on consistent phase 2 results and a large market opportunity.

• Coramitug for ATTR cardiomyopathy is moving to phase 3 with Novo Nordisk, with a milestone-driven deal valued at $1.23 billion.

• PRX012, an anti-Abeta antibody for Alzheimer’s, showed robust amyloid reduction but higher-than-expected ARIA rates; exploring transferrin-based approaches to mitigate this.

• X19 in neurodegenerative disease is in phase 1, with Bristol Myers Squibb to decide on phase 2 advancement next year.

• Up to $105 million in clinical milestones are achievable in 2026, mainly from coramitug and PRX019 programs.

Financial and partnership strategy

• Shareholder value prioritized through potential share repurchases and accretive financial activities.

• Partnership programs span four assets: two entering phase 3, one in phase 2 (readout in 2027), and one in phase 1.

• 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 is milestone-based, with $100 million received and next milestone estimated at $50 million upon phase 3 enrollment.

• Remaining coramitug milestones are tied to commercial sales, not included in current cash guidance.