Prothena (PRTA) investor relations material

Strategic priorities and partnerships

• Focus on advancing a pipeline targeting neurodegenerative and rare proteinopathies, with multiple late-stage clinical programs and strong industry collaborations.

• Up to $105 million in clinical milestones expected by year-end 2026, including a $50 million milestone for coramitug and a potential $55 million milestone for PRX019.

• Share repurchase program authorized up to $100 million, with $22.3 million repurchased in 1H 2026.

• Partnerships with Roche, Novo Nordisk, and Bristol Myers Squibb could yield up to $3 billion in downstream milestones and royalties.

Pipeline highlights and clinical progress

• Prasinezumab (Parkinson's): Phase 3 PARAISO trial ongoing, with Phase 2 data showing delayed motor progression and favorable safety; peak sales potential >$3.5 billion.

• Coramitug (ATTR-CM): Phase 3 CLEOPATTRA trial ongoing; Phase 2 showed significant NT-proBNP reduction and cardiac improvements; multi-billion dollar market potential.

• Moponetug (Alzheimer's): Phase 2 TargetTau-1 trial fully enrolled; targets tau MTBR, with preclinical and Phase 1 data supporting efficacy and safety.

• PRX019 (Neurodegeneration): Phase 1 completed; eligible for $55 million milestone pending BMS decision by YE 2026.

• TDP-43 CYTOPE (ALS): Preclinical program using CYTOPE technology to target intracellular pTDP-43 aggregates, showing promising preclinical efficacy.

• PRX012-TfR (Alzheimer's): Preclinical program leveraging transferrin receptor technology for improved brain delivery and amyloid reduction.

Financial and operational outlook

• Cash position expected to fund advancement of the pipeline and preclinical portfolio, including TDP-43 CYTOPE and PRX012-TfR programs.

• Ongoing and future clinical milestones include BMS decision on PRX019 (2026), moponetug Phase 2 completion (2027), and Phase 3 completions for prasinezumab and coramitug (2029).

• Potential for additional research collaborations and licensing deals for unpartnered programs.

• Plans to return capital to shareholders via share repurchases or other means.