Prothena (PRTA) Evercore ISI 8th Annual HealthCONx Conference summary

Pipeline and program updates

• Two phase III programs advancing: prasinezumab for early Parkinson's (with Roche) and coramitug for ATTR cardiomyopathy (with Novo), both with recent positive data and phase III initiations in late 2024.

• Phase II Alzheimer's program targeting tau (with Bristol Myers Squibb) and phase I neurodegeneration program (X019) ongoing, with key data expected in 2027.

• Unpartnered programs progressing, including PRX012 for Alzheimer's, with efforts to enhance blood-brain barrier penetration using transferrin technology.

• Up to $105 million in clinical milestones anticipated in 2026 for coramitug enrollment; share repurchase program approved for 2026.

• Additional data on CYTOPE and ALS program expected, following recent presentations.

Scientific and clinical insights

• PRX012 shows robust amyloid reduction, with over 80% of patients amyloid negative at 18 months using subcutaneous monthly dosing.

• ARIA rate for PRX012 is approximately 40%, with ongoing efforts to mitigate this effect, including exploring pre-symptomatic patient populations.

• Transferrin-based brain shuttle technology may allow for a threefold dose reduction and potentially improved CNS distribution and ARIA profile.

• FDA guidance may reduce preclinical requirements for novel molecular entities, with ongoing discussions about IND-enabling toxicology packages.

• Fast-track status for tau-targeting phase II program reflects regulatory conviction in tau as a key Alzheimer's target.

Partnership and collaboration strategy

• Strategic partnerships with Roche, Novo, and Bristol Myers Squibb drive late-stage programs, with active scientific and clinical collaboration.

• Partner decisions to advance programs are based on rigorous internal criteria and recent compelling data, especially for prasinezumab and coramitug.

• Support for partner programs includes scientific input and clinical trial execution, with more intensive involvement in early-stage studies.

• Licensing and collaboration opportunities for transferrin-based anti-A beta antibodies depend on the strength of preclinical and clinical data.

• Ongoing evaluation of deal value and timing for data disclosure to maximize partnership potential.