Prothena Corp. Plc Q4 FY2020 earnings call

• Progress in rare peripheral amyloid disease: Announced plans to initiate Phase III AFFIRM AL Study of Birtamimab in Mayo Stage IV patients, and Phase 1 results of PRX004 showing improvements in neuropathy and cardiac function in ATTR amyloidosis patients.
• Neurodegenerative disease pipeline: Advanced PRX005 (anti-tau antibody) and PRX012 (anti-beta antibody) in Alzheimer's disease, and prasinezumab in Parkinson's disease with positive Phase 2 results.
• Unique platform: Prothena's protein dysregulation platform, focusing on epitope targeting to specifically target pathogenic proteins and spare normal function, with multiple programs showing clinical proof of concept.
• Collaborations: Potential $140 million in payments from Roche and BMS, enabling funding of pipeline through key milestones.

Net cash used in operating and investing activities was $81 million compared to guidance of $75 million to $85 million. Net loss was $111 million compared to guidance of $101 million to $118 million. As of December 31, 2020, Prothena had $298 million in cash, cash equivalents, and restricted cash, with no debt.

• 2021 full-year net cash used in operating and investing activities expected $51 million to $74 million, including $60 million milestone payment from Roche upon first patient dosed in prasinezumab's late-stage Phase II-b study.
• Expected to end 2021 with approximately $235 million in cash.
• Estimated full-year 2021 net loss $79 million to $111 million, including $20 million non-cash share-based compensation expense.

Forward-looking statements subject to risks, uncertainties, and factors causing actual results to differ materially, as discussed in the press release and SEC filings. Risks include those associated with clinical development, regulatory approval, and commercialization of pipeline programs.

Q: Jay Olson asked about differences between prasinezumab and cinpanemab besides epitope and feedback on Pasadena part one.

A: Gene Kinney and Wagner Zago discussed epitope targeting, selectivity of prasinezumab for aggregated alpha-synuclein, and upcoming data on Pasadena part one.

Q: Michael Yee asked about Bristol Celgene collaboration and PRX012 vs aducanumab.

A: Gene Kinney and Tran Nguyen discussed PRX012's epitope targeting similar to aducanumab and Birtamimab, and ongoing collaboration with BMS with milestones tied to IND filings.

Q: Charles Duncan asked about AFFIRM AL p-value and PRX004 CNS penetration.

A: Gene Kinney and Wagner Zago discussed FDA discussions on AFFIRM AL's p-value and PRX004's subcutaneous delivery potentially reducing ARIA risk while maintaining efficacy.

Q: Robert Hazlett asked about Bristol collaboration milestones and Celgene principles.

A: Tran Nguyen explained collaboration milestones for $80M and $55M, and ongoing engagement with BMS team involved in the collaboration.

Q: Kennen McKay asked about Birtamimab in AL amyloidosis and Darzalex.

A: Radhika Tripuraneni and Tran Nguyen discussed Birtamimab's survival benefit over standard of care and Dara's lack of survival impact in Mayo Stage IV patients.

Q: Tazeen Ahmad asked about pandemic impact on AL amyloidosis study enrollment.

A: Gene Kinney and Radhika Tripuraneni discussed that Mayo Stage IV patients are prioritized for treatment and care, with protocols in place to manage COVID, and patients likely prioritized for vaccination.