Prothena's 2024 Q4 Earnings Call: Key Contradictions on Patient Trials, Drug Safety, and Market Potential

These are the key contradictions discussed in Prothena's latest 2024Q4 earnings call, specifically including: Patient Enrollment and Trial Timelines, ARIA Rates and Dose Levels, Birtamimab's Impact on Early Mortality, Market Opportunity for Birtamimab, and AFFIRM-AL Trial Enrollment and Expectations:



Clinical Trial Progress and readout Expectations:
- Prothena is nearing significant inflection points in 2025, with key clinical trials including Birtamimab's Phase 3 AFFIRM-AL trial expected to announce top-line results by Q2 2025.
- The company is optimistic about demonstrating survival benefits and expects to submit a BLA to the FDA for potential U.S. launch by the second half of 2026, driven by the need to address early mortality in AL amyloidosis patients.

Alzheimer's Disease Pipeline:
- Prothena's Alzheimer's disease portfolio includes PRX012 and PRX123, with initial ASCENT trial results for PRX012 expected around mid-year 2025.
- The company aims to address the unmet needs of early Alzheimer's patients with unique programs designed for easy-to-use, at-home administration and prevention and treatment options.

Commercial Opportunity and Market Dynamics:
- Prothena's birtamimab is positioned as a potential multi-billion-dollar global commercial opportunity, with an established market and significant unmet need in AL amyloidosis for patients at risk of early mortality.
- The company plans to independently commercialize birtamimab in the U.S. and evaluate European launch timing, leveraging a consolidated prescriber base and existing relationships with KOLs to ensure market awareness and incorporation into treatment guidelines.

Financial Performance and Guidance:
- For 2024, Prothena's net cash used in operating and investing activities was $150.3 million, within the guidance range, and ended the year with $472.2 million in cash, in line with expectations.
- For 2025, the company anticipates net cash used in operating and investing activities to be between $168 million and $175 million, with an estimated net loss of $197 million to $205 million, including $41 million in non-cash share-based compensation expense.