2025-05-26-Jefferies-普罗西娜公司（PRTA）_令人失望但并不意外的III期AL淀粉样变性数据-转为持有_9页_270kb

Prothena Corporation PLC (PRTA) equity research report dated May 27, 2025, provides an update on their Phase III study in AL amyloidosis.

• Phase III Result: The study failed, missing the primary endpoint (HR = 0.915, p-value = 0.768) and both secondary endpoints. The failure was largely anticipated based on pre-existing analysis.
• Rationale for Failure: Contributing factors included numerous baseline imbalances favoring the control arm, high variability in overall survival influenced by patient factors, and the introduction of darzalex as background therapy. Mayo Stage IV subgroup data were also considered in light of prior baseline differences.
• Company Response/Next Steps: Prothena management acknowledged the drug showed no trends and will discontinue it. They plan to cut operating expenses (estimated 25-50%) and evaluate shareholder options. Future focus includes the Phase I/II Alzheimer's drug (PRX-004) data in August (APOE4 heterozygotes cohort first), which is viewed cautiously. A wholly-owned dual Aβ/tau vaccine (PRX123) is also under development. Further details follow in June.
• Financials: Prothena has high cash burn ($3-6 cash balance estimated for late 2025/early 2026 based on their model) and negative EPS guidance for early 2025.
• Valuation/Rating: Jefferies maintains a HOLD rating on PRTA with a $6 price target. The rationale includes high R&D risk from AL data and future Alzheimer's programs, combined with cash burn and a challenging capital markets environment.

This summary covers the key analysis points including risks, catalysts, valuation and recommendation from the Jefferies Equity Research report dated May 27, 2025.

• Risk Factors: High clinical trial risk in AD/amyloidosis, safety concerns and access/affordability.
• Catalysts: August Phase I/II Alzheimer's data (APOE4 heterozygotes); planned updates in June regarding the Phase III AL data impact and restructuring status.
• Valuation: HOLD rating, SOTP valuation incorporating pipeline, $6 price target.