Prothena Corporation plc
Key statistics
from XBRL data in SEC filingsAI briefing
from the latest 10-K, 10-Q and 8-K eventsProthena is a late-stage clinical biotechnology company developing therapies for neurodegenerative and rare peripheral amyloid diseases, with all active clinical programs partnered with large pharmaceutical companies.
What they do
Prothena focuses on protein dysregulation to develop therapeutics for diseases such as Parkinson's disease, ATTR amyloidosis with cardiomyopathy, Alzheimer's disease, and ALS. Its pipeline includes partnered programs with Roche, Novo Nordisk, and Bristol Myers Squibb, as well as early-stage wholly-owned research including the CYTOPE technology. The company has no marketed products and generates revenue primarily from collaboration agreements.
Revenue drivers
- Collaboration and license agreements — Revenue from partners Roche, Novo Nordisk, and BMS, primarily from upfront payments, milestones, and cost reimbursements. Total revenue fell to $9.7M in 2025 from $135.2M in 2024, reflecting the wind-down of certain collaboration activities.
- Roche collaboration (prasinezumab) — Prasinezumab targets alpha-synuclein for Parkinson's disease; Roche is conducting the Phase 3 PARAISO trial. Revenue from this collaboration is tied to development milestones and potential royalties; no product sales yet.
- Novo Nordisk collaboration (coramitug) — Novo Nordisk acquired Prothena's ATTR amyloidosis business; coramitug is in Phase 3 CLEOPATTRA for ATTR-CM. The deal is valued up to $1.2 billion, with milestones and royalties potential.
- Bristol Myers Squibb collaboration (moponetug and PRX019) — BMS is developing moponetug (BMS-986446) in Phase 2 TargetTau-1 for early Alzheimer's disease, and PRX019 in Phase 1. Collaboration payments contribute to revenue.
Recent performance
For full-year 2025, Prothena reported revenue of $9.7M and a net loss of $244.1M, with diluted EPS of -$4.53. Operating cash flow was -$163.6M in 2025. In Q2 2026, revenue was $1.0M; net cash used in operating and investing activities was $25.7M in Q2, and net cash provided for the first six months of 2026 was $3.2M. Cash and restricted cash at June 30, 2026 were $289.1M.
Strategy
Prothena's stated strategy is to advance its partnered clinical programs while investing in early-stage research, particularly the CYTOPE technology for intracellular targets. The company is actively seeking new research collaborations and licensing deals with large pharmaceutical companies. It plans to continue supporting clinical trials led by Roche, Novo Nordisk, and BMS, while also conducting preclinical work on PRX012. Management emphasizes efficient development and capital management, including share repurchases.
Risks
- Dependence on partners — All clinical-stage programs are partnered; Prothena relies on Roche, Novo Nordisk, and BMS for development and commercialization, and any partner decision could impact future milestones and revenue.
- Significant operating losses and need for capital — The company has incurred substantial net losses ($244.1M in 2025) and expects to continue losing money; it may require additional financing to fund operations.
- Clinical trial risks — Phase 3 trials (PARAISO, CLEOPATTRA) and Phase 2 (TargetTau-1) are ongoing; failures or delays could impair collaboration value and future revenue.
- Limited revenue base — Annual revenue is highly dependent on one-time collaboration payments; 2025 revenue of $9.7M is a sharp decline from prior years, highlighting volatility.
Outlook
Management expects primary completion of PARAISO and CLEOPATTRA in 2029, and TargetTau-1 completion in the first half of 2027. They anticipate ending 2026 with approximately $259 million in cash (midpoint), reflecting share repurchases. Partnered programs could generate up to approximately $3 billion in aggregate future milestone payments plus royalties. Over the next 12-24 months, they plan to continue research collaborations exploring CYTOPE technology.