Prothena Reports Third Quarter 2026 Financial Results and Business Highlights
PROTHENA CORP PUBLIC LTD CO (PRTA) filed an SEC Form 8-K — Results of Operations and Financial Condition. Exhibit 99.1 PRESS RELEASE Prothena Reports Third Quarter 2026 Financial Results an d Business Highlights • Net cash used in operating and investing activities was $12.0 million in the third quarter and net cash used in operating and investing activities was $8.9 million for the
How this was made
The 30-second read
Why it matters
The earnings release provides the first public view of Q3 2026 financials, narrowing loss and showing cash strength, which may influence short‑term price action.
Market read
Primary earnings disclosure for a micro‑cap biotech; relevance mainly to traders focused on biotech earnings and pipeline updates.
What to watch
Upcoming Phase 3 trial readouts in 2029 could dominate longer‑term valuation.
Prothena Reports Third Quarter 2026 Financial Results and Business Highlights
Third-quarter net loss, R&D expense and G&A expense were lower than the prior-year period, while the company maintained its full-year 2026 cash-use and year-end cash guidance. The quarter had $0.6 million of total revenue, and the clinical pipeline remains dependent on partnered Phase 3 programs with primary completions expected in 2029.
Key metrics
shortened, hover for the filing’s print| Metric | Value | q/q | y/y |
|---|---|---|---|
| Total revenue, third quarter 2026GAAP | $600K | – | – |
| Collaboration revenue, third quarter 2026GAAP | $620K | – | – |
| Revenue from license and intellectual property, third quarter 2026GAAP | — | – | – |
| Research and development expenses, third quarter 2026GAAP | $8.4M | – | – |
| General and administrative expenses, third quarter 2026GAAP | $10.6M | – | – |
| Restructuring expenses, third quarter 2026GAAP | $400K | – | – |
| Total operating expenses, third quarter 2026GAAP | $19.44M | – | – |
| Loss from operations, third quarter 2026GAAP | −$18.82M | – | – |
| Other income, net, third quarter 2026GAAP | $2.31M | – | – |
| Loss before income taxes, third quarter 2026GAAP | −$16.51M | – | – |
| Provision for (benefit from) income taxes, third quarter 2026GAAP | $2K | – | – |
| Net loss, third quarter 2026GAAP | $16.5M | – | – |
| Basic and diluted net loss per ordinary share, third quarter 2026GAAP | $0.32 | – | – |
| Shares used to compute basic and diluted net loss per share, third quarter 2026GAAP | 51.44M | – | – |
| Non-cash share-based compensation expense, third quarter 2026GAAP | $6.4M | – | – |
| Research and development non-cash share-based compensation expense, third quarter 2026GAAP | $1.8M | – | – |
| General and administrative non-cash share-based compensation expense, third quarter 2026GAAP | $4.6M | – | – |
| Total revenue, first nine months of 2026GAAP | $52.7M | – | – |
| Collaboration revenue, first nine months of 2026GAAP | $2.66M | – | – |
| Revenue from license and intellectual property, first nine months of 2026GAAP | $50.05M | – | – |
| Research and development expenses, first nine months of 2026GAAP | $29.9M | – | – |
| General and administrative expenses, first nine months of 2026GAAP | $34.2M | – | – |
| Restructuring credit, first nine months of 2026GAAP | $1.4M | – | – |
| Total operating expenses, first nine months of 2026GAAP | $62.60M | – | – |
| Loss from operations, first nine months of 2026GAAP | −$9.89M | – | – |
| Other income, net, first nine months of 2026GAAP | $7.52M | – | – |
| Net loss, first nine months of 2026GAAP | $2.4M | – | – |
| Basic and diluted net loss per ordinary share, first nine months of 2026GAAP | $0.05 | – | – |
| Net cash used in operating and investing activities, third quarter 2026GAAP | $12M | – | – |
| Net cash used in operating and investing activities, first nine months of 2026GAAP | $8.9M | – | – |
| Cash, cash equivalents and restricted cash, September 30, 2026GAAP | $272.2M | – | – |
| Debt, September 30, 2026GAAP | no debt | – | – |
| Ordinary shares outstanding, October 29, 2026other | approximately 51.3 million ordinary shares | – | – |
Full year 2026 outlook
- NoteNet cash used in operating and investing activities: $18 to $23 million
- NoteCash, cash equivalents and restricted cash at year-end: approximately $259 million (midpoint)
- NoteEstimated net loss: $25 to $30 million
- NoteEstimated non-cash share-based compensation expense: $26 million
- NoteThis financial guidance does not include any potential additional cash utilized as part of a share repurchase program.
Capital returns
- Prothena repurchased 501,492 ordinary shares in the third quarter of 2026.
- Prothena repurchased 788,990 ordinary shares in the first quarter of 2026.
- Prothena repurchased 1,454,898 ordinary shares in the second quarter of 2026.
- Prothena repurchased an aggregate of 2,745,380 ordinary shares during the first nine months of 2026 with $26.6 million, excluding commissions and expenses, under its up to $100.0 million share repurchase program, which expires on December 31, 2026.
What drove it
- Third-quarter and first-nine-month 2026 R&D expense decreases versus the same periods in the prior year were primarily due to lower clinical trial expenses, lower personnel expenses and lower consulting expenses.
- Third-quarter and first-nine-month 2026 G&A expense decreases versus the same periods in the prior year were primarily due to lower personnel expenses and consulting expenses.
- First-nine-month 2026 total revenue was primarily from a $50.0 million milestone payment from Novo related to the ongoing Phase 3 clinical trial for coramitug and collaboration revenue from Bristol Myers Squibb related to the partial performance of the PRX019 Phase 1 clinical trial obligation.
- Roche is conducting the Phase 3 PARAISO trial of prasinezumab, with primary completion expected in 2029.
- Novo is conducting the Phase 3 CLEOPATTRA trial of coramitug, with primary completion expected in 2029.
- Bristol Myers Squibb is conducting the Phase 2 TargetTau-1 trial of moponetug, with data readout expected in the first half of 2027.
Concerns
- Third-quarter total revenue was $0.6 million, compared with $2.4 million for the third quarter of 2025.
- The company reported a net loss of $16.5 million for the third quarter of 2026.
- The reported $50.0 million Novo milestone contributed to first-nine-month revenue; third-quarter revenue consisted of $620 thousand of collaboration revenue.
- Primary completions for the partnered Phase 3 PARAISO and CLEOPATTRA trials are expected in 2029.
- Full-year 2026 financial guidance excludes any potential additional cash utilized as part of a share repurchase program.
What to watch
- Bristol Myers Squibb's expected first-half 2027 data readout from the Phase 2 TargetTau-1 trial of moponetug.
- Expected 2027 primary completion of the open-label study of 89Zr-coramitug.
- Expected 2029 primary completions of Roche's Phase 3 PARAISO trial and Novo's Phase 3 CLEOPATTRA trial.
- Full-year 2026 net cash used in operating and investing activities versus the guided $18 to $23 million.
- The remaining activity under the up to $100.0 million share repurchase program, which expires on December 31, 2026.
- Progress of multiple CYTOPE technology research collaborations over the next 12 to 24 months.
Balance sheet and cash flow
- As of September 30, 2026, cash and cash equivalents were $271,368 thousand.
- Restricted cash, non-current was $860 thousand as of September 30, 2026.
- Total assets were $283,520 thousand as of September 30, 2026.
- Total liabilities were $14,683 thousand as of September 30, 2026.
- Total shareholders’ equity was $268,837 thousand as of September 30, 2026.
- Net cash used in operating and investing activities was $12.0 million in the third quarter and $8.9 million for the first nine months of 2026.
Analysis
Prothena reported a third-quarter 2026 net loss of $16.5 million, compared with a net loss of $36.5 million in the third quarter of 2025. Basic and diluted net loss per ordinary share was $0.32, compared with $0.68. Total revenue was $0.6 million, compared with $2.4 million, and consisted of $620 thousand of collaboration revenue. The release did not provide a sequential comparison for these quarterly results.
Expense reduction was the principal reported driver of the lower third-quarter loss. R&D expenses were $8.4 million versus $28.9 million, and G&A expenses were $10.6 million versus $13.2 million. Management attributed the R&D reduction to lower clinical trial, personnel and consulting expenses, while lower personnel and consulting expenses drove the G&A reduction. Total non-cash share-based compensation expense was $6.4 million versus $7.2 million.
For the first nine months of 2026, total revenue was $52.7 million, compared with $9.7 million in the first nine months of 2025. The release identified a $50.0 million Novo milestone related to the ongoing Phase 3 coramitug trial as the principal source of the period's revenue, together with Bristol Myers Squibb collaboration revenue. The company reported a $2.4 million net loss for the first nine months, compared with a $222.5 million net loss in the prior-year period. R&D was $29.9 million versus $120.3 million, and G&A was $34.2 million versus $46.7 million.
Liquidity at September 30, 2026 was $272.2 million in cash, cash equivalents and restricted cash, with no debt. Net cash used in operating and investing activities was $12.0 million in the third quarter and $8.9 million for the first nine months. The company continues to expect full-year 2026 net cash used in operating and investing activities of $18 to $23 million, estimated net loss of $25 to $30 million, estimated non-cash share-based compensation expense of $26 million, and approximately $259 million of year-end cash, cash equivalents and restricted cash at the midpoint.
Capital allocation included repurchases of 501,492 ordinary shares in the third quarter. Across the first nine months, Prothena repurchased 2,745,380 ordinary shares with $26.6 million, excluding commissions and expenses, under the up to $100.0 million program expiring December 31, 2026. The company stated that its financial guidance excludes potential additional cash used for repurchases.
Pipeline progress remains centered on partnered clinical programs. Roche's Phase 3 PARAISO trial of prasinezumab and Novo's Phase 3 CLEOPATTRA trial of coramitug have primary completions expected in 2029. Bristol Myers Squibb's Phase 2 TargetTau-1 moponetug trial has an expected data readout in the first half of 2027. The company is also advancing wholly owned preclinical TDP-43 CYTOPE and PRX012-TfR programs and has multiple CYTOPE research collaborations ongoing over the next 12 to 24 months.
Management, verbatim
During the quarter, Roche and Novo highlighted prasinezumab at Roche’s Pharma Day and coramitug at Novo’s Capital Markets Day, underscoring the potential of these Prothena-originated programs to address significant unmet needs in Parkinson’s disease and ATTR amyloidosis with cardiomyopathy, respectively.
Gene Kinney, Ph.D., President and Chief Executive Officer, Prothena
Both programs are in Phase 3 clinical trials, PARAISO (prasinezumab) and CLEOPATTRA (coramitug), with primary completions expected in 2029.
Gene Kinney, Ph.D., President and Chief Executive Officer, Prothena
Bristol Myers Squibb continues to conduct the Phase 2 TargetTau-1 trial evaluating moponetug in patients with early Alzheimer’s disease, with data readout expected in the first half of 2027.
Gene Kinney, Ph.D., President and Chief Executive Officer, Prothena
Not in the filing
stated, not guessed- Non-GAAP revenue, earnings, EPS, margin and cash flow metrics were not reported.
- Gross profit and gross margin were not reported.
- Operating cash flow was not separately reported.
- Free cash flow was not reported.
- Quarterly capital expenditure was not reported.
- Dividend information was not reported.
- No reportable operating segments or segment revenue were provided.
- Prior-quarter figures for the reported third-quarter income statement metrics were not provided.
- Percentage year-over-year and quarter-over-quarter changes were not printed for the reported financial metrics.
- A previous-release outlook was not provided, so no comparison with prior guidance is available.
- Revenue guidance, gross-margin guidance, operating-expense guidance and tax-rate guidance were not provided.
Written by an AI language model from the company’s SEC earnings filing (Form 8-K Item 2.02, or Form 6-K for a foreign private issuer). Every figure is checked against the filing text, and a metric the filing does not print, or whose value, prior period and change do not add up, is dropped from the metrics. The model can still misread a table, in the metrics or in the text, so check a number in the filing before you rely on it. Consensus estimates, price targets and share-price reactions are not shown because they are not in the filing. AI-generated research, not investment advice.
Background
Prothena (NASDAQ:PRTA) is a late‑stage clinical biotech with collaborations with Roche, Novo, and Bristol Myers Squibb.
Ticker impact
Prothena filed an 8‑K reporting Q3 2026 results, showing a narrowed net loss and cash position.
likely upward pressure as investors digest the loss improvement and cash balance
The primary disclosure of earnings shows a material improvement versus the prior year, which can attract buying interest.
Market effects
Biotech sector may see modest uplift as a late‑stage biotech reports improved financials.
Limited to US‑listed biotech investors.
Low global impact beyond sector peers.
Counterpoint
The loss remains sizable; skeptics may view the improvement as insufficient for a rally.
Key entities
- partnerRoche
Conducting Phase 3 PARAISO trial for prasinezumab.
- partnerNovo
Running Phase 3 CLEOPATTRA trial for coramitug.
