Revenue is highly volatile and milestone-driven, with a -77.1% quarter-over-quarter decline to $1.0M in 2026Q2, while operating margins swing wildly from 50.5% to -20.9% depending on the timing of these payments.
Prothena Corporation plc (PRTA) annual income statement — 16-year revenue, gross profit & net income history
| Metric | TTM | Dec'25 | Dec'24 | Dec'23 | Dec'22 | Dec'21 | Dec'20 | Dec'19 | Dec'18 | Dec'17 | Dec'16 | Dec'15 | Dec'14 | Dec'13 | Dec'12 | Dec'11 | Dec'10 |
|---|
| Sales/Revenue | 54.53M | 9.68M | 135.16M | 91.37M | 53.91M | 200.58M | 853K | 814K | 955K | 27.52M | 1.05M | 1.61M | 50.85M | 676K | 2.66M | 507K | 1.24M |
| Revenue Growth % | 427.32% | -92.84% | 47.92% | 69.5% | -73.13% | 23414.3% | 4.79% | -14.76% | -96.53% | 2508.44% | -34.35% | -96.84% | 7422.78% | -74.57% | 424.26% | -59.21% | - |
| Cost of Goods Sold | 30.8M | 3.7M | 0 | 0 | 0 | 0 | 74.88M | 50.84M | 101.18M | 134.55M | 119.53M | 58.44M | 38.45M | 26.05M | 34.14M | 0 | 0 |
| COGS % of Revenue | - | 38.23% | - | - | - | - | 8778.9% | 6245.21% | 10595.08% | 488.92% | 11330.24% | 3636.53% | 75.61% | 3853.85% | 1284.39% | - | - |
| Gross Profit | 23.73M | 5.98M | 135.16M | 91.37M | 53.91M | 200.58M | -74.03M | -50.02M | -100.23M | -107.03M | -118.48M | -56.83M | 12.4M | -25.38M | -31.48M | 507K | 1.24M |
| Gross Margin % | 43.52% | 61.77% | 100% | 100% | 100% | 100% | -8678.9% | -6145.21% | -10495.08% | -388.92% | -11230.24% | -3536.53% | 24.39% | -3753.85% | -1184.39% | 100% | 100% |
| Gross Profit Growth % | - | -95.57% | 47.92% | 69.5% | -73.13% | 370.94% | -48% | 50.09% | 6.35% | 9.66% | -108.47% | -558.25% | 148.87% | 19.39% | -6309.27% | -59.21% | - |
| Operating Expenses | 86.49M | 190.54M | 289.72M | 282.41M | 185.46M | 128.6M | 38.7M | 35.67M | 143.66M | 182.77M | 160.59M | 81.54M | 57.5M | 41.1M | 44.07M | 29.75M | 13.4M |
| OpEx % of Revenue | - | 1967.6% | 214.36% | 309.08% | 344.05% | 64.12% | 4537.28% | 4382.68% | 15043.46% | 664.17% | 15221.8% | 5074.3% | 113.07% | 6080.33% | 1657.94% | 5868.05% | 1078.44% |
| Selling, General & Admin | 49.45M | 59.39M | 67.2M | 61.84M | 49.9M | 46.32M | 38.7M | 35.74M | 42.48M | 48.23M | 41.06M | 23.11M | 19.05M | 15.05M | 9.93M | 5.58M | 3.62M |
| SG&A % of Revenue | - | 613.3% | 49.72% | 67.68% | 92.57% | 23.09% | 4537.28% | 4390.17% | 4448.38% | 175.25% | 3891.56% | 1437.77% | 37.46% | 2226.48% | 373.55% | 1100.39% | 291.07% |
| Research & Development | 64.95M | 134.85M | 222.52M | 220.57M | 135.56M | 82.28M | 75.09M | 50.84M | 101.18M | 134.55M | 119.53M | 58.44M | 38.45M | 26.05M | 34.14M | 24.17M | 9.79M |
| R&D % of Revenue | - | 1392.52% | 164.64% | 241.4% | 251.48% | 41.02% | 8803.4% | 6245.21% | 10595.08% | 488.92% | 11330.24% | 3636.53% | 75.61% | 3853.85% | 1284.39% | 4767.65% | 787.37% |
| Other Operating Expenses | -1.86M | -3.7M | 0 | 0 | 0 | 0 | -75.09M | -50.9M | 2.74M | -2.35M | 571K | 26K | 310K | -225K | 0 | 0 | 0 |
| Operating Income | -62.76M | -184.56M | -154.56M | -191.04M | -131.56M | 71.97M | -112.73M | -85.7M | -158.85M | -155.25M | -159.53M | -79.94M | -6.65M | -40.43M | -41.41M | -29.24M | -12.16M |
| Operating Margin % | -115.09% | -1905.82% | -114.36% | -209.08% | -244.05% | 35.88% | -13216.18% | -10527.89% | -16634.03% | -564.17% | -15121.8% | -4974.3% | -13.07% | -5980.33% | -1557.94% | -5768.05% | -978.44% |
| Operating Income Growth % | - | -19.41% | 19.09% | -45.21% | -282.78% | 163.84% | -31.55% | 46.05% | -2.32% | 2.68% | -99.58% | -1102.24% | 83.55% | 2.37% | -41.6% | -140.45% | - |
| EBITDA | -60.29M | -180.86M | -153.67M | -190.11M | -130.81M | 73.09M | -111.22M | -84.13M | -155.64M | -152.19M | -157.11M | -79.13M | -5.91M | -39.77M | -40.94M | -28.85M | -11.97M |
| EBITDA Margin % | -110.56% | -1867.6% | -113.7% | -208.06% | -242.67% | 36.44% | -13038.69% | -10335.75% | -16297.28% | -553.03% | -14891.75% | -4924.14% | -11.61% | -5882.69% | -1540.33% | -5690.93% | -963.07% |
| EBITDA Growth % | 78.52% | -17.69% | 19.17% | -45.33% | -278.98% | 165.72% | -32.2% | 45.94% | -2.27% | 3.13% | -98.54% | -1239.84% | 85.15% | 2.87% | -41.9% | -141.02% | - |
| D&A (Non-Cash Add-back) | 2.47M | 3.7M | 893K | 928K | 744K | 1.11M | 1.51M | 1.56M | 3.22M | 3.07M | 2.43M | 806K | 743K | 660K | 468K | 391K | 191K |
| EBIT | -43.61M | -200.83M | -128.93M | -160.48M | -125.61M | 71.92M | -112.73M | -85.76M | -152.42M | -153.91M | -158.96M | -79.94M | -6.65M | -40.43M | -41.41M | -29.24M | -12.16M |
| Net Interest Income | 10.97M | 14.14M | 25.82M | 31.01M | 6.35M | 42K | 1.37M | 8.2M | 2.69M | -142K | 556K | 196K | 79K | 71K | 5K | 0 | 0 |
| Interest Income | 10.97M | 14.14M | 25.82M | 31.01M | 6.35M | 42K | 1.37M | 8.2M | 6.39M | 3.55M | 1.42M | 196K | 79K | 71K | 5K | 0 | 0 |
| Interest Expense | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3.7M | 3.69M | 863K | 0 | 0 | 0 | 0 | 0 | 0 |
| Other Income/Expense | 19.15M | -16.27M | 25.63M | 30.56M | 5.95M | -54K | 1.87M | 8.4M | 2.74M | -2.35M | 571K | 26K | 310K | -154K | 5K | 0 | 0 |
| Pretax Income | -43.61M | -200.83M | -128.93M | -160.48M | -125.61M | 71.92M | -110.86M | -77.3M | -156.12M | -157.6M | -158.96M | -79.91M | -6.34M | -40.58M | -41.41M | -29.24M | -12.16M |
| Pretax Margin % | -79.97% | -2073.82% | -95.39% | -175.64% | -233.01% | 35.86% | -12996.6% | -9496.07% | -16347.12% | -572.71% | -15067.68% | -4972.68% | -12.47% | -6003.11% | -1557.75% | -5768.05% | -978.44% |
| Income Tax | 384K | 43.26M | -6.62M | -13.45M | -8.66M | 4.95M | 283K | 379K | -470K | -4.37M | 1.14M | 701K | 811K | 415K | 6K | 426K | 320K |
| Effective Tax Rate % | -0.88% | -21.54% | 5.13% | 8.38% | 6.89% | 6.88% | -0.26% | -0.49% | 0.3% | 2.77% | -0.72% | -0.88% | -12.79% | -1.02% | -0.01% | -1.46% | -2.63% |
| Net Income | -43.99M | -244.09M | -122.31M | -147.03M | -116.95M | 66.97M | -111.14M | -77.68M | -155.65M | -153.24M | -160.11M | -80.61M | -7.15M | -41M | -41.41M | -29.67M | -12.48M |
| Net Margin % | -80.67% | -2520.57% | -90.49% | -160.92% | -216.95% | 33.39% | -13029.78% | -9542.63% | -16297.91% | -556.84% | -15176.11% | -5016.3% | -14.06% | -6064.5% | -1557.98% | -5852.07% | -1004.18% |
| Net Income Growth % | 85.48% | -99.57% | 16.81% | -25.72% | -274.62% | 160.26% | -43.08% | 50.09% | -1.57% | 4.29% | -98.62% | -1027.44% | 82.56% | 1% | -39.57% | -137.7% | - |
| Net Income (Continuing) | -43.99M | -244.09M | -122.31M | -147.03M | -116.95M | 66.97M | -111.14M | -77.68M | -155.65M | -153.24M | -160.11M | -80.61M | -7.15M | -41M | -41.41M | -29.67M | -12.48M |
| Discontinued Operations | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Minority Interest | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| EPS (Diluted) | -0.84 | -4.53 | -2.27 | -2.76 | -2.47 | 1.38 | -2.78 | -1.95 | -3.93 | -4.07 | -4.66 | -2.66 | -0.29 | -2.20 | -2.84 | -1.68 | -0.71 |
| EPS Growth % | 85.11% | -99.56% | 17.75% | -11.74% | -278.99% | 149.64% | -42.56% | 50.38% | 3.44% | 12.66% | -75.19% | -817.24% | 86.82% | 22.54% | -69.05% | -136.62% | - |
| EPS (Basic) | - | -4.53 | -2.27 | -2.76 | -2.47 | 1.51 | -2.78 | -1.95 | -3.93 | -4.07 | -4.66 | -2.66 | -0.29 | -2.20 | -2.84 | -1.68 | -0.71 |
| Diluted Shares Outstanding | 52.15M | 53.83M | 53.77M | 53.22M | 47.37M | 48.46M | 39.91M | 39.88M | 39.56M | 37.65M | 34.35M | 30.33M | 24.67M | 18.61M | 14.59M | 17.68M | 17.68M |
| Basic Shares Outstanding | 52.15M | 53.83M | 53.77M | 53.22M | 47.37M | 44.23M | 39.91M | 39.88M | 39.56M | 37.65M | 34.35M | 30.33M | 24.67M | 18.61M | 14.59M | 17.68M | 17.68M |
| Dividend Payout Ratio | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
Quick answers to the most common questions about buying PRTA stock.
For fiscal year 2025, Prothena Corporation plc (PRTA) reported total revenue of $9.7M. This represents a 679.1% increase compared to $1.2M in 2010.
Prothena Corporation plc (PRTA) reported a net loss of $244.1M for the fiscal year ending 2025.
Prothena Corporation plc (PRTA) reported an operating income of $-184.6M, resulting in an operating profit margin of -1905.8%. This margin reflects the operational efficiency of the business before interest and taxes.
Prothena Corporation plc (PRTA) generated $6.0M in gross profit for the year, representing a gross profit margin of 61.8%. This demonstrates the company's core pricing power and production efficiency.
Key Metrics
Top Statement Risk
Lumpy, milestone-driven revenue
Metrics are mathematically derived from official filings.
Revenue Volatility Defines Growth Profile
Prothena's revenue trajectory is defined by extreme lumpiness, with quarterly swings from $51.1M in 2026Q1 to just $1.0M in 2026Q2, a pattern that suggests reliance on non-recurring milestones or licensing payments rather than sustainable product sales.
The company's revenue history shows no discernible organic growth trend, with quarters of significant revenue (e.g., $132.0M in 2024Q2, $51.1M in 2026Q1) followed by quarters of near-zero revenue. This pattern is inconsistent with a commercial-stage biotech and indicates that reported top-line figures are driven by episodic events, likely collaboration or license fees, making forward revenue forecasting highly speculative.
Gross Margin Distorted by Milestone Accounting
Reported gross margins are structurally misleading, swinging from 100% in most quarters to negative 43.9% in 2025Q4, a volatility that appears driven by the timing of revenue recognition and associated cost of sales rather than underlying pricing power or manufacturing efficiency.
The gross margin profile is not indicative of a traditional manufacturing or services business. The negative margin in 2025Q4, where COGS of $942K exceeded revenue of $21K, suggests the recognition of costs related to a prior-period revenue event. This accounting treatment means gross margin is not a reliable metric for assessing Prothena's core operational profitability.
R&D Dominates Cost Structure, SG&A Stable
Research and development is the primary cost driver, consuming between $8.8M and $64.1M per quarter, while SG&A remains relatively stable in the $12.6M to $17.6M range, indicating a cost structure heavily weighted towards pipeline investment over commercial infrastructure.
The significant quarterly variation in R&D expense, from a low of $8.8M in 2026Q2 to a high of $64.1M in 2024Q1, suggests that spending is tied to specific clinical trial milestones or program advancements rather than a steady operational run-rate. The relative stability of SG&A implies a lean corporate overhead, but the overall cost base remains substantial relative to the company's inconsistent revenue generation.
Operating Leverage Absent Amidst Cash Burn
There is no evidence of positive operating leverage, as operating losses have persisted for eight of the last ten quarters, with the operating margin swinging wildly from -1630.6% to 50.5%, a pattern that underscores the absence of a scalable, profitable core business model.
The company's operating income is entirely dependent on the timing of large, non-recurring revenue events. In quarters with significant revenue, such as 2026Q1, the business can achieve positive operating income ($25.8M). However, in all other quarters, the fixed cost base of R&D and SG&A generates substantial operating losses, demonstrating that the cost structure is not aligned with a predictable revenue stream.
Sustainability of Milestone-Driven Model
The core analytical challenge is whether Prothena's financial model, which shows a net loss of $18.6M in 2026Q2 on $1.0M of revenue, is sustainable without a continuous pipeline of new, large-scale licensing deals or partnership milestones to offset its persistent cash burn.
The income statement reveals a business that is not self-funding. The reliance on episodic revenue to cover a consistent quarterly cost base of approximately $20M-$30M in R&D and SG&A creates significant financial risk. Investors should monitor the company's cash position and pipeline progress closely, as the model appears vulnerable to any delays or failures in securing new, material collaboration agreements.