| Three months ended December 31, | Year ended December 31, | |||||||||||||||
| 2025 | 2024 | 2025 | 2024 | |||||||||||||
| (amounts in millions) | ||||||||||||||||
| Total revenue | $ | 203 | $ | 227 | $ | 944 | $ | 705 | ||||||||
| Operating expenses | $ | 418 | $ | 337 | $ | 1,326 | $ | 1,180 | ||||||||
| Operating expenses on a non-GAAP basis | $ | 375 | $ | 301 | $ | 1,192 | $ | 1,050 | ||||||||
| Loss from operations | $ | (215 | ) | $ | (110) | $ | (382 | ) | $ | (475 | ) | |||||
| Loss from operations on a non-GAAP basis | $ | (172 | ) | $ | (74) | $ | (248 | ) | $ | (345 | ) | |||||
| (1) | Reconciliation of GAAP to non-GAAP basis contained later in this release. |
| • | Revenue for the year ended December 31, 2025 substantially exceeded expectations due to continued commercial success. In addition, Ionis earned substantial R&D revenue, including a $280 million upfront payment for the global license of sapablursen to Ono Pharmaceutical Co., Ltd. in the second quarter of 2025 |
| • | Operating expenses for the year ended December 31, 2025 were in line with expectations and increased year over year from investments related to commercialization efforts for TRYNGOLZA, DAWNZERA and WAINUA |
| • | Cash and short-term investments of $2.7 billion as of December 31, 2025, included refinancing proceeds Ionis plans to use to repay its 2026 Convertible Notes |
| • | TRYNGOLZA® (olezarsen), the first FDA-approved treatment for adults living with familial chylomicronemia syndrome (FCS) as an adjunct to diet |
| o | Generated net product sales of $50 million in the fourth quarter of 2025, a 56% increase over the prior quarter, and $108 million for the year ended December 31, 2025 |
| o | Approved and launched in the European Union (EU) as an adjunct to diet in adult patients for the treatment of genetically confirmed FCS |
| • | Olezarsen on track to launch this year as a transformational medicine for severely elevated triglycerides (sHTG), assuming approval |
| o | Positive groundbreaking results in the pivotal Phase 3 CORE and CORE2 studies in sHTG presented at the American Heart Association Conference, in a late-breaking session, and published in the New England Journal of Medicine |
| o | sNDA submitted for marketing approval in U.S. |
| • | DAWNZERA™ (donidalorsen), the first and only RNA-targeted prophylactic therapy for hereditary angioedema (HAE) in patients 12 years of age and older |
| o | Generated net product sales of $7 million in the fourth quarter of 2025, in the first full quarter on the market |
| ▪ | Encouraging early launch momentum with prescriptions written for all patient segments and growing number of repeat prescribers |
| o | Approved in the European Union (EU) in January and recently launched for the routine prevention of recurrent attacks of HAE in patients 12 years of age and older |
| o | Positive one-year results from OASISplus open-label extension cohort published in the Journal of Asthma and Allergy |
| • | Zilganersen on track for launch this year as the first and only medicine to demonstrate clinically meaningful and disease-modifying impact in children and adults with Alexander disease (AxD), assuming approval |
| o | NDA submitted with approval decision anticipated in H2:2026 |
| o | Expanded access program (EAP) in U.S. underway |
| • | SPINRAZA® (nusinersen) for the treatment of spinal muscular atrophy (SMA) generated global sales of $356 million and $1.5 billion resulting in royalty revenue of $54 million and $212 million in the fourth quarter and the year ended December 31, 2025, respectively |
| o | High dose approved and launched in the EU; under review for marketing approval in U.S. (PDUFA date of April 3, 2026) |
| o | Positive high dose results from pivotal DEVOTE study published in Nature Medicine |
| • | WAINUA® (eplontersen) (WAINZUA in EU) for the treatment of adults with polyneuropathy of hereditary transthyretin-mediated amyloidosis (ATTRv-PN) generated sales of $69 million and $212 million resulting in royalty revenue of $16 million and $49 million in the fourth quarter and the year ended December 31, 2025, respectively |
| o | Launches underway in numerous regions, including the EU; recently approved in China; additional submissions in progress to expand WAINUA access globally |
| • | Bepirovirsen, a potential first-in-class medicine for chronic hepatitis B (CHB), achieved primary endpoint and demonstrated a statistically significant and clinically meaningful functional cure rate in B-Well 1 and B-Well 2 Phase 3 studies |
| o | Presentation planned for European Association for the Study of the Liver (EASL) Congress 2026, assuming acceptance |
| o | Global regulatory filings planned beginning in Q1:2026 with 2026 anticipated launch, assuming approval |
| • | Ulefnersen for the treatment of FUS-ALS granted U.S. Fast Track designation |
| • | Sapablursen for the treatment of polycythemia vera (PV) demonstrated positive Phase 2 results, which were presented at American Society of Hematology (ASH) conference; Ono advancing sapablursen into Phase 3 development |
| • | Opemalirsen for the treatment of APOL1-mediated chronic kidney disease (AMKD) granted U.S. Fast Track designation |
| Three months ended December 31, | Year ended December 31, | |||||||||||||||
| 2025 | 2024 | 2025 | 2024 | |||||||||||||
| Revenue: | (amounts in millions) | |||||||||||||||
| Commercial revenue: | ||||||||||||||||
| Product sales, net: | ||||||||||||||||
| TRYNGOLZA sales, net | $ | 50 | $ | - | $ | 108 | $ | - | ||||||||
| DAWNZERA sales, net | 7 | - | 8 | - | ||||||||||||
| Total product sales, net | 57 | - | 116 | - | ||||||||||||
| Royalty revenue: | ||||||||||||||||
| SPINRAZA royalties | 54 | 64 | 212 | 216 | ||||||||||||
| WAINUA royalties | 16 | 10 | 49 | 20 | ||||||||||||
| Other royalties | 6 | 3 | 24 | 21 | ||||||||||||
| Total royalty revenue | 76 | 77 | 285 | 257 | ||||||||||||
| Other commercial revenue | 8 | 9 | 35 | 36 | ||||||||||||
| Total commercial revenue | 141 | 86 | 436 | 293 | ||||||||||||
| Research and development revenue: | ||||||||||||||||
| Collaborative agreement revenue | 52 | 97 | 466 | 333 | ||||||||||||
| WAINUA joint development revenue | 10 | 44 | 42 | 79 | ||||||||||||
| Total research and development revenue | 62 | 141 | 508 | 412 | ||||||||||||
| Total revenue | $ | 203 | $ | 227 | $ | 944 | $ | 705 | ||||||||
| Full Year 2026 Guidance | |||
| Revenue | $800- $825 million | ||
| Operating loss on a non-GAAP basis | $500-550 million | ||
| Cash, cash equivalents and short-term investments | ~$1.6 billion |
| Three months ended December 31, | Year ended December 31, | |||||||||||||||
| 2025 | 2024 | 2025 | 2024 | |||||||||||||
| (unaudited) | ||||||||||||||||
| Revenue: | ||||||||||||||||
| Commercial revenue: | ||||||||||||||||
| Product sales, net | $ | 57 | $ | - | $ | 116 | $ | - | ||||||||
| Royalty revenue | 76 | 77 | 285 | 257 | ||||||||||||
| Other commercial revenue | 8 | 9 | 35 | 36 | ||||||||||||
| Total commercial revenue | 141 | 86 | 436 | 293 | ||||||||||||
| Research and development revenue: | ||||||||||||||||
| Collaborative agreement revenue | 52 | 97 | 466 | 333 | ||||||||||||
| WAINUA joint development revenue | 10 | 44 | 42 | 79 | ||||||||||||
| Total research and development revenue | 62 | 141 | 508 | 412 | ||||||||||||
| Total revenue | 203 | 227 | 944 | 705 | ||||||||||||
| Expenses: | ||||||||||||||||
| Cost of sales | 8 | 4 | 16 | 11 | ||||||||||||
| Research, development and patent | 280 | 245 | 916 | 902 | ||||||||||||
| Selling, general and administrative | 130 | 88 | 394 | 267 | ||||||||||||
| Total operating expenses | 418 | 337 | 1,326 | 1,180 | ||||||||||||
| Loss from operations | (215 | ) | (110 | ) | (382 | ) | (475 | ) | ||||||||
| Other income (expense): | ||||||||||||||||
| Interest expense related to the sale of future royalties | (18 | ) | (19 | ) | (73 | ) | (73 | ) | ||||||||
| Other income, net | 5 | 22 | 75 | 88 | ||||||||||||
| Loss before income tax benefit (expense) | (228 | ) | (107 | ) | (380 | ) | (460 | ) | ||||||||
| Income tax benefit (expense) | (1 | ) | 3 | (1 | ) | 6 | ||||||||||
| Net loss | $ | (229 | ) | $ | (104 | ) | $ | (381 | ) | $ | (454 | ) | ||||
| Basic and diluted net loss per share | $ | (1.41 | ) | $ | (0.66 | ) | $ | (2.38 | ) | $ | (3.04 | ) | ||||
| Shares used in computing basic and diluted net loss per share | 162 | 158 | 160 | 150 | ||||||||||||
| Three months ended December 31, | Year ended December 31, | |||||||||||||||
| 2025 | 2024 | 2025 | 2024 | |||||||||||||
| (unaudited) | ||||||||||||||||
| As reported research, development and patent expenses according to GAAP | $ | 280 | $ | 245 | $ | 916 | $ | 902 | ||||||||
| Excluding compensation expense related to equity awards | (29 | ) | (25 | ) | (90 | ) | (92 | ) | ||||||||
| Non-GAAP research, development and patent expenses | $ | 251 | $ | 220 | $ | 826 | $ | 810 | ||||||||
| As reported selling, general and administrative expenses according to GAAP | $ | 130 | $ | 88 | $ | 394 | $ | 267 | ||||||||
| Excluding compensation expense related to equity awards | (13 | ) | (11 | ) | (42 | ) | (37 | ) | ||||||||
| Non-GAAP selling, general and administrative expenses | $ | 117 | $ | 77 | $ | 352 | $ | 230 | ||||||||
| As reported operating expenses according to GAAP | $ | 418 | $ | 337 | $ | 1,326 | $ | 1,180 | ||||||||
| Excluding compensation expense related to equity awards | (43 | ) | (36 | ) | (134 | ) | (130 | ) | ||||||||
| Non-GAAP operating expenses | $ | 375 | $ | 301 | $ | 1,192 | $ | 1,050 | ||||||||
| As reported loss from operations according to GAAP | $ | (215 | ) | $ | (110 | ) | $ | (382 | ) | $ | (475 | ) | ||||
| Excluding compensation expense related to equity awards | (43 | ) | (36 | ) | (134 | ) | (130 | ) | ||||||||
| Non-GAAP loss from operations | $ | (172 | ) | $ | (74 | ) | $ | (248 | ) | $ | (345 | ) | ||||
| As reported net loss according to GAAP | $ | (229 | ) | $ | (104 | ) | $ | (381 | ) | $ | (454 | ) | ||||
| Excluding compensation expense related to equity awards and related tax effects | (43 | ) | (36 | ) | (134 | ) | (130 | ) | ||||||||
| Non-GAAP net loss | $ | (186 | ) | $ | (68 | ) | $ | (247 | ) | $ | (324 | ) | ||||
| December 31, 2025 | December 31, 2024 | |||||||
| (unaudited) | ||||||||
| Assets: | ||||||||
| Cash, cash equivalents and short-term investments | $ | 2,677 | $ | 2,298 | ||||
| Contracts receivable | 66 | 92 | ||||||
| Other current assets | 247 | 230 | ||||||
| Property, plant and equipment, net | 123 | 94 | ||||||
| Right-of-use assets | 239 | 162 | ||||||
| Other assets | 172 | 127 | ||||||
| Total assets | $ | 3,524 | $ | 3,003 | ||||
| | ||||||||
| Liabilities and stockholders’ equity: | ||||||||
| Current portion of deferred contract revenue | $ | 74 | $ | 79 | ||||
| 0% convertible senior notes due 2026, net – current | 432 | - | ||||||
| Other current liabilities | 277 | 229 | ||||||
| 0% convertible senior notes due 2030, net | 751 | - | ||||||
| 1.75% convertible senior notes due 2028, net | 568 | 565 | ||||||
| 0% convertible senior notes due 2026, net | - | 629 | ||||||
| Liability related to sale of future royalties, net | 551 | 542 | ||||||
| Long-term lease liabilities | 262 | 162 | ||||||
| Long-term obligations, less current portion | 28 | 52 | ||||||
| Long-term deferred contract revenue | 92 | 157 | ||||||
| Total stockholders’ equity | 489 | 588 | ||||||
| Total liabilities and stockholders’ equity | $ | 3,524 | $ | 3,003 | ||||
| New Product Launches | |||||
| Program | Indication | Location | |||
| DAWNZERA | HAE | EU | Achieved | ||
| Olezarsen | sHTG | U.S. | • | ||
| Zilganersen | Alexander disease | U.S. | • | ||
| Bepirovirsen | CHB | U.S. & Japan | • | ||
| Regulatory Actions | ||||||
| Program | Indication | Regulatory Action | ||||
| Donidalorsen | HAE | EU approval decision | Achieved | |||
| Olezarsen | sHTG | U.S. approval decision | • | |||
| EU submission | • | |||||
| Zilganersen | Alexander disease | U.S. submission | • | |||
| U.S. approval decision | • | |||||
| Nusinersen (high dose) | SMA | EU approval decision | Achieved | |||
| U.S. approval decision | • | |||||
| Eplontersen | ATTR-CM | Regulatory submission(s) | • | |||
| Bepirovirsen | HBV | Regulatory submission(s) | • | |||
| Regulatory decision(s) | • | |||||
| Pelacarsen | Lp(a)- CVD | U.S. submission | • | |||
| Key Phase 3 Clinical Events | ||||||
| Program | Indication | Event | ||||
| Obudanersen | Angelman syndrome | Phase 3 enrollment completion | • | |||
| Bepirovirsen | HBV | B-Well data | Achieved | |||
| Pelacarsen | Lp(a)-CVD | Lp(a) HORIZON data | • | |||
| Eplontersen | ATTR-CM | CARDIO-TTRansform data | • | |||
| Sefaxersen | IgAN | IMAGINATION data | • | |||
| Ulefnersen | FUS-ALS | FUSION data | • | |||
| Salanersen | SMA | Phase 3 initiation | • | |||
| Sapablursen | Polycythemia Vera | Phase 3 initiation | • | |||
| Key Phase 2 Clinical Events | ||||||
| Program | Indication | Event | ||||
| IONIS-MAPTRx/ BIIB080 | Alzheimer’s disease | Phase 2 CELIA data | • | |||
| Tominersen | Huntington’s disease | Phase 2 GENERATION HD2 data | • | |||
| Tonlamarsen | Uncontrolled hypertension | Phase 2 data | • | |||
| (1) | Timing expectations based on current assumptions and subject to change. |
| • | Indicates that the milestone is anticipated in 2026. |