Ionis (NASDAQ: IONS) details 2025 results and 2026 financial outlook

Rhea-AI Filing Summary

Ionis Pharmaceuticals reported fourth-quarter and full-year 2025 results and issued 2026 guidance. Full-year revenue rose to $944 million from $705 million, driven by commercial growth and R&D collaboration revenue, including a $280 million upfront payment for sapablursen licensing.

TRYNGOLZA generated $108 million in 2025 net product sales in its first launch year, helping lift commercial revenue 49% year over year. Despite this growth, the company posted a 2025 GAAP net loss of $381 million and a non-GAAP operating loss of $248 million, both improved versus 2024.

Cash, cash equivalents and short-term investments increased to $2.7 billion as of December 31, 2025, aided by convertible debt refinancing. For 2026, Ionis guides to $800–$825 million in revenue, a non-GAAP operating loss of $500–$550 million, and year-end liquidity of about $1.6 billion, while continuing to invest in multiple independent launches and a broad late-stage pipeline.

Insights

Biotech equity analyst

Ionis shows strong 2025 revenue growth but guides to continued investment-driven losses in 2026.

Ionis delivered full-year 2025 revenue of $944 million, up from $705 million, with commercial revenue rising 49% as TRYNGOLZA contributed $108 million in its first year and DAWNZERA began to add sales. A $280 million sapablursen upfront payment also boosted R&D revenue.

Profitability remains negative, though trends improved. GAAP net loss narrowed to $381 million from $454 million, and non-GAAP operating loss to $248 million from $345 million, even as operating expenses increased to support independent launches and pipeline development.

Guidance for 2026—revenue of $800–$825 million and a non-GAAP operating loss of $500–$550 million—reflects the absence of the $280 million one-time sapablursen payment and higher commercial investments. Management highlights cash, cash equivalents and short-term investments of $2.7 billion at year-end 2025 and targets cash flow breakeven in 2028, contingent on execution of launches and late-stage programs.

false000087401500008740152026-02-252026-02-25

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of report (Date of earliest event reported):  February 25, 2026

IONIS PHARMACEUTICALS, INC.

(Exact Name of Registrant as Specified in Charter)

Delaware

(State or Other Jurisdiction of Incorporation)

000-19125		33-0336973
(Commission File No.)		(IRS Employer Identification No.)

2855 Gazelle Court

Carlsbad, CA 92010

(Address of Principal Executive Offices and Zip Code)

Registrant’s telephone number, including area code: (760) 931-9200

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐
Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading symbol		Name of each exchange on which registered
Common Stock, $.001 Par Value		“IONS”		The Nasdaq Stock Market, LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (Section 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (Section 240.12b-2 of this chapter).

  Emerging growth company                ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.   ☐

Item 2.02 Results of Operations and Financial Condition.

On February 25, 2026, Ionis Pharmaceuticals, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter and fiscal year ended December 31, 2025.  In addition to disclosing results that are determined in accordance with Generally Accepted Accounting Principles (“GAAP”), the Company also discloses pro forma or non-GAAP results of operations, which are adjusted from GAAP to exclude non-cash compensation expense related to equity awards and the related tax effects. The Company is presenting pro forma information excluding non-cash compensation expense and the related tax effects because the Company believes it better enables financial statement users to assess and compare its historical performance and project its future operating results and cash flows.  A copy of the release is furnished with this report as an exhibit pursuant to “Item 2.02. Results of Operations and Financial Condition” of Form 8-K in accordance with SEC Release Nos. 33-8216 and 34-47583.

The information in this Current Report on Form 8-K and the Exhibit attached hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933 or the Exchange Act, regardless of any general incorporation language in such filing.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.	Description
99.1	Press Release dated February 25, 2026.
104	Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	Ionis Pharmaceuticals, Inc.
Dated:  February 25, 2026	By:	/s/ Patrick R. O’Neil
		Patrick R. O’Neil
		Executive Vice President, Chief Legal Officer and General Counsel

Exhibit 99.1

Ionis reports fourth quarter and full year 2025 financial results and highlights progress on key programs

- TRYNGOLZA^® generated $108 million in net product sales in 2025, the first year of launch –

- Olezarsen sHTG launch preparations on track, sNDA submitted -

- Exceeded 2025 financial guidance, 2026 guidance reflects commitment to independently deliver a steady cadence of innovative medicines to patients -

CARLSBAD, Calif., February 25, 2026 – Ionis Pharmaceuticals, Inc. (Nasdaq: IONS) (the “Company”) today reported financial results and provided key updates for the fourth quarter and year ended December 31, 2025.

“2025 was a defining year for Ionis, marked by the successful execution of our first two independent launches and multiple positive data readouts across our pipeline, positioning Ionis for continued success in 2026,” said Brett P. Monia, Ph.D., chief executive officer of Ionis. “This year, we are poised for two additional independent launches of groundbreaking therapies — olezarsen for severe hypertriglyceridemia, our first launch in a broad patient population, and zilganersen for Alexander disease, our first launch from our leading neurology pipeline. Our partnered pipeline is also on track for multiple groundbreaking Phase 3 readouts, beginning with the recent positive data for bepirovirsen in chronic hepatitis B to be followed by two cardiovascular outcome trials — the pelacarsen Lp(a) HORIZON trial mid-year 2026 and the eplontersen CARDIO-TTRansform trial in the second half of 2026. Together, this progress positions Ionis to continue delivering a steady cadence of transformative medicines to people living with serious diseases, fueling substantial growth and long-term value creation.”

Fourth Quarter and Full Year 2025 Summary Financial Results⁽¹⁾:

		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.

1

Recent Financial Highlights

• 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

Fourth Quarter and Full Year 2025 Financial Results

“In 2025 we exceeded our revenue guidance, driven by growing commercial revenue from our independent launches and substantial R&D revenue from continued pipeline success,” said Elizabeth L. Hougen, chief financial officer of Ionis. “In 2026, we will continue to invest in go-to-market activities to support our ongoing and upcoming independent launches, including the recent expansion of our top-tier sales force ahead of our expected olezarsen sHTG launch. We anticipate growth in product revenues, together with additional royalties, to position Ionis to achieve cash flow breakeven in 2028 and generate substantial and sustainable positive cash flow for years to come.”

Recent Highlights - Wholly Owned Medicines

• 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

2

• 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

Recent Highlights – Partnered Medicines

• 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

3

Revenue

Ionis’ revenue was comprised of the following:

		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

Commercial revenue for the fourth quarter and the year ended December 31, 2025, increased 64% and 49%, respectively, compared to the same periods in 2024. This increase was primarily driven by TRYNGOLZA product sales. Higher royalty revenue also contributed to the year over year increase.

The remainder of the Company’s revenue came from programs under its R&D collaborations, including a $280 million upfront payment for the global license of sapablursen to Ono Pharmaceutical Co., Ltd. in the second quarter of 2025, reflecting the value that Ionis’ pipeline and technology continue to generate.

Operating Expenses

Operating expenses increased modestly for the fourth quarter and the year ended December 31, 2025, which was in line with expectations. The increase was driven by investments to support the launches of TRYNGOLZA, DAWNZERA and WAINUA.

Balance Sheet

As of December 31, 2025, Ionis’ cash, cash equivalents and short-term investments increased to $2.7 billion, compared to $2.3 billion on December 31, 2024, primarily due to the refinancing proceeds Ionis received from its convertible debt issuance in the fourth quarter, which Ionis plans to use to repay its 2026 Convertible Notes.

4

2026 Financial Guidance

The Company’s 2026 financial guidance reflects its evolution to a fully integrated commercial-stage biotechnology company independently launching multiple medicines and advancing commercialization efforts for additional upcoming planned launches. As a result, the Company expects to earn substantial revenue from numerous diverse sources, including increasing commercial revenue. The Company is currently awaiting acceptance of its olezarsen sNDA submission, as such the Company’s 2026 financial guidance assumes a standard review timeline. With acceptance anticipated shortly, the Company expects to provide TRYNGOLZA and DAWNZERA product level guidance at its first quarter 2026 earnings. The Company expects a modest increase in its non-GAAP operating expenses in line with its plan to invest in independent launches and advance its wholly owned pipeline of innovative medicines. The Company expects that these investments will enable Ionis to deliver accelerating value. Overall, the Company anticipates total revenue to grow approximately 20 percent year over year and its non-GAAP operating loss to be similar to 2025, excluding the one-time sapablursen upfront payment recognized in 2025.

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

Webcast and Other Updates

Management will host a conference call and webcast to discuss Ionis’ fourth quarter and full year 2025 results at 8:30 a.m. Eastern time on Wednesday, February 25, 2026. Interested parties may access the webcast here. A webcast replay will be available for a limited time at the same address. To access the Company’s fourth quarter and full year 2025 earnings slides click here.

Ionis’ Marketed Medicines

INDICATION for TRYNGOLZA^® (olezarsen)

TRYNGOLZA^® (olezarsen) was approved by the U.S. Food and Drug Administration as an adjunct to diet to reduce triglycerides in adults with familial chylomicronemia syndrome (FCS).

IMPORTANT SAFETY INFORMATION

CONTRAINDICATIONS

TRYNGOLZA is contraindicated in patients with a history of serious hypersensitivity to TRYNGOLZA or any of the excipients in TRYNGOLZA. Hypersensitivity reactions requiring medical treatment have occurred.

WARNINGS AND PRECAUTIONS

Hypersensitivity Reactions

Hypersensitivity reactions (including symptoms of bronchospasm, diffuse erythema, facial swelling, urticaria, chills and myalgias) have been reported in patients treated with TRYNGOLZA. Advise patients on the signs and symptoms of hypersensitivity reactions and instruct patients to promptly seek medical attention and discontinue use of TRYNGOLZA if hypersensitivity reactions occur.

5

ADVERSE REACTIONS

The most common adverse reactions (incidence >5% of TRYNGOLZA-treated patients and >3% higher frequency than placebo) were injection site reactions, decreased platelet count and arthralgia.

Please see full Prescribing Information for TRYNGOLZA.

INDICATION for DAWNZERA^TM (donidalorsen)

DAWNZERA™ (donidalorsen) was approved by the U.S. Food and Drug Administration for prophylaxis to prevent attacks of hereditary angioedema (HAE) in adult and pediatric patients 12 years of age and older.

IMPORTANT SAFETY INFORMATION

CONTRAINDICATIONS

DAWNZERA is contraindicated in patients with a history of serious hypersensitivity reactions, including anaphylaxis, to donidalorsen or any of the excipients in DAWNZERA.

WARNINGS AND PRECAUTIONS

Hypersensitivity Reactions

Hypersensitivity reactions, including anaphylaxis, have been reported in patients treated with DAWNZERA. If signs and symptoms of serious hypersensitivity reactions occur, discontinue DAWNZERA and institute appropriate therapy.

ADVERSE REACTIONS

Most common adverse reactions (incidence ≥ 5%) are injection site reactions, upper respiratory tract infection, urinary tract infection, and abdominal discomfort.

Please see full Prescribing Information for DAWNZERA.

INDICATION for WAINUA^® (eplontersen)

WAINUA injection, for subcutaneous use, 45 mg is indicated for the treatment of the polyneuropathy of hereditary transthyretin-mediated amyloidosis in adults.

IMPORTANT SAFETY INFORMATION for WAINUA^® (eplontersen)

WARNINGS AND PRECAUTIONS

Reduced Serum Vitamin A Levels and Recommended Supplementation WAINUA leads to a decrease in serum vitamin A levels. Supplement with recommended daily allowance of vitamin A. Refer patient to an ophthalmologist if ocular symptoms suggestive of vitamin A deficiency occur.

ADVERSE REACTIONS

Most common adverse reactions (≥9% in WAINUA-treated patients) were vitamin A decreased (15%) and vomiting (9%).

Please see link to U.S. Full Prescribing Information for WAINUA.

For more information about SPINRAZA and QALSODY, visit https://www.spinraza.com/ and https://www.qalsody.com/, respectively. QALSODY is approved under accelerated approval based on reduction in plasma neurofilament light chain (NfL) observed in patients treated with QALSODY. Continued approval may be contingent upon verification of clinical benefit in confirmatory trial(s).

6

About Ionis Pharmaceuticals, Inc.

For three decades, Ionis has invented medicines that bring better futures to people with serious diseases. Ionis currently has marketed medicines and a leading pipeline in neurology, cardiometabolic disease and select areas of high patient need. As the pioneer in RNA-targeted medicines, Ionis continues to drive innovation in RNA therapies in addition to advancing new approaches in gene editing. A deep understanding of disease biology and industry-leading technology propels our work, coupled with a passion and urgency to deliver life-changing advances for patients. To learn more about Ionis, visit Ionis.com and follow us on X (Twitter), LinkedIn and Instagram.

Ionis Forward-looking Statements

This press release includes forward-looking statements regarding Ionis’ business, financial guidance and the therapeutic and commercial potential of our commercial medicines, additional medicines in development, technologies and our expectations regarding development and regulatory milestones. Any statement describing Ionis’ goals, expectations, financial or other projections, intentions or beliefs is a forward-looking statement and should be considered an at-risk statement. Such statements are subject to certain risks and uncertainties including those inherent in the process of discovering, developing and commercializing medicines that are safe and effective for use as human therapeutics, and in the endeavor of building a business around such medicines. Ionis’ forward-looking statements also involve assumptions that, if they never materialize or prove correct, could cause its results to differ materially from those expressed or implied by such forward-looking statements. Although Ionis’ forward-looking statements reflect the good faith judgment of its management, these statements are based only on facts and factors currently known by Ionis. Except as required by law, we undertake no obligation to update any forward-looking statements for any reason. As a result, you are cautioned not to rely on these forward-looking statements. These and other risks concerning Ionis’ programs are described in additional detail in Ionis’ annual report on Form 10-K for the year ended December 31, 2024, and most recent Form 10-Q, which are on file with the Securities and Exchange Commission. Copies of these and other documents are available from the Company.

In this press release, unless the context requires otherwise, “Ionis,” “Company,” “we,” “our” and “us” all refer to Ionis Pharmaceuticals and its subsidiaries.

IONIS^® is a registered trademark of Ionis Pharmaceuticals, Inc. TRYNGOLZA^® is a registered trademark of Ionis Pharmaceuticals, Inc. DAWNZERA^TM is a trademark of Ionis Pharmaceuticals, Inc. AKCEA^TM is a trademark of Akcea Therapeutics, Inc. TEGSEDI^TM is a trademark of Akcea Therapeutics, Inc. WAYLIVRA^TM is a trademark of Akcea Therapeutics, Inc. SPINRAZA^® and QALSODY^® are registered trademarks of Biogen. WAINUA^® is a registered trademark of the AstraZeneca group of companies.

Ionis Investor Contact:

D. Wade Walke, Ph.D.

IR@ionis.com

760-603-2331

Ionis Media Contact:

Hayley Soffer

media@ionis.com

760-603-4679

7

IONIS PHARMACEUTICALS, INC.

SELECTED FINANCIAL INFORMATION

Condensed Consolidated Statements of Operations

(In Millions, Except Per Share Data)

		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

8

IONIS PHARMACEUTICALS, INC.

Reconciliation of GAAP to Non-GAAP Basis:

Condensed Consolidated Operating Expenses, Loss From Operations, and Net Loss

(In Millions)

		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	)

Reconciliation of GAAP to Non-GAAP Basis

As illustrated in the Selected Financial Information in this press release, non-GAAP operating expenses, non-GAAP loss from operations, and non-GAAP net loss were adjusted from GAAP to exclude compensation expense related to equity awards and the related tax effects. Compensation expense related to equity awards are non-cash. These measures are provided as supplementary information and are not a substitute for financial measures calculated in accordance with GAAP. Ionis reports these non-GAAP results to better enable financial statement users to assess and compare its historical performance and project its future operating results and cash flows. Further, the presentation of Ionis’ non-GAAP results is consistent with how Ionis’ management internally evaluates the performance of its operations.

9

IONIS PHARMACEUTICALS, INC.

Condensed Consolidated Balance Sheets

(In Millions)

		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

10

Key 2026 Value Driving Events⁽¹⁾

	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.

#   #   #

11

FAQ

How did Ionis Pharmaceuticals (IONS) perform financially in full-year 2025?

Ionis reported full-year 2025 revenue of $944 million, up from $705 million in 2024, driven by commercial growth and collaboration revenue. GAAP net loss improved to $381 million from $454 million, and non-GAAP operating loss narrowed to $248 million from $345 million.

What were the key commercial revenue drivers for Ionis Pharmaceuticals (IONS) in 2025?

Commercial revenue reached $436 million in 2025, a 49% increase over 2024. New launch TRYNGOLZA generated $108 million in net product sales, DAWNZERA added $8 million, and royalty revenue from products like SPINRAZA and WAINUA totaled $285 million.

What 2026 financial guidance did Ionis Pharmaceuticals (IONS) provide?

For 2026, Ionis guides to revenue of $800–$825 million, a non-GAAP operating loss of $500–$550 million, and year-end cash, cash equivalents and short-term investments of about $1.6 billion, reflecting continued investment in independent launches and its wholly owned pipeline.

How did Ionis Pharmaceuticals’ (IONS) cash position and debt change by December 31, 2025?

As of December 31, 2025, cash, cash equivalents and short-term investments increased to $2.677 billion from $2.298 billion. The company issued new 0% convertible senior notes due 2030, while planning to use refinancing proceeds to repay its 2026 convertible notes.

What non-GAAP metrics does Ionis Pharmaceuticals (IONS) highlight, and why?

Ionis reports non-GAAP operating expenses, loss from operations, and net loss by excluding non-cash compensation expense related to equity awards and related tax effects. Management believes these non-GAAP measures help users better assess historical performance and project future operating results and cash flows.

How did Ionis Pharmaceuticals’ (IONS) quarterly 2025 results compare year over year?

For the quarter ended December 31, 2025, Ionis generated $203 million in revenue versus $227 million a year earlier. Quarterly GAAP loss from operations widened to $215 million from $110 million, while non-GAAP loss from operations increased to $172 million from $74 million.

Filing Exhibits & Attachments

4 documents

Press Releases

• EX-99.1 EXHIBIT 99.1 442.8 KB

Other Documents

• EX-101 XBRL TAXONOMY EXTENSION SCHEMA 3.8 KB
• EX-101 XBRL TAXONOMY EXTENSION LABEL LINKBASE 21.5 KB
• EX-101 XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE 15.7 KB