Form 8-K

8-K — IONIS PHARMACEUTICALS INC

Accession: 0001140361-26-017637

Filed: 2026-04-29

Period: 2026-04-29

CIK: 0000874015

SIC: 2834 (PHARMACEUTICAL PREPARATIONS)

Item: Results of Operations and Financial Condition

Item: Financial Statements and Exhibits

Documents

8-K — ef20071749_8k.htm (Primary)

EX-99.1 — EXHIBIT 99.1 (ef20071749_ex99-1.htm)

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8-K

8-K (Primary)

Filename: ef20071749_8k.htm · Sequence: 1

false000087401500008740152026-04-292026-04-29

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): April 29, 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 April 29, 2026, Ionis Pharmaceuticals, Inc. (the “Company”) issued a press release announcing

the Company’s financial results for the quarter ended March 31, 2026. 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 related to equity awards 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 April 29, 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: April 29, 2026

By:

/s/ Patrick R. O’Neil

Patrick R. O’Neil

Executive Vice President, Chief Legal Officer and General Counsel

EX-99.1 — EXHIBIT 99.1

EX-99.1

Filename: ef20071749_ex99-1.htm · Sequence: 2

Exhibit 99.1

Ionis reports first quarter 2026 financial results and highlights progress on key programs

- TRYNGOLZA® (olezarsen) showed increasing demand in FCS driven by strong launch execution –

- Olezarsen sNDA accepted by the FDA for Priority Review; sHTG

launch preparations on track –

– Increasing annual TRYNGOLZA peak net sales guidance to >$3B for sHTG –

- Zilganersen NDA for Alexander disease accepted for Priority

Review, paving way for Ionis’ first independent launch from leading neurology pipeline –

- Strong first-quarter performance and outlook for the year supports improved 2026 financial guidance -

CARLSBAD, Calif., April 29, 2026 – Ionis Pharmaceuticals, Inc. (Nasdaq: IONS) (the “Company”) today reported financial results and provided key updates for the first quarter ended March 31, 2026.

“Ionis’ strong performance in the first quarter of 2026 underscores the strength of our commercial and R&D engines. Our independent launches are increasingly

contributing to revenue, driven by strong commercial execution, and we are on track for two additional groundbreaking independent launches in 2026 — olezarsen for severe hypertriglyceridemia, our first medicine for a broad patient population, and

zilganersen for Alexander disease, the first launch from our leading neurology pipeline,” said Brett P. Monia, Ph.D., chief executive officer of Ionis. “In addition, we look forward to multiple key value-driving events this year, including results

from pivotal Phase 3 partnered programs. These include presentation of positive bepirovirsen data in chronic hepatitis B next month at EASL, as well as results from the landmark pelacarsen Lp(a) HORIZON and eplontersen CARDIO-TTRansform

cardiovascular outcomes trials later this year.”

First Quarter 2026 Summary Financial Results(1):

Three months

ended

March 31,

2026

2025

(amounts in

millions)

Total revenue

246

132

Operating expenses

364

278

Operating expenses on a non-GAAP basis

321

249

Loss from operations

(118

)

(146

)

Loss from operations on a non-GAAP basis

(75

)

(117

)

(1)

Reconciliation of GAAP to non-GAAP basis contained later in this release.

First Quarter 2026 Financial Highlights

•

Revenue increased 87% in the first quarter of 2026 compared to the same period last year, driven by continued commercial success. In addition, Ionis earned substantial R&D revenue, including $95 million in payments from both clinical

and regulatory milestones from multiple partnerships

•

Operating expenses for the quarter ended March 31, 2026 were in line with expectations and increased year over year primarily from investments related to the commercialization efforts for TRYNGOLZA and DAWNZERA as well as launch

preparations for olezarsen in sHTG and zilganersen in Alexander disease

•

Cash and short-term investments were $1.9 billion as of March 31, 2026. The change in cash and short-term investments from year end 2025 was primarily related to the $633 million the Company used for the maturity of the 0% convertible

notes due on April 1, 2026

•

Increasing annual olezarsen peak net sales guidance to >$3 billion from >$2 billion to reflect increasing confidence in the sHTG market opportunity for olezarsen

First Quarter 2026 Financial Results

“Ionis entered 2026 with strong momentum. We continued this momentum with the first quarter financial results reflecting increased commercial revenue from our

independent launches and robust R&D revenue when compared to the same period last year,” said Elizabeth L. Hougen, chief financial officer of Ionis. “Based on our strong year-to-date revenue performance, accelerating momentum and positive

outlook for the rest of the year, we are improving our 2026 financial guidance. The strong performance we expect in 2026 will support substantial growth and long-term value creation and our goal of reaching cash-flow breakeven in 2028.”

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

Generated U.S. net product sales of $27 million in the first quarter of 2026, reflecting continued strong demand, offset by a decrease in net price

Launch initiated in the European Union (EU) by Sobi

•

Olezarsen on track to launch this year as a transformational medicine for severe hypertriglyceridemia (sHTG), assuming approval

sNDA accepted by the FDA for Priority Review for the treatment of sHTG with a Prescription Drug User Fee Act (PDUFA) target action date of June 30, 2026

The European Medicines Agency (EMA) accepted an indication extension application in March for the treatment of adult patients with sHTG

•

DAWNZERA™ (donidalorsen), the first and only RNA-targeted prophylactic therapy for hereditary angioedema (HAE) in patients 12 years of age and older

Generated U.S. net product sales of $16 million in the first quarter of 2026, an increase of 125% versus the fourth quarter of 2025

Launch initiated in the EU by Otsuka

Positive one-year results from OASISplus open-label extension cohort published in the Journal of Asthma and Allergy

•

Zilganersen on track to launch this year as the first and only medicine to demonstrate clinically meaningful and disease-modifying benefit in children and adults with Alexander disease (AxD), assuming approval

New Drug Application (NDA) for AxD accepted by FDA for Priority Review with PDUFA target action date of September 22, 2026

Expanded access program (EAP) in U.S. underway

Positive additional results from the pivotal study presented at the American Academy of Neurology 2026 annual meeting

Recent Highlights – Partnered Medicines

•

SPINRAZA® (nusinersen) for the treatment of spinal muscular atrophy (SMA) generated global sales of $374

million in the first quarter of 2026, resulting in royalty revenue of $44 million

SPINRAZA high dose regimen approved and launched in the U.S. and EU

•

WAINUA® (eplontersen) (WAINZUA in EU) for the treatment of adults

with polyneuropathy of hereditary transthyretin-mediated amyloidosis (ATTRv-PN) generated global sales of $51 million in the first quarter of 2026, resulting in royalty revenue of $11 million

Launches underway in numerous regions, including the EU and China; submissions in progress to expand WAINUA access globally

Phase 3 CARDIO-TTRansform study design and baseline characteristics to be presented at the Annual Congress of the Heart Failure Association of the ESC 2026

•

Bepirovirsen, a potential first-in-class medicine for chronic hepatitis B (CHB), achieved the primary endpoint demonstrating a statistically significant and clinically meaningful functional cure rate in the B-Well 1 and B-Well 2 Phase 3

studies

GSK to present the positive Phase 3 data at the European Association for the Study of the Liver (EASL) Congress 2026

On track for a 2026 launch with global regulatory filings underway, assuming approval

■

NDA filing accepted by FDA for Priority Review with PDUFA date of October 26, 2026; granted Breakthrough Therapy designation

■

Accepted for regulatory review in EU, Japan, and China

Revenue

Ionis’ revenue was comprised of the following:

Three months ended

March 31,

2026

2025

Revenue

(amounts in millions)

Commercial revenue:

Product sales, net:

TRYNGOLZA sales, net

DAWNZERA sales, net

Total product sales, net

Royalty revenue:

SPINRAZA royalties

WAINUA royalties

Other royalties

Total royalty revenue

Other commercial revenue

Total commercial revenue

108

Research and development revenue:

Collaborative agreement revenue

120

WAINUA joint development revenue

Total research and development revenue

138

Total revenue

246

132

Commercial revenue for the first quarter ended March 31, 2026, increased 42%, compared to the same period in 2025. This increase was primarily driven by TRYNGOLZA and

DAWNZERA product sales. Higher research and development revenue also contributed to the year-over-year revenue increase including approximately $95 million in milestone payments from multiple partnerships.

Operating Expenses

Operating expenses for the first quarter ended March 31, 2026, were driven from investments primarily related to commercialization efforts for TRYNGOLZA and DAWNZERA

as well as launch preparations for olezarsen in sHTG and zilganersen in Alexander disease.

Balance Sheet

As of March 31, 2026, Ionis’ cash, cash equivalents and short-term investments decreased to $1.9 billion, compared to $2.7 billion on December 31, 2025. At March 31,

2026, Ionis had an escrow deposit of $633 million, which the Company used for the maturity of its 0% convertible notes due on April 1, 2026.

2026 Financial Guidance

Ionis improved its 2026 financial guidance to reflect the strong revenue performance experienced year-to-date and the Company’s outlook for the balance of 2026.

Overall, the Company increased total revenue and decreased operating loss both by $75 million. The improvements were driven by Priority Review for TRYNGOLZA, strong first quarter R&D revenue and the anticipated continued success of the

Company’s ongoing commercial launches.

Full Year 2026 Guidance

Guidance

New

Guidance

Total Revenue

$800-825 million

$875-900 million

TRYNGOLZA product sales, net

$100-110 million

DAWNZERA product sales, net

$110-120 million

Operating loss on a non-GAAP basis

$500-550 million

$425-475 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’ first quarter 2026 results at 8:30 a.m. Eastern time on Wednesday, April 29, 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 first quarter 2026 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.

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 DAWNZERATM (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).

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, 2025, 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. DAWNZERATM

is a trademark of Ionis Pharmaceuticals, Inc. AKCEATM is a trademark of Akcea Therapeutics, Inc. TEGSEDITM is a trademark of Akcea Therapeutics, Inc. WAYLIVRATM 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

IONIS PHARMACEUTICALS, INC.

SELECTED FINANCIAL INFORMATION

Condensed Consolidated Statements of Operations

(In Millions, Except Per Share Data)

Three months ended

March 31,

2026

2025

(unaudited)

Revenue:

Commercial revenue:

Product sales, net

Royalty revenue

Other commercial revenue

Total commercial revenue

108

Research and development revenue:

Collaborative agreement revenue

120

WAINUA joint development revenue

Total research and development revenue

138

Total revenue

246

132

Expenses:

Cost of sales

Research, development and patent

210

201

Selling, general and administrative

151

Total operating expenses

364

278

Loss from operations

(118

)

(146

)

Other income (expense):

Interest expense related to the sale of future royalties

(17

)

(19

)

Other income, net

Loss before income tax expense

(93

)

(147

)

Income tax expense

Net loss

(93

)

(147

)

Basic and diluted net loss per share

(0.56

)

(0.93

)

Shares used in computing basic and diluted net loss per share

165

159

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

March 31,

2026

2025

(unaudited)

As reported cost of sales according to GAAP

Excluding compensation expense related to equity awards (1)

Non-GAAP cost of sales

As reported research, development and patent expenses according to GAAP

210

201

Excluding compensation expense related to equity awards

(25

)

(20

)

Non-GAAP research, development and patent expenses

185

181

As reported selling, general and administrative expenses according to GAAP

151

Excluding compensation expense related to equity awards

(18

)

Non-GAAP selling, general and administrative expenses

133

As reported operating expenses according to GAAP

364

278

Excluding compensation expense related to equity awards

(43

)

(29

)

Non-GAAP operating expenses

321

249

As reported loss from operations according to GAAP

(118

)

(146

)

Excluding compensation expense related to equity awards

(43

)

(29

)

Non-GAAP loss from operations

(75

)

(117

)

As reported net loss according to GAAP

(93

)

(147

)

Excluding compensation expense related to equity awards and related tax effects

(43

)

(29

)

Non-GAAP net loss

(50

)

(118

)

(1)

Amounts appear as zero due to rounding in millions.

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.

IONIS PHARMACEUTICALS, INC.

Condensed Consolidated Balance Sheets

(In Millions)

March 31,

December 31,

2026

2025

(unaudited)

Assets:

Cash, cash equivalents and short-term investments

1,919

2,677

Escrow deposits

633

Contracts receivable

Other current assets

312

247

Property, plant and equipment, net

142

123

Right-of-use assets

235

239

Other assets

135

172

Total assets

3,450

3,524

Liabilities and stockholders’ equity:

Current portion of deferred contract revenue

0% convertible senior notes due April 2026 – current

433

432

Other current liabilities

215

277

0% convertible senior notes due 2030, net

752

751

1.75% convertible senior notes due 2028, net

569

568

Liability related to sale of future royalties, net

558

551

Long-term lease liabilities

259

262

Long-term obligations, less current portion

Long-term deferred contract revenue

Total stockholders’ equity

491

489

Total liabilities and stockholders’ equity

3,450

3,524

Key 2026 Value Driving Events(1)

New Product Launches

Program

Indication

Location

DAWNZERA

HAE

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

Achieved

Zilganersen

Alexander disease

U.S. submission

Achieved

U.S. approval decision

•

Nusinersen

(high dose)

SMA

EU approval decision

Achieved

U.S. approval decision

Achieved

Eplontersen

ATTR-CM

Regulatory submission(s)

•

Bepirovirsen

HBV

Regulatory submission(s)

Achieved

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

Achieved

(1)

Timing expectations based on current assumptions and subject to change.

•

Indicates that the milestone is anticipated in 2026.

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- Definition

Address Line 1 such as Attn, Building Name, Street Name

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No definition available.

+ Details

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- Definition

Name of the City or Town

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No definition available.

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Balance Type:

Period Type:

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- Definition

Code for the postal or zip code

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No definition available.

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- Definition

Name of the state or province.

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No definition available.

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Name:

dei_EntityAddressStateOrProvince

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- Definition

A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

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- Definition

Indicate if registrant meets the emerging growth company criteria.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

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Name:

dei_EntityEmergingGrowthCompany

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- Definition

Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

+ References

No definition available.

+ Details

Name:

dei_EntityFileNumber

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duration

- Definition

Two-character EDGAR code representing the state or country of incorporation.

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No definition available.

+ Details

Name:

dei_EntityIncorporationStateCountryCode

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Data Type:

dei:edgarStateCountryItemType

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- Definition

The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

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Name:

dei_EntityRegistrantName

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- Definition

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

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Name:

dei_EntityTaxIdentificationNumber

Namespace Prefix:

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- Definition

Local phone number for entity.

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No definition available.

+ Details

Name:

dei_LocalPhoneNumber

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- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 13e

-Subsection 4c

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Name:

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Namespace Prefix:

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Data Type:

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Balance Type:

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- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14d

-Subsection 2b

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Name:

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Namespace Prefix:

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- Definition

Title of a 12(b) registered security.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b

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Name:

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Data Type:

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Balance Type:

Period Type:

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- Definition

Name of the Exchange on which a security is registered.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection d1-1

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Name:

dei_SecurityExchangeName

Namespace Prefix:

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Data Type:

dei:edgarExchangeCodeItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14a

-Subsection 12

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Name:

dei_SolicitingMaterial

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Data Type:

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Period Type:

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- Definition

Trading symbol of an instrument as listed on an exchange.

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No definition available.

+ Details

Name:

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Namespace Prefix:

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Balance Type:

Period Type:

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- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Securities Act

-Number 230

-Section 425

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