# EDGAR Filing Document

**Accession Number:** 0000874015
**File Stem:** 0001140361-26-000435
**Filing Date:** 2026-1
**Character Count:** 19335
**Document Hash:** 3b23ddb476de380cda7e99a5e38911d2
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001140361-26-000435.hdr.sgml**: 20260107

**ACCESSION NUMBER**: 0001140361-26-000435

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 14

**CONFORMED PERIOD OF REPORT**: 20260107

**ITEM INFORMATION**: Regulation FD Disclosure

**ITEM INFORMATION**: Other Events

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260107

**DATE AS OF CHANGE**: 20260107

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** IONIS PHARMACEUTICALS INC
- **CENTRAL INDEX KEY:** 0000874015
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 330336973
- **STATE OF INCORPORATION:** CA
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-19125
- **FILM NUMBER:** 26513876

**BUSINESS ADDRESS:**
- **STREET 1:** 2855 GAZELLE COURT
- **CITY:** CARLSBAD
- **STATE:** CA
- **ZIP:** 92010
- **BUSINESS PHONE:** 7609319200

**MAIL ADDRESS:**
- **STREET 1:** 2855 GAZELLE COURT
- **CITY:** CARLSBAD
- **STATE:** CA
- **ZIP:** 92010

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ISIS PHARMACEUTICALS INC
- **DATE OF NAME CHANGE:** 19930328

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### UNITED STATES 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): January 7, 2026

## IONIS PHARMACEUTICALS, INC.
(Exact Name of Registrant as Specified in Charter)

#### Delaware
(State or Other Jurisdiction of Incorporation)

---

| | |
|:---|:---|
| **000-19125**<br>| **33-0336973**<br>|
| (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**

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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:

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| | | |
|:---|:---|:---|
| Title of each class | Trading symbol | Name of each exchange on which registered |
| Common Stock, $.001 Par Value<br>| "IONS"<br>| The Nasdaq Stock Market, LLC<br>|

---

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.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ☐

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| | |
|:---|:---|
| **Item 7.01** | **Regulation FD Disclosure.** |

---

On January 7, 2026, Ionis Pharmaceuticals, Inc. ("Ionis," "we," "us" or "our company") issued a press release announcing that our partner, GSK, reported positive results from two pivotal Phase 3 studies, B-Well 1 and B-Well 2, evaluating the safety and efficacy of bepirovirsen, an investigational antisense oligonucleotide ("ASO") for the treatment of chronic hepatitis B ("CHB"). A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

The information in this Item 7.01 and the exhibit attached hereto shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (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, as amended, or the Exchange Act, regardless of any general incorporation language in such filing.

---

| | |
|:---|:---|
| **Item 8.01** | **Other Events.** |

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On January 7, 2026, we announced that our partner, GSK, reported positive results from two pivotal Phase 3 studies, B-Well 1 and B-Well 2, evaluating the safety and efficacy of bepirovirsen, an investigational ASO for the treatment of CHB. The studies included over 1,800 patients from 29 countries. GSK licensed bepirovirsen from us and we have collaborated on its development.

CHB is a major health challenge affecting over 250 million people worldwide and is the leading cause of liver cancer. The current standard of care, nucelos(t)ide analogues, often requires lifelong therapy and the functional cure rates remain low, typically only 1%. Functional cure for CHB is when the virus can no longer be detected in the blood as measured by the sustained loss of hepatitis B surface antigen (HBsAg), a viral protein that signals ongoing infection, and undetectable hepatitis B virus DNA for at least 24 weeks after a finite course of treatment. Functional cure is associated with significant reduction in the risk of long-term liver complications, including liver cancer, as well as all-cause mortality.

The B-Well studies met their primary endpoint, and bepirovirsen demonstrated a statistically significant and clinically meaningful functional cure rate. Functional cure rates were significantly higher with bepirovirsen plus standard of care compared with standard of care alone. Results were statistically significant across all ranked endpoints, including in patients with baseline surface antigen (HBsAg) <=1000 IU/ml where an even greater effect was demonstrated. The studies demonstrated an acceptable safety and tolerability profile consistent with what was reported in other studies.

Full results will be submitted for presentation at an upcoming scientific congress, published in a peer-reviewed journal and used to support regulatory submissions to health authorities worldwide. If approved, bepirovirsen has the potential to become the first finite, six-month therapeutic option for CHB and to serve as a backbone for future sequential treatment strategies.

Bepirovirsen has been recognized by global regulatory authorities for its innovation and potential to address significant unmet need in hepatitis B with Fast Track designation from the US FDA, Breakthrough Therapy designation in China and SENKU designation in Japan.

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GSK licensed bepirovirsen from us in 2019 under a collaborative development and licensing agreement. Under the terms of the agreement, we received an upfront payment, license fee and development milestone payments and are eligible to receive an additional $150 million in regulatory and sales milestone payments as well as tiered royalties of 10-12% on net sales of bepirovirsen.

#### Forward-Looking Statements
Certain statements contained in this report are forward-looking statements that involve a number of risks and uncertainties. Such forward-looking statements include, without limitation, statements regarding Ionis' business, the therapeutic and commercial potential of bepirovirsen, our commercial medicines, additional medicines in development and technologies, and Ionis' expectations regarding development and regulatory milestones. Words such as "anticipate," "believe," "could," "continue," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "should," "target," "will," "would" and similar expressions are intended to identify forward-looking statements, though not all forward-looking statements necessarily contain these identifying words. For such statements, Ionis claims the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995. Actual events or results may differ materially from Ionis' expectations. Factors that could cause actual results to differ materially from the forward-looking statements include, but are not limited to, 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. Additional factors that could cause actual results to differ materially from those stated or implied by Ionis' forward-looking statements are disclosed in Ionis' filings with the Securities and Exchange Commission, including in the section captioned "Risk Factors" in Ionis' most recent Annual Report on Form 10-K and subsequently filed Quarterly Reports on Form 10-Q. These forward-looking statements represent Ionis' judgment as of the time of this report. Ionis disclaims any intent or obligation to update these forward-looking statements, other than as may be required under applicable law.

---

| | |
|:---|:---|
| **Item 9.01** | **Financial Statements and Exhibits.** |

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(d) Exhibits.

---

| | |
|:---|:---|
| **<u>Exhibit No.</u>** | **<u>Description</u>** |
| [99.1](ef20062477_ex99-1.htm) | Press Release dated January 7, 2026. |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document). |

---

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#### 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.** | **Ionis Pharmaceuticals, Inc.** |
| Dated: January 7, 2026 | By: | /s/ Patrick R. O'Neil |
|  |  | **Patrick R. O'Neil** |
|  |  | Executive Vice President, Chief Legal Officer and General Counsel |

---

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## Exhibit 99.1

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#### Exhibit 99.1

#### <br>
**Ionis partner GSK announces positive topline results from B-Well 1 and B-Well 2 Phase 3 studies for bepirovirsen, a potential first-in-class medicine for chronic hepatitis B**

*<br> - Primary endpoint met in both trials –*

<br> - Bepirovirsen demonstrated a statistically significant and clinically meaningful functional cure rate –

<br> - Chronic hepatitis B (CHB) accounts for ~56% of liver cancer cases and affects more than 250 million people worldwide –

<br> - Global regulatory filings planned from Q1 2026 –

**CARLSBAD, Calif., January 7, 2026 --** <u>Ionis Pharmaceuticals, Inc.</u> (Nasdaq: IONS) partner GSK today announced positive results from two pivotal Phase 3 studies, B-Well 1 and B-Well 2, evaluating the safety and efficacy of bepirovirsen, an investigational antisense oligonucleotide (ASO) for the treatment of chronic hepatitis B (CHB). The studies included over 1,800 patients from 29 countries. GSK licensed bepirovirsen from Ionis and the two companies have collaborated on its development.

CHB is a major health challenge affecting over 250 million people worldwide and is the leading cause of liver cancer. The current standard of care, nucelos(t)ide analogues, often requires lifelong therapy and the functional cure rates remain low, typically only 1%. Functional cure for CHB is when the virus can no longer be detected in the blood as measured by the sustained loss of hepatitis B surface antigen (HBsAg), a viral protein that signals ongoing infection, and undetectable hepatitis B virus DNA for at least 24 weeks after a finite course of treatment. Functional cure is associated with significant reduction in the risk of long-term liver complications, including liver cancer, as well as all-cause mortality.

The B-Well studies met their primary endpoint, and bepirovirsen demonstrated a statistically significant and clinically meaningful functional cure rate. Functional cure rates were significantly higher with bepirovirsen plus standard of care compared with standard of care alone. Results were statistically significant across all ranked endpoints, including in patients with baseline surface antigen (HBsAg) <=1000 IU/ml where an even greater effect was demonstrated. The studies demonstrated an acceptable safety and tolerability profile consistent with what was reported in other studies.

"CHB is one of the most common, persistent viral infections in the world, with currently no approved therapy that can achieve meaningful functional cure. Bepirovirsen is uniquely positioned to effectively treat CHB based on its potential to reduce the replication of hepatitis B virus, suppress hepatitis B surface antigen and stimulate the immune system," said Brett P. Monia, Ph.D., chief executive officer, Ionis. "Today's positive results are made possible by the strategic collaboration between Ionis and GSK, and demonstrate that bepirovirsen has the potential to bring hope to the millions of people living with CHB. This is the first of five anticipated Phase 3 readouts from Ionis' partnered programs this year, underscoring the broad applicability of our technology."

Full results will be submitted for presentation at an upcoming scientific congress, published in a peer-reviewed journal and used to support regulatory submissions to health authorities worldwide. If approved, bepirovirsen has the potential to become the first finite, six-month therapeutic option for CHB and to serve as a backbone for future sequential treatment strategies.

------

![](image00001.jpg)<br>

Bepirovirsen has been recognized by global regulatory authorities for its innovation and potential to address significant unmet need in hepatitis B with Fast Track designation from the US FDA, Breakthrough Therapy designation in China and SENKU designation in Japan.

GSK licensed bepirovirsen from Ionis in 2019 under a collaborative development and licensing agreement. Under the terms of the agreement, Ionis received an upfront payment, license fee and development milestone payments and is eligible to receive an additional $150 million in regulatory and sales milestone payments as well as tiered royalties of 10-12% on net sales of bepirovirsen.

#### About B-Well 1 and B-Well 2
B-Well 1 (NCT05630807) and B-Well 2 (NCT05630820) trials are global multi-center, randomized, double-blind, placebo-controlled trials conducted in 29 countries. They assessed the efficacy, safety, pharmacokinetic profile, and the durability of functional cure in nucleos(t)ide analogue (NA)-treated participants with chronic hepatitis B and baseline surface antigen (HBsAg) ≤3000 IU/ml. The primary endpoint assessed the proportion of participants achieving functional cure in patients with baseline surface antigen (HBsAg) ≤3000 IU/ml. A key secondary endpoint evaluated functional cure in participants with baseline HBsAg ≤1000 IU/ml. Functional cure is defined as hepatitis B surface antigen (HBsAg) loss and undetectable HBV DNA for at least 24 weeks after a finite course of treatment.

#### About Chronic Hepatitis B (CHB)
Hepatitis B is a viral infection that can cause both acute and chronic liver disease. Chronic hepatitis B occurs when the immune system is unable to clear the virus, resulting in long-lasting infection that affects more than 250 million people worldwide. The disease causes approximately 1.1 million deaths each year, and accounts for approximately 56% of liver cancer cases globally. Many patients often require lifelong antiviral therapy for viral suppression; making functional cure a critical goal in disease management.

#### About bepirovirsen
Bepirovirsen is an investigational antisense oligonucleotide (ASO) designed to recognize and orchestrate the destruction of the genetic components (i.e. RNA) of the hepatitis B virus that can lead to chronic disease, potentially allowing a person's immune system to regain control. Bepirovirsen inhibits the replication of viral DNA in the body, suppresses the level of hepatitis B surface antigen (HBsAg) in the blood, and stimulates the immune system to increase the chances of a durable and sustained response.

#### About Ionis Pharmaceuticals, Inc.
For three decades, Ionis has invented medicines that bring better futures to people with serious diseases. Ionis has marketed medicines and a leading pipeline in neurology, cardiometabolic and other 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 <u>Ionis.com</u> and follow us on <u>X (Twitter)</u>, <u>LinkedIn</u> and <u>Instagram</u>.

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![](image00001.jpg)<br>

#### Forward-looking Statements

This press release includes forward-looking statements regarding Ionis' business and the therapeutic and commercial potential of bepirovirsen, our commercial medicines, additional medicines in development and technologies. 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 Pharmaceuticals<sup>®</sup> is a trademark of Ionis Pharmaceuticals, Inc.

#### Ionis Investor Contact:
D. Wade Walke, Ph.D.

<u>IR@ionis.com</u>

760-603-2331

#### Ionis Media Contact:
Hayley Soffer

<u>media@ionis.com</u>

760-603-4679

###

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