Form 8-K

8-K — SUPERNUS PHARMACEUTICALS, INC.

Accession: 0001104659-26-117937

Filed: 2026-10-22

Period: 2026-10-21

CIK: 0001356576

SIC: 2834 (PHARMACEUTICAL PREPARATIONS)

Item: Other Events

Item: Financial Statements and Exhibits

Documents

8-K — tm2628092d1_8k.htm (Primary)

EX-99.1 — EXHIBIT 99.1 (tm2628092d1_ex99-1.htm)

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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): October 21, 2026

Supernus

Pharmaceuticals, Inc.

(Exact name of registrant

as specified in its charter)

Delaware

001-35518

20-2590184

(State or other jurisdiction of

incorporation or organization)

(Commission

File Number)

(I.R.S.

Employer Identification No.)

9715

Key West Ave

Rockville

20850

(Address

of Principal Executive Offices)

(Zip

Code)

Registrant’s telephone

number, including area code: (301) 838-2500

Not Applicable

(Former name or former address,

if changed since last report.)

Securities registered pursuant to Section 12(b)

of the Exchange Act

Title of

each class

Trading Symbol

Name of each

exchange on which registered

Common

Stock, $0.001 par value per share

SUPN

The Nasdaq

Stock Market LLC

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 (see

General Instruction A.2. below):

¨ 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))

Indicate by

check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405

of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). ¨

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 8.01 Other Events.

On October 21, 2026, Supernus Pharmaceuticals,

Inc. (the “Company”) issued a press release announcing that the U.S. Food and Drug Administration (“FDA”) has

recognized seven years of orphan-drug exclusive approval for ONAPGO (apomorphine HCl) for the treatment of motor fluctuations in adults

with advanced Parkinson’s disease. The seven-year market exclusivity for ONAPGO began on February 3, 2025, the date of FDA approval.

The Company also announced it submitted a supplemental New Drug Application to the FDA for a second supplier for ONAPGO and continues

to expect potential FDA approval of the second supplier by mid-year 2027.

Item 9.01

Financial Statements and Exhibits.

(d)

Exhibits

Exhibit

99.1 – Press Release dated October 21, 2026

Exhibit 104 – The cover page

from this Current Report on Form 8-K, formatted in Inline XBRL.

SIGNATURES

Pursuant to the requirements of the Securities

Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

SUPERNUS PHARMACEUTICALS, INC.

DATED: October 21, 2026

By:

/s/ Timothy C. Dec

Timothy C. Dec

Senior Vice President and Chief Financial Officer

EX-99.1 — EXHIBIT 99.1

EX-99.1

Filename: tm2628092d1_ex99-1.htm · Sequence: 2

Exhibit 99.1

Supernus Announces

Orphan Drug Exclusivity for ONAPGO™ (apomorphine HCl)

Orphan-drug exclusivity

provides seven years of market exclusivity for ONAPGO

Additionally,

the Company submitted an sNDA to the FDA for a second supplier for ONAPGO, with potential approval by mid-year 2027

ROCKVILLE, Md.,

October 21, 2026 – Supernus, Inc. (Nasdaq: SUPN), a biopharmaceutical company focused on developing and commercializing products

for the treatment of central nervous system (CNS) diseases, announced today that the U.S. Food and Drug Administration (FDA) has recognized

seven years of orphan-drug exclusive approval for ONAPGO (apomorphine HCl) for the treatment of motor fluctuations in adults with advanced

Parkinson’s disease. ONAPGO is the first and only subcutaneous apomorphine infusion device for the treatment of motor fluctuations

in adults with advanced Parkinson’s disease.

The seven-year

market exclusivity for ONAPGO began on February 3, 2025, the date of FDA approval. The FDA's Orphan Drug Designation program is designed

to advance the development of drugs that treat a condition affecting 200,000 or fewer U.S. patients annually.

In addition, the

Company submitted a supplemental New Drug Application (sNDA) to the FDA for a second supplier for ONAPGO and continues to expect potential

FDA approval of the second supplier by mid-year 2027.

"Securing

orphan-drug exclusivity marks an important milestone for individuals and families navigating Parkinson's disease. This designation validates

the urgent need for targeted therapies and helps safeguard continued innovation in a long-underserved community," said Jack Khattar,

President and Chief Executive Officer of Supernus Pharmaceuticals. "In addition to resolving the supply issue from earlier this

year, submitting our sNDA further reinforces our ongoing commitment to providing novel treatments for patients with Parkinson's disease,

backed by our unwavering focus on ensuring an uninterrupted drug supply for every patient in need."

More information

about ONAPGO, including Full Prescribing Information and Medication Guide, is available here: www.onapgo.com.

About Supernus,

Inc.

Supernus, Inc.

is a biopharmaceutical company focused on developing and commercializing products for the treatment of central nervous system (CNS) diseases.

Our diverse neuroscience

portfolio includes approved treatments for attention-deficit hyperactivity disorder (ADHD), dyskinesia in Parkinson's disease (PD) patients

receiving levodopa-based therapy, hypomobility in PD, postpartum depression (PPD), epilepsy, migraine, cervical dystonia, and chronic

sialorrhea. We are developing a broad range of novel product candidates for CNS disorders.

For more information,

please visit www.supernus.com.

Forward-Looking

Statements

This press release

includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements do not

convey historical information but relate to predicted or potential future events that are based upon management's current expectations.

These statements are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or

implied by such statements. In addition to the factors mentioned in this press release, such risks and uncertainties include, but are

not limited to, the Company's ability to sustain and increase its profitability; the Company's ability to raise sufficient capital to

fully implement its corporate strategy; the implementation of the Company's corporate strategy; the Company's future financial performance

and projected expenditures; the Company's ability to increase the number of prescriptions written for each of its products and the products

of its subsidiaries; the Company's ability to increase its net revenue from its products and the products of its subsidiaries; the Company's

ability to commercialize its products and the products of its subsidiaries; the Company's ability to enter into future collaborations

with pharmaceutical companies and academic institutions or to obtain funding from government agencies; the Company's product research

and development activities, including the timing and progress of the Company's clinical trials, and projected expenditures; the Company's

ability to receive, and the timing of any receipt of, regulatory approvals to develop and commercialize the Company's product candidates

or manufacture ONAPGO at the second supplier; the Company's ability to protect its intellectual property and the intellectual property

of its subsidiaries and operate its business without infringing upon the intellectual property rights of others; the Company's expectations

regarding federal, state and foreign regulatory requirements; the therapeutic benefits, effectiveness and safety of the Company's product

candidates; the accuracy of the Company's estimates of the size and characteristics of the markets that may be addressed by its product

candidates; the Company's ability to increase its manufacturing capabilities for its products, including ONAPGO, and product candidates;

the Company's projected markets and growth in markets; the Company's product formulations and patient needs and potential funding sources;

the Company's staffing needs; changes to laws and regulations applicable to our industry, the impact of macroeconomic factors, such as

economic downturns or uncertainty, international conflict, trade disputes and tariffs; and other risk factors set forth from time to

time in the Company's filings with the Securities and Exchange Commission made pursuant to Section 13 or 15(d) of the Securities Exchange

Act of 1934, as amended. The Company undertakes no obligation to update the information in this press release to reflect events or circumstances

after the date hereof or to reflect the occurrence of anticipated or unanticipated events.

Supernus, Inc.

Contacts

Jack A. Khattar, President and CEO

Tim Dec, Senior Vice President and CFO

Supernus, Inc.

(301) 838-2591

Investors

Peter Vozzo

ICR Healthcare

(443) 213-0505

Email: peter.vozzo@icrhealthcare.com

Media

Diana Torres-Bixby

Burson Global

+1 917 686 0517

Email: Diana.torres-bixby@bursonglobal.com

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