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 2, 2014

Supernus Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

Delaware

(State or other jurisdiction of
Incorporation)

Registrant’s telephone number, including area code:  (301) 838-2500

Not Applicable

(Former name or former address, if changed since last report.)

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):

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

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

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

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

Item 8.01                                           Other Events

On October 2, 2014, Supernus Pharmaceuticals, Inc issued a press release announcing that it initiated litigation against generic drug makers Actavis plc, Actavis, Inc., Actavis Laboratories FL, Inc., Actavis Pharma, Inc., Watson Laboratories, Inc., and Anda, Inc. for infringement of three patents covering its antiepileptic drug Trokendi XR®.  A copy of this press release is furnished as Exhibit 99.1 hereto and is incorporated herein by reference.

Item 9.01                                           Financial Statements and Exhibits

(d)                                 Exhibit

The following document is furnished as an Exhibit pursuant to Item 8.01 hereof:

Exhibit 99.1 — Press Release dated October 2, 2014.

2

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.

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EXHIBIT INDEX

4

Exhibit 99.1

FOR IMMEDIATE RELEASE

Supernus Sues Actavis for Infringement of Trokendi XR® Patents

Rockville, MD., October 2, 2014 — Supernus Pharmaceuticals, Inc. (Nasdaq:SUPN) announced that earlier today it sued generic drug makers Actavis plc, Actavis, Inc., Actavis Laboratories FL, Inc., Actavis Pharma, Inc., Watson Laboratories, Inc., and Anda, Inc. (collectively “Actavis”) for infringement of three patents covering its antiepileptic drug Trokendi XR®.  Supernus’ United States Patents Nos. 8,298,576, 8,298,580, and 8,663,683 cover once-a-day topiramate formulations and methods of treating seizures using those formulations.  Patent protection for Trokendi XR® does not expire until 2029.

The Complaint—filed in the U.S. District Court for the District of New Jersey—alleges that Actavis infringed Supernus’ Trokendi XR® patents by submitting to the Food and Drug Administration (“FDA”) an Abbreviated New Drug Application (“ANDA”) seeking to market a generic version of Trokendi XR® prior to the expiration of Supernus’ patents.  Filing its Complaint within 45 days of receiving Actavis’ Paragraph IV certification notice entitles Supernus to an automatic stay preventing the FDA from approving Actavis’ ANDA for 30 months.

Supernus President and CEO Jack Khattar confirmed that “Supernus intends to vigorously enforce its patent rights.”

Supernus is represented by attorneys from Frommer Lawrence and Haug LLP and its corporate counsel, Saul Ewing LLP.

About Supernus Pharmaceuticals, Inc.

Supernus Pharmaceuticals, Inc. is a specialty pharmaceutical company focused on developing and commercializing products for the treatment of central nervous system, or CNS, diseases. The Company has two marketed products for epilepsy, Oxtellar XR® (extended-release oxcarbazepine) and Trokendi XR® (extended-release topiramate). The Company is also developing several product candidates in psychiatry to address large market opportunities in ADHD, including ADHD patients with impulsive aggression. These product candidates include SPN-810 for impulsive aggression in ADHD and SPN-812 for ADHD.

Forward Looking Statements

This press release contains forward-looking statements regarding the Company’s ability to defend and enforce its intellectual property rights covering Trokendi XR®. Actual results may differ materially from those in these forward-looking statements as a result of various factors, including, but not limited to, the ability of Supernus to finance potential litigation and to prevail in any such proceeding to successfully defend its intellectual property rights. For a further description of these and other risks facing the Company, please see the risk factors described in the Company’s Annual Report Form 10-K that was filed with the United States Securities and Exchange Commission on March 21, 2014 under the caption “Risk Factors” and the updates to these risk factors in the Company’s quarterly report form 10-Q filed with the commission on August 12, 2014.  Forward-looking statements speak only as of the date of this press release, and the Company undertakes no obligation to update or revise these statements, except as may be required by law.

CONTACTS:

Jack A. Khattar, President and CEO

Gregory S. Patrick, Vice President and CFO

Supernus Pharmaceuticals, Inc.

301-838-2591

or

INVESTOR CONTACT:

COCKRELL GROUP

877-889-1972

investorrelations@thecockrellgroup.com

cockrellgroup.com