Washington, D.C. 20549
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported): June 10, 2021
Supernus Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)
(State or other jurisdiction of incorporation or organization)
(Commission File Number)
(I.R.S. Employer Identification No.)
9715 Key West Ave
(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 classTrading SymbolName of each exchange on which registered
Common Stock, $0.001 par value per shareSUPNThe 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 Item.

On June 10, 2021, Newron Pharmaceuticals S.p.A. (“Newron”), Zambon S.p.A. (“Zambon”) and Supernus Pharmaceuticals, Inc. (the “Company”), through its subsidiary MDD US Operations, LLC (collectively, “Plaintiffs”), initiated litigation against generic drug makers Aurobindo Pharma Limited, Aurobindo Pharma USA Inc., MSN Laboratories Private Limited (“MSN”), Optimus Pharma Pvt Ltd, Prinston Pharmaceutical, Inc., RK Pharma, Inc. and Zenara Pharma Private Limited (collectively, “Defendants”) for infringement of three patents covering XADAGO®, the Company’s once-daily product indicated as adjunctive treatment to levodopa/carbidopa in patients with Parkinson’s Disease experiencing “off” episodes. United States Patent Nos. 8,076,515, 8,278,485 and 8,283,380 (collectively, the “XADAGO Patents”) cover the pharmaceutical formulation of and methods of treatment with safinamide. The XADAGO Patents expire between June 2027 and March 2031. The Company has a license agreement with Zambon, Newron’s partner, related to the XADAGO Patents, and as a new chemical entity, XADAGO is under the 5 year FDA exclusivity period that expires on March 21, 2022.

The Complaint – filed in the U.S. District Court for the District of Delaware – alleges that the Defendants infringed the XADAGO Patents by submitting to the U.S. Food and Drug Administration (FDA) Abbreviated New Drug Applications (ANDAs) seeking to market a generic version of XADAGO prior to the expiration of the patents. Filing the Complaint within 45 days of receiving each of the Defendants’ Paragraph IV notice letters triggers a stay of FDA approval of Defendants’ ANDAs.

Item 9.01 Financial Statements and Exhibits.
(d) Exhibits
Exhibit 104 – The cover page from this Current Report on Form 8-K, formatted in Inline XBRL.


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. 

DATED: June 25, 2021By:/s/ James P. Kelly
  James P. Kelly
Executive Vice-President and Chief Financial Officer