SEC FILE NUMBER: 001-35518
CUSIP NUMBER: 868459 10 8
Washington, D.C. 20549
FORM 12b-25
(Check One):
    Form 10-K
   Form 20-F
   Form 11-K
  Form 10-Q
   Form 10-D
   Form N-SAR
   Form N-CSR
For Period Ended:  March 31, 2022                         
 Transition Report on Form 10-K
 Transition Report on Form 20-F
 Transition Report on Form 11-K
 Transition Report on Form 10-Q
 Transition Report on Form N-SAR
 For the Transition Period Ended: ___________________
Nothing in this form shall be construed to imply that the Commission has verified any information contained herein.
If the notification relates to a portion of the filing checked above, identify the item(s) to which the notification relates: Not applicable.
 Supernus Pharmaceuticals, Inc.
 Full Name of Registrant
Former Name if Applicable
9715 Key West Avenue
Address of Principal Executive Office (Street and Number)
Rockville, MD 20850
City, State and Zip Code 

PART II - RULES 12b-25(b) AND (c)
If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate)
 (a)The reason described in reasonable detail in Part III of this form could not be eliminated without unreasonable effort or expense
(b)The subject annual report, semi-annual report, transition report on Form 10-K, Form 20-F, Form 11-K, Form N-SAR or Form N-CSR, or portion thereof, will be filed on or before the fifteenth calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q or subject distribution report on Form 10-D, or portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and
 (c)The accountant’s statement or other exhibit required by Rule 12b-25(c) has been attached if applicable.
State below in reasonable detail why Forms 10-K, 20-F, 11-K, 10-Q, 10-D, N-SAR, N-CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.
Supernus Pharmaceuticals, Inc. (the “Company”) is unable to file its quarterly report on Form 10-Q for the quarter ended March 31, 2022, without unreasonable effort or expense, due to a delay in obtaining and compiling information required to be included in its Form 10-Q. Such delay was a result of the Company’s late filing of its Annual Report on Form 10-K for the year ended December 31, 2021, which delay could not be eliminated by the Company without unreasonable effort and expense. The Company currently anticipates that its Form 10-Q for the quarter ended March 31, 2022 will be filed as soon as practicable, and no later than five days calendar days following its prescribed due date.
(1) Name and telephone number of person to contact in regard to this notification
Timothy C. Dec 
(Name) (Area Code) (Telephone Number)
(2)    Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months or for such shorter period that the registrant was required to file such report(s) been filed? If the answer is no, identify report(s).

(3)    Is it anticipated that any significant change in results of operations from the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof?


If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.
This Form 12b-25 includes “forward-looking statements,” which may be identified by the use of words such as “anticipates,” “will,” “believes,” “intends,” “plans,” “expects” and other similar words and expressions that predict or indicate future events or trends that are not statements of historical matters. These forward-looking statements include statements and expectations about the Company’s results and the timing of the filing of its Quarterly Report on Form 10-Q for the period ended March 31, 2022. Forward-looking statements are based on information available at the time those statements are made and/or management’s good faith belief as of that time with respect to future events, and are subject to risks and uncertainties that could cause actual performance or results to differ materially from those expressed in or suggested by the forward-looking statements. Such risks and uncertainties include, without limitation, the risk that, upon completion of further procedures, the financial results for the period ended March 31, 2022 are different than the results described in this Form 12b-25, the risk that the Company is unable to complete its closing procedures in a timely manner to file its Quarterly Report on Form 10-Q as indicated in this Form 12b-25, as well as subsequent periodic and current reports filed with the SEC, which are available on the SEC website at Readers are cautioned not to place undue reliance on forward-looking statements, which speak only as of the date on which they are made. The Company disclaims any obligation to update or correct any forward-looking statements made herein due to the occurrence of events after the issuance of this report except as required under federal securities laws.
Supernus Pharmaceuticals, Inc.
(Name of Registrant as Specified in Charter)

has caused this notification to be signed on its behalf by the undersigned hereunto duly authorized.
Date: May 10, 2022By:/s/ Timothy C. Dec
Timothy C. Dec
Senior Vice President and Chief Financial Officer
INSTRUCTION:  The form may be signed by an executive officer of the registrant or by any other fully authorized representative. The name and title of the person signing the form shall be typed or printed beneath the signature. If the statement is signed on behalf of the registrant by an authorized representative (other than an executive officer), evidence of the representative's authority to sign on behalf of the registrant shall be filed with the form.