Sec Form 4 Filing - SHEFFERY MICHAEL B @ SUPERNUS PHARMACEUTICALS INC - 2012-05-04

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person SHEFFERY MICHAEL B 2. Issuer Name and Ticker or Trading Symbol SUPERNUS PHARMACEUTICALS INC [ SUPN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O ORBIMED ADVISORS LLC,, 601 LEXINGTON AVENUE, 54TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 05/04/2012 (Street) NEW YORK, NY10022 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 05/04/2012 C 1,668,472 A 1,668,472 I ( 2 ) By OrbiMed Private Investments II, LP Common Stock 05/04/2012 C 624,710 A 624,710 I ( 2 ) By OrbiMed Private Investments II (QP), LP Common Stock 05/04/2012 C 206,816 A 206,816 I ( 2 ) By UBS Juniper Crossover Fund, L.L.C. Common Stock 05/04/2012 P 734,128 A $ 5 2,402,600 I ( 2 ) by OrbiMed Private Investments II LP Common Stock 05/04/2012 P 274,873 A $ 5 899,583 I ( 2 ) By OrbiMed Private Investments II (QP), LP Common Stock 05/04/2012 P 90,999 A $ 5 297,815 I ( 2 ) By UBS Juniper Crossover Fund, L.L.C

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Series A Preferred Stock ( 1 ) 05/04/2012 C 6,673,891 12/22/2005 ( 1 ) Common Stock 1,668,472 $ 0 0 I ( 2 ) By OrbiMed Private Investments II, LP Series A Preferred Stock ( 1 ) 05/04/2012 C 2,498,842 12/22/2005 ( 1 ) Common Stock 624,710 $ 0 0 I ( 2 ) By OrbiMed Private Investments II (QP), LP Series A Preferred Stock ( 1 ) 05/04/2012 C 827,627 12/22/2005 ( 1 ) Common Stock 206,816 $ 0 0 I ( 2 ) By UBS Juniper Crossover Fund, L.L.C.

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other SHEFFERY MICHAEL B C/O ORBIMED ADVISORS LLC, 601 LEXINGTON AVENUE, 54TH FLOOR NEW YORK, NY10022 X Signatures /s/ Gregory S. Patrick, as attorney-in-fact 05/07/2012 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each share of Series A Preferred Stock automatically converted into 0.25 shares of Common Stock (together the shares of Series A Preferred Stock and the shares of Common Stock, the "Shares") without payment of consideration upon the closing of the Issuer's initial public offering. Any fractional shares upon the conversion were paid out in cash. The shares of Series A Preferred Stock do not have an expiration date. ( 2 )Mr. Sheffery is a member of OrbiMed Advisors LLC, the managing member of OrbiMed Capital GP II LLC, which is the general partner of OrbiMed Private Investments II, LP and OrbiMed Private Investments II (QP), LP. Investment professionals employed by OrbiMed Advisors LLC manage UBS Juniper Crossover Fund, L.L.C.'s investment portfolio on behalf of UBS Juniper Management, L.L.C. Mr. Sheffery disclaims beneficial ownership of the Shares and this report shall not be deemed an admission that such reporting person is the beneficial owner of such Shares, except to the extent of his pecuniary interest, if any, in the Shares by virtue of his interest in OrbiMed Advisors LLC.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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