Sec Form 4 Filing - Essetifin SPA @ REGENERX BIOPHARMACEUTICALS INC - 2018-03-13

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 Essetifin SPA 2. Issuer Name and Ticker or Trading Symbol REGENERX BIOPHARMACEUTICALS INC [ RGRX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) VIA SUDAFRICA, 20 3. Date of Earliest Transaction (MM/DD/YY) 03/13/2018 (Street) ROME, L600144 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ 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 03/13/2018 P 11,584,795 ( 1 ) A $ 0.23 25,506,521 D ( 5 ) ( 6 ) Common Stock 03/13/2018 P 6,348,878 ( 2 ) A $ 0.23 31,855,399 D ( 6 )

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 Convertible Promissory Note (right to buy) $ 0.06 03/13/2018 P 09/12/2013 ( 3 ) Common Stock ( 3 ) $ 150,000 2,500,000 ( 4 ) D ( 5 ) ( 6 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Essetifin SPA VIA SUDAFRICA, 20 ROME, L600144 X CAVAZZA PAOLO VIA TESSERETE, 10 LUGANO, V800000 X Cavazza Enrico VIA SUDAFRICA, 20 ROME, L600144 X Cavazza Francesca VIA SUDAFRICA, 20 ROME, L600144 X Cavazza Silvia VIA SUDAFRICA, 20 ROME, L600144 X Cavazza Preta Martina VIA SUDAFRICA, 20 ROME, L600144 X Signatures Essetifin S.p.A. By: /s/ Marino Zigrossi 03/14/2018 Signature of Reporting Person Date /s/ Marino Zigrossi for Enrico Cavazza by power of attorney 03/14/2018 Signature of Reporting Person Date /s/ Marino Zigrossi for Francesca Cavazza by power of attorney 03/14/2018 Signature of Reporting Person Date /s/ Marino Zigrossi for Silvia Cavazza by power of attorney 03/14/2018 Signature of Reporting Person Date /s/ Marino Zigrossi for Martina Cavazza Preta by power of attorney 03/14/2018 Signature of Reporting Person Date /s/ Fabio Poma for Paolo Cavazza by power of attorney 03/14/2018 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents shares sold by Sinaf S.A., a Luxembourg corporation ("Sinaf"), and purchased by Essetifin S.p.A., an Italian corporation ("Essetifin"), pursuant to a purchase agreement by and between Sinaf and Essetifin (the "Sinaf Agreement"). ( 2 )Represents shares sold by Taufin International S.A., a Luxembourg corporation ("Taufin"), and purchased by Essetifin, pursuant to a purchase agreement by and between Taufin and Essetifin. ( 3 )Represents a $150,000 convertible promissory note (the "Note") sold by Sinaf and purchased by Essetifin for an aggregate of $183,780.82, pursuant to the Sinaf Agreement. The reporting person purchased the Note on September 12, 2013, from the issuer in a private placement. The Note and any accrued interest thereon are convertible at the option of the holder at any time prior to repayment of the Note into common stock at a conversion price of $0.06 per share. The Note is payable upon the written demand of the holder thereof at any time after September 10, 2018 (the "Maturity Date"). Interest accrues on the unpaid principal amount at a rate equal to 5% per annum, but it is not due and payable until the written demand of the holder for payment on or after the Maturity Date. The current outstanding principal amount, if converted into common stock, would result in the issuance of 2,500,000 shares. The number of shares of common stock to be issued upon conversion will be fixed on the conversion date. ( 4 )Does not include shares issuable at the election of the reporting person upon conversion of accrued interest into shares of common stock. ( 5 )Paolo Cavazza previously reported indirect ownership of such securities due to his ownership interest in Sinaf, which is a directly wholly-owned subsidiary of Aptafin S.p.A., which is owned indirectly by Paolo Cavazza and members of his family. Paolo Cavazza continues to have an indirect interest in such shares through his ownership interest in Essetifin. ( 6 )Dispositive power over the shares of common stock owned by Essetifin is shared by Enrico Cavazza, Silvia Cavazza, Francesca Cavazza, Martina Cavazza Preta and Paolo Cavazza. Each of Enrico Cavazza, Silvia Cavazza, Francesca Cavazza, Martina Cavazza Preta and Paolo Cavazza disclaims beneficial ownership of all shares of common stock held by Essetifin except to the extent of any pecuniary interest therein.

Remarks: Exhibit List: Exhibit 99.1 - Joint Filers' Signatures

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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