UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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): January 2, 2013

REGENERX BIOPHARMACEUTICALS, INC.

(Exact Name of Registrant as Specified in its Charter)

Registrant’s telephone number, including area code: (301) 208-9191

(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):

¨ 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))

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

As reported on a Current Report on Form 8-K filed on January 6, 2012, the Company previously entered into letter agreements with each of J.J. Finkelstein, the Company’s President and Chief Executive Officer, David Crockford, the Company’s vice president of clinical and regulatory affairs, and Allan Goldstein, the Company’s chief scientific advisor and a member of the Company’s board of directors, relating to their employment with the Company. In addition, the Company entered into change of control agreements with each of Mr. Finkelstein, Mr. Crockford and Dr. Goldstein, providing for the payment of severance obligations upon specified terminations of employment.

On July 2, 2012, the Board of Directors of the Company approved, and the Company and each officer entered into, amendments to each of the letter agreements to extend their terms through December 31, 2012. The Company and each officer also entered into amended and restated change in control agreements to, among other things, extend their respective terms through December 31, 2012.

On January 2, 2013, the Company and each officer entered into amended letter agreements which amended the temporary employment letter and the amended and restated change in control agreements to extend their respective terms through June 30, 2013. Under the letter agreements, as extended, Mr. Finkelstein and Dr. Goldstein will continue to receive a salary at a rate of $50.00 per hour, subject to deductions and withholdings, while Mr. Crockford will continue receive a salary at a rate of $96.01 per hour for work related to the Company’s grant from the National Heart Lung & Blood Institute and $50.00 per hour for all other work, in each case subject to deductions and withholdings. Mr. Finkelstein’s typical work schedule will continue to be up to 100 hours per month and Dr. Goldstein’s typical work schedule will continue to be up to 32 hours per month, in each case with no guaranteed minimum number of hours. Mr. Crockford’s typical work schedule will continue to be up to 20 hours per month for non-grant work, with no guaranteed minimum number of hours. In accordance with the letter agreements, the employment termination date for each officer will be June 30, 2013, unless terminated prior to that date by such officer or by the Company.

Under the change in control agreements, as extended, each officer is eligible to receive severance payments upon specified change in control transactions. If a Change in Control (as defined in the agreement) is consummated by June 30, 2013, and prior to June 30, 2013, or within 12 months following the Change in Control, the Company terminates the officer’s employment for any reason, other than Cause (as defined in the agreement) or the officer’s death or disability, or if the officer resigns for Good Reason (as defined in the agreement), then:

Each officer will be required to execute a general release and waiver of all legal claims prior to receiving any severance payment. The compensation provided pursuant to the change in control agreements will be the only severance benefits to which Messrs. Finkelstein or Crockford or Dr. Goldstein may be entitled upon termination of their employment with the Company.

Item 9.01 Financial Statements and Exhibits.

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.

EXHIBIT INDEX