UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K/A

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 17, 2017 (May 20, 2016)

HEMISPHERX BIOPHARMA, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (215) 988-0080

1617 JFK Boulevard, Suite 500, Philadelphia, PA 19103

(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):

EXPLANATORY NOTE

This Amendment No. 1 to the Current Report on Form 8-K (this “Amendment”) amends the Current Report on Form 8-K of Hemispherx Biopharma, Inc. filed with the Securities and Exchange Commission (the “SEC”) on January 17, 2017 (the “Form 8-K”) for the sole purpose of adding revised disclosure about the Amended and Restated Early Access Agreement (the “Agreement”), between the Company and Impatients N.V., d/b/a myTomorrows (“myTomorrows”) and refiling the Agreement as Exhibit 10.1 (certain portions of which are omitted pursuant to a request for confidential treatment of such omitted information submitted to the SEC).

Other than as described above, no changes are made to the Form 8-K and, unless expressly stated, this Amendment does not reflect events occurring after the filing of the Form 8-K, nor does it modify or update in any way the disclosures contained in the Form 8-K. Accordingly, this Amendment should be read in conjunction with the Form 8-K and our other filings made with the SEC subsequent to the filing of the Form 8-K.

Item 1.01 Entry into a Material Definitive Agreement.

On May 24, 2016, we entered into an amended and restated five year agreement (the “Impatients Agreement”) with Impatients, N.V. (“myTomorrows”), a Netherlands based company, for the commencement and management of an Early Access Program (“EAP”) in Europe and Turkey (the “Territory”) related to CFS. Pursuant to the agreement, myTomorrows, as our exclusive service provider and distributor in the Territory, is performing EAP activities. These activities will be directed to (a) the education of physicians and patients regarding the possibility of early access to innovative medical treatments not yet the subject of a Marketing Authorization (regulatory approval) through named-patient use, compassionate use, expanded access and hospital exemption, (b) patient and physician outreach related to a patient-physician platform, (c) the securing of Early Access Approvals (exemptions and/or waivers required by regulatory authorities for medical treatments prior to Marketing Authorization) for the use of such treatments, (d) the distribution and sale of such treatments pursuant to such Early Access Approvals, (e) pharmacovigilance (drug safety) activities and/or (f) the collection of data such as patient-reported outcomes, doctor-reported experiences and registry data. We are supporting these efforts and supplying Ampligen® to myTomorrows at a predetermined transfer price. In the event that we receive Marketing Authorization in any country in the Territory, we will pay myTomorrows a royalty on products sold. Pursuant to the Impatients Agreement, the royalty would be a percentage of Net Sales (as defined in the Impatients Agreement) of Ampligen® sold in the Territory where Marketing Authorization was obtained, and the maximum royalty would be a percentage of Net Sales. The formula to determine the percentage of Net Sales will be based on the number of patients that are entered into the EAP. The Company believes that disclosure of the exact maximum royalty rate and royalty termination date could cause competitive harm. However, to assist the public in gauging these terms, the actual maximum royalty rate is somewhere between 2% and 10% and the royalty termination date is somewhere between 8 and 15 years from the First Commercial Sale of a product within a specific country. The parties established a Joint Steering Committee comprised of representatives of both parties to oversee the EAP. No assurance can be given that activities under the EAP will result in Marketing Authorization or the sale of substantial amounts of Ampligen® in the Territory. In 2017, the Company commenced sales of recently manufactured Ampligen® in international programs.

The foregoing description of the Agreement is qualified in its entirety by reference to the full text of the Agreement, a copy of which is attached hereto as Exhibit 10.1, and which is incorporated herein in its entirety by this reference.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No. Description

10.1       May 20, 2016 Amended And Restated Early Access Agreement with Impatients N.V.*

* Confidential portions of this exhibit have been redacted and filed separately with the Securities and Exchange Commission pursuant to a confidential treatment request in accordance with Rule 24b-2 of the Securities Exchange Act of 1934, as amended.

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.