UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-Q/A

(Amendment No. 1)

Quarterly Report Pursuant to Section 13
or 15(d)

of the Securities Exchange Act of 1934



For the Quarterly Period Ended March 31,
2016



Commission File Number: 1-13441



HEMISPHERX BIOPHARMA, INC.

(Exact name of registrant as specified in
its charter)



|Delaware                        |  | 52-0845822         
|------------------------------- |  | -------------------
|(State or other jurisdiction of |  | (I.R.S. Employer   
|incorporation or organization)  |  | Identification No.)



1617 JFK Boulevard, Suite 500, Philadelphia,
PA 19103

(Address of principal executive offices)
(Zip Code)



(215) 988-0080

(Registrant's telephone number, including
area code)



(Former name,
former address and former fiscal year, if changed since last report)



Indicate by check mark whether the registrant
(1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding
12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.

x
Yes  ̈ No



Indicate by check mark whether the registrant
has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted
and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or such shorter
period that the registrant was required to submit and post such files).

xYes
 ̈ No



Indicate by check mark whether the registrant
is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definition of
“large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2
of the Exchange Act. (Check one):



| ̈ | Large accelerated filer |  ̈ | Accelerated filer        
|- | ----------------------- | - | -------------------------
| ̈ | Non-accelerated filer   | x | Smaller reporting company



Indicate by check mark whether the registrant
is a shell company (as defined in Rule 12b-2 of the Exchange Act).  ̈ Yes x
No



247,918,529 shares of common stock were outstanding as of May
6, 2016.











EXPLANATORY NOTE



This Amendment No. 1 on Form 10-Q/A ("Amendment No.
1") amends our Quarterly Report on Form 10-Q for the quarter ended March 31, 2016 that was filed with the Securities and Exchange
Commission, or SEC, on May 16, 2016 (the "Original Filing"). We are filing this Amendment No. 1 solely for the purpose
of attaching as Exhibits 10.1 and 10.2 amended redacted copies of the Sales, Marketing, Distribution and Supply Agreement dated
March 3, 2016 with Scientific Products Pharmaceutical Co. LTD and the Licensing agreement dated April 13, 2016 with Lonza Sales
AG.



As required by Rule 12b-15 under the Securities Exchange
Act of 1934, as amended, Item 15 of Part IV of the Original Filing has been amended to contain currently dated certifications from
our Chief Executive Officer and Chief Financial Officer. The currently dated certifications are attached hereto as Exhibits 31.1
and 31.2. Because no financial statements of Hemispherx Biopharma, Inc. are contained in this Amendment No. 1, we are not including
certifications pursuant to 18 U.S.C. 1350.



No other changes, other than described above, are made to
the Original Filing other than to update the cover page and Exhibit Index of the Original Filing. Unless expressly stated, this
Amendment No. 1 does not reflect events occurring after the filing of the Original Filing, nor does it modify or update in any
way the disclosures contained in the Original Filing. Accordingly, this Amendment No. 1 should be read in conjunction with our
Original Filing and our other filings made with the SEC subsequent to the filing of the Original Filing.



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Part II – OTHER INFORMATION



ITEM 6: Exhibits



| | (a) | Exhibits
| | --- | --------



|10.1 |  | Sales, Marketing, Distribution and Supply Agreement dated March 3, 2016 with Scientific Products Pharmaceutical Co. LTD (1)                                                                                                                                                                                                                                                                                                    
|---- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|     |  |                                                                                                                                                                                                                                                                                                                                                                                                                                
|10.2 |  | Licensing Agreement dated April 13, 2016 with Lonza Sales AG. (1)                                                                                                                                                                                                                                                                                                                                                              
|     |  |                                                                                                                                                                                                                                                                                                                                                                                                                                
|31.1 |  | Certification pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 from the Company's Chief Executive Officer.                                                                                                                                                                                                                                                                                                            
|     |  |                                                                                                                                                                                                                                                                                                                                                                                                                                
|31.2 |  | Certification pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 from the Company's Chief Financial Officer.                                                                                                                                                                                                                                                                                                            
|     |  |                                                                                                                                                                                                                                                                                                                                                                                                                                
|32.1 |  | Certification pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 from the Company's Chief Executive Officer.                                                                                                                                                                                                                                                                                                            
|     |  |                                                                                                                                                                                                                                                                                                                                                                                                                                
|32.2 |  | Certification pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 from the Company's Chief Financial Officer.                                                                                                                                                                                                                                                                                                            
|     |  |                                                                                                                                                                                                                                                                                                                                                                                                                                
|101  |  | The following materials from Hemispherx’ Quarterly Report on Form 10-Q for the period ended March 31, 2016 formatted in eXtensible Business Reporting Language (“XBRL”): (i) Condensed Balance Sheets; (ii) Condensed Consolidated Statements of Comprehensive Loss; (iii) Changes in Stockholders' Equity; (iv) Condensed Consolidated Statements of Cash Flows; and (v) Notes to Condensed Consolidated Financial Statements.
|     |  |                                                                                                                                                                                                                                                                                                                                                                                                                                
|(1)  |  | Confidential portions of this exhibit have been redacted and filed separately with the Commission pursuant to a confidential treatment request in accordance with Rule 24b-2 of the Securities Exchange Act of 1934, as amended.                                                                                                                                                                                               



-3-







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 thereunto duly authorized.



|                      | HEMISPHERX BIOPHARMA, INC.         
|--------------------- | -----------------------------------
|                      |                                    
|                      | /s/ Thomas K. Equels               
|                      | Thomas K. Equels, Esq.             
|                      | Chief Executive Officer & President
|                      |                                    
|                      | /s/ Adam Pascale                   
|                      | Adam Pascale                       
|                      | Chief Financial Officer            
|                      |                                    
|Date: August 29, 2016 |                                    



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