SecProbe.io

September 15, 2010
 William A. Carter, M.D. Chief Executive Officer Hemispherx Biopharma, Inc. 1617 JFK Boulevard  Philadelphia, PA 19103
Re: Hemispherx Biopharma, Inc.
 Form 10-K for the year ended December 31, 2009
Form 10-K/A for the year ended December 31, 2009 File No. 1-13441

Dear Mr. Carter:
We have reviewed your filings and have the following comments. In some of our
comments, we may ask you to provide us w ith information so may better understand your
disclosure.
 Please respond to this letter within te n business days by providing the requested
information or by advising us when you will provide the requested response. If you do not believe a comment applies to your facts and circ umstances or do not believe an amendment is
appropriate, please tell us why in your response. Please furnish us a letter on EDGAR under the
form type label CORRESP that keys  your response to our comment.

After reviewing your response, we may have additional comments.

Form 10-K for the fiscal year ended December 31, 2009

 Item 1. Business, page 1

 General

1. We note your discussion throughout  the Business section of various agreements with
third parties and the agreements  listed in the exhibit index to the filing.  Please provide
draft disclosure to be included in an am ended Form 10-K clarifying which agreements
are considered material to the company and to further describe all material terms of each,
including the financial obligations of each party and the duration and termination provisions.  To the extent you have listed ag reements in the exhib it index but have not
described them in the filing, please advise us as to your reasoning, or, alternatively,
provide a discussion of the material terms in  the Business section of the filing.  To the
extent any agreements listed in the exhibit index are no longer in effect or have been
terminated, please consider rem oving them from the list.

William A. Carter, M.D. Hemispherx Biopharma, Inc. September 15, 2010 Page 2

Our Products, page 2

2. Please provide draft disclosure to be included in an amende d Form 10-K to disclose the
following information for each of your major research and development projects:

• The costs incurred during each period presented and to date on the project;
• The nature, timing and estimated costs of the efforts necessary to complete the
project;
• The anticipated completion dates;
• The risks and uncertainties associated with completing development on schedule,
and the consequences to operations, financ ial position and liquidity if the project
is not completed timely; and finally
• The period in which material net cash in flows from significant projects are
expected to commence.
 If you do not maintain any research and develo pment costs by project, disclose that fact
and explain why management does not maintain  and evaluate resear ch and development
costs by project.  Provide other quantitative or  qualitative disclosure that indicates the
amount of the company’s resource s being used on the project.

Please disclose the amount or range of estimat ed costs and timing to complete the phase
in process and each future phase. To the extent that information is not estimable, disclose
those facts and circumstances indicating the uncertainties th at preclude you from making
a reasonable estimate.

Item 10. Directors and Executive Officer s and Corporate Governance, page 48

3. Please provide draft disclosure to be incl uded in an amended Fo rm 10-K discussing the
specific experience, qualifications, attributes or  skills that led to the conclusion that each
director should serve on the board of the company, as required by newly revised Item 401(e)(1) of Regulation S-K.  Pl ease note that the present disc losure of each individual’s
business experience alone is not sufficient to comply with this requirement.

Audit Committee and Audit Committee Expert, page 51

4. Please provide draft disclosure to be in cluded in an amended Form 10-K clearly
explaining why you do not have an audit comm ittee financial expert, as required by Item
407(d)(5)(i)(C) of Regulation S-K.

William A. Carter, M.D. Hemispherx Biopharma, Inc. September 15, 2010 Page 3

Consolidated Financial Statements
 (17) Fair value, page F-33

5. You determined that warrants with cash settle ment features were liabilities.  However,
you assumed that the fair value of the warrants was zero based on a model which determines the probability that the cash settle ment feature condition will arise.  Please tell
us why it is appropriate to assign no value to  the warrants under each scenario that you
considered in determining the fair value of  the warrants.  Please cite us for the
authoritative accounting literatur e that you relied upon to valu e the warrants under each
scenario.
 Form 10-K/A filed April 30, 2010

 General

6. We note that you have not included any disc losure in response to Item 402(s) of
Regulation S-K.  Please descri be the process you undertook to  reach this conclusion and
present your analysis supporting the conclusion that such disclosure was not necessary.
 Compensation Discussion and Analysis

 Annual Bonus, page 5

7. Please provide draft disclosure  to be included in an ame nded Form 10-K which discusses
the following information:
• The “corporate, department and indivi dual performance goals,” referenced on
pages 5 and 6, applicable to each named executive officer and used to determine
annual bonuses for the 2009 fiscal year.
• How each goal was weighted, if applicable. To the extent that any of the
performance goals were quantitative, your disclosure should also be quantitative.
• The threshold, target, and maximum levels  of achievement of each performance
goal, if applicable.
• The intended relationship between the le vel of achievement of corporate and
individual performance goals and th e amount of bonus to be awarded.
• The evaluation by the Committee of the level of achievement by each named
executive officer of the corporate and indi vidual performance goals applicable to
them individually.
• How this level of achievement translated  into the actual bonus es awarded for the
2009 fiscal year.
• The percentage of base salary awarded in  the form of an incentive bonus to each
named executive officer as a result of the company’s performance.  To the extent

William A. Carter, M.D. Hemispherx Biopharma, Inc. September 15, 2010 Page 4

factors other than the corporate goals were considered, please disclose these
factors.

Summary Compensation Table, page 12

8. Please revise your Summary Co mpensation Table to comply with newly revised Item
402(c)(2)(v) and (vi) of Regulation S-K.

We urge all persons who are responsible for th e accuracy and adequacy of the disclosure
in the filing to be certain that the filing include s the information the Securities Exchange Act of
1934 and all applicable Exchange Act rules requir e.  Since the company and its management are
in possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.
 In responding to our comments, please provi de a written statement from the company
acknowledging that:
• the company is responsible for the adequacy an d accuracy of the disclo sure in the filing;

• staff comments or changes to disclosure in response to staff comments do not foreclose
the Commission from taking any action with respect to the filing; and

• the company may not assert staff comments as  a defense in any proceeding initiated by
the Commission or any person under the federa l securities laws of  the United States.

You may contact Sasha Parikh, Staff Accountant, at (202) 551-3627 or Gus Rodriguez,
Accounting Branch Chief, at (202) 551-3752 if you have questions regarding the processing of
your response as well as any questions regarding comments on the financial statements and
related matters.  Please contac t Laura Crotty, Staff Attorney, at (202) 551-3563 with questions
on any of the other comments.  In this regard, do not hesitate to cont act me at (202) 551-3679.

Sincerely,

Jim B. Rosenberg Senior Assistant Chief Accountant