SecProbe.io

December 29, 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 December 23, 2010 re sponse to our December 3, 2010 letter and
have the following comments.
 Please respond to this letter within te n business days by providing the requested
information or by advising us when you will provide this information.  Please furnish us a letter on EDGAR under the form type label CORRESP th at keys your response to our comments.
 After reviewing the information provided, we may raise additional comments.

Appendix A to your December 23, 2010 response

 Critical Accounting Policies

1. We note you identify warrant liability as a critical policy in your proposed revised
disclosure to be included in an amendment to your December 31, 2010 Form 10-K.  The intent of identifying critical policies is to id entify those that  require material assumptions
and estimates which if different assumptions and estimates were made would materially
affect the financial statements.  Please revi se your proposed disclo sure to explain how
this policy requires significant estimates and quantify the effect on the financial
statements of changes in estimates in each  year presented and the reasons for those
changes.  Please also disclose why you select ed the volatility measure that you selected.
If the volatility assumption is based on an average method, please disclose why you
chose not to rely exclusively on your historical volatility.  Please also disclose the peer
group of companies used to determine the av erage volatility assumption, the weight given
to companies in the peer group in compu ting the average vola tility assumption and
whether the companies in the peer group of co mpanies are similar to you in terms of size,
product and market capitalization.

William A. Carter, M.D. Hemispherx Biopharma, Inc. December 29, 2010 Page 2

 (17) Fair Value

2. Please revise your disclosure regarding the wa rrant liability classi fied as level 3 to
include a descripti on of the inputs and  valuation technique(s) used to measure fair value
and a discussion of changes in valuation tech niques and related inputs, if any, during the
period as well as a reconciliation of the be ginning and ending balances, separately
presenting changes during the peri od. Refer to ASC 820-10-50.

3. Please provide us supplementally with the inpu ts used in the Black Scholes model at each
valuation date (March 2010, June 2009/ 2010, September 2009/2010), to determine the
fair value of the warrant liability, similar to that provided for the period ended December
31, 2009. In your response, explain why any assu mptions remained consistent from those
used at December 31, 2009 (i.e. volatility), if true, and th e accounting literature that
supports your accounting treatment.    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 questio ns regarding the comment.  In this regard, do not hesitate to
contact me at (202) 551-3679.
Sincerely,

Jim B. Rosenberg Senior Assistant Chief Accountant