SecProbe.io

November 4, 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 October 8, 2010 res ponse to our September 15, 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 responses to our comments.
 After reviewing the information provided, we may raise additional comments and/or
request that you amend your filing.

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

 Item 1. Business

 Our Products, page 2

1. We acknowledge your response to prior comment 2.  Please disclose th e costs incurred to
date related to Ampligen.  Y ou also indicated that you are in process of undergoing the
tests needed for the validation phase to addr ess the issues identified in the CRL.  Since
you are aware of what needs to be done to comply with the FDA requirements, it appears
that costs could be estimated or a range of estimated costs could be determined.  Please revise your proposed disclosure  to indicate the na ture, timing and estimated costs of the
efforts necessary to complete the Ampligen project and the anticipated completion dates
or the reason that an estimate cannot be made.

William A. Carter, M.D. Hemispherx Biopharma, Inc. November 4, 2010 Page 2

 (17) Fair value, page F-33

2. We acknowledge your response to prior commen t 5.  You stated that the probability-
adjusted Black-Scholes value of your warrant s is zero.  Please tell us the assumed
probability of an event taking place that would cause cash settlement.  Please also tell us
the various factors considered  that decreased the likelihood of a Fundamental Transaction
occurring that would require cash settlement.  Please provide us w ith your analysis that
supports the probability of each of these factors to be zero and that the value of the
warrants is zero for each scenario considere d, including scenarios that do not require cash
settlement.
 Form 10-K/A filed April 30, 2010

 Summary Compensation Table, page 12

3. We note your response to our prior comment 8. It appears that the figures in the 2008
Stock Awards and Option Awards columns of the Summary Compensation Table on page
A-41 of your response letter have not changed from the disclosure included in your Form
10-K for the fiscal year ended December 31, 2008. Please confirm that the all figures
appearing on page A-41 of your response were  calculated in accordance with FASB ASC
718.

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