HEMISPHERX BIOPHARMA, iNC. One Penn Center 1617 JFK Boulevard Philadelphia, PA 19103 Telephone 215-988-0080 Fax 215-988-0080 April 23,2009 Securtites and Exchange Commission 100 F Street, NE Washington, D.C. 20549 Re: Hemispherx Biopharma, Inc. Form S-1 4-9-2009 Sec filing No. 333-158518 ------------------------------ FORM RW --------- Dear Sir or Madam, We request that the above referenced Form S-1 be withdrawn. We tagged this filing as S-1 but it should have been tagged as POS AM. This withdrawal request is being made because we have to refile this document under the correct tag POS AM. If you have any questions or comments in regard to this withdrawal request, please cantact me at the above address. Very truly yours, /s/ Charles T. Bernhardt ------------------------ Charles T. Bernhardt,CFO