Re: Generex Biotechnology Corporation - Amendment to Jun 17 05 Warrant

Exhibit 4.2

October 26, 2005

c/o Highbridge Capital Management, LLC

9 West 57^th Street

27^th Floor

New York, New York

USA 10019

Attention: Ari J. Storch / Adam J. Chill

Dear Sirs:

We make reference to the common stock purchase warrant issued by Generex Biotechnology Corporation (the “Company”) to Smithfield Fiduciary LLC (“Smithfield”) on June 17, 2005 pursuant to which the Company granted to Smithfield the entitlement to purchase up to 609,756 shares of the Company’s common stock at $0.82 per share (the “Warrant”).

The Initial Exercise Date (as that term is defined in the Warrant) of the Warrant is expressed therein as the 181^st day after the date thereof. The Company hereby confirms that, in consideration of the exercise by Smithfield of not less than 100% of the Warrant and the delivery to the Company of a Notice of Exercise in respect thereof on or before the close of business on October 27, 2005, the Company has agreed to abridge the Initial Exercise Date and to honor the aforementioned Notice of Exercise.

Yours truly,

Mark A. Fletcher

Executive Vice-President, General Counsel

maf:hs