Exhibit 10.1

EX-10.1 2 sigmatauletter.htm SIGMA TAU LETTER Sigma Tau Letter

Exhibit 10.1

Sigma-Tau Pharmaceuticals. Inc.

800 South Frederick Ave., Suite 300

Gathersburg, MD 20877

Tel: 301 ###-###-####

Fax ###-###-####

February 21, 2007

Christopher J. Schaber, Ph.D.

President & CEO

DOR BioPharma, Inc.

1101 Brickell Avenue, Suite 701-S

Miami, FL 33131-3105

Dear Chris,

Ref: Letter of Intent, January 2, 2007

After careful consideration, in recognition of the unsolicited proposal from Cell Therapeutics, Inc. to acquire DOR, Sigma-Tau Pharmaceuticals, Inc, has determined that it will not consider a counter or matching proposal for acquisition.

Therefore, in the interest of all current shareholders of DOR, this letter should serve as notification that Sigma-Tau Pharmaceuticals will forego the remainder of its exclusivity period under the January 2, 2007 Letter of Intent to allow DOR the option of pursuing all other possible merger and/or acquisition alternative with other interested parties.

However, please note that it remains the intent of Sigma-Tau Pharmaceuticals to continue evaluate with DOR the potential of a European collaboration for orBec.

Yours Truly,

/s/ Gregg Lapointe

Gregg Lapointe

Chief Operating Officer

Cc: Ms. Lorenza Laureti, Director of Legal Affairs