Ann Arbor, Michigan, April 6, 2004 -- Aastrom Biosciences, Inc. (NasdaqSC: ASTM) announced today that the exercise price of the warrants issued to a group of institutional investors was $1.65 per share of common stock rather than the $1.42 per share of common stock, as originally stated in a press release issued by the Company yesterday, April 5, 2004. The warrants were issued by the Company to the institutional investors who purchased 8 million shares of common stock, through a registered direct offering from an existing shelf registration statement, for aggregate gross proceeds of approximately $9.1 million. At the corrected exercise price, the warrants could generate approximately $4 million in proceeds to Aastrom, if exercised.

A registration statement relating to these securities has been filed with the U.S. Securities and Exchange Commission. A prospectus and prospectus supplement relating to this transaction may be obtained directly from the Company (Investor Relations, P.O. Box 376, Ann Arbor, Michigan, 48106) or from the U.S. Securities and Exchange Commission website at www.sec.gov.

This press release does not constitute an offer to sell or the solicitation of an offer to buy, and these securities cannot be sold in any state in which this offer, solicitation, or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

CONTACTS:

Kris M. Maly or Becky Anderson
Investor Relations Department
Aastrom Biosciences, Inc.
Phone: (734) 930-5777

Kevin McGrath
Cameron Associates
Phone: (212) 245-4577