NEW YORK, NEW YORK – January 21, 2004 – Callisto Pharmaceuticals, Inc. (OTCBB:CLSP), a biopharmaceutical company primarily focused on the development of drugs to treat multiple myeloma, other cancers and osteolytic bone disease, announced today the completion of a private placement of approximately 3.9 million shares of its common stock for aggregate proceeds of approximately $5.86 million. Callisto intends to use a portion of the net proceeds from the private placement for working capital and to further the clinical trials of its lead drug candidate, Atiprimod.

The common stock sold to the private placement investors has not been registered under the Securities Act of 1933. Accordingly, these shares may not be offered or sold in the United States, except pursuant to the effectiveness of a registration statement or an applicable exemption from the registration requirements of the Securities Act. Callisto has agreed to file a registration statement covering resales of the shares by the private placement investors. This press release shall not constitute an offer to sell or the solicitation of an offer to buy the common stock. This press release is being issued pursuant to and in accordance with Rule 135c under the Securities Act.

About Callisto Pharmaceuticals, Inc.
Callisto is a biopharmaceutical company primarily focused on the development of drugs to treat multiple myeloma, other cancers and osteolytic bone disease. Callisto’s lead drug candidate, Atiprimod, is a small-molecule, orally available drug with antiproliferative and antiangiogenic activity. Atiprimod successfully completed Phase I clinical trials in rheumatoid arthritis patients and Callisto plans to enter Atiprimod in a safety and proof-of-principle clinical trial in multiple myeloma patients. The drug is also being explored as an agent to treat osteolytic bone disease. In addition,

Callisto has programs focused on the development of an analog of the human intestinal hormone, uroguanylin, to treat colon cancer, and drugs to protect against staphylococcal and streptococcal bioweapons, protecting against the devastating effects of toxic shock syndrome. Callisto has two operating subsidiaries, Callisto Research Labs, LLC and Synergy Pharmaceuticals Inc. Callisto has an exclusive worldwide license from AnorMED Inc. to develop, manufacture, use and sell Atiprimod. For additional information, visit www.callistopharma.com.

Included in this release are “forward-looking” statements. Such statements are indicated by words such as “expect,” “should,” “anticipate” and similar words indicating uncertainty in facts and figures. Although Callisto believes that the expectations reflected in such forward-looking statements are reasonable, it can give no assurance that such expectations reflected in such forward-looking statements will prove to be correct. Callisto’s actual results could differ materially from those anticipated in the forward-looking statements as a result of various factors.

Contact:
Contact Information:
Marty Tullio
Managing Member
McCloud Communications LLC
949.566.9860
marty@McCloudCommunications.com

Gary S. Jacob, Ph.D.
CEO
Callisto Pharmaceuticals, Inc.
212.297.0010


Source: Callisto Pharmaceuticals, Inc.