Washington, DC 20549

                                    FORM 8-K

                                 CURRENT REPORT

     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

        Date of Report (Date of earliest event reported): April 19, 2004

                         Callisto Pharmaceuticals, Inc.
             (Exact name of registrant as specified in its charter)

Delaware                                 333-63474           13-3894575
(State or other jurisdiction             (Commission         IRS Employer
of incorporation or organization)        File Number)        Identification No.)

                        420 Lexington Avenue, Suite 2500
                            New York, New York 10170
                    (Address of principal executive offices)

Registrant's telephone number, including area code: (212) 297-0010

          (Former name or former address, if changed since last report)

Item 5   Other Events and Required FD Disclosure.

         On April 19, 2004, Callisto Pharmaceuticals, Inc., a Delaware
corporation ("Callisto"), issued a press release announcing that it raised
approximately $4.84 million in gross proceeds through a private placement of
approximately 2.15 million shares of Callisto Common Stock. The Common Stock was
sold at a price of $2.25 per share. A copy of the press release is attached
hereto as Exhibit 99.1.

         The securities issued in the private placement have not been registered
under the Securities Act of 1933, as amended, and until so registered the
securities may not be offered or sold in the United States absent registration
or availability of an applicable exemption from registration. Pursuant to the
Common Stock Purchase Agreement, Callisto is required to prepare and file with
the Securities and Exchange Commission, within 30 days after the closing date, a
registration statement for the purpose of registering for resale all of the
shares of Callisto Common Stock sold in the private placement.

         The foregoing description of the private placement does not purport to
be complete and is qualified in its entirety by reference to the Common Stock
Purchase Agreement dated April 19, 2004, which is attached hereto as Exhibit
10.1, which is incorporated herein by this reference.

Item 7   Financial Statements, Pro Forma Financial Information and Exhibits.

(c)      Exhibits.

         Exhibit Number              Description

         10.1                        Common Stock Purchase Agreement, dated as
                                     of April 19, 2004 by and among the
                                     Registrant and the purchasers set forth on
                                     Exhibit A thereto.

         99.1                        Press Release dated April 19, 2004.


         Pursuant to the requirements of the Securities Exchange Act of 1934,
the Registrant has duly caused this report to be signed on its behalf by the
undersigned, hereto duly authorized.

Dated: April 19, 2004

                                           CALLISTO PHARMACEUTICALS, INC.

                                           By: /s/ Gary S. Jacob
                                               Gary S. Jacob, Ph.D.
                                               Chief Executive Officer