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): February 3, 2005

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

Delaware                                001-32325          13-3894575
(State or other jurisdiction            (Commission        IRS Employer
of incorporation or organization)       File Number)       Identification No.)

                        420 Lexington Avenue, Suite 1609
                            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)

         Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions:

         /  / Written communication pursuant to Rule 425 under the Securities
              Act (17 CFR 230.425)

         /  / Soliciting material pursuant to Rule 14a-12 under the Exchange
              Act (17 CFR 240.14a-12)

         / /  Pre-commencement communications pursuant to Rule 14d-2(b) under 
              the Exchange Act (17 CFR 240.14d-2(b))

         / /  Pre-commencement communications pursuant to Rule 13e-4(c) under 
              the Exchange Act (17 CFR 240.13e-4(c))

 ITEM 8.01        OTHER EVENTS.

         Callisto Pharmaceuticals, Inc. (the "Company") hereby discloses a
 description of complete responses in a Phase I study of Annamycin in patients
 with relapsed/ refractory acute myeloid ("AML") and lymphoid leukemias ("ALL").

          Twenty-one patients with relapsed/refractory AML (n=18) or ALL (n=3)
were enrolled in this Phase I trial which commenced in April 1999 at The
University of Texas M.D. Anderson Cancer Center with Dr. Michael Andreeff as the
Principal Investigator. The study enrolled 21 patients, of which 20 were
evaluable. An abstract on the outcome of this trial was presented at the 2001
ASCO Annual Meeting, Abstract No. 1211. Of the 21 registered patients, one
patient (AML) was enrolled but not treated. The median age of patients in the
trial was 58. The maximum tolerated dose ("MTD") in the leukemia trial was
determined to be 280 mg/m2 daily x 3 days with grade 3/4 hepatoxicity and
mucositis observed at the higher dose level. Two patients achieved complete
responses ("CR"), one AML and one ALL patient. The AML patient achieved a CR at
280 mg/m2/day X 3 days, taking 5 weeks to achieve CR with two consolidations.
The CR duration was 13 weeks, and the patient failed further salvage. Survival
post treatment was 30 weeks. The ALL patient achieved a CR at 350 mg/m2/day X 3
days, taking 6 weeks to achieve CR with one consolidation, with clearance of CNS
leukemia. The CR duration was 5+ weeks, and the patient expired in CR. Survival
post treatment was 11 weeks.


         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 hereunto duly authorized.

Dated:   February 3, 2005

                             CALLISTO PHARMACEUTICALS, INC.

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