Callisto Pharmaceuticals Granted Orphan Drug Designation For Atiprimod To Treat Carcinoid Tumors

Callisto Pharmaceuticals, Inc. (Amex: KAL), a biopharmaceutical company primarily focused on the development of drugs to treat cancer, announced today that the Office of
Orphan Products Development of the United States Food and Drug
Administration (FDA) has granted orphan drug designation to the company's
drug candidate Atiprimod for the treatment of carcinoid tumors. Atiprimod,
a small molecule antiangiogenic drug, is being developed by Callisto to
treat advanced carcinoid tumors as well as relapsed multiple myeloma
patients. Callisto plans to begin a Phase II clinical trial in advanced
carcinoid cancer patients in the coming months.



"This marks an important step for Callisto's Atiprimod program,"
commented Callisto Chief Executive Officer Dr. Gary S. Jacob. "Callisto is
planning an ambitious program of clinical development of Atiprimod in the
carcinoid indication and the designation of orphan drug status gives
additional assurance that we are well protected against any potential
competition."



About Orphan Drug Designation



The Orphan Drug Act is intended to encourage development of products
for rare diseases affecting fewer than 200,000 people in the United States.
Orphan drug designation, along with approval by the FDA for
commercialization of Atiprimod, entitles Callisto to seven years of market
exclusivity in the United States, provided Callisto continues to meet
certain conditions established by the FDA. During the seven-year
exclusivity period, the FDA will not accept or approve other applications
to market the same medicinal product for the same therapeutic indication.



For products designated as orphan drugs, the FDA not only provides
market protection for the developing company, but also provides certain tax
credits, eligibility for research grants and protocol assistance,
opportunities for regulatory agency assistance on review of clinical
protocols, and waiver of the Prescription Drug User Fee Act (PDUFA) filing
fee.



About Atiprimod



Atiprimod is in clinical trials for advanced carcinoid tumors and
relapsed multiple myeloma (MM). A small-molecule, orally available drug
with antiproliferative and antiangiogenic activity, Atiprimod began an
open-label Phase I/IIa clinical trial in relapsed MM patients in May 2004,
and the trial has been extended to higher dosages of drug. Notably,
Atiprimod was found to give encouraging activity in a cohort of carcinoid
cancer patients in a Phase I clinical trial in advanced cancer patients. In
June 2006 interim results from the trial were released showing that 3 of
the 5 patients on the drug gave measurable tumour regressions and loss of
debilitating symptoms. Callisto recently announced plans to open a Phase II
clinical trial of Atiprimod in advanced carcinoid patients in 3Q 2006.
















About Callisto Pharmaceuticals, Inc.



Callisto is a biopharmaceutical company focused on the development of
new drugs to treat various forms of cancer and other serious afflictions.
Callisto's drug candidates in development currently include anti-cancer
agents in clinical development, in addition to drugs for other significant
health care markets, including ulcerative colitis. One of the Company's
lead drug candidates, Atiprimod, is in development to treat advanced
carcinoid cancer and relapsed multiple myeloma, a blood cancer. Atiprimod
is presently in Phase I/IIa human clinical trials in relapsed multiple
myeloma patients, and advanced cancer patients, respectively. A second drug
candidate, L-Annamycin, is being developed as a treatment for forms of
relapsed acute leukemia, a currently incurable blood cancer. Callisto
initiated a clinical trial of L-Annamycin in adult relapsed acute
lymphocytic leukemia patients in 4Q 2005. L-Annamycin, is from the
anthracycline family of proven anti-cancer drugs, has a novel therapeutic
profile, including activity against resistant diseases and significantly
reduced cardiotoxicity, or damage to the heart, compared to currently
available drug alternatives. Callisto also has drugs in preclinical
development for gastro-intestinal inflammation, and cancer. Callisto has
exclusive worldwide licenses from AnorMED Inc. and M.D. Anderson Cancer
Center to develop, manufacture, use and sell Atiprimod and L-Annamycin,
respectively. Callisto is also listed on the Frankfurt Stock Exchange under
the ticker symbol CA4, more information at callistopharma.



Forward-Looking Statements



Certain statements made in this press release are forward-looking. 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. As
discussed in the Callisto Pharmaceuticals Annual Report on Form 10-K/A for
the year ended December 31, 2005, and other periodic reports, as filed with
the Securities and Exchange Commission, actual results could differ
materially from those projected in the forward-looking statements as a
result of the following factors, among others: uncertainties associated
with product development, the risk that products that appeared promising in
early clinical trials do not demonstrate efficacy in larger-scale clinical
trials, the risk that Callisto will not obtain approval to market its
products, the risks associated with dependence upon key personnel and the
need for additional financing.


Callisto Pharmaceuticals, Inc
callistopharma