The News

TRISENOX® U.S. Marketing Exclusivity Extended to 2018 - CTI expands TRISENOX® use in Europe with launch in Italy

21/04/2004

April 21, 2004 Seattle—Cell Therapeutics, Inc. (CTI) (NASDAQ and Nuovo Mercato: CTIC)announced that the U.S. Patent and Trademark office has issued a patent directed to TRISENOX® (arsenic trioxide) injection that extends CTI’s marketing exclusivity for the drug from 2007 to 2018. With a longer period of exclusivity, CTI has committed to expanding TRISENOX sales in Europe and launched TRISENOX earlier this month in Italy for the treatment of relapsed/refractory acute promyelocytic leukemia (APL). In addition to Italy,TRISENOX is commercially available in the United States, United Kingdom, Ireland, France, Spain, Germany, Austria, the Netherlands, Sweden, Denmark and Finland. CTI also plans to launch the drug in Portugal, Greece, Belgium, and Norway.

“The newly issued TRISENOX U.S. patent extends our period of market exclusivity 11 years past the original orphan drug exclusivity period and provides the rationale for further investment in international registration directed trials targeting larger commercial indicationssuch as front-line APL, multiple myeloma, and other blood-related and solid tumor malignancies. Following the successful expansion of our European commercial infrastructure earlier this year, the launch of TRISENOX in Italy brings the total number of European countries where we market TRISENOX to 10. These European markets combined represent approximately 99 percent of the population of the United States,” stated James A. Bianco, M.D. President and CEO of CTI. “Our investments in new management and expanded commercial infrastructure could add significantly to future cash flows and have a significant effect on our P&L in 2005 and beyond.”

The U.S. patent, which was formally issued on April 20, 2004 as patent number 6,723,351,relates to methods for treating APL patients and covers all of the drug’s approved uses. CTI is the exclusive licensee to this patent and has been advised that the patent will be listed in the FDA Orange Book against approval of generic versions of TRISENOX until the patent expires in October 2018.

“TRISENOX is a highly effective therapy for first- and subsequent-relapse APL, with an 87 percent complete remission rate. We are pleased that APL patients in Italy now have access to it," said Prof. Sergio Amadori, Tor Vergata, University of Rome. “APL patients whose disease has relapsed have few treatment options. Given the response rates we have seen with TRISENOX in this patient population, I believe there will be a high adoption rate for its use in Italy.”

TRISENOX is also being evaluated in an ambitious development program in more than 40 clinical and investigator-sponsored trials in front-line APL and other malignancies including multiple myeloma, myelodysplastic syndrome, non-Hodgkin’s lymphoma, hormone refractory prostate cancer, melanoma, glioblastoma, and acute and chronic leukemias. With extended patent coverage, CTI will move forward with plans to initiate pivotal studies of TRISENOX in combination with other agents in hematologic malignancies.

About TRISENOX®
TRISENOX® is marketed by CTI. TRISENOX® was approved for marketing in 2000 by the U.S. Food and Drug Administration and in March 2002 by the European Commission to treat patients with relapsed or refractory APL, a rare, life-threatening form of leukemia.

WARNING: TRISENOX® should be administered under the supervision of a physician who is experienced in the management of patients with acute leukemia. Some patients with APL treated with TRISENOX® have experienced differentiation syndrome -- with symptoms similar to retinoic acid syndrome. Arsenic trioxide can cause QT prolongation (which can lead to torsade de pointes) and complete atrioventricular block.

The most common adverse events associated with TRISENOX® have been generally manageable, reversible and usually did not require interruption of therapy. These have included hypokalemia, hypermagnesemia, hyperglycemia and thrombocytopenia as reported in 13 percent of the patients (n=40). Abdominal pain, dyspnea, hypoxia, bone pain and neutropenia were reported in 10 percent of these patients, while arthralgia, febrile neutropenia and disseminated intravascular coagulation were reported in eight percent of patients.

About Cell Therapeutics, Inc.
Based in Seattle, CTI is a biopharmaceutical company committed to developing an integrated portfolio of oncology products aimed at making cancer more treatable.

This announcement includes forward-looking statements that involve a number of risks and uncertainties, the outcome of which could materially and/or adversely affect actual future results. Specifically, the risks and uncertainties that could affect the continued development of TRISENOX® include risks associated with preclinical and clinical developments in the biopharmaceutical industry in general and with TRISENOX® in particular including, without limitation, the potential failure of TRISENOX® to prove safe and effective for treatment of APL, multiple myeloma and myelodysplasia, non-Hodgkin’s lymphoma, hormone refractory prostate cancer, melanoma, glioblastoma, and acute and chronic leukemia, determinations by regulatory, patent and administrative governmental authorities, competitive factors, the potential failure to achieve returns on our investments in international registration directed trials targeting larger commercial indications for TRISENOX®, technological developments, costs of developing, producing and selling TRISENOX®, and the risk factors listed or described from time to time in the Company’s filings with the Securities and Exchange Commission including, without limitation, the Company’s most recent filings on Forms 10-K, 8-K and 10-Q.

For further information please contact:
Investors
Cell Therapeutics, Inc.
Leah Grant
T: 206.282.7100 F: 206.272.4010
E: invest@ctiseattle.com
www.cticseattle.com/investors.htm
Media
Cell Therapeutics, Inc.
Candice Douglass
T: 206.272.4472 F: 206.272.4010
E: media@ctiseattle.com
www.cticseattle.com/media.htm
Cell Therapeutics, Inc. (Europe)
Karl Hanks
T: 39 026 103 5807
F: 39 026 103 5601
E: karl.hanks@ctimilano.com