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Cell Therapeutics, Inc. To Initiate Pivotal Trial for Pixantrone in Relapsed Aggressive Non-Hodgkin’s Lymphoma

04/03/2004

First randomized controlled trial using FDA Special Protocol Assessment (SPA)procedure will target potential market of 30,000 NHL patients in the U.S.

Mar. 4, 2004 Seattle—Cell Therapeutics, Inc. (CTI) (NASDAQ and Nuovo Mercato: CTIC)announced that the U.S. Food and Drug Administration has provided guidance through the Special Protocol Assessment (SPA) process for a randomized pivotal trial of Pixantrone in the treatment of relapsed, aggressive non-Hodgkin’s lymphoma (NHL).
The trial protocol and supporting data are in the final stages of review with the FDA and initiation of the pivotal study is planned for later this month. The trial is designed to examine the complete response (CR)rate, time to tumor progression, and overall survival of patients with aggressive NHL who have failed front-line and at least one second-line multi-agent chemotherapy regimen. Patients will be randomized to receive either Pixantrone or another currently used, single-agent drug of physician’s choice. FDA has indicated that Pixantrone would qualify for accelerated approval based upon the successful conclusion of this trial and supporting data from ongoing and completed clinical studies.
The trial is expected to enroll approximately 320 patients with enrollment taking approximately 12 months to complete.
“Current single-agent treatments for patients who have failed two or more prior multi-agent regimens produce partial responses in only about 10 to 15 percent of patients and those responses are typically short-lived, lasting on average approximately three months. Complete responses are not typically reported in this population of patients with currently available single-agents and are considered by international lymphoma experts and the FDA as the “gold standard” to demonstrate a clinically meaningful benefit to patients with this disease,” stated James A. Bianco, M.D., President and CEO of CTI.
“Although anthracyclines are the most potent class of drugs for treating this disease, the cumulative heart damage associated with their use in front-line regimens prevents patients from receiving further treatment with these drugs, leaving them with no approved effective treatment options.” The design for this pivotal trial was supported by phase I/II data from approximately 170 patients with relapsed or refractory, aggressive NHL treated with Pixantrone. In our phase I/II experience of among 36 elderly, relapsed, aggressive NHL patients, 12 patients (33 percent)had significant shrinkage of their tumors with seven patients (20 percent) experiencing a complete disappearance (CR) of their cancer.
Importantly, the responses were long-lived with a median duration of response of more than 11 months. The results from these studies indicate that the regimen was generally well tolerated; some dosing was delayed or omitted due to myelosuppression. With the initiation of this pivotal study, CTI has two phase III and five phase II clinical studies of Pixantrone planned or ongoing involving single-agent or combination therapy in the treatment of first, second, or third-line aggressive NHL or indolent NHL. In the United States,it is estimated that more than 33,000 patients receive salvage therapy for third-line or greater NHL each year, with more than 60,000 patients receiving multi-agent chemotherapy for frontline or second-line treatment. Special Protocol Assessment Process The special protocol assessment process provides a forum for FDA and the sponsor to reach agreement as to the design, execution, and analyses proposed in protocols reviewed under this process. In general, these assessments are considered binding on the review division as well as the sponsor, unless public health concerns unrecognized at the time of a protocol assessment become evident or other scientific concerns arise.

About Pixantrone Pixantrone (pronounced Pick-san-troan) is an investigational agent under development for the potential treatment of various hematological malignancies, solid tumors and immunological disorders. It was developed to improve the activity and safety of the anthracycline family of anti-cancer agents. Anthracyclines have been shown to be very active clinically in a number of tumor types. However, they are usually associated with cumulative heart damage that prevents them from being used in a large proportion of patients. Pixantrone has been designed to reduce the potential for these severe cardiotoxicities, as well as to potentially increase activity and simplified administration compared to the currently marketed anthracyclines.

About Cell Therapeutics, Inc.
Headquartered 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 development of Pixantrone include risks associated with preclinical and clinical developments in the biopharmaceutical industry in general and
with development of Pixantrone in particular including, without limitation, the potential failure of Pixantrone to prove safe and effective for treatment of non-Hodgkin’s lymphoma, determinations by regulatory, patent and administrative governmental authorities, competitive factors, technological developments, costs of developing, producing and selling Pixantrone, 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