Preliminary Clinical Results of XYOTAX(TM) in Combination with Platinates Provide Encouraging Anti-Tumor Activity in Heavily Pre-treated Patients with Recurrent Solid Tumors

Studies Support the Investigation of XYOTAX(TM) in Front-Line Treatment of Patients with Ovarian Cancer

SEATTLE, Sept. 24 /PSA Rising/ -- Seattle-Cell Therapeutics, Inc. (CTI) (Nasdaq: CTIC) announced today that XYOTAX(TM) was featured in five presentations at the European Cancer Conference (ECCO) in Copenhagen this week. Two of the presentations, both studies of XYOTAX(TM) in combination with platinates in patients with solid tumors, report preliminary data that showed an overall response rate of 68 percent (30 of 44 patients). The majority of patients on the two studies had tumor types that are either intrinsically resistant to or had developed resistance to taxane and/or platinate therapy.

"I am very impressed with the tolerability profile of XYOTAX(TM). On my study, we have patients who have received more than eight cycles of treatment and are continuing on therapy," said John Nemunaitis, M.D., medical director at the Mary Crowley Medical Research Center in Dallas, Texas. "But what is even more impressive is that 11 of the 22 patients had failed prior paclitaxel and in these patients we are either seeing a response or prolonged stable disease."

In both clinical trials XYOTAX(TM) was easily administered as a 10-minute infusion, without the need for steroid pre-medication and with manageable side effects at doses evaluated in these studies up to 250mg/m2. XYOTAX(TM) in combination with platinates was well tolerated with patients who achieved a partial response receiving a median of 8.6 cycles (range 2-12) and with those who achieved stable disease receiving a median of four cycles (range 2-6). Side effects were consistent with those reported for platinates and included grade 3 neuropathy (nine patients), grade 4 neutropenia (19 patients), and grade 4 thrombocytopenia (8 patients).

"We are particularly encouraged to see the high response rate in the ovarian cancer patients on the two studies, with six of the nine patients (67 percent) achieving a partial response," said Jack W. Singer, M.D., Research Chair of CTI. "The safety and tolerability of the combination of XYOTAX(TM) and platinum is impressive given that these patients were heavily pre-treated, having received on average three prior chemotherapy regimens (range 1-10)."

The following is a summary of the results of the two studies: XYOTAX in Patients with Solid Tumors Tumor Type Partial Response (PR) Stable Disease (SD) PR + SD Ovarian 6/9 (66%) 2/9 (22%) 8/9 (89%) Sensitive* 1 0 Resistant** 5 2 Other Tumors 2/35 (6%) 20/35 (57%) 22/35 (63%) *Sensitive disease is classified as >6 months from prior platinum/taxane therapy **Resistant disease is classified as relapse ?6 months from prior platinum/taxane therapy

"These data further support the investigation of XYOTAX(TM) in the treatment of front-line ovarian cancer," said Singer. "In November 2002 the Gynecologic Oncology Group (GOG) agreed to conduct a phase III trial of XYOTAX(TM) in front-line ovarian cancer patients. The GOG is scheduled to discuss the phase III trial design with the FDA in the fourth quarter of this year."

About XYOTAX(TM)

XYOTAX(TM) is a pharmaceutical that links paclitaxel, the active ingredient in Taxol(R), to a biodegradable polyglutamate polymer. This polymer technology results in a new chemical entity, designed to selectively deliver higher and potentially more effective levels of active chemotherapeutics to tumors. Blood vessels in tumor tissue, unlike blood vessels in normal tissue, are porous to molecules like polyglutamate. Based on preclinical studies, it appears that XYOTAX(TM) is preferentially trapped in the tumor blood vessels allowing significantly more of the dose of chemotherapy to localize in the tumor. Because more of the chemotherapy is targeted to the tumor and the levels of chemotherapy delivered to normal tissue are reduced, XYOTAX(TM) may be potentially more effective and have less severe side effects than currently available chemotherapeutics.

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. For additional information, please visit www.cticseattle.com.

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 XYOTAX(TM) include risks associated with preclinical and clinical developments in the biopharmaceutical industry in general and with XYOTAX(TM) in particular including, without limitation, the potential failure of XYOTAX(TM) to prove safe and effective for treatment of ovarian cancer, determinations by regulatory, patent and administrative governmental authorities, competitive factors, technological developments, costs of developing, producing and selling XYOTAX(TM), 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.

SOURCE Cell Therapeutics, Inc.

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