Oral presentation at international lymphoma conference shows investigational regimen resulted in 82 percent overall survival and 78 percent progression-free survival rates in patients receiving radioimmunotherapy Confirmatory phase III clinical trial is presently being conducted in this patient population

LUGANO, Switzerland | June 9, 2008 | In an oral presentation today at the 10th International Conference on Malignant Lymphoma in Lugano, Switzerland, Paul A. Hamlin, M.D., of Memorial Sloan-Kettering Cancer Center, presented results of an investigator-sponsored trial of the investigational regimen consolidating rituximab-CHOP (R-CHOP) with 90Yttrium Ibritumomab Tiuxetan (Zevalin(R)) radioimmunotherapy in high risk, elderly patients with previously untreated high-intermediate and high risk diffuse large B-cell lymphoma (DLBCL). Cell Therapeutics, Inc. (CTI) (Nasdaq and MTA: CTIC) markets Zevalin in the United States.

"In a high risk, elderly patient population with significant comorbidities, sequential R-CHOP followed by radioimmunotherapy resulted in excellent complete response and overall and progression-free survival rates," concluded Hamlin. "This approach is now the focus of an international phase III study."

"Improvement of relapse-free survival in these patients is an important unmet need since the outcome is poor for patients who relapse with this disease and who cannot tolerate intensive salvage therapy and stem cell transplantation," said Jack W. Singer, M.D., Chief Medical Officer at CTI. "The survival data from this study are highly encouraging compared to historical data and provide the rationale for a registration-directed randomized trial of Zevalin consolidation in higher risk patients with DLBCL."

Results of the Study

Historical studies provided as background in the presentation indicate that approximately 50 percent of elderly patients with high risk diffuse large B-cell lymphoma (DLBCL) relapse after treatment with R-CHOP. Treatment options for patients who are ineligible for autologous stem cell transplant are limited. In this analysis, of the 63 patients enrolled on the study, 39 patients had been treated with Zevalin. The median age is 75 years (range 62-86); Karnofsky performance status was 80 percent in 59 percent of patients with a median performance status of 70 percent; prognostic score was high-intermediate/high in 53 percent and 47 percent of patients, respectively. Moderate or high impact comorbidity is present in 86 percent. In the intent-to-treat population, progression-free (PFS) and overall survival (OS) were 59 percent and 65 percent, respectively, at 22 months. In the 39 patients who received Zevalin, PFS and OS were 78 percent and 82 percent, respectively, at 26 months. Responses improved in 11 patients who received Zevalin, with eight patients improving from an unconfirmed (CRu) to a confirmed complete response (CR) and three patients improving from a partial response (PR) to a CR/CRu. The side effects reported included blood count suppression: 26 percent and 36 percent grade 3/4 neutropenia, 15 percent grade 3 anemia, and 36 percent and 31 percent grade 3/4 thrombocytopenia. Six patients had delayed blood count recovery for more than 12 weeks. One patient developed myelodysplasia and two patients died after Zevalin was given, one from a suspected brain hemorrhage and one from congestive heart failure.

About Zevalin(R)

Zevalin(R) (Ibritumomab Tiuxetan) is a form of cancer therapy called radioimmunotherapy and is indicated as part of the Zevalin therapeutic regimen for treatment of relapsed or refractory, low-grade or follicular B-cell non-Hodgkin’s lymphoma, including patients with rituximab refractory follicular NHL. It was approved by the FDA in February of 2002 as the first radioimmunotherapeutic agent for the treatment of NHL.

Rare deaths associated with an infusion reaction symptom complex have occurred within 24 hours of rituximab infusions. Yttrium-90 Zevalin administration results in severe and prolonged cytopenias in most patients. Severe cutaneous and mucocutaneous reactions have been reported. The most serious adverse reactions of the Zevalin therapeutic regimen were primarily hematologic, including neutropenia, thrombocytopenia, and anemia. Infusion-related toxicities were associated with pre-administration of rituximab. The risk of hematologic toxicity correlated with the degree of bone marrow involvement prior to Zevalin therapy. Myelodysplasia or acute myelogenous leukemia was observed in 2 percent of patients (8 to 34 months after treatment). Zevalin should only be used by health care professionals qualified by training and experience in the safe use of radionuclides.

Patients and healthcare professionals can visit http://www.zevalin.com for more information.

About Cell Therapeutics, Inc.

Headquartered in Seattle, CTI is a biopharmaceutical company committed to developing an integrated portfolio of oncology products. For additional information, please visit http://www.CellTherapeutics.com.

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This press release 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 Zevalin include risks associated with preclinical and clinical developments in the biopharmaceutical industry in general and with Zevalin in particular including, without limitation, the potential failure of Zevalin to prove safe and effective for treatment of high risk elderly DLBCL, determinations by regulatory, patent and administrative governmental authorities, competitive factors, technological developments, costs of developing, producing and selling Zevalin, 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. Except as may be required by law, CTI does not intend to update or alter its forward-looking statements whether as a result of new information, future events, or otherwise.

SOURCE: Cell Therapeutics, Inc.