Cell Therapeutics Reports New Data Demonstrating That Complete Responses to Pixuvri Are Correlated With Prolonged Survival in Patients With Relapsed or Refractory Aggressive NHL

SEATTLE, June 11 /PRNewswire-FirstCall/ -- Cell Therapeutics, Inc. (the "Company") (Nasdaq and MTA: CTIC) today reported exploratory analyses of the data at study completion from the Company's pivotal PIX301 trial of Pixuvri(TM) (pixantrone dimaleate), the first randomized controlled trial in patients with relapsed or refractory, aggressive non-Hodgkin's lymphoma ("NHL"). These analyses demonstrated that patients who achieved a complete response (CR)/unconfirmed complete response (CRu) to Pixuvri had up to a 63% probability of being alive at 24 months compared to a 20% probability for patients treated with comparator agents. The study showed a 21% improvement in overall survival for all patients who received Pixuvri that was independent of factors known to influence survival like prior rituximab use, international prognostic index (IPI) score, prior stem cell transplant, baseline level of LDH (lactate dehydrogenase), or refractory status based on univariate Cox regression analyses of survival. These data were presented at a Company-sponsored lymphoma expert panel during the 15th Congress of the European Hematology Association.

"The overall strength of evidence, including the significant increases observed in clinically-important parameters like overall response rates (ORR) and progression free survival (PFS), provides important support to the clinical benefit of Pixuvri compared to current single-agent treatment in a setting where there are no approved or consensus therapies for relapsed or refractory aggressive NHL," said Dr. Andreas Engert, University Hospital of Cologne. "The updated end-of-study survival data demonstrates a lasting benefit of achieving a CR/CRu with Pixuvri, with 8 of the 12 patients known alive at end of study having achieved a CR/CRu. It is particularly notable that overall survival was not influenced by important risk factors, and also that 76% of the patients who achieved a CR/CRu with Pixuvri failed to respond to or had a lesser response to their last multi-agent therapy. I look forward to working with the Company as it prepares for submission of its Marketing Authorization Application ("MAA") for Pixuvri to the European Medicines Agency ("EMEA")."

About Pixantrone

Pixantrone is a novel aza-anthracenedione that has distinct structural and physio-chemical properties that make its anti-tumor activity unique in this class of agents. Similar to anthracyclines, pixantrone inhibits Topo-isomerase II but unlike anthracyclines--rather than intercalation with DNA--pixantrone alkylates DNA--forming stable DNA adducts, with particular specificity for CpG rich, hyper-methylated sites. These structural differences resulted in significantly enhanced anti-lymphoma activity compared to doxorubicin in preclinical models. In addition, the structural motifs on anthracycline-like agents that are responsible for the generation of oxygen free radicals and the formation of toxic drug-metal complexes have also been modified in pixantrone to prevent the binding of iron and perpetuation of superoxide production--both of which are the putative mechanism for anthracycline induced acute cardiotoxicity. These novel pharmacologic differences may allow re-introduction of anthracycline like potency in the treatment of relapsed/refractory aggressive lymphoma without unacceptable rates of cardiotoxicity.

About PIX301 (EXTEND) Clinical Trial

Pixantrone was studied in the Company's EXTEND, or PIX301, clinical trial, which was a phase III single-agent trial of pixantrone for patients with relapsed refractory aggressive NHL who received two or more prior therapies and who were sensitive to treatment with anthracyclines The results of the EXTEND trial showed that patients randomized to treatment with pixantrone achieved a significantly higher rate of confirmed and unconfirmed complete remissions compared to patients treated with standard chemotherapy, had a significantly increased overall response rate and experienced a statistically significant improvement in median progression free survival. Pixantrone was safely administered at the proposed dose and schedule in the PIX301 clinical trial in heavily pre-treated patients. The most common (incidence greater than or equal to 10%) grade 3/4 adverse events reported for pixantrone-treated subjects across studies were neutropenia and leukopenia. Use of growth factor support was minimal. Other common adverse events (any grade) included infection, anemia, leukopenia, thrombocytopenia, asthenia, pyrexia and cough. Overall, the incidence of grade 3 or greater cardiac adverse events was 7% (5 patients) on the pixantrone arm and 2% (1 patient) on the comparator arm. There were an equal number of deaths due to an adverse event in both the pixantrone and comparator arm.

About Cell Therapeutics, Inc.

Headquartered in Seattle, the Company 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.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 and the trading price of the Company's securities. 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 pixantrone in particular, including, without limitation, the potential failure of pixantrone to prove safe and effective for the treatment of relapsed or refractory, aggressive NHL as determined by the EMEA, that the Company may not submit its MAA to the EMEA, that there may not be a correlation between CR/CRu's and progression free survival, that pixantrone may not show an overall improvement rate in survival for patients independent of factors known to influence survival, the Company's ability to continue to raise capital as needed to fund its operations, 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, 10-Q and 8-K. Except as may be required by law, the Company 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.