New Class of Platinum-Based Anti-Tumor Drugs, Bisplatinates, Demonstrates Potent Anti-Tumor Activity and Ability to Overcome Resistance to Currently Available Platinum-Based Agents

Cell Therapeutics, Inc. (CTI) (Nasdaq and MTA: CTIC) announced today that its new class of platinum-based anti-tumor compounds, termed bis-platinates, demonstrated a stronger anti-tumor potency and activity compared to currently available platinum-based compounds as well as the ability to overcome cisplatin-resistance in cancer cell lines. The results were presented in a paper titled "Novel Bis-platinum Complexes Endowed with an Improved Pharmacological Profile," by Laura Gatti et al. that was published in the online edition of the journal Molecular Pharmaceutics. Platinum-based compounds, such as cisplatin and oxaliplatin, are the cornerstone in the treatment of testicular, ovarian, colorectal, lung and other cancers but their effectiveness is limited by the relatively low therapeutic ratio, the ratio of the maximally tolerated dose of the drug to the effective dose, and the frequent occurrence of drug resistance leading to cancer recurrence. The novel bis-platinum compounds represent a completely new class of platinum-based drugs called bisplatinates.

The bis-platinum based compounds, unlike the currently approved platinum-based compounds, contain two platinum atoms and work by binding to and damaging both strands of DNA making it much more difficult for cancer cells to repair the damage. The research demonstrated through cancer cell assays and animal tumor models that the bis-platinum complexes exhibited greater cytotoxic potency and anti-tumor effect compared to cisplatin and oxaliplatin. There was more than a 200-fold increase in percent accumulation in tumor cells of the bisplatinum compounds compared to cisplatin and oxaliplatin. The bisplatinates were substantially more active against human tumors grown in an immunodeficient preclinical model than the standard palatinate compounds, oxaliplatin, carboplatin and cisplatin. Furthermore, the bis-platinum compounds demonstrated the ability to overcome tumor resistance to cisplatin mediated by DNA mismatch repair defects. The complexes showed marked anti-tumor efficacy in platinum refractory tumors, with significant activity in terms of tumor growth inhibition and tumor growth delay.

"Platinum-based compounds are cornerstone agents in the treatment of very common cancers such as cancers of the lung, colon, and ovary and are also widely used in other gynecological tumors, testicular cancers, and cancers of the esophagus, head and neck. They are increasingly being used for salvage therapy in lymphoma. However, resistance to palatinate compounds is common. The current results are encouraging as they demonstrate that the bisplatinates are not only more effective in human tumor models than the current agents, but also capable of overcoming some forms of palatinate resistance," said Jack Singer, M.D., Chief Medical Officer of CTI.

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. For additional information, please visit our website.

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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 securities of CTI. 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 bis-platinum based compounds in particular, including, without limitation, the potential failure of bis-platinums to prove effective in inhibiting or delaying tumor growth or to overcome cisplatin resistance or to be safe or effective in animals or humans, that CTI does not enter clinical trials for the bis-platinates in 2010, CTI'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 CTI's filings with the Securities and Exchange Commission including, without limitation, CTI's most recent filings on Forms 10-K, 10-Q and 8-K. 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.


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