High Rates of Pathological Complete Response in Patients with Advanced Esophageal Cancer in OPAXIO™ Phase II Study Reported in American Journal of Clinical Oncology

SEATTLE, Feb. 23, 2011 /PRNewswire/ -- Cell Therapeutics, Inc. ("CTI") (Nasdaq and MTA: CTIC) announced today that updated phase II study results of OPAXIO (paclitaxel poliglumex) in patients with advanced esophageal cancer conducted by the Brown University Oncology Group were published in the February 3, 2011 issue of the American Journal of Clinical Oncology, Dipetrillo, et al., which demonstrate that 38% (15/40) of the patients receiving OPAXIO in combination with cisplatin and concurrent radiation achieved a pathologic or endoscopic complete response.  A pathological complete response, observed in 32% of patients in the study, is recorded only when the esophagus is surgically removed after therapy and no tumor can be found microscopically.  In historical studies, pathologic complete response has correlated with prolonged survival.

"We are pleased to have the impressive and potentially important results of the paclitaxel poliglumex phase II esophageal study published in a peer reviewed journal," said Dr. Howard Safran, M.D., director of the Brown University Oncology Group.  "In this study, the treatment was well tolerated and we did not see the severe side effects that are typically experienced with standard treatment options.  If these data can be validated in a randomized controlled trial, the use of paclitaxel poliglumex along with cisplatin and radiation could provide an important treatment alternative for patients with lower esophageal cancer with an attractive risk-benefit profile."

The phase II study conducted by the Brown University Oncology Group enrolled 40 patients with pathologically-confirmed, locally-advanced adenocarcinoma or squamous cell carcinoma of the esophagus or gastro-esophageal junction with no evidence of distant metastases.  The patients received weekly paclitaxel poliglumex (50mg/m2) and cisplatin (25mg/m2) for six weeks with concurrent 50.5Gy of radiation. The updated data demonstrated that of the 37 patients who underwent surgery, 12 patients achieved a pathologic complete response.  Additionally, three patients achieved a complete clinical endoscopic response and refused surgery.  Importantly, only one patient required a feeding tube and one patient used total parenteral nutrition. There were no grade 4 hematologic adverse events. Grade 3 hematologic adverse events included neutropenia (6%) and grade 3 non-hematologic toxicities included nausea (7%), esophagitis (7%), and fatigue (5%).

"This phase II study with OPAXIO demonstrated an encouragingly high rate of complete disappearance of cancer in patients that underwent potentially curative surgery following chemoradiotherapy.  Moreover, the therapy had a low incidence of the severe inflammation of the esophagus that frequently requires a feeding tube observed with the current standard regimens," said Jack Singer, M.D., Chief Medical Officer of CTI. "We believe that this study provides preliminary clinical support to our belief that paclitaxel poliglumex is a potent and tumor-selective radiosensitizer."

About OPAXIO™

OPAXIO™ (paclitaxel poliglumex, CT-2103), which was formerly known as XYOTAX™, is an investigational, biologically enhanced, chemotherapeutic that links paclitaxel, the active ingredient in Taxol®, to a biodegradable polyglutamate polymer, which results in a new chemical entity. When bound to the polymer, the chemotherapy is rendered inactive, potentially sparing normal tissue's exposure to high levels of unbound, active chemotherapy and its associated toxicities. Blood vessels in tumor tissue, unlike blood vessels in normal tissue, are porous to molecules like polyglutamate. Based on preclinical studies, it appears that OPAXIO is preferentially distributed to tumors due to their leaky blood vessels and trapped in the tumor bed allowing significantly more of the dose of chemotherapy to localize in the tumor than with standard paclitaxel. Once inside the tumor cell, enzymes metabolize the protein polymer, releasing the paclitaxel chemotherapy.

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 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 CTI's securities. Specifically, the risks and uncertainties that could affect the development of OPAXIO include risks associated with preclinical and clinical developments in the biopharmaceutical industry in general, and with OPAXIO in particular, including, without limitation, the potential for OPAXIO to be proved safe and effective (or to achieve response rates) for the treatment of the indications noted in this press release or any other indication, determinations by regulatory, patent and administrative governmental authorities, the potential that OPAXIO will not produce high rates of complete remission in patients with advanced esophageal or other cancers, that OPAXIO may not be a selective radiosensitizer, that the data described in this press release may not be validated in a randomized controlled trial, CTI's ability to continue to raise capital as needed to fund its operations, competitive factors, technological developments, and costs of developing, producing and selling OPAXIO. You should also review 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.

SOURCE Cell Therapeutics, Inc.