Updated results from phase III EXTEND clinical trial of pixantrone released

Dec 7 2009

Cell Therapeutics, Inc. ("CTI") (Nasdaq and MTA: CTIC) announced today that Ruth Pettengell, M.D. of St. George's Hospital, University of London during a session at the 2009 American Society of Hematology ("ASH") Annual Meeting updated results from the pivotal phase III EXTEND (PIX 301) clinical trial of pixantrone (the "PIX 301 EXTEND trial") in relapsed or refractory, aggressive non-Hodgkin's lymphoma ("NHL") patients who have failed 2 or more prior therapies. Updated analyses with additional follow-up data were conducted; these analyses and additional follow-up data support the initial clinical trial results. Subgroup analyses examining the effect of age, IPI score, disease status, or prior anthracycline doses on Progression Free Survival (PFS) demonstrated that pixantrone consistently improved PFS across subgroups compared with other chemotherapy agents. With patients in follow-up period at least 9 months from end of treatment, pixantrone provided a 250% relative improvement in 1 year PFS (21% Vs 6%) over comparator and a 115% increase in median overall PFS (5.6 months Vs 2.6 months,>

"The results of the PIX301 trial continue to impress me as we gain additional follow-up data and information from exploratory sensitivity analyses," noted Dr. Ruth Pettengell, the principal investigator on the study. "The robustness of the drug's effect on prolonging progression free survival across all important risk factors lends to the strength and credibility of the clinical benefit provided to patients in the trial."

The PIX 301 EXTEND (Expanding the reach of anthracyclines with piXanTronE in relapsed or refractory aggressive Nhl Disease) trial was a phase III single-agent trial of pixantrone for patients with relapsed or refractory, aggressive NHL who received two or more prior therapies and who were sensitive to treatment with anthracyclines. The trial enrolled 140 patients and patients were randomized to receive either pixantrone or another single-agent drug currently used for the treatment of this patient population and selected by the physician.

Results of the PIX301 phase III trial presented demonstrated improvement across primary and secondary endpoints of the study at a minimum of nine-month follow-up from end of treatment. Pixantrone produced CR / CRu rate of 25.7% versus 7.1% for the comparator arm, p-value = 0.005. Overall response rate also increased significantly in patients that received pixantrone (40.0% pixantrone arm versus 14.3%,>

Results presented also included a patient subgroup analysis demonstrating that complete response (CR), partial response (PR) and PFS were robust irrespective of risk factors or prior therapy. Pixantrone also provided superior disease control rates over comparator arm with 22 of comparator recipients progressing within the first evaluation point versus 14 for pixantrone recipients.

Despite 50% of patients exceeding cumulative lifetime anthracycline limits (501 - 900 mg/m2), only two cases of congestive heart failure on independent cardiologist assessment were attributed to pixantrone, occurring at lowest drug exposure (<501mg/m2). The follow-up period for the study is ongoing.

"We are pleased that the PIX 301 EXTEND trial of pixantrone not only met its study objective but continues to demonstrate clinical benefit in the follow up period across patient demographics, and risk factors," said James A. Bianco, M.D., Chief Executive Officer of CTI. "We continue to work expeditiously with the FDA as we progress pixantrone through regulatory review to potential approval and commercialization."

The most common (incidence greater than or equal to 10%) grade 3-4 adverse events reported for pixantrone-treated subjects across the studies were neutropenia and leucopenia. Other common adverse events (any grade) included infection, anemia, leucopenia, thrombocytopenia, asthenia, pyrexia, and cough. Although the grade 3/4 cardiac disorder was similar among the two treatment groups (1.5% vs. 1.5%), there was a higher incidence of serious cardiac disorders in patients treated with pixantrone than among patients who received comparator agents (6/68 or 8.8% vs. 3/67 or 4.5%).