ATLANTA, June 4 /PRNewswire-FirstCall/ -- At the 2006 Annual Meeting of the American Society of Clinical Oncology (ASCO), data from Cell Therapeutics, Inc.'s (CTI) (Nasdaq: CTIC; MTAX) phase III STELLAR trials of XYOTAX(TM) (paclitaxel poliglumex) in patients with non-small cell lung cancer (NSCLC) were presented.
Effect of Gender on Outcome in the STELLAR 3 and 4 Trials (Abstract #7039)
In a poster discussion presentation Helen Ross, M.D., Medical Oncologist at the Oregon Clinic and Director of Lung Cancer Research at the Earle A. Chiles Research Institute in Portland, Oregon, presented a composite analysis of the STELLAR 3 and 4 studies, which demonstrated that XYOTAX had a significant impact on survival in women compared to those on the control arms, while men had similar survival in both arms of the studies. In addition, in women younger than 55 years old, overall survival was prolonged for patients on the XYOTAX arm compared to the control arm (HR: 0.51, p=0.03), whereas in women 55 years and older, overall survival was similar between treatment groups (HR: 0.75, p=0.134). In STELLAR 3, estrogen levels were available for the majority (92 percent) of women on the trial. Patients with pre-menopausal estrogen levels (serum estrogen >30 pg/mL), regardless of age, had a significant improvement in survival when treated with XYOTAX in combination with carboplatin compared to patients treated with paclitaxel plus carboplatin (HR: 0.54, p=0.039), but survival was similar between the two arms of the study in patients with post-menopausal estrogen levels (HR: 1.20, p=0.676).
"Most women think that breast cancer is more of a threat than lung cancer, but more women are expected to die from lung cancer than from breast, ovarian, uterine and cervical cancers combined. It is a serious health crisis that most women are unaware of," said Dr. Ross.
"This presentation highlights the importance of gender and genetics on the differential response to treatment for lung cancer. Lung cancer in women is often diagnosed late, making it much more difficult to treat. More awareness of lung cancer and factors such as estrogen that might explain the impact on outcome is needed," Ross concluded.
Table 1. Comparison of survival (days) in pre- and post-menopausal women
MEDIAN
OVERALL SURVIVAL 1-YEAR SURVIVAL
XYOTAX Control HR pP-value XYOTAX Control
Pre-menopausal
STELLAR 3 239 167 0.66 0.011 38% 22%
STELLAR 4 NE 188 0.38 0.146 51% 16%
Composite 309 181 0.56 0.008 43% 19%
Post-menopausal
STELLAR 3 NE 347 0.71 0.523 50% 36%
STELLAR 4 320 163 0.47 0.312 40% 17%
Composite 320 263 0.62 0.256 47% 30%
Analysis of Prognostic Factors using Cox Regression Analysis in the STELLAR 3 and 4 Trials (Abstract #7113)
In a poster presentation Mary O'Brien, M.D., Consultant Medical Oncologist at The Royal Marsden Hospital in London, presented an analysis of prognostic factors using Cox regression analysis. O'Brien concluded that weight loss, presence of extra-thoracic metastasis, low LCS (lung cancer symptom) scores, and high LDH (lactate dehydrogenase -- a tumor marker) were significant negative prognostic factors for PS2 (ECOG performance status 2) patients with NSCLC. Significant differences in survival based on geographic region seen in STELLAR 3 highlighted the importance of stratification by region. Subgroup analysis by randomization strata showed no difference in survival between treatment arms, however trends toward improved survival for women receiving XYOTAX were observed in STELLAR 3 and 4.
Analysis of Prognostic Factors using Cox Regression Analysis in the STELLAR 2 Trial (Abstract #7040)
In a poster discussion presentation Philip D. Bonomi, M.D., Director of Medical Oncology, Rush-Presbyterian-St. Luke's Medical Center in Chicago, presented an analysis of prognostic factors using Cox regression analysis. Both overall survival and response were similar between the treatment arms. Patients in the XYOTAX arm had significantly less anemia, neutropenia, febrile neutropenia, infection, hair loss, fatigue, mucositis, and gastrointestinal and respiratory symptoms, and a reduced requirement for supportive measures to manage the effects of myelosuppression. Overall, grade 3 neurotoxicity was significantly increased in the XYOTAX arm; however, in patients receiving XYOTAX at a dose of 175 mg/m2, grade 3 neuropathy was equivalent to the control.
Bonomi concluded that the prognostic factors for this group of second-line patients were virtually identical to those seen in chemo-naive NSCLC patients, reported by O'Brien (above). In addition, shorter interval from previous chemotherapy was also an important negative prognostic factor and it was recommended that in the future the interval from previous systemic chemotherapy be described in phase II trials and included as a stratification factor in phase III studies.
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About the STELLAR Trials
The STELLAR trials are among the largest randomized, phase III trials to date in either second-line non-small cell lung cancer (NSCLC) or first-line PS2 NSCLC patients. STELLAR 2 tested XYOTAX versus docetaxel for the potential second-line treatment of NSCLC patients. STELLAR 3 tested carboplatin in combination with either XYOTAX or paclitaxel for the potential first-line treatment of poor performance status (PS2) patients with NSCLC. STELLAR 4 tested XYOTAX versus either gemcitabine or vinorelbine for the potential first-line treatment of poor performance status (PS2) patients with NSCLC.
About XYOTAX
XYOTAX(TM) (paclitaxel poliglumex) is a biologically-enhanced chemotherapeutic that links paclitaxel, the active ingredient in Taxol(R), 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. Once inside the tumor cell, enzymes metabolize the protein polymer, releasing the paclitaxel chemotherapy. Based on preclinical studies, it appears that XYOTAX 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. Preclinical and clinical studies support that XYOTAX metabolism by lung cancer cells may be influenced by estrogen, which could lead to enhanced release of paclitaxel and efficacy in women with lung cancer compared to standard therapies.
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 http://www.cticseattle.com/.
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 XYOTAX(TM) include risks associated with preclinical and clinical developments in the biopharmaceutical industry in general and with XYOTAX in particular including, without limitation, the potential failure of XYOTAX to prove safe and effective for treatment of non-small cell lung cancer, determinations by regulatory, patent and administrative governmental authorities, competitive factors, technological developments, costs of developing, producing and selling XYOTAX, 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. CTI is under no obligation to (and expressly disclaims any such obligation to) update or alter its forward-looking statements whether as a result of new information, future events, or otherwise.
