[Updated Xyotax PGT202 PII results]
>>NEW YORK, Feb. 15 /PRNewswire-FirstCall/ -- In a presentation at the BIO CEO & Investor conference today, James A. Bianco, M.D., President and CEO of Cell Therapeutics, Inc. (CTI) (Nasdaq and MTAX: CTIC) presented updated results of a phase II study of XYOTAX in combination with carboplatin among 35 women and 39 men with advanced non-small cell lung cancer (NSCLC). Unlike the STELLAR 3 and 4 trials, where only patients with poor performance status (PS2) were enrolled, there was no restriction on performance status in the phase II trial, known as PGT202. The study was analyzed for overall survival by gender and by estrogen levels to confirm the observation of enhanced efficacy in the presence of estrogen seen in the STELLAR first-line trials. Estimated one-year survival of women receiving XYOTAX is 36 percent compared to only 16 percent of their male counterparts. Consistent with the results seen in the STELLAR 3 trial (XYOTAX/carboplatin), the 12 women with normal estrogen levels (>/=30 pg/ml) survived longer than the 22 women with post-menopausal, low estrogen levels. The estimated median survival for women with low estrogen levels was 128 days (4.2 months) while the median survival among women with normal estrogen levels was 218 days (7.2 months). At the time of last contact, nine of 12 women (75 percent) with normal estrogen levels were alive compared to nine of 22 women (41 percent) with low estrogen levels.
"This phase II study supports what we observed and reported in our prior first-line study of XYOTAX and carboplatin (STELLAR 3) and substantially strengthens the likelihood that the beneficial effect of estrogen on XYOTAX efficacy is valid," stated Bianco. "This gives us a high degree of confidence that we are on the right path by investing in the PIONEER gender-specific study and broadens the potential applicability to all first-line patients, not just PS2 patients."
In a composite analysis of two prior randomized trials (STELLAR 3 and 4), in 198 women with advanced NSCLC who were PS2, patients randomized to receive XYOTAX had a statistically significant improvement in overall survival compared to women treated with comparator agents (hazard ratio 0.70, log rank p=0.03) with one-year survival estimates of 40% vs. 25% (p=0.01). Results among men were similar to the comparator agents. The most common side effects were neuropathy and myelosuppression. Survival significantly correlated with pre-menopausal age and pre-menopausal estrogen levels, where available, consistent with preclinical findings showing that estrogen enhances the biodistribution and release of paclitaxel from the polyglutamate polymer in tumor-bearing tissues, such as the lungs, allowing potentially greater tumor exposure to chemotherapy than can be achieved with standard chemotherapy agents.
About XYOTAX
XYOTAX (paclitaxel poliglumex) is a 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. Once inside the tumor cell, enzymes metabolize the protein polymer, releasing the paclitaxel chemotherapy. Based on preclinical studies, it appears that XYOTAX is preferentially trapped in the tumor blood vessels allowing significantly more of the dose of chemotherapy to localize in the tumor. 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 over standard therapies.<
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Cheers, Tuck |
