A Biologically Enhanced Paclitaxel

OPAXIO™ (Oh-packs-ee-oh) (paclitaxel poliglumex, CT-2103; formerly known as XYOTAX) is our biologically enhanced chemotherapeutic that links paclitaxel to a biodegradable polyglutamate polymer, resulting in a new chemical entity.

Taxanes, including paclitaxel (Taxol^®) and docetaxel (Taxotere^®), are widely used for the treatment of various solid tumors, including non-small cell lung, ovarian, breast, and prostate cancers. According to the Tandem Cancer Audit 2006, more than half of the taxane used in taxane-sensitive advanced cancers is in lung and ovarian cancers.

Improved Paclitaxel Delivery

OPAXIO was designed to deliver paclitaxel preferentially to tumor tissue. By linking paclitaxel to a biodegradable amino acid carrier, the conjugated chemotherapeutic agent is inactive in the bloodstream, sparing normal tissues the toxic side effects of chemotherapy. Once inside tumor tissue the conjugated chemotherapeutic agent is activated and released by the action of an enzyme called cathepsin B. The activity of this enzyme and thus the rate of release of paclitaxel poliglumex is increased in the presence of estrogen. Preclinical and clinical studies support that OPAXIO 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.

Because the polymer is water-soluble, OPAXIO can be administered without solvents and other required premedications. It also can be infused over an average of ten to twenty minutes. OPAXIO remains stable in the bloodstream for several days after administration; this prolonged circulation allows the passive accumulation of OPAXIO in tumor tissue.

OPAXIO Clinical Research

We are currently studying OPAXIO in pivotal trials for non-small cell lung cancer (NSCLC), ovarian, and other cancers.

OPAXIO Regulatory Strategy

In March 2008, we submitted and the European Medicines Agency (EMEA) accepted for review a marketing authorization application (MAA) seeking European approval for OPAXIO on equivalent effectiveness (non-inferiority) and improved safety as a single-agent in first-line PS2 NSCLC patients.

In the United States, we plan to seek approval for the drug’s use in maintenance of ovarian cancer following complete remission after first-line treatment.

OPAXIO was formerly branded by CTI as XYOTAX. Taxol^® is a registered trademark of the Bristol-Meyers Squibb Company. Taxotere^® is a registered trademark of Aventis Pharma S.A.