Phase 2 study of Opaxio for advanced esophageal cancer

Cell Therapeutics announced that updated Phase 2 study results of Opaxio (paclitaxel poliglumex, CT-2103) in patients with advanced esophageal cancer demonstrated that 38% (15/40) patients receiving Opaxio in combination with cisplatin and concurrent radiation achieved a pathologic or endoscopic complete response.  This study 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 metastasis. 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.

Opaxio, formerly known as Xyotax, is a biologically enhanced chemotherapeutic that links paclitaxel to a biodegradable polyglutamate polymer. Binding paclitaxel to the polymer potentially spares normal tissue's exposure to high levels of unbound paclitaxel and its associated toxicities. Blood vessels in tumor tissue, unlike blood vessels in normal tissue, are porous to molecules like polyglutamate, thus leading to preferential distribution of Opaxio to tumor tissues due to their leaky blood vessels. Once inside the tumor cell, enzymes metabolize the protein polymer, releasing the paclitaxel chemotherapy.

For more information call (206) 282-7100 or visit www.CellTherapeutics.com.