Opaxio Produces High Rates Of Pathologic Complete Remission In Patients with Advanced Esophageal Cancer

Study paves way for potential registration trial as radiation sensitiser

Cell Therapeutics (CTI) has announced that in a study from Brown University, patients with cancer of the lower esophagus demonstrated a high rate of complete remission (CR) when given Opaxio (paclitaxel poliglumex), a biologically enhanced paclitaxel, when administered in combination with standard cisplatin and concurrent radiation. The study will be presented at the Annual Meeting of the International Society of Gastrointestinal Oncology (ISGIO) in Philadelphia, Pennsylvania.

The phase II 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. Of the first 28 patients undergoing surgery, all with adenocarcinoma, eight of 28 (28.5%), have achieved a pathologic CR.

No patients required a feeding tube, in contrast to historical studies using the standard regimen where the large majority of patients require a feeding tube. There were no grade 4 hematologic toxicities; grade 3 hematologic toxicity included neutropenia (n=2) and anemia (n=1). Four of 35 patients experienced grade 4 non-hematologic toxicities, which included electrolyte abnormalities, glucose intolerance, hypersensitivity reaction and thromboembolus. Eleven of 35 patients had grade 3 non-hematologic toxicities including electrolyte abnormalities (n=5), nausea (n=3), dysphagia (n=2), fatigue (n=2), glucose intolerance (n=2), and hypersensitivity reaction (n=1). Grade 3 anorexia was reported in only one patient who subsequently was given total parenteral nutrition. No patients developed neuropathy.

Howard Safran, head of the Brown University Oncology Group, said: "These are very promising results, as standard platinum, 5-FU, and radiation-based regimens for this disease are accompanied by a high incidence of severe radiation esophagitis, requiring patients to receive nutrition through feeding tubes. Paclitaxel poliglumex's selective radiation enhancement preclinical profile is being validated by the high rates of pathologic complete remission and low rates of severe regional side effects we have observed in this phase 2 study. Our results justify proceeding to a randomised, controlled trial to definitively prove the impressive clinical benefit we have observed in our experience with this novel bioengineered paclitaxel agent."

Jack Singer, chief medical officer at CTI, said: "We look forward to discussing with the Food and Drug Administration a potential phase III registration strategy for this indication. This would be the first registration study for a radiation sensitising agent in this indication."