Biopharmaceutical company, Cell Therapeutics, Inc. (CTI) announced that the Gynaecologic Oncology Group (GOG) has completed patient enrollment in the GOG-0212 phase III clinical trial of investigational agent paclitaxel poliglumex (Opaxio) as maintenance therapy in ovarian cancer.

"Although initial treatment is effective in putting this disease in remission, there is a high relapse rate for patients with ovarian cancer and there are limited treatment options when their cancer returns," said Larry J Copeland, MD, Department of Obstetrics and Gynaecology, Ohio State University Comprehensive Cancer Centre, group vice chair of the GOG and chair of the GOG-0212 study. "This study was designed to investigate whether Opaxio when used in a maintenance setting could keep these women in remission and as a result extend the lives of these patients. We are very pleased to have completed enrollment in this important study."

"This is a significant achievement for the GOG being the largest maintenance study for patients with ovarian cancer ever conducted having enrolled 1,150 patients," said James A Bianco, MD, president and CEO of CTI. "There is a significant unmet need in keeping a patient's cancer from returning following initial treatment, and we are hopeful that Opaxio has the potential to serve this role in ovarian cancer."

The trial is being conducted and managed by the GOG, which is one of the National Cancer Institute's (NCI) funded cooperative cancer research groups focused on the study of gynaecologic malignancies.

The GOG-0212 study is a randomized, multicentre, open label phase III trial of either monthly Opaxio or paclitaxel for up to 12 consecutive months compared to surveillance among women with advanced ovarian cancer who have no evidence of disease following first-line platinum-taxane based therapy. For purposes of registration, the primary endpoint of the study is overall survival of patients treated with Opaxio compared to no maintenance therapy. Secondary endpoints are progression-free survival, safety and quality of life. The statistical analysis plan calls for up to four interim analyses and one final analysis, each with boundaries for early closure for superior efficacy or for futility. The first interim analysis was conducted in January 2013, which passed the futility boundary and continued with no changes.

Opaxio (paclitaxel poliglumex, CT-2103), is an investigational, 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, paclitaxel is inactive, potentially sparing normal tissue's exposure to high levels of paclitaxel and its associated toxicities. Blood vessels in tumour tissue, unlike blood vessels in normal tissue, are porous to macromolecules such as Opaxio. Based on preclinical studies, it appears that Opaxio is preferentially distributed to tumours due to their leaky blood vessels and trapped in the tumour bed, allowing significantly more of the dose of chemotherapy to localize in the tumour than with standard paclitaxel. Once inside the tumour cell, enzymes metabolize the protein polymer, releasing active paclitaxel. Unlike standard radiosensitizing agents, Opaxio appears tumor selective and does not appear to enhance radiation toxicity to normal tissues.

The GOG is a not-for-profit organization of more than 300 member institutions with the purpose of promoting excellence in the quality and integrity of clinical and basic scientific research in the field of gynecologic malignancies. The GOG is committed to maintaining the highest standards in clinical trials development, execution, analysis and distribution of results.

CTI is committed to the development and commercialization of an integrated portfolio of oncology products aimed at making cancer more treatable.