Nektar Therapeutics, a biopharmaceutical company, has initiated an investigator-sponsored trial evaluating etirinotecan pegol (NKTR-102) in patients with bevacizumab (avastin)-resistant high-grade glioma.

Etirinotecan pegol is a targeted topoisomerase I inhibitor designed for prolonged tumour cell exposure, which is believed to penetrate the vasculature of the tumour environment more readily than normal vasculature.

The Phase 2 study, which is being conducted at Stanford Cancer Institute, is expected to enrol approximately 20 patients who will receive etirinotecan pegol once every three weeks as monotherapy.

Stanford Cancer Institute professor of neurology and neurosurgery, and principle investigator of the study, Dr Lawrence Recht said the patients with bevacizumab-resistant high-grade glioma currently have minimal or no treatment options to aid disease management.

"We know that the mechanism of topoisomerase I inhibition has resulted in anti-tumor activity in gliomas in the past," Dr Recht added.

"As a result, we are interested in evaluating etirinotecan pegol, this new targeted topoisomerase I inhibitor, which provides sustained exposure of drug metabolite to tumor cells."

The six-week progression free survival (PFS) rate is the primary endpoint of the open label, single-arm trial, while the secondary endpoints include survival from time of first etirinotecan pegol infusion, overall survival from diagnosis date or confirmation of high-grade glioma, and the safety profile of etirinotecan pegol in patients with bevacizumab-resistant high-grade glioma.

Nektar senior vice president and chief medical officer Robert Medve said etirinotecan pegol has shown promising results in drug-resistant solid tumours, including advanced and pre-treated breast and ovarian cancers.

"Recognizing the high unmet need in glioma, we are very pleased to support Dr. Recht and his colleagues with this study of single-agent etirinotecan pegol in this setting," Medve added.