The trial determined the safety of administering MetXia locally to the pancreatic tumor. The initial stage study also confirmed gene transfer at the tumor site following local delivery and identified an optimal dose for the second stage of the trial.
The two-stage phase II trial is designed to evaluate MetXia and the chemotherapy prodrug cyclosphosphamide (CPA) in patients undergoing palliative surgery for pancreatic cancer. The trial is being conducted at the Royal Liverpool University Hospital.
In the first stage of the trial, two dose levels of MetXia were assessed in six patients in combination with a low dose of CPA. Each patient had two administrations of MetXia, prior and subsequent to surgery, followed by CPA. Both dose levels of MetXia were safe and well tolerated. Importantly, dose dependent expression of the specific human cytochrome P450 gene, delivered by MetXia, was observed in tumor biopsies taken at surgery.
MetXia comprises a highly engineered retrovirus that delivers the P450 gene to tumor cells. The enzyme encoded by the P450 gene activates CPA to a form that destroys cells.
Following the encouraging results in stage one of the trial, patient recruitment is commencing for the second stage with a fixed dose of MetXia and increasing doses of CPA. Stage two will accrue up to 25 patients and will determine the optimal dose of CPA. This second stage of the trial is designed to evaluate clinical benefit as well as safety. An additional clinical trial site in London is expected to open for part two of the trial. Preliminary efficacy data is expected in early 2006.