Light Sciences Oncology has announced that a new pre-clinical study has yielded evidence that its novel light-activated drug Aptocine (formerly Litx) may enhance anti-tumour immunity and prevent metastases.

The pre-clinical study was conducted at the Roswell Park Cancer Institute in Buffalo, New York, where Aptocine was used to treat primary tumours and examine prevention of metastases in the 4T1 tumour model, an aggressive, spontaneously metastasising murine mammary tumour model that mirrors human breast cancer.

To determine whether the therapy could enhance anti-tumour immunity and reduce metastases, the lymph node (LN) cells from treated and control mice were transferred to naïve recipient mice. Recipients were challenged with a tumourigenic dose of 4T1 cells three days after adoptive transfer and primary and secondary tumour growth in the recipients was examined.

Aptocine treatment significantly prolonged survival in treated animals. All treated animals survived to termination at 24 days while median survival for controls was eight days.

This drug acts as an in-vivo vaccine – challenging a naïve mouse with tumour 40 days after transferring immune cells from an Aptocine-treated animal still conferred immune protection.

Aptocine (talaporfin sodium) is a water-soluble drug activated by an included small, single-use, disposable drug activator. It is designed to provide tolerable, effective and repeatable treatments for cancer patients.

Packaged with Aptocine, the drug activator contains a tiny array of LEDs at the end of a very narrow (only 1.2mm wide) flexible coated micro-wire.

The results of the study will be presented at the annual American Society of Clinical Oncology meeting in Orlando, Florida, on 30 May 2009.