BrachySil trial given thumbs up
BrachySil trial, which has confirmed expectations that the compound
(32P-BioSilicon) is safe and effective at tumour progression and
raises possibilities of an effective weapon against liver cancer.
The company's clinical development of this brachytherapy (short range intratumoural radiotherapy) involved trials, carried out on four patients with inoperable liver cancer, delivering the active substance via a fine gauge direct needle delivery procedure. The tests showed no product related adverse side effects and up to 60 per cent regression of tumours.
BrachySil is based on pSivida's BioSilicon, which takes the form of nanostructured porous silicon that can be machined into powders, microspheres, or just about any other structure whilst retaining its ability to carry and release active components.
In drug delivery applications, BioSilicon has significant advantages over rival polymer slow release drug delivery systems in animal trials. For example, it boasts higher loading rates, and the rate of release (achieved as the BioSilicon breaks down in the body), can be controlled to extend from days to months, according to the company.
Current brachytherapy products suffer from a lack of versatility. They generally involve delivery via the hepatic artery and, in cases, result in radioactivity becoming associated with healthy tissue, In contrast, BrachySil is administered directly into tumours restricting radioactivity to the tumour itself.
Because of these limitations, current brachytherapy approaches mean that localised radioactive treatment of tumours is limited only to liver and prostate cancer. The direct delivery nature of pSivida's new approach means that it should be more widely applicable, minimise side effects and maximise dose size, and will be relatively inexpensive.
The latest stuidy reveals that the active ingredient in BrachySil, radioactive 32P-BioSilicon, remains in the tumour with no or insignificant detectable radioactive leakage. This observation serves a greater purpose to the development of a simple procedure for an interventional radiologist to selectively treat specific tumours.
The current brachytherapy market is growing and is estimated to be worth more than $1 billion (€813 million) per year. BrachySil could expand the current market size through application to other cancers as a result of these latest trials. The procedure is undertaken without surgery under local anaesthetic and patients are discharged the following day.
pSivida's managing director Gavin Rezos said: "Product launch for BrachySil is scheduled for 2007, following the Phase IIB trial next year. The expectation that BrachySil will follow a 'device-based' regulatory route means shorter development and registration timeframes."
"Second stage commercialisation will target other major cancers to extend the range of potential applications of BrachySil."
The company also disclosed plans to produce a multi injector, currently in design phase, to treat larger tumours with multiple implantations from a single entry.
