Scotia's Foscan Leads The Way In PDT

Photodynamic therapy promises a rapid advancement in the ability tocombat a wide range of cancers, according to recent research. Photosensitizers such as Dusa's Levulan (aminolaevulinic acid) and QLT PhotoTherapeutics Photofrin (porfimer sodium) are already on the market, but look set to be superceded by second-generation compounds such as Scotia's Foscan (temoporfin), which suggest that it may now be possible to treat and cure certain cancers, as well as to provide palliation when the disease is more advanced, says the company.

There are many benefits to PDT over surgery and radiotherapy, says Stephen Bown of the UK-based National Medical Laser Center. It offers localized destruction of diseased tissue just about anywhere in the body, with no open surgery required. In addition, excellent healing has been seen following the procedure; the connective tissue is retained, thus the tumor can be replaced via the regeneration of normal tissue. The procedure may also be repeated if an incomplete response is obtained, or the tumor recurs, as there is no cumulative toxicity.

First-Generation PDT PDT began with the use of hematoporphyrin derivative, which is still in worldwide use. However, it is extracted from bovine blood and is not pure, nor does it have a standard photophysical activity, says Scotia.