Texaphyrins are ‘Texas-sized’ porphyrins featuring
a penta-aza core and are marketed by Pharmacyclics
(Sunnyvale, CA, USA) as a photosensitizer (see http://www.pcyc.com). Under the trade name Lutrin™,
lutetium texaphyrin is undergoing Phase II clinical trials as
a possible therapy for breast cancer.
The main advantage
of using texaphyrins as PDT agents is their strong
absorbency at a much longer wavelength (732 nm) so that
treatment can be carried out effectively on a larger tumour
or at a greater depth.
The lutetium texaphyrin derivative,
Antrin™, is also in Phase I clinical trials for angioplasty of
atherosclerotic cardiovascular disease and the treatment
and prevention of restenosis, while another derivative,
Optrin™, is in Phase I trials for AMD.
In addition, the
company is also developing radiosensitizers and
chemosensitizers based on the texaphyrin framework with
the radiation sensitizer, Xcytrin™, currently in Phase III
clinical trials for the treatment of brain metastases and
Phase I trials for newly diagnosed primary brain tumours.