The expected 1-2 week cutaneous photosensitivity following talaporfin administration is considerably shorter than that associated with other commonly used agents like porfimer sodium and mTHPC [18, 19].
Animal studies have established the safety and potential efficacy of PDT for pancreatic cancer using a variety of photosensitisers including mTHPC, dihaematoporphyrin ether (DHE), and 5-ALA [22-24].
Previous hamster studies have looked at the effect of PDT with mTHPC, with which the optimum drug light interval is up to 4 days for treating cancers of the pancreas .
However, in humans, the distances are much greater, so that as long as the light delivery fibre is separated from the duodenum by more than about 1 cm (for example by positioning the fibre tip 1 cm deep into the pancreatic tissue), duodenal damage is unlikely, as shown in the clinical studies with mTHPC.
Previous work has also looked at the effect of PDT with mTHPC on cancers of pancreatic origin transplanted into the hamster pancreas .
mTHPC: Meso-tetrahydroxyphenyl chlorin PDT: Photodynamic therapy DLI: Drug light interval.
MacRobert et al., "Photodynamic therapy of a transplanted pancreatic cancer model using metatetrahydroxyphenylchlorin (mTHPC)," British Journal of Cancer, vol.