LONDON - Shares in Scotia Pharmaceuticals plc dropped by more than a quarter on Friday following a journal article report that six of 14 volunteers in a safety study of its photodynamic therapy drug foscan had developed serious burns at the site of the injection. The shares fell from #1.53 to #1.13 on the news.

Scotia, based in Stirling, Scotland, said it was aware of the study, which was submitted to the regulatory authorities as part of the applications for market approval. Heather King, director of investor relations, told BioWorld International, "We wouldn't typically expect to see burns of this severity, and we were already reviewing the study." The incidence of burns in the study is significantly higher than in foscan trials overall, where mild to moderate photosensitivity reactions were reported in around 10 percent of more than 800 patients who have received the drug.

Foscan accumulates in tumors, which are then destroyed by targeted light rays. The general advice to patients is to avoid sunlight for 14 days after injection and to gradually build up exposure. Scotia believes that the burns occurred because there was leakage of foscan at the site of the injection. Although a rare occurrence, "We are aware that this can happen, and if so the advice is to cover the skin [at the injection site] completely for up to three months," Chris Blackwell, director of drug development, told BioWorld International. This procedure was followed in other patients when leakage occurred, avoiding serious burns.

He added that foscan is a purple liquid, meaning that any leakage should be evident from a visual inspection. "In reviewing this study we are looking into the high incidence of burns, as we know that if you follow the procedures they can be avoided."

Blackwell said he does not believe this study "will have any effect on the likelihood of our receiving approval for this product from the regulatory authorities." However, the timing is bad because Scotia is in advanced negotiations with potential marketing partners for foscan.

King said the company had seen and commented on a draft of the paper, which appeared in the British Medical Journal. These comments were not reflected in the final version of the paper, which Scotia did not see before publication, nor was the company aware of the publication date.