LONDON - Scotia Pharmaceuticals plc is considering what further action to take in response to a journal article reporting that six volunteers suffered serious burns in a pharmacokinetic study of its photodynamic therapy agent Foscan, after doctors called into question the way the study was performed.
Surgeons in the UK, Holland and Germany who have treated more than 100 patients with Foscan said, "It is clear that established clinical guidelines were ignored" in the performance of the study.
Shares in the company, based in Stirling, Scotland, fell by more than 25 percent when the article was published in the British Medical Journal (BMJ) on May 6. The timing was particularly bad because Scotia is in advanced negotiations with potential marketing partners.
Responding to the article, Graham Putnam, an oral and maxillofacial surgeon at Carlisle Hospital in Cumbria, and surgeons at four other hospitals, note that they have treated more than 100 oral cancer patients with Foscan. Sixteen patients had an adverse reaction but only one required treatment. The surgeons say it appears that the burns in the safety trial are due to extravasation (leakage) at the time of injection, "which protocol demands should be covered by an occlusive dressing for three months."
Furthermore, the effects of inappropriate sunlight exposure following Foscan administration have been known since 1994, and the surgeons say they are, "concerned that this complication should have been allowed to occur in a research unit." These comments were made in a letter to the BMJ.
Scotia also believes extravasation is the cause of the burns, and it is reviewing the trial to try and verify this. All 14 subjects in the study reported localized photosensitivity in their infusion arm, whereas in a separate pharmacokinetic study involving 23 patients with head and neck cancer there were no such reactions.
While it does not dispute the data, which were included in the regulatory submission, Scotia says the report creates a misleading impression of the true incidence, severity, and overall risk of burns and other photosensitivity reactions to Foscan and said, "This has lead to inaccurate media comment and speculation."
Director of investor relations Heather King told BioWorld International, "The findings as reported are correct. But what is not correct is the context. Six volunteers were burned, but this should be viewed in the context of over 950 [patients and volunteers] who have received Foscan. It is misleading not to point this out."
King would not confirm reports that Scotia is considering legal action against the four authors of the paper, but said the company is "keeping all its options open." Two of the authors are employed by the contract research organization that carried out the trial on Scotia's behalf.