Photodynamic therapy with new sublingual sensitiser Photosoft®E4 for cancer: a case series

Abstract

Background: An increasing number of patients seek complementary therapies for cancer treatment, the leading cause of death in the developed world. Photodynamic therapy (PDT), the combination of light and a photosensitiser agent, has provided some promising results in cancer therapy. New photosensitiser agents are continuously being developed to improve tolerability and effectiveness. There is a need to objectively evaluate clinical data from PDT patients.Methods: Here we report a case series using the new sublingually administered, chlorophyll-based photosensitiser Photosoft®E4 and an external laser light in a group of ten adult cancer patients not undergoing other concurrent therapies. PDT was administered for three treatment cycles with an average of 14 light treatments per patient, consisting of agent administration and laser treatment on alternate days over 3 months. Safety, tolerability and effectiveness on tumour palliation were monitored. Results: Patients in this study presented with a variety of cancer types and stages; half of the patients had breast cancer, and 40% had metastases. We found Photosoft®E4 to be safe and highly tolerable. However, overall disease status was not improved in our group of patients. Conclusions: Future research is required to determine the bioavailability of Photosoft®E4 and its uptake in tumour tissue, pharmacokinetics and dosing regimen, as well as the best mode of light delivery for the in vivo sensitiser activation.