Темопорфин

Temoporphin, a second generation photosensitizer, was launched in UK for the photodynamic therapy (PDT) of advanced head and neck cancers. This porphyrin derivative can be synthesized from pyrrole and 3-hydroxybenzaldehyde. The pharmacological activity is initiated, 4 days after intravenous injection, by laser-light photoactivation of temoporphin, that has selectively accumulated in cancer tissues. The resulting generation of highly reactive oxygen species leads to malignant cells death thereby inducing tumor necrosis up to a depth of 15 mm. An advantage of temoporphin over other photosensitizing agents is its extreme sensitivity to wavelengths of light that penetrate tissues, resulting in lower light/dose and irradiation time. PDT with intravenous temoporphin has produced relatively high complete and partial response rates in head and neck cancers, with higher response rates generally observed with higher light dose. Temoporphin is well-tolerated and does not preclude surgery/radiotherapy as a later option. Adverse effects were photosensitivity and pain at the injection site.

Temoporfin is a synthetic chlorin with light-activated actions. When administered systemically, temoporfin accumulates in tumor cells. When stimulated with light (650-652 nm) in the presence of oxygen, reactive oxygen species are generated, leading to necrosis within the tumor. Different approaches to using photodynamic therapy with temoporfin in palliative care are currently of interest.