In photodynamic therapy (PDT), a compound with photosensitizing properties (photosensitizer, PS) is selectively accumulated in malignant or damaged tissues. The subsequent activation of the PS by visible light, generates reactive oxygen species, mainly singlet oxygen 1O2, responsible for cell toxicity of cancer cells and tumor regression. There are three main mechanisms described by which 1O2 contributes to the destruction of tumors by PDT: direct cellular damage, vascular shutdown and activation of immune response against tumor cells. The advantages of PDT over other conventional cancer treatments are its low systemic toxicity and its ability to selectively destroy tumors accessible to light.
This allows for minimally invasive treatment of early disease or pre-cancer, or early detection and diagnosis. Effective targeting of damaged cells and preserving healthy tissue.
Photocure Technology provides important qualities that enhance the properties of photodynamic technology for diagnosis and therapy. Photocure Technology is:
- Uniquely selective for diseased cells.
- Effective and safe.
- Minimally invasive.
The proven strength of Photocure Technology is built on the following key characteristics:
- Utilizes the cells' own photosensitizers: The cells' own photosensitizers, i.e. porphyrins, are formed following administration of our optimized precursors (building-blocks). Diseased cells grow more rapidly than healthy cells, and will therefore take up and convert more of the precursors into porphyrins than healthy cells.
- Tailor-made precursors: We carefully design precursors to provide a high selectivity for the malignant cells.
- Local administration and illumination: The substance is applied locally, i.e. confined to the desired area, and is then illuminated. Uptake into the blood is minimized, avoiding photosensitivity of the patient.
An example of the unique selectivity of Photocure Technologyis demonstrated in bladder cancer. The selective technology allows a more complete or thorough diagnosis leading to enhanced disease management.
CIS in white light CIS in blue light.
The left image shows the inside of a bladder with bladder cancer (carcinoma in situ) in white light. By Blue Light Cystoscopy with Hexvix®/Cysview®, the cancer cells light up red as can be seen on the image to the right.
Another example is the use in non-melanoma skin cancer where the cancer lesion is effectively treated leaving normal skin unharmed.
Basal cell carcinoma before treatment
Basal cell carcinoma after PDT treatment
Photocure Technology is currently applied in several disease areas:
- Bladder cancer - Hexvix®, Cysview®
- Non-melanoma skin cancer - Metvix
- HPV/precancerous lesions of the cervix (Cevira® - Phase 3 ready)
- Acne (Visonac® - Phase 3 ready)
- Improving the appearance of skin - Allumera®