Foscan is a solution for injection containing the active substance temoporfin (1 or 4 mg/ml).
|Table of Contents|
|What is it used for?|
|How is it used?|
|How does it work?|
|How has it been studied?|
|What benefits has it shown during the studies?|
|What is the risk associated?|
|Why has it been approved?|
Foscan is used to relieve the symptoms of advanced head and neck squamous cell carcinoma (a type of cancer that starts in the cells lining the mouth, nose, throat or ear). It is used in patients in whom other treatments have stopped working, and who are not suitable for radiotherapy (treatment with radiation), surgery or systemic chemotherapy (medicines used to treat cancer; ?systemic? means that they are given as treatments throughout the body).
The medicine can only be obtained with a prescription.
Foscan must only be given in a specialist cancer centre where a team can assess the patient?s treatment under the supervision of a doctor who has experience in photodynamic therapy (treatment that uses light). Treatment with Foscan is a two-step process: the medicine is given first, before it is activated using a laser. The medicine is given by an indwelling intravenous cannula (a thin tube permanently inserted into a vein) as a single slow injection over at least six minutes. The dose is 0.15 mg per kilogram body weight. Four days later, the entire surface of the tumour and the surrounding 0.5-cm margin is illuminated with light from a laser at a specific wavelength, using a fibre-optic cable, for around three minutes and 20 seconds. Each area of the tumour should be illuminated only once during each treatment. During treatment, other areas of the body should be shielded from the light so that the activation of the medicine is limited to the tumour. If a second treatment is necessary, this should take place at least four weeks later.
The active substance in Foscan, temoporfin, is a photosensitising agent (a substance that changes when exposed to light). When Foscan is injected, temoporfin is distributed within the body, including within the tumour. When it is illuminated with laser light of a specific wavelength, temoporfin is activated and reacts with oxygen in the cells to create a highly reactive and toxic type of oxygen. This kills the cells by reacting with and destroying their components, such as their proteins and DNA. By restricting the illumination to the tumour, cell damage is limited to the tumour cells, leaving other areas of the body unaffected.
Foscan has been studied in four main studies involving a total of 409 patients with head or neck cancer. The first three studies looked at whether the tumour was eradicated after up to three treatments with Foscan in a total of 189 patients. The fourth study looked at the reduction of symptoms in 220 patients with advanced head or neck cancer who could not receive surgery or radiotherapy. In all studies, the response was assessed between 12 and 16 weeks after the final treatment with Foscan, but Foscan was not compared with any other treatment.
The results of the first three studies were insufficient to support the use of Foscan in the eradication of head and neck cancer tumours. However, in the study looking at improving symptoms of advanced head and neck cancer, 28 (22%) of the 128 patients assessed had a significant improvement in their most troubling symptom. Around a quarter of the patients in this study also had a reduction in tumour size.
The most common side effects with Foscan (seen in more than 1 patient in 10) are pain at the injection site, at the site of the tumour or in the face, haemorrhage (bleeding), scarring, mouth necrosis (death of cells or tissue in the mouth), dysphagia (difficulty swallowing), face oedema (swelling) and constipation. For the full list of all side effects reported with Foscan, see the Package Leaflet. Foscan should not be used in people who may be hypersensitive (allergic) to temoporfin or any of the other ingredients. Foscan must not be used in patients with porphyria (an inability to break down porphyrins), other diseases made worse by light, allergy to porphyrins, or tumours that are spreading into a blood vessel or that are next to where the laser is to be shone. Foscan must also not be used in patients who have an operation planned in the next 30 days, who have an eye disease that is likely to need examination using a ?slit lamp? (an instrument used by eye specialists to look into the eye) in the next 30 days, or who are already being treated with another medicine that increases sensitivity to light. Patients receiving Foscan should take care to avoid exposure to bright light for up to six months after injection to avoid skin burns. See the Package Leaflet for full details.
The Committee for Medicinal Products for Human Use (CHMP) concluded that Foscan?s effects on relieving the symptoms associated with advanced head and neck cancer were of interest. Therefore, the Committee decided that Foscan?s benefits are greater than its risks for the palliative treatment of patients with advanced head and neck squamous cell carcinoma who have failed other treatments and are not suitable for radiotherapy, surgery or systemic chemotherapy. The Committee recommended that Foscan be given marketing authorisation.
Foscan was originally authorised under ?Exceptional Circumstances?, because, as the disease is rare and for scientific reasons, limited information was available at the time of approval. As the company had supplied the additional information requested, the ?Exceptional Circumstances? ended on 21 May 2008.