Weekly Dose: multiple sclerosis drug fingolimod comes from fungus Chinese medicine calls ‘eternal youth’
Fingolimod is a drug used to treat multiple sclerosis (MS), an autoimmune disease. It is an immunosuppressant, which means it works by suppressing the immune system.
Fingolimod is an oral medication and is marketed in Australia under the brand name Gilenya®.
What is multiple sclerosis?
Multiple sclerosis (MS) is a chronic disabling disease that involves the central nervous system, made up of the brain and spinal cord.
While the exact cause of MS is unknown, current evidence suggests an abnormal immune-system response leads to the development of increased numbers of white blood cells, called lymphocytes. This causes damage to the nerve cells in the brain and spinal cord.
The damage is mainly characterised by unravelling of the outer layer, called a myelin sheath, of the affected nerve cells. Then, lesions form which interrupt the transmission of nerve signals.
Common symptoms of MS include muscle weakness and numbness, difficulty with thinking, fatigue, dizziness and visual disturbances.
The disease course of MS commonly involves a pattern of attacks where symptoms are severe, followed by relatively symptom-free periods.
History of fingolimod
Medications that suppress the immune system have a history with fungus.
One of the earliest immunosuppresant medications, cyclosporin – used to prevent rejection of an organ transplant – was derived from fungus. Its success led to further investigations of fungi as a source of immunosuppresant compounds.
Fingolimod was first derived from the fungus Isaria sinclairii in 1992. In Chinese medicine, this fungus is known as “eternal youth”.
How does fingolimod work?
Fingolimod suppresses the abnormal immune system response in people with MS, by acting on a specific receptor (S1P-type-1) on lymphocytes. This reduces the circulation of the abnormally activated cells and nerve damage potential.
Further reading: Explainer: how do drugs work?
Fingolimod is also thought to have some protective effects by reducing inflammation in the central nervous system, as well as premature cell death. There is also some evidence it helps repair the damage to the myelin sheath damage.
Fingolimod was the first oral medication developed to treat MS. Its predecessors, such as interferon beta, were in injectable form. This has been a major breakthrough for patients who find injections unpleasant.
Studies have shown fingolimod reduces the relapse rate of MS attacks by more than 50% compared to placebo. This is a significant reduction when compared to its predecessors.
What are the side effects?
The most common side effects of fingolimod include viral infections, headaches, back pain, diarrhoea and cough.
Using fingolimod has been associated with more serious but less common side effects such as vision disturbances, irregular heart beat and infections such as herpes, which have the potential to become life-threatening due to a suppressed immune system.
Doctors will screen patients before starting therapy. This involves assessing a patient’s risk of side effects due to other chronic conditions and medications. Ongoing monitoring for side effects during treatment is also necessary.
The majority of side effects will disappear once treatment with fingolimod stops.
Availability and cost
Fingolimod became available on the Australian Pharmaceutic Benefits Scheme in 2011. It is available to patients whose diagnosis is confirmed with an x-ray or scan and who have had at least two attacks within a two-year period.
For those who qualify for treatment, one month’s treatment, which involves one 0.5mg capsule per day, will cost A$38.30 for general patients or A$6.20 for those with a concession card.
The cost of one month’s therapy to the Australian Government is A$2314.50.
Between July 2014 and June 2015, A$134,752,870 was spent on supplying fingolimod to eligible patients, making it the tenth top medication by cost to the Australian government.
Who shouldn’t use it?
Fingolimod can’t be used in women who are or intending to become pregnant as it is thought to cause harm to the developing foetus.
Fingolimod is not to be used in patients under 18 years of age due to a lack of research in the paediatric population. It should also not be used at the same time as other medications that treat MS.