What is an anti-JAK drug?
- Anti-JAK drugs target and block a specific enzyme in the body called Janus kinase (JAK) in order to reduce the inflammatory response.
- These enzymes play a crucial role in regulating our immune system.
- They act as a switch that can activate signals inside our cells, including those of inflammation.
Indication and dosage
- There are several anti-JAK drugs available in tablet form.
- The advantage of anti-JAKs is their short half-life; this means that they act very quickly and remain in the body for only a short time. This is why they are taken daily (once or twice a day).
- They are prescribed for a number of autoinflammatory diseases.
- They are prescribed by your specialist doctor on a special prescription.
Pre-therapy assessment
Before starting treatment, a check-up called ‘pre-biotherapy’ is carried out to :
- rule out any contraindications to treatment
- rule out any infection (tuberculosis, dental infection, etc.).
- update compulsory vaccinations:
➢an immunisation against chickenpox is necessary. If you have never had chickenpox, vaccination is recommended (live attenuated vaccine).
Shingles vaccination is recommended before treatment is started (live attenuated vaccine) or as soon as the inactivated vaccine is available, during treatment.
Tolerance
- Anti-JAK treatment is usually well tolerated.
- Biological monitoring is required, initially on a monthly basis and then more frequently.
- Anti-JAKs increase the risk of thrombosis and could increase the cardiovascular risk in patients at risk.
- Your doctor will take this information into account when prescribing anti-JAK and will weigh up the benefits/risks according to your disease, its severity and your history.
Practical questions
When should Anti-JAK treatment be stopped?
- Infection/fever: inform your doctor immediately in order to assess the need to start anti-infectious treatment quickly and/or temporarily stop anti-JAK treatment, depending on the severity of the infection.
- Shingles: inform your doctor immediately so that antiviral treatment can be started rapidly
anti-viral treatment and to temporarily stop anti JAK treatment until recovery.
- Surgery:
➢it is not necessary to interrupt treatment in the case of minor procedures such as scaling, tooth extraction or the fitting of a dental implant.
➢However, in the event of major surgery, a temporary interruption of treatment should be discussed with your specialist doctor (generally 7 days before the operation).
- Pregnancy and breast-feeding (see next page)
Vaccination under Anti-JAK
- The only vaccines contraindicated are live attenuated vaccines. If such a vaccination is necessary due to travel, you should inform your specialist doctor so that treatment can be temporarily suspended.
- Annual flu and pneumococcal vaccinations are strongly recommended.
strongly recommended.
Fertility, pregnancy & breastfeeding
In the absence of sufficient data, anti-JAKs are contraindicated during pregnancy and effective contraception is required when treatment is initiated.
- As a precaution, anti-JAK treatment should be interrupted or not resumed during breast-feeding.
- In men, anti-JAK treatment may be followed up if paternity is desired: no adverse effect on fertility has been demonstrated.