PAM has recently approached Dr. Heselynn Hussein (Rheumatologist) to enquire about the latest small molecule treatments for Psoriatic Arthritis called Janus Kinase (JAK) Inhibitors. JAK inhibitors are a type of immune modulating medication. Below is the information provided by Dr. Heselynn Hussein:
Janus kinase (JAK) inhibitors are a group of drugs which fall under the category of disease-modifying anti-rheumatic drugs (DMARDs). They are the first oral option which compare favourably with existing biologics but they are not biologics. They are small molecules and are also called targeted synthetic DMARDs (tsDMARDs). This is because they were developed to target a particular molecular structure.
Psoriatic arthritis is a chronic inflammatory disease which causes inflammation of the joints. JAK inhibitors act by suppressing activity of one or more of the Janus Kinase family of enzymes.
Janus kinase molecules can activate specific immune cells and induce expression of certain chemical messengers called cytokines. Cytokines are involved in inflammation. Thereby by blocking the signalling pathway and cytokine pathways which are involved in causing inflammation in psoriatic arthritis, JAK inhibitors can help inhibit the inflammatory process.
Clinical trials show that they are more effective than conventional DMARDs but are just as effective as biological DMARDs.
There have not been clinical trials of JAK inhibitors for psoriatic arthritis in Malaysia although they have been conducted for rheumatoid arthritis.
At time of writing, there are three JAK inhibitors available in Malaysia but only two are approved by the local regulatory body to be used in psoriatic arthrits being Tofacitinib and Upacitinib (Xeljanz and Rinvoq). As this mode of treatment is just as effective as biologics, this treatment can be costly. Medical information provided by:
Dr. Heselynn Hussein
Consulltant Rheumatologist Subang Jaya Medical Centre
Previously Consultant Rheumatologist and Head of Department of Medicine,
Graduated from University of Wales College of Medicine, Cardiff, U.K
Trained in rheumatology in Hospital Universiti Kebangsaan Malaysia & University Hospital Birmingham Trust, Birmingham, United Kingdom
Update: Information provide to PAM indicate that JAK Inhibitors prices range in Malaysia from RM 2500 to RM 3500 a month. We take note that patient assistance programmes are available via pharmaceutical companies. Please contact your rheumatologist for the latest updates on pricing.