An entire class of popular arthritis medications – JAK Inhibitors – may expose users to risks of heart attack, stroke, blood clots, cancer, and death, according to a new Summary Safety Review issued by Health Canada.

The review comes on the heels of two prior Safety Reviews which linked these risks to Xeljanz, Canada's most popular JAK Inhibitor. Now as a result of the latest Health Canada findings, manufacturers of all JAK Inhibitors will need to warn patients and doctors about the potential risks.

JAK Inhibitors are oral medications for arthritis which are growing in popularity

Janus Kinase (JAK) Inhibitors are prescription drugs that are approved to treat chronic inflammatory diseases such as rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis. JAK inhibitors are typically prescribed when other medicines do not work and are particularly appealing to patients because they are sold in tablet form and can be taken orally.

Since the first JAK Inhibitor (Xeljanz) was approved for use in Canada less than a decade ago, the drugs have been steadily increasing in popularity. Annual prescriptions in Canada have jumped from just over 10,000 in 2016 to upwards of 90,000 or more in 2021.

In recent years, Health Canada linked Xeljanz to potentially life-threatening risks

Health Canada's latest Summary Safety Review findings come on the heels of two prior Safety Reviews issued by the department which found issues with Xeljanz (tofacitinib).

The Reviews, each published within the past three years, found links to exist between Xeljanz – a medication used by thousands of Canadians for treating chronic inflammatory diseases – and risks of thrombosis and serious heart-related problems and cancer, respectively, and led Health Canada to require updates to the risk warnings for the drug. (Read my prior blog for more info). Those prior findings ultimately led Health Canada to expand its investigation to encompass the other JAK Inhibitors approved for use in Canada: Olumiant (baricitinib) and Rinvoq (upadacitinib).

All JAK Inhibitors will now need warnings about risks blood clots, cancer, heart attacks

The latest Review, issued in September 2022, confirms Health Canada's earlier findings about Xeljanz and determines that Olumiant and Rinvoq may have similar risks.

Health Canada concluded that the findings were "supportive of the need for precautionary measures" and manufacturers will need to "update and align these risks" in product documents.

Xeljanz and Xeljanz XR (tofacitinib) class action

Siskinds LLP and Siskinds' Québec-based affiliate, Siskinds, Desmeules, are seeking to recover compensation for Canadians who suffer injuries resulting from their use of prescription Xeljanz. Siskinds Desmeules has filed a class action alleging that the makers of Xeljanz failed to adequately warn users of Xeljanz, and their health care providers, that Xeljanz increases the risk of major adverse cardiovascular events, including death, heart attack, coronary revascularization, stroke, hospitalization for heart failure, and cancer.

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