Many patients crippled with moderate to severe atopic dermatitis were ecstatic when Dupilumab, whose brand name is Dupixent was approved in 2017. During the trials that led to its approval, there were few reported minor, though manageable side effects. The only serious side effect reported at that time was inflammation of the transparent lining of the white part of the eyes called conjunctivitis. The later rarely led to discontinuation of this supposed miracle drug. The miracle came with a hefty price tag as weekly subcutaneous injection cost about $50,000 per year.
Dupilumab is a monoclonal antibody which means it is manufactured to only attack one target in the body. In eczema, the offending target is interleukin 4. In eczema or atopic prone individuals, it contributes to the development of eczema. Interleukins, such as interleukin 4, are normal components of our immune system produced by our white cells and are used for signaling in our immune system. Blocking interleukin 4 (IL 4) also effects another signaling agent, interleukin 13. By blocking these chemicals atopic dermatitis or eczema is improved in many of these suffering individuals improving their quality of life.
Unfortunately, there might be a major problem with Dupilimab on the horizon. There are cases now being reported where people treated with Dupilumab are developing inflammation of their joints called inflammatory arthritis plus inflammation where tendons and ligaments join the bone called enthesitis. It has been suggested that perhaps interleukin 4 and interleukin 13 (IL 13) are needed to prevent damage to the cartilage lining the joints. By suppressing these 2 chemicals in the hopes of relieving the symptoms of atopic dermatitis, an unintended consequence is painful joint inflammation in some people treated with Dupixent.
This story is not new in medical history. There are a host of medications that were first approved for prescription use but were later withdrawn from the market due to newly discovered side effects. “One-Third Of New Drugs Had Safety Problems After FDA Approval.”
Finding a side effect after approval is especially common after approval of biologics such as Dupilumab.
One psoriasis medication Raptiva (efalizumab), another biologic, needed to be pulled off the market in 2009 after it was found to potentially reactivate a virus that could cause severe brain damage called progressive multifocal leukoencephalopathy (PML).
While Dupilumab is still an excellent drug for moderate to severe atopic dermatitis only time will tell if this newly discovered side effect will impact its continued use and approval status.
Here is an interesting list of medications that were first approved by governmental agencies but later withdrawn when unacceptable side effects came to light.