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Dupixent, the brand name for the drug dupilumab, is made by Sanofi and Regeneron. It’s used to treat conditions like atopic dermatitis (AD), asthma and more. However, research shows that the medication has been linked to a significantly higher risk of developing a rare skin cancer.

A study published in the Journal of the American Academy of Dermatology compared patients with AD who used Dupixent to those with the condition who didn’t use the drug. Researchers found that Dupixent users had a roughly four-times greater risk of developing a rare cancer called cutaneous T-cell lymphoma (CTCL).

No increased risk was seen for other cancers. According to the study, most CTCL cases were diagnosed more than one year after patients started taking the drug.

A second study, published in Dermatologic Therapy, also reported an increased risk of CTCL among Dupixent users. The risk was highest within the first year of treatment, and people over 60 were more susceptible.

What Is Dupixent?

Dupixent is a biologic medication, meaning it’s made from living cells that target specific parts of the immune system. The drug works by blocking certain proteins involved in inflammation.

Doctors prescribe Dupixent to treat:

  • Bullous pemphigoid: An uncommon skin condition that results in large blisters filled with fluid.
  • Chronic spontaneous urticaria: Itchy red skin welts lasting at least six weeks.
  • Eosinophilic esophagitis: A chronic immune system disease that makes it hard to swallow.
  • Moderate to severe uncontrolled eczema: A skin condition resulting in itchy, dry patches of skin.
  • Prurigo nodularis: A skin condition resulting in itchy skin bumps.

Dupixent can also be used as an additional therapy to help treat:

  • Chronic obstructive pulmonary disease: A condition that causes difficulty breathing.
  • Oral steroid-dependent asthma: Asthma that is difficult to manage and requires steroids.
  • Uncontrolled chronic rhinosinusitis with nasal polyps: An inflammatory sinus disease with benign, small growths in your nasal passages and sinuses.
  • Uncontrolled moderate-to-severe eosinophilic asthma: Asthma resulting from high amounts of white blood cells in your lung’s airways.

What Is CTCL?

CTCL is an uncommon form of cancer. It impacts white blood cells known as T-cells, which causes the cells to attack the skin. The condition progresses slowly and isn’t normally life-threatening.

According to the Mayo Clinic, symptoms of cutaneous T-cell lymphoma include:

  • A widespread, itchy, scaly rash
  • Discolored patches that can appear brown, grey, pink or red
  • Enlarged lymph nodes
  • Hair loss
  • Lumps on your skin that may break open
  • Scaly patches or raised areas on the skin that may itch
  • Skin patches that look lighter than the surrounding skin
  • Thickened skin on your palms or the soles of your feet

If you have any of these symptoms, contact your doctor.

Safety Concerns and U.S. Food & Drug Administration Monitoring

While Dupixent has helped many people, some users have reported serious side effects.

According to the U.S. Food & Drug Administration’s Adverse Event Reporting System (FAERS), 87,451 adverse events have been reported for dupilumab and Dupixent so far this year, including cases of CTCL.

This report does not mean that the drug caused the adverse reactions. FAERS data is based on voluntary self-reports and is not proof that the medication caused the events. Additionally, numbers may be under- or over-reported.

The U.S. Food & Drug Administration put Dupixent on a watch list for potential regulatory action in late 2024. An update has not been released as of August 2025.

Law firms have begun investigating cases involving patients who developed CTCL after taking Dupixent. If you developed CTCL after using Dupixent, talk to an attorney to see if you’re eligible to file a lawsuit.