Photo of Sanofi headquarters

Dupixent, which is the brand name of dupilumab, is produced by Sanofi and Regeneron. According to the manufacturers, the drug has been prescribed to over one million people worldwide to help treat atopic dermatitis (AD) and other conditions.

However, recent research suggests that Dupixent could be linked to a higher risk for developing a rare type of skin cancer called cutaneous T-cell lymphoma (CTCL).

A study published in the Journal of the American Academy of Dermatology compared people with AD who took Dupixent to those who did not take the medication. They found that patients who used the drug had about a four-times higher risk of developing CTCL.

A second analysis, published in Dermatologic Therapy, confirmed these findings. It showed the risk of CTCL was highest in patients over 60 and within the first year of using the medication.

What Is Dupixent?

Dupixent is a biologic medication, which means it’s made from living cells designed to target specific areas of the immune system. It works by blocking specific proteins that cause inflammation.

Dupixent can treat or be used as an additional therapy for several chronic conditions, including:

  • Bullous pemphigoid: A skin ailment that results in fluid-filled blisters.
  • Chronic obstructive pulmonary disease: An airway and lung disease that makes it hard to breathe.
  • Chronic spontaneous urticaria: Skin welts that are itchy, red and last at least six weeks.
  • Eosinophilic esophagitis: An immune system disease that makes swallowing difficult.
  • Moderate to severe uncontrolled eczema: Also known as atopic dermatitis (AD), this causes itchy, dry patches of skin.
  • Oral steroid-dependent asthma: Asthma that requires steroids and is hard to manage.
  • Prurigo nodularis: A skin condition that results in itchy skin bumps.
  • Uncontrolled chronic rhinosinusitis with nasal polyps: An inflammatory sinus disease with small, benign growths in your sinuses and nasal passages.
  • Uncontrolled moderate-to-severe eosinophilic asthma: Asthma caused by high numbers of white blood cells in your airways.

Symptoms of CTCL

CTCL often looks like other common skin conditions, which may delay diagnosis. According to Mayo Clinic, symptoms can include:

  • A widespread, itchy, scaly rash
  • Discolored patches on your skin
  • Enlarged lymph nodes
  • Hair loss
  • Scaly patches or raised skin that might be itchy
  • Skin lumps that may break open
  • Thickened skin on the soles of your feet or palms

If you’ve taken Dupixent and developed any of these symptoms, talk to your doctor.

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

Dupixent has worked well for many patients, but it’s also been linked to serious side effects.

According to the U.S. Food & Drug Administration’s Adverse Event Reporting System (FAERS), over 87,000 adverse events involving Dupixent and dupilumab have been reported so far in 2025. Among these are reports of CTCL.

FAERS data is based on self-reports, which can’t prove that the drug directly caused the events. Additionally, the data may not be entirely accurate.

In late 2024, the U.S. Food & Drug Administration placed Dupixent on its watch list for potential regulatory action. As of August 2025, the agency has not released an update on its evaluation.

Several law firms are investigating claims from patients who developed CTCL after using Dupixent. Consider speaking with a lawyer if you took Dupixent and were later diagnosed with CTCL.