Skin Biopsies Before Dupixent: What the Recommendation Means for Patients

Why Biopsies Before Dupixent Are Being Discussed

Dupixent (dupilumab) is widely prescribed for moderate-to-severe eczema, also called atopic dermatitis. Recent coverage reports that some experts now recommend a skin biopsy before a patient starts Dupixent. The concern is about telling ordinary eczema apart from an early cutaneous T-cell lymphoma (CTCL).

This post explains what that discussion is about and why it matters if you or a family member was diagnosed with CTCL after using Dupixent. It also covers why a diagnosis made before you started the drug does not automatically rule you out.

The litigation is at an early stage, and very little has been established. Everything below about the lawsuits describes allegations under examination. None of it is a finding by any court.

What Cutaneous T-Cell Lymphoma Is

CTCL is a group of rare cancers that start in white blood cells called T cells and show up first in the skin. The two forms named most often in these lawsuits are:

• Mycosis fungoides, the most common form, which often appears as flat, scaly patches or thicker plaques on the skin.
• Sézary syndrome, a rarer and more aggressive form that involves the skin and the blood.

According to the National Cancer Institute, early mycosis fungoides can look like other common skin conditions, including eczema and psoriasis. Doctors usually need a biopsy, and sometimes more than one, to confirm the diagnosis. That overlap is at the heart of the biopsy discussion.

What the Biopsy Recommendation Reportedly Says

According to recent reporting, some experts have suggested that patients with atypical or treatment-resistant eczema, especially adults whose eczema began later in life, should have a skin biopsy before starting Dupixent. The stated goal is to check whether the rash is really eczema or an early lymphoma.

It is important to be clear about what this is and is not:

• It is a clinical recommendation that has been discussed in medical and legal coverage.
• It is not a finding that Dupixent causes cancer.
• We have not confirmed any FDA label change requiring a biopsy before treatment. Patients can check current prescribing information on the FDA website.

If you are taking Dupixent now, do not stop or change your treatment without talking to your doctor.

The Two Claims Being Pleaded

Lawsuits against Sanofi and Regeneron make two separate allegations. A full picture of the litigation needs both.

1. The drug may cause or accelerate a lymphoma. Plaintiffs allege that Dupixent may cause a cutaneous T-cell lymphoma, or may speed up one that was developing. This is an allegation being examined in court and has not been proven.

2. The drug may mask a lymphoma the patient already had. Plaintiffs also allege that, in a patient whose rash was actually an early lymphoma, Dupixent may have temporarily improved the skin and hidden the early warning signs. The claim is that this delayed the correct diagnosis. This allegation is also under examination and has not been proven.

The biopsy discussion bears directly on the second claim. If a biopsy before treatment could have told eczema apart from lymphoma, plaintiffs argue that patients and doctors should have been warned about that risk.

Diagnosed Before Starting Dupixent? You May Still Have Questions Worth Asking

Many people assume that if their lymphoma was present before they ever took Dupixent, they have no claim. That is not automatically true.

Under the second claim, the question is not only whether the drug started the cancer. It is also whether treatment may have hidden symptoms and pushed back the date the lymphoma was correctly identified. A person whose CTCL was there early, but whose diagnosis came later, may fall within what plaintiffs are pleading.

Whether any individual claim fits depends on the medical records, the timeline, and the law that applies. A lawyer can review those facts with you.

Where the Litigation Stands

Reporting indicates that federal Dupixent injury lawsuits have been consolidated in federal court in New Jersey. The Judicial Panel on Multidistrict Litigation decides when similar federal cases are grouped before one judge. Information about the court is available from the U.S. District Court for the District of New Jersey.

Consolidation is a case-management step. It lets one judge handle shared questions, like evidence exchange and expert testimony, efficiently. It is not a finding that Dupixent caused anyone’s lymphoma, and it says nothing about how any case will turn out.

Because the litigation is so new, we are not going to estimate how many people may file or what any case could be worth.

What the Research Shows So Far

Some published case reports and studies, which can be searched on PubMed, have described CTCL diagnoses in patients treated with dupilumab. Researchers have discussed whether these reports reflect an association, a missed diagnosis made before treatment, or something else.

The science is still developing. Researchers have not established that Dupixent causes CTCL, and the lawsuits will test that question through expert evidence.

Records That Can Help Tell Your Story

If you were diagnosed with CTCL after using Dupixent, these records are often useful to gather:

• Biopsy and pathology reports, including any taken before you started Dupixent.
• Dermatology notes describing your rash, when it began, and how it responded to treatment.
• Pharmacy and prescription records showing when you started and stopped Dupixent.
• Oncology records showing when and how the lymphoma was diagnosed.

You do not need to have every record in hand before talking to a lawyer. Much of it can be requested on your behalf.

Take the Next Step

A cutaneous T-cell lymphoma diagnosis is frightening, and questions about whether a medication played a part can make it harder. You deserve clear information about your options.

You can learn more on our Dupixent lymphoma litigation page. If you or a loved one used Dupixent and was later diagnosed with mycosis fungoides, Sézary syndrome, or another CTCL, including if the lymphoma may have been present before treatment, request a free case review. There is no cost to have your situation reviewed, and no obligation to proceed.