Dupixent has been prescribed to patients with atopic dermatitis, commonly known as eczema, as well as asthma and several other inflammatory conditions. The injectable biologic medication has provided relief for many patients, but a growing number of lawsuits are raising questions about a potential association between Dupixent and certain forms of T-cell lymphoma.

Patients have filed product liability lawsuits against Dupixent manufacturers Regeneron Pharmaceuticals and Sanofi-Aventis alleging that the companies failed to adequately warn patients and healthcare providers about a potential risk of cutaneous T-cell lymphoma (CTCL) and related T-cell lymphomas.

The lawsuits generally allege that Dupixent may cause, accelerate, exacerbate, or reveal previously undiagnosed T-cell lymphoma in certain patients. The manufacturers dispute the allegations, and a causal relationship between Dupixent and CTCL has not been established.

In June 2026, federal Dupixent product liability lawsuits were centralized in the U.S. District Court for the District of New Jersey as MDL No. 3180, In re: Dupixent (Dupilumab) Products Liability Litigation.

If you or a loved one used Dupixent and were later diagnosed with CTCL, mycosis fungoides, Sézary syndrome, or another T-cell lymphoma, the Law Offices of Jason Turchin may be able to help evaluate a potential claim.

What Is Dupixent?

Dupixent, known generically as dupilumab, is an injectable biologic medication developed and marketed by Regeneron Pharmaceuticals and Sanofi.

Dupixent is used to treat several inflammatory conditions, including:

• Atopic dermatitis
• Asthma
• Chronic rhinosinusitis with nasal polyps
• Eosinophilic esophagitis
• Prurigo nodularis
• Certain other inflammatory conditions

The medication works by blocking signaling pathways involving interleukin-4 and interleukin-13, which play roles in inflammatory responses.

The developing litigation does not allege that Dupixent is ineffective for every patient. Instead, plaintiffs contend that patients and doctors should have received stronger information concerning an alleged potential association with T-cell lymphoma.

What Do Dupixent Cancer Lawsuits Allege?

Plaintiffs generally allege that Regeneron and Sanofi knew or should have known about information suggesting a potential association between Dupixent and T-cell lymphoma but failed to adequately warn patients and healthcare providers.

Among other allegations, lawsuits contend that:

• Dupixent may cause or contribute to CTCL in certain patients.
• Dupixent may accelerate an existing but undiagnosed T-cell lymphoma.
• The medication may reveal or “unmask” CTCL that was initially diagnosed as eczema.
• Manufacturers failed to provide adequate warnings regarding the alleged lymphoma risk.
• Patients and physicians were not adequately advised about appropriate screening or monitoring.
• Earlier warnings may have resulted in additional testing and earlier cancer diagnoses.

Regeneron itself has disclosed that product liability lawsuits have been filed alleging that Dupixent caused or exacerbated patients’ T-cell lymphoma.

What Is Cutaneous T-Cell Lymphoma?

Cutaneous T-cell lymphoma is a rare type of cancer involving T lymphocytes, a type of white blood cell.

CTCL primarily affects the skin and can initially cause symptoms such as:

• Red patches
• Dry or scaly skin
• Persistent rashes
• Itching
• Raised plaques
• Skin tumors
• Changes in skin pigmentation

One of the most common forms of CTCL is mycosis fungoides.

Another form is Sézary syndrome, which can involve widespread skin symptoms and malignant T cells circulating in the blood.

Why Is CTCL Particularly Important for Patients Taking Dupixent for Eczema?

One of the complicated issues underlying the litigation is that early CTCL can resemble eczema.

A patient experiencing an unexplained rash may initially receive a diagnosis of atopic dermatitis and subsequently be prescribed Dupixent.

If the skin condition is actually early-stage CTCL rather than eczema, plaintiffs allege that Dupixent may potentially exacerbate or accelerate the underlying disease.

Researchers are continuing to examine whether Dupixent:

• Causes CTCL in some patients
• Accelerates an existing lymphoma
• Unmasks a previously undiagnosed cancer
• Has no causal relationship but is prescribed to patients whose CTCL was initially mistaken for eczema

What Does the Recent Dupixent Lawsuit Allege?

Recent lawsuits allege that patients developed CTCL or other T-cell lymphomas after receiving Dupixent injections and that the manufacturers failed to adequately disclose the potential risk.

One plaintiff reportedly filed a complaint in June 2026 alleging that he developed mycosis fungoides, a form of CTCL, after beginning Dupixent treatment.

His lawsuit alleges that Sanofi and Regeneron failed to warn him and his healthcare providers about the potential lymphoma risk while he was using the medication.

According to reports regarding the developing litigation, he alleges that he will require continued medical treatment and monitoring.

Other Dupixent Cancer Lawsuits

Several other patients and families have brought similar claims.

For example, one user that she used Dupixent for atopic dermatitis for several years and was subsequently diagnosed with CTCL. Her lawsuit alleges that Dupixent caused or contributed to the cancer or accelerated previously undiagnosed disease.

Another plaintiff filed a product liability lawsuit alleging that Dupixent caused or accelerated her CTCL. Her case has since been transferred into the federal Dupixent MDL in New Jersey.

A wrongful death lawsuit has also been reported involving a woman who was prescribed Dupixent and was subsequently diagnosed with aggressive peripheral T-cell lymphoma.

FDA Review of a Potential CTCL Safety Signal

Federal regulators have also examined the potential association.

According to reports regarding the litigation, the FDA identified CTCL as a potential serious safety signal involving Dupixent in late 2024.

A safety signal means that regulators identified information warranting further investigation. It does not mean that the FDA determined Dupixent causes CTCL.

Plaintiffs contend that the developing research and safety information warranted additional warnings to physicians and patients.

Dupixent Lawsuits Consolidated in New Jersey Federal Court

A major development occurred on June 4, 2026, when the U.S. Judicial Panel on Multidistrict Litigation centralized federal Dupixent lawsuits.

The cases are proceeding as:

In re: Dupixent (Dupilumab) Products Liability Litigation, MDL No. 3180

The litigation is pending in the U.S. District Court for the District of New Jersey before U.S. District Judge Zahid N. Quraishi. The initial centralized cases involve allegations that Dupixent caused or exacerbated CTCL and related injuries.

The Judicial Panel noted that the litigation involves common factual questions regarding the alleged relationship between Dupixent and CTCL, the manufacturers’ knowledge of the alleged risks, and the adequacy of warnings.

What Is a Dupixent MDL?

An MDL, or multidistrict litigation, allows similar federal lawsuits pending throughout the country to be coordinated before one federal judge for pretrial proceedings.

This can help streamline:

• Discovery
• Depositions
• Document production
• Expert testimony
• Scientific evidence
• Pretrial motions

An MDL is different from a class action.

Each plaintiff generally maintains an individual lawsuit and must establish their own diagnosis, Dupixent use, causation, injuries, and damages.

Centralization also does not mean the defendants have been found liable.

Who May Qualify for a Dupixent Cancer Lawsuit?

Potential claims may be evaluated for individuals who:

• Used Dupixent
• Were subsequently diagnosed with CTCL
• Developed mycosis fungoides
• Developed Sézary syndrome
• Developed another potentially relevant T-cell lymphoma
• Required chemotherapy, radiation, phototherapy, or other cancer treatment
• Experienced progression of previously undiagnosed lymphoma

The precise criteria for potential claims may evolve as the MDL progresses.

A diagnosis following Dupixent use does not automatically establish that the medication caused the cancer.

Symptoms of Cutaneous T-Cell Lymphoma

Potential CTCL symptoms may include:

• Persistent rash
• Severe itching
• Dry or scaly patches
• Red skin
• Thickened plaques
• Skin tumors
• Enlarged lymph nodes
• Changes in skin pigmentation

These symptoms can overlap with eczema and other dermatological conditions.

Anyone concerned about symptoms or their diagnosis should discuss them with an appropriate healthcare provider rather than changing medication based solely on information about litigation.

Should I Stop Taking Dupixent?

Patients should not stop or change a prescribed medication solely because of a lawsuit or online information.

Questions about Dupixent treatment should be discussed with the healthcare provider who prescribed the medication or another qualified medical professional.

A physician may consider a patient’s:

• Diagnosis
• Symptoms
• Treatment response
• Medical history
• Risks associated with discontinuing treatment
• Need for additional testing

Legal claims and medical treatment decisions are separate issues.

What If My Eczema Became Worse While Taking Dupixent?

Worsening or unusual skin symptoms do not necessarily mean a patient has CTCL. However, because CTCL can sometimes resemble eczema, persistent or atypical symptoms may warrant medical evaluation.

Patients may want to discuss concerns with their dermatologist, particularly when a rash:

• Does not improve with treatment
• Changes significantly
• Continues to spread
• Develops unusual plaques or tumors
• Returns despite treatment

Only appropriate medical testing can determine whether a patient has lymphoma.

How Is CTCL Diagnosed?

Doctors may use several methods to evaluate suspected CTCL.

Depending on the patient’s symptoms, testing may include:

• Physical examination
• Skin biopsy
• Blood testing
• Immunophenotyping
• Molecular testing
• Imaging
• Lymph node evaluation

Some patients may require multiple biopsies before receiving a definitive diagnosis because early CTCL can resemble other skin conditions.

Treatment for CTCL and T-Cell Lymphoma

Treatment varies significantly based on the subtype and stage of disease.

Potential treatment may include:

• Phototherapy
• Radiation therapy
• Chemotherapy
• Topical medications
• Immunotherapy
• Targeted medications
• Stem-cell transplantation

Some patients may require ongoing monitoring and treatment for years.

Potential Claims in a Dupixent Lawsuit

Dupixent plaintiffs have raised several product liability theories.

Failure to Warn

A central allegation is that the manufacturers failed to adequately warn doctors and patients about the alleged potential association between Dupixent and T-cell lymphoma.

Negligence

Plaintiffs may allege that manufacturers failed to exercise reasonable care in researching, testing, monitoring, or communicating potential risks.

Misrepresentation

Some lawsuits allege that Dupixent’s safety profile was presented without adequately communicating information concerning the alleged lymphoma risk.

Product Liability

Depending on applicable state law, plaintiffs may pursue additional claims involving the alleged safety of the medication and adequacy of its warnings.

Each potential claim should be evaluated individually.

What Evidence May Help Support a Dupixent Lawsuit?

Potentially relevant evidence may include:

• Dupixent prescription records
• Pharmacy records
• Medical records
• Dermatology records
• Treatment dates
• Dosage information
• Skin biopsy reports
• Pathology reports
• CTCL diagnosis records
• Oncology records
• Photographs of skin symptoms
• Chemotherapy records
• Radiation records
• Medical bills

Records documenting the patient’s skin condition before, during, and after Dupixent treatment may be particularly important.

What If I Was Initially Diagnosed With Eczema?

An initial eczema diagnosis may be highly relevant to the investigation.

Because early CTCL may resemble atopic dermatitis, medical records can help establish:

• When symptoms first appeared
• How the condition was originally diagnosed
• When Dupixent treatment began
• How the patient’s symptoms responded
• When doctors began suspecting lymphoma
• When biopsies were performed
• When CTCL was diagnosed

Medical experts may ultimately evaluate whether Dupixent caused, contributed to, accelerated, or simply coincided with the patient’s disease.

Compensation in a Dupixent Cancer Lawsuit

Depending on applicable law and the circumstances, plaintiffs may seek compensation for losses associated with their alleged injuries.

Medical Expenses

Potential damages may include costs associated with:

• Oncology treatment
• Chemotherapy
• Radiation
• Phototherapy
• Hospitalization
• Diagnostic testing
• Medication
• Future cancer treatment

Lost Income

Patients unable to work during cancer treatment may potentially seek compensation for lost wages and reduced earning capacity.

Pain and Suffering

Depending on applicable law, damages may potentially be available for physical pain, emotional distress, disability, and reduced quality of life.

Future Medical Care

Certain forms of lymphoma may require prolonged treatment and monitoring.

A potential claim may therefore include anticipated future medical expenses when supported by appropriate evidence.

Wrongful Death

Families may potentially have wrongful death claims when they allege that Dupixent caused or contributed to a T-cell lymphoma that resulted in a patient’s death.

The availability of damages depends on applicable state law and the facts of the individual case.

What Should You Do If You Were Diagnosed With CTCL After Taking Dupixent?

If you used Dupixent and were later diagnosed with CTCL or another T-cell lymphoma:

1. Continue working with your healthcare providers regarding medical treatment.
2. Do not discontinue prescribed medication without medical guidance.
3. Preserve Dupixent prescription and pharmacy records.
4. Obtain dermatology records from before and during treatment.
5. Preserve pathology and biopsy reports.
6. Keep oncology and treatment records.
7. Document when Dupixent treatment began and ended.
8. Save medical bills and insurance records.
9. Preserve photographs documenting changes in your skin condition.
10. Consider speaking with an experienced product liability attorney about whether your circumstances may fit the developing litigation.

Statutes of limitation may apply, making timely review important.

How the Law Offices of Jason Turchin May Help

The Law Offices of Jason Turchin represents individuals nationwide in pharmaceutical product liability and serious injury claims.

Our firm may assist by:

• Reviewing Dupixent usage history
• Obtaining medical and pharmacy records
• Reviewing CTCL and T-cell lymphoma diagnoses
• Evaluating the timing between Dupixent treatment and diagnosis
• Monitoring developments in MDL No. 3180
• Working with medical experts when appropriate
• Evaluating potential failure-to-warn claims
• Pursuing compensation through litigation when appropriate

Cases may be handled on a contingency fee basis. Attorney’s fees and costs are waived if there is no recovery.

Frequently Asked Questions

Is there a Dupixent cancer lawsuit?

Yes. Multiple product liability lawsuits have been filed alleging that Dupixent caused or exacerbated CTCL and that its manufacturers failed to adequately warn patients and healthcare providers.

Does Dupixent cause cancer?

According to recent lawsuits, studies have allegedly reported an association between Dupixent treatment and CTCL, but researchers continue to investigate whether the medication causes, accelerates, or unmasks the disease or whether CTCL was already present and initially mistaken for eczema.

What cancer is involved in Dupixent lawsuits?

The litigation primarily concerns cutaneous T-cell lymphoma (CTCL), including mycosis fungoides. Some allegations also involve other forms of T-cell lymphoma.

What is mycosis fungoides?

Mycosis fungoides is the most common form of cutaneous T-cell lymphoma. It primarily affects the skin and may initially resemble eczema or other chronic skin conditions.

Is there a Dupixent class action?

The federal litigation is an MDL, not a class action. Federal Dupixent product liability lawsuits have been centralized as MDL No. 3180 in the District of New Jersey.

When was the Dupixent MDL created?

The U.S. Judicial Panel on Multidistrict Litigation ordered centralization on June 4, 2026.

Who are the defendants in the Dupixent lawsuits?

The litigation principally involves Regeneron Pharmaceuticals and Sanofi-Aventis and related entities involved in developing and marketing Dupixent.

What if I took Dupixent years ago?

A potential claim may still warrant evaluation depending on when you used Dupixent, when symptoms developed, when you received a lymphoma diagnosis, and the applicable statute of limitations.

Should I stop taking Dupixent because of the lawsuits?

Do not stop or change prescribed medication based solely on litigation reports. Patients concerned about Dupixent should discuss their individual risks and treatment options with their healthcare providers.

Contact a Dupixent Cancer Lawsuit Lawyer

If you or a loved one used Dupixent and were later diagnosed with cutaneous T-cell lymphoma, mycosis fungoides, Sézary syndrome, or another potentially related T-cell lymphoma, the Law Offices of Jason Turchin may be able to help evaluate your potential legal options.

Call (800) 337-7755 or chat with us for a free consultation.

Attorney’s fees and costs are waived if there is no recovery.