Dupixent Lymphoma Lawsuit: Investigating Cancer Risks Linked to Dupilumab

Dupixent (dupilumab) has become a widely prescribed biologic for conditions like moderate-to-severe eczema (atopic dermatitis), asthma, chronic sinusitis with nasal polyps, and eosinophilic esophagitis. While many patients have benefited from the drug, new medical research and case reports suggest a significantly increased risk of certain lymphomas and other blood cancers in some patients taking Dupixent.

In March 2025, the U.S. Food and Drug Administration (FDA) issued a safety alert after identifying a possible connection between Dupixent and cutaneous T-cell lymphoma (CTCL), a rare form of non-Hodgkin lymphoma that primarily affects the skin. The FDA has since confirmed that it is monitoring alarming reports of CTCL in Dupixent users and evaluating whether to update the drug’s warning label.

CohenMalad, LLP is actively investigating Dupixent-related cancer claims, particularly lymphoma cases, and representing patients and families seeking compensation for serious injuries or the loss of a loved one.

What Is Dupixent (Dupilumab)?

Dupixent (dupilumab) is a monoclonal antibody that blocks the interleukin-4 receptor alpha subunit (IL-4Rα), disrupting IL-4 and IL-13 signaling pathways that are central to allergic and type-2 inflammatory diseases. It is FDA-approved to treat:

• Moderate-to-severe atopic dermatitis (eczema)
• Moderate-to-severe asthma
• Chronic rhinosinusitis with nasal polyps
• Eosinophilic esophagitis, and other evolving indications

Despite these benefits, recent publications and adverse event data have raised serious concerns about Dupixent’s potential to trigger, accelerate, or unmask T-cell lymphomas and other hematologic malignancies.

Emerging Evidence Linking Dupixent and Lymphoma

Several recent studies and case series have examined a possible relationship between Dupixent and lymphoma, particularly CTCL and other T-cell or NK/T-cell lymphomas:

• Increased CTCL risk in atopic dermatitis patients. Multiple cohort studies have found that patients treated with dupilumab for atopic dermatitis had a significantly increased relative risk of developing cutaneous T-cell lymphoma compared to patients who did not receive the drug, with some analyses suggesting roughly a four-fold higher risk.
• Higher lymphoma risk in asthma patients. A 2025 population-based cohort study of asthma patients reported that dupilumab-treated individuals had an increased risk of lymphoma, especially T-cell and natural killer (NK)-cell lymphomas.
• Case reports and series of T-cell malignancies after Dupixent. Published reports describe patients who developed CTCL, mycosis fungoides (MF), Sézary syndrome, anaplastic large cell lymphoma, and other hematologic malignancies after initiating dupilumab therapy.
• Possible “unmasking” of underlying cancer. Some researchers believe Dupixent may unmask or accelerate pre-existing but undiagnosed CTCL in patients initially thought to have severe eczema, rather than causing entirely new cancers.

To date, the FDA-approved Dupixent label has not added a specific lymphoma or CTCL cancer warning, even though emerging data and case reports have prompted increased regulatory scrutiny and litigation.

Lymphoma and Leukemia Diagnoses Under Investigation

CohenMalad, LLP is particularly interested in representing patients who took Dupixent and were later diagnosed with lymphoma, leukemia, or related blood cancers.

We are especially focused on T-cell lymphomas and related conditions, including:

• CTCL (Cutaneous T-Cell Lymphoma)
• Extranodal NK/T-cell lymphoma
• Mycosis fungoides (MF)
• Extranodal NK/T-cell lymphoma, nasal type
• Sézary syndrome (SS)
• Subcutaneous panniculitis-like T-cell lymphoma
• Lymphomatoid papulosis
• Primary cutaneous peripheral T-cell lymphoma
• Granulomatous slack skin
• Adult T-cell leukemia/lymphoma (ATL)
• Anaplastic large cell lymphoma (ALCL)

We are also reviewing cases involving:

• Other non-Hodgkin lymphomas
• Leukemia and other serious hematologic malignancies
• Deaths where Dupixent may have contributed to or accelerated a lymphoma diagnosis

If you or a loved one developed any of these conditions after using Dupixent, you may be eligible to pursue a Dupixent lymphoma lawsuit.

Symptoms That May Suggest a Lymphoma or T-Cell Cancer

Patients who receive Dupixent for eczema, asthma, or other inflammatory conditions can sometimes mistake early signs of lymphoma for a flare of their underlying disease. That’s part of what makes CTCL and other T-cell lymphomas so challenging to detect.

You should speak to your doctor promptly if you notice:

• New or worsening skin patches, plaques, or nodules that are scaly, itchy, or burning
• Persistent red or purple lesions that don’t respond to usual eczema treatments
• Thickened or tumorous skin areas, especially on sun-protected sites
• Swollen lymph nodes in the neck, armpits, or groin
• Unexplained weight loss, night sweats, or persistent fevers (“B symptoms”)
• Ongoing fatigue or frequent infections

Only a qualified medical professional can diagnose lymphoma or leukemia. If you are concerned about new or changing symptoms while on Dupixent, do not stop or change your medication on your own. Instead, consult your prescribing doctor or a specialist right away.

What Do Dupixent Lymphoma Lawsuits Allege?

Patients and families bringing Dupixent lawsuits generally allege that the drug manufacturers, Sanofi and Regeneron:

• Failed to adequately warn doctors and patients that Dupixent could cause, accelerate, or unmask T-cell lymphomas such as CTCL
• Downplayed or ignored safety signals suggesting a cancer risk while continuing to aggressively market the drug
• Failed to conduct appropriate testing or post-marketing surveillance to fully understand Dupixent’s long-term cancer risks
• Negligently designed, manufactured, and marketed the drug despite mounting evidence of serious hematologic malignancies in certain patients

Some lawsuits involve catastrophic injuries or fatal lymphoma diagnoses, alleging that patients might have made different treatment choices—or been more closely monitored—if proper cancer warnings had been provided.

Who May Qualify for a Dupixent Lymphoma Lawsuit?

You may be eligible to pursue a claim if:

• You were prescribed Dupixent (dupilumab) for eczema, asthma, chronic sinusitis with nasal polyps, eosinophilic esophagitis, or other approved uses; and
• You were later diagnosed with CTCL or another T-cell lymphoma, leukemia, or serious hematologic malignancy, especially one of the conditions listed above; and
• Your diagnosis occurred after starting Dupixent, generally with no prior history of lymphoma or leukemia; and
• A doctor has linked, or may be willing to evaluate, a potential connection between your Dupixent use and your cancer diagnosis.

Families who lost a loved one to lymphoma or leukemia after Dupixent exposure may also have a wrongful death claim.

Every case is fact-specific. Statutes of limitation and other deadlines can be strict and vary by state, so it is important to speak with an attorney as soon as possible to protect your rights.

What Compensation Could Be Available?

While no lawyer can guarantee a recovery, successful pharmaceutical and product liability lawsuits may allow injured patients and families to pursue compensation for:

• Past and future medical expenses
• Lost income and diminished earning capacity
• Pain and suffering, mental anguish, and loss of enjoyment of life
• Caregiving costs and other out-of-pocket losses
• In wrongful death cases, funeral expenses and the family’s loss of support and companionship
• In some cases, punitive damages, designed to punish especially wrongful corporate conduct

An experienced drug-injury attorney can evaluate the facts of your situation and advise you on potential damages in your specific case.