Dupixent Lawsuit for T-Cell Lymphoma

Dupixent, also known by its generic name dupilumab, is a biologic medication prescribed to treat atopic dermatitis, asthma, and other inflammatory conditions. It works by targeting specific immune pathways involved in allergic inflammation. For many patients with moderate to severe eczema, Dupixent has provided relief where topical medications failed. As a result, it has become one of the most widely prescribed biologic drugs for skin and respiratory conditions.

But for a growing number of patients, the experience with Dupixent has been very different. Over the past several years, doctors and researchers have reported cases in which patients treated with Dupixent were later diagnosed with cutaneous T-cell lymphoma, a rare form of non-Hodgkin lymphoma that primarily affects the skin. These reports have led to increasing scrutiny of whether Dupixent can worsen, accelerate, or mask CTCL in certain patients.

Lawyers across the country are now reviewing Dupixent lawsuits on behalf of patients who developed CTCL, mycosis fungoides, or Sézary syndrome after receiving Dupixent injections. Call us today at 800-553-8082 or contact us online.

What Is Cutaneous T-Cell Lymphoma?

Cutaneous T-cell lymphoma is a cancer of the immune system involving malignant T cells that migrate to the skin. In its early stages, CTCL often looks nearly identical to eczema, psoriasis, or other chronic inflammatory skin conditions. Patients may experience rashes, plaques, itching, or redness that come and go over time.

This overlap is a major problem. CTCL can go undiagnosed for years because biopsies may initially be inconclusive and symptoms resemble benign skin disease. By the time CTCL is definitively diagnosed, the disease may be more advanced and harder to treat.

The most common forms of CTCL are mycosis fungoides and Sézary syndrome. Both are serious conditions that can require lifelong treatment and, in advanced cases, can be fatal.

How Dupixent Fits Into CTCL Allegations

The concern raised in Dupixent lymphoma lawsuits is not that Dupixent causes cancer in every user. Instead, plaintiffs allege that Dupixent can trigger, accelerate, or obscure CTCL in a subset of patients who were misdiagnosed with eczema or other inflammatory skin conditions.

In many reported cases, patients started Dupixent for presumed dermatitis and initially experienced some symptom improvement. That improvement reinforced the belief that the condition was inflammatory rather than malignant. Over time, however, the disease progressed, worsened, or failed to behave like typical eczema. Further testing later revealed CTCL.

Plaintiffs argue that by suppressing visible inflammation without addressing the underlying disease process, Dupixent may delay diagnosis of CTCL and allow the cancer to progress unchecked.

Allegations in Current Dupixent Lawsuits

Recent lawsuits, including federal cases filed against Regeneron Pharmaceuticals and Sanofi-Aventis, lay out similar allegations. Plaintiffs claim that:

• Dupixent caused or aggravated cutaneous T-cell lymphoma

• The manufacturers knew or should have known about the risk of CTCL

• Dupixent’s labeling failed to warn doctors and patients about this risk

• Patients were not advised to rule out CTCL before starting Dupixent

• Continued treatment delayed diagnosis and worsened outcomes

In one recently filed federal lawsuit, the plaintiff alleges that he was prescribed Dupixent for atopic dermatitis and used the drug for approximately one year before being diagnosed with both mycosis fungoides and Sézary syndrome. The complaint alleges that earlier warnings or clearer prescribing guidance could have led to earlier diagnosis and less severe disease progression.

These lawsuits are grounded primarily in failure-to-warn claims, along with negligence and related product liability theories.

Medical Evidence Being Cited in Dupixent CTCL Claims

Several studies and case series are frequently cited in connection with Dupixent lymphoma litigation. Observational database studies have reported higher rates of CTCL diagnoses among patients treated with dupilumab compared to similar patients who were not exposed to the drug.

Other reports include case series where patients treated with Dupixent for presumed eczema initially improved, then experienced disease progression consistent with CTCL. These patterns have been discussed in dermatology journals and conferences, particularly in patients with adult-onset or treatment-resistant dermatitis.

While no single study proves causation, plaintiffs argue that the collective evidence is strong enough that manufacturers should have provided clearer warnings and guidance to prescribers.

Are These Dupixent Lawsuits Class Actions?

Dupixent CTCL lawsuits are not class actions. Each patient’s case depends heavily on individual medical history, biopsy results, timing of Dupixent use, and disease progression. That said, if enough cases are filed, the litigation could eventually be consolidated in federal multidistrict litigation for pretrial proceedings.

For now, these cases are being evaluated and filed individually.

Who May Qualify for a Dupixent Lawsuit?

You may have a viable Dupixent lawsuit if:

• You were prescribed Dupixent for eczema, asthma, or another approved use

• You were later diagnosed with cutaneous T-cell lymphoma

• Your condition worsened, progressed, or was delayed while on Dupixent

• You were diagnosed with mycosis fungoides or Sézary syndrome

• Your medical records show prolonged treatment despite atypical symptoms

Not every Dupixent patient with CTCL will qualify, but many cases deserve careful review.

What Happens Next in Dupixent Litigation?

Dupixent lawsuits are still in the early stages. Most activity right now involves medical record review, pathology evaluation, and case screening. As more cases are filed, courts may consider consolidation, coordinated discovery, and expert proceedings.

Patients considering a claim should not wait. Statutes of limitations apply, and delays can make cases harder to prove.

Are Lawyers Demanding a Dupixent Recall?

Maybe there should be a Dupixent recall.  That question is above our pay grade. But these lawsuits are not a push to recall the product.  They are pushing to tell doctors and patients of the risks so they can make informed decisions.

So failure to warn is the spine of these cases. A manufacturer that knows or should know that a subset of patients with adult-onset or refractory dermatitis may actually harbor early CTCL has a duty to communicate that risk.  The practical content of the warning is straightforward. Before initiating treatment in adults with atypical clinical courses and biopsy-suspicious lesions, consider T-cell clonality. After initiation, if the disease evolves in a way that is not typical for eczema, at the very least, do not keep escalating dupilumab while you “see if it helps.” Stop and investigate. Nothing about those messages conflicts with approved labeling. Everything about them tracks the real-world cases now in the lit

Design defect is less obvious in a biologic case than in a mechanical device case, but it is not off the table. Plaintiffs’ lawyers can credibly argue that the risk mitigation design around dupilumab was defective because it did not build in guardrails for a known diagnostic gray zone. In a world where early mycosis fungoides can masquerade as eczema for years, a “safe” design includes robust prescriber education, explicit biopsy prompts in adult-onset disease, and clear stop rules when the clinical course deviates from eczema norms. That is risk management by design, and its absence is actionable where it predictably leads to delayed diagnosis and worse outcomes.

Plaintiffs’ attorneys will flesh all of this out.  But this will still be a failure to warn claim at its core.

What Is the Status of the Dupixent Lawsuits?

Lawyers have only started advertising and investigating these cases over the last month, so we are still at the very beginning. Right now, this is intake and record-building, not active litigation.

Will this lead to a Dupixient class action? No, but it will likely lead to federal multidistrict litigation (MDL), which shares some components with a class action lawsuit, but allows victims to retain their individual claims.

What do we have to do to get there? First, you need individual Dupixent lawsuits filed in courts around the country. Once enough are on the books, the Judicial Panel on Multidistrict Litigation can be asked to centralize them before a single judge. That is the point where you start to see case management orders, coordinated discovery, and a pathway toward bellwether trials.

So the posture today is early, much earlier than many victims probably want. If the first complaints are filed later in 2025 or 2026, MDL consolidation could follow within a year. From there, discovery and expert battles will take another year or two. That means realistic settlement pressure is several years away.

For patients living with a lymphoma diagnosis, that timeline is hard to hear. But history shows that once filings increase and the science is tested in court, these cases move faster than you might expect. The important takeaway is that Dupixent lawsuits are just starting to form. What happens now – medical records are collected, clients are identified, and experts are engaged – sets the stage for how strong the litigation will be when it gets underway.  What you do want to do is initiate your claim now to avoid statute of limitations problems or other challenges that can arise from delays.Who Qualifies for a Dupixent Lawsuit?

Right now, our attorneys are looking most closely at people who received Dupixent injections for eczema, asthma, or other approved conditions and were later diagnosed with a T-cell lymphoma, including cutaneous T-cell lymphoma, mycosis fungoides, or Sézary syndrome. These are the cases most likely to move forward. If that sounds like your situation (or a family member’s) it is worth speaking with a Dupixent lawyer to understand your legal options.

The strongest Dupixent lawsuits will likely involve patients who received the drug for eczema, asthma, or other approved uses and were later diagnosed with a T-cell lymphoma, most often CTCL, mycosis fungoides, or Sézary syndrome. These are the cases where the medical evidence lines up most closely with what researchers are now documenting.

Potential Dupixient Settlement Amounts