Dupixent CTCL Studies Highlighted Cancer Risks For Years, Lawsuit Alleges

Lawsuit claims clinical trials identified a link between side effects of Dupixent and CTCL before the drug was ever approved by the FDA.

A Colorado woman has filed a product liability lawsuit alleging manufacturers of Dupixent knew for years that their eczema treatment could cause users to develop cutaneous T-cell lymphoma (CTCL), yet withheld information about the potential cancer risks to protect the massive profits generated by the blockbuster drug.

The complaint (PDF) was brought by Anne Gibson in the U.S. District Court for the District of New Jersey on August 3. It names Sanofi-Aventis U.S. LLC, Genzyme Corporation and Regeneron Pharmaceuticals Inc. as the defendants.

Gibson claims she was prescribed Dupixent to treat atopic dermatitis and was later diagnosed with a rare form of cancer she alleges was caused by the drug.

Dupixent CTCL Risks

Approved by the U.S. Food and Drug Administration (FDA) in 2017, Dupixent (dupilumab) was originally designed for the treatment of atopic dermatitis, a form of eczema. However, over the past decade, the drug maker has continued to push for expanded use of the injections to treat a number of different conditions that impact the skin and respiratory system, including asthma, chronic obstructive pulmonary disease (COPD) and other health problems caused by overactive immune systems.

Despite claims by the drug manufacturer that the treatment was safe, there has been growing evidence in recent years that suggests Dupixent side effect may cause certain users to develop a rare form of non-Hodgkin’s lymphoma that primarily affects the skin, known as cutaneous T-cell lymphoma (CTCL).

In light of these concerns, Gibson joins plaintiffs nationwide who have filed similar Dupixent CTCL lawsuits alleging that the manufacturers knew, or should have known, of the drug’s cancer risks, yet failed to properly inform doctors or their patients about the potential cancer risks.

Dupixent CTCL Allegations

According to the complaint, Gibson was prescribed Dupixent in March 2021 for the treatment of atopic dermatitis. She continued to receive Dupixent injections until February 2023, at which time she received a CTCL diagnosis.

The cancer diagnosis has led to Gibson having to endure “extensive treatments,” including phototherapy, chemotherapy and radiation. Despite those treatments, the lawsuit indicates Gibson will likely require medical monitoring for the rest of her life.

In addition, Gibson maintains her physician would not have prescribed Dupixent for the treatment of her atopic dermatitis if the manufacturer had adequately warned about the alleged risk of CTCL. In that case, she argues she would not have used the medication.

Gibson indicates the manufacturers knew Dupixent carried a risk even before its approval, but decided to keep that information to themselves. She notes that the drug’s phase II clinical trials reported that a patient developed CTCL long before the drug hit the market.

Dupixent CTCL Studies

The FDA Medical Review for Dupixent indicated that the patient was diagnosed with stage IV Mycosis fungoides, the most common form of CTCL, after just 35 days of treatment and seven 300 mg Dupixent injections. Numerous studies have followed, raising the same safety signals.

During the third phase of Dupixent trials, key to winning FDA approval, three more patients developed CTCL. Reports note that Mycosis fungoides was one of the most common adverse events leading patients to stop taking the drug.

Those types of findings continued once Dupixent hit the market. In November 2018, French researchers published a case report published in Annales de Dermatologie et de Vénéréologie. Those findings detailed how a woman developed CTCL after just three months of Dupixent treatment. A similar case report linking Dupixent use to a CTCL diagnosis was published in May 2019.

“One month of Dupixent treatment failed to alleviate atopic dermatitis symptoms, and instead induced a flare-up of cutaneous lesions. This exacerbation of erythematous lesions prompted physicians to order a skin biopsy. Based on the results of histopathology and computed tomography scans, the patient was diagnosed with Mycosis fungoides and Dupixent was discontinued. Despite a long history of atopic dermatitis, these authors proposed that this patient may have had Mycosis fungoides that was misdiagnosed as atopic dermatitis.”

– Anne Gibson v. Sanofi-Aventis U.S. LLC. et al.

A series of studies have followed over the years, with many warning that Dupixent seemed to cause, or accelerate CTCL. Despite that, no warnings were supplied, even as the drug’s use became more widespread. Gibson and other plaintiffs indicate the company is consciously placing patients at risk in order to preserve profits.

According to a fourth quarter report released by Regeneron on July 30, Dupixent brought in $6 billion in sales over the last year, increasing by 38%. The sales overall pushed Regeneron, which received a $2.11 billion cut of the revenue, to a 17% revenue increase.

The lawsuit raises allegations of failure to warn, negligence, fraudulent misrepresentation and negligent misrepresentation. It seeks both compensatory and punitive damages.

Dupixent CTCL Lawsuits

Gibson’s complaint will be merged with other Dupixent CTCL lawsuits in the District of New Jersey before U.S. District Judge Zahid N. Quraishi as part of a multidistrict litigation (MDL) for coordinated discovery and pretrial proceedings.

Judge Quraishi will eventually be expected to have attorneys prepare several representative Dupixent claims to serve as possible early test trials. These “bellwether” cases would provide an opportunity to see how juries respond to evidence and testimony likely to be repeated throughout the litigation.

Although the results of those trials will not be binding on other claims, the outcomes will be closely watched and could be key in potential Dupixent settlement negotiations.

However, if no such settlement or other resolution is reached after the pretrial proceedings and test trials, Judge Quraishi could begin remanding the cases back to their original districts for individual trial dates.

Sign up for more legal news that could affect you or your family.