How to File a Dupixent Lawsuit
How do I file a Dupixent lawsuit?
Filing a Dupixent lawsuit involves several key steps:
Step 1: Free Consultation
Contact an experienced mass tort attorney who handles pharmaceutical cases.
During the consultation, you will discuss your Dupixent use, CTCL diagnosis, and potential claim value.
The attorney will evaluate whether your case meets eligibility requirements.
Consultations are completely free and confidential with no obligation to proceed.
Step 2: Gather Documentation
Your attorney will request medical records including:
Dupixent prescription records and pharmacy records.
Skin biopsy and pathology reports confirming CTCL diagnosis.
Treatment records for cancer therapy.
Medical bills and financial documentation.
Step 3: Sign Retainer Agreement
If your case qualifies, you will sign a contingency fee agreement.
This contract outlines attorney fees (typically 33-40%) and case expense policies.
You pay nothing upfront—fees are only collected if you win.
Step 4: File Complaint
Your attorney prepares and files a legal complaint in the appropriate court.
The complaint outlines allegations against Sanofi and Regeneron, describes your injuries, and demands compensation.
Defendants are served with the complaint and must respond within 30-60 days.
Step 5: Discovery and MDL
Your case may be consolidated into a Multidistrict Litigation (MDL) with similar cases.
Discovery involves exchanging documents, taking depositions, and gathering expert testimony.
This phase typically lasts 1-2 years.
Step 6: Settlement or Trial
Most cases settle through negotiations without trial.
If settlement cannot be reached, your case proceeds to jury trial.
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What is the deadline to file a Dupixent lawsuit?
Statutes of limitations impose strict deadlines for filing lawsuits.
These deadlines vary by state but generally range from 1-3 years from:
The date of CTCL diagnosis.
The date you discovered (or reasonably should have discovered) that Dupixent caused your cancer.
State-by-state variations:
California: 2 years from discovery of injury.
New York: 3 years from accrual of the claim.
Florida: 4 years for personal injury (2 years for medical malpractice if applicable).
Texas: 2 years from discovery of injury.
Illinois: 2 years from date of injury.
Discovery rule:
Many states follow a "discovery rule" where the statute of limitations begins when you knew or should have known about the injury and its cause.
For Dupixent cases, this is typically the date of CTCL diagnosis or when your doctor informed you the cancer may be drug-related.
Tolling for minors:
If the injured party is under 18, statutes of limitations may be tolled (paused) until they reach adulthood.
Wrongful death claims:
Wrongful death statutes are often shorter (1-2 years from date of death).
Missing the statute of limitations deadline permanently bars your claim—no exceptions.
Even if you think you have time, consult an attorney immediately to avoid losing your rights.
Where are Dupixent lawsuits filed?
Dupixent lawsuits can be filed in state or federal courts depending on:
State court:
Cases filed under state product liability or negligence laws.
Jurisdiction typically based on where plaintiff resides or where injury occurred.
Federal court:
Cases involving diversity jurisdiction (plaintiff and defendants from different states with amount in controversy exceeding $75,000).
Federal question jurisdiction if claims involve federal law issues.
Multidistrict Litigation (MDL):
As Dupixent cases increase, they may be consolidated into a federal MDL.
MDL centralizes pretrial proceedings before a single judge to streamline discovery and avoid duplicative efforts.
Individual cases retain their separate identities but share common discovery.
Bellwether trials (test cases) are conducted to gauge jury responses and inform settlement negotiations.
If a case does not settle, it may be remanded to the original filing court for trial.
Potential MDL court:
Dupixent cases may be consolidated in the U.S. District Court for the Northern District of Illinois (Chicago), where Sanofi and Regeneron are headquartered and where early cases have been filed.
Alternatively, the Judicial Panel on Multidistrict Litigation may select a different jurisdiction based on convenience and case distribution.
Your attorney will determine the best jurisdiction for filing your case to maximize chances of favorable outcome.
How much does it cost to file a Dupixent lawsuit?
There are no upfront costs to file a Dupixent lawsuit.
Mass tort attorneys work on contingency fee agreements, meaning:
You pay nothing out of pocket to hire an attorney.
Attorney fees are only collected if you win through settlement or jury verdict.
Typical contingency fees range from 33% to 40% of the total recovery.
If you lose, you owe nothing (though some agreements may require repayment of case expenses).
Fee structure example:
If your case settles for $300,000 and your attorney's fee is 33%:
Attorney fee: $99,000
Client receives: $201,000 (before case expenses)
Case expenses:
Expenses may include medical record retrieval, expert witness fees, court filing fees, deposition costs, and travel expenses.
Some attorneys advance these costs and deduct them from the settlement.
Others include expenses within the contingency percentage.
Clarify expense policies in your retainer agreement before signing.
Fee negotiations:
Contingency percentages may be negotiable depending on case strength and complexity.
Higher fees (35-40%) may apply if the case proceeds to trial rather than settling.
No recovery, no fee:
If your case is unsuccessful, you owe nothing to your attorney (in most agreements).
This structure allows injured patients to pursue justice without financial risk.
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What happens after I file a lawsuit?
After filing your Dupixent lawsuit, the legal process unfolds in several phases:
Defendants' response (30-60 days):
Sanofi and Regeneron file an answer denying allegations or a motion to dismiss.
Motions to dismiss argue the complaint fails to state a valid claim.
If motion is denied, the case proceeds to discovery.
MDL transfer (3-6 months):
If your case is consolidated into an MDL, it is transferred to the MDL court.
A liaison counsel or steering committee coordinates plaintiff efforts.
Your individual attorney remains involved but works with the broader legal team.
Discovery (1-2 years):
Both sides exchange relevant documents including internal company communications, clinical trial data, medical literature, and plaintiff medical records.
Depositions are taken of plaintiffs, treating physicians, company employees, and expert witnesses.
Interrogatories (written questions) and requests for admissions are exchanged.
Expert reports:
Plaintiffs' medical and scientific experts prepare reports linking Dupixent to CTCL.
Defendants' experts argue against causation or minimize damages.
Daubert hearings may be held to challenge expert testimony admissibility.
Bellwether trials (2-4 years after filing):
A small number of representative cases proceed to trial.
Outcomes inform both sides about jury attitudes and case values.
Bellwether verdicts often trigger settlement negotiations.
Settlement negotiations:
Individual settlements may occur at any stage.
Global settlements resolve large numbers of claims using tiered compensation matrices.
Plaintiffs can accept settlement offers or opt to continue pursuing their case.
Trial (if no settlement):
Cases that do not settle proceed to jury trial.
Trials typically last 2-4 weeks.
Jury verdicts may be appealed, extending the process.
Throughout this process, your attorney keeps you informed and advises on critical decisions like settlement offers.
What evidence is needed to win a Dupixent lawsuit?
Winning a Dupixent lawsuit requires proving four elements:
1. Duty:
Pharmaceutical manufacturers have a duty to design safe drugs and warn about known risks.
2. Breach:
Sanofi and Regeneron breached this duty by:
Failing to adequately warn about CTCL risk.
Concealing or downplaying safety signals from clinical trials and post-market surveillance.
Continuing to market Dupixent despite knowledge of cancer risk.
Evidence:
Internal company documents showing awareness of cancer risk.
Clinical trial data revealing increased lymphoma rates.
FDA adverse event reports documenting CTCL cases.
Expert testimony from pharmacologists and regulatory specialists.
3. Causation:
Dupixent caused or substantially contributed to your CTCL diagnosis.
Evidence:
Medical literature establishing biological plausibility (e.g., JAMA Dermatology study).
Temporal relationship between Dupixent use and cancer onset.
Exclusion of alternative causes through differential diagnosis.
Expert testimony from oncologists and immunologists.
4. Damages:
You suffered actual harm as a result.
Evidence:
Medical records documenting diagnosis, treatment, and ongoing care.
Medical bills and hospital records.
Pay stubs and tax returns showing lost income.
Expert testimony on future medical needs and lost earning capacity.
Testimony from you and family members about pain, suffering, and reduced quality of life.
Your attorney and legal team gather and present this evidence to maximize chances of favorable settlement or verdict.
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Can I file a lawsuit if I signed a consent form?
Yes, signing a consent form or patient agreement does not prevent you from filing a lawsuit.
Consent forms typically state that you understand potential risks and side effects.
However, these waivers do not absolve manufacturers of liability if:
The consent form did not adequately disclose CTCL risk.
The manufacturer knew or should have known about cancer risk but failed to update warnings.
The informed consent process was deficient or misleading.
Product liability claims are distinct from medical malpractice:
You are not suing your doctor for prescribing Dupixent.
You are suing the manufacturers for failing to warn about known dangers.
Consent forms govern the doctor-patient relationship but do not shield drug companies from liability.
Courts generally hold that consent forms cannot waive claims for:
Fraudulent concealment of risks.
Failure to provide adequate warnings.
Design defects or manufacturing errors.
Your attorney will review any consent forms you signed to determine if they impact your case.
In most instances, these forms do not bar product liability claims.
What if I can't afford medical treatment?
If you cannot afford ongoing medical treatment for CTCL, explore these options:
Health insurance:
Medicare, Medicaid, or private insurance should cover most cancer treatments.
If you lost coverage due to job loss, COBRA or ACA marketplace plans may be available.
Hospital financial assistance:
Most hospitals offer charity care or reduced-cost programs for low-income patients.
Clinical trials:
Participating in CTCL clinical trials may provide free cutting-edge treatments.
Patient assistance programs:
Pharmaceutical companies and nonprofits offer free or discounted medications for eligible patients.
Medical liens:
Some attorneys arrange for treatment on a lien basis where providers are paid from settlement proceeds.
Do not delay filing a lawsuit due to inability to pay for treatment.
Your lawsuit seeks compensation for past, current, and future medical expenses.
Successful resolution can cover all treatment costs and more.
Your attorney can help connect you with resources to ensure you receive necessary care during the litigation process.
How long does the entire process take?
Dupixent litigation is expected to follow a typical mass tort timeline:
2025-2026: Case building and consolidation
Attorneys file individual cases.
Courts consolidate cases into MDL.
Discovery begins.
2026-2027: Discovery and bellwether selection
Both sides exchange millions of pages of documents.
Depositions of key witnesses.
Selection of bellwether trial cases.
2027-2028: Bellwether trials
First test cases go to trial.
Outcomes inform settlement negotiations.
2028-2029: Settlement negotiations
Global settlement programs may be established.
Individual cases begin settling.
2029-2031: Mass settlements
Majority of cases resolve.
Total timeline: 2-4 years from filing to resolution for most cases.
Factors that can extend timelines include:
Appeals of bellwether verdicts.
Difficulty in settlement negotiations.
Complex medical causation issues.
Continued filing of new cases.
Early filers often see faster resolution, particularly if selected for bellwether trials or early settlement tracks.
Time is critical. Statutes of limitations may bar claims if you wait.
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