Humira lawsuits fall into four distinct categories: personal injury claims alleging the drug caused fungal infections, cancers, and nerve damage; antitrust actions challenging AbbVie’s patent strategy for blocking cheaper biosimilars; pricing fraud class actions over inflated list prices; and government enforcement cases targeting marketing practices and alleged kickbacks. Most injury cases have closed, the central antitrust case was dismissed and affirmed on appeal, a major pricing class action is now before the Seventh Circuit, and marketing claims have been resolved through multimillion-dollar settlements in which AbbVie denied wrongdoing.
Personal Injury Claims Over Infections, Cancer, and Nerve Damage
Starting in the early 2010s, patients who took Humira sued Abbott Laboratories, AbbVie’s predecessor, alleging the drug caused serious harm the company failed to warn about. The injuries clustered into three groups: life-threatening fungal infections such as histoplasmosis and blastomycosis, cancers including lymphoma and leukemia, and neurological damage such as optic neuritis, peripheral neuropathy, and demyelinating diseases including multiple sclerosis.
The core legal theory was failure to warn. One lawsuit alleged the company knew by 2005 of a three- to five-fold increased cancer risk but did not warn patients until the FDA required updated labeling in 2009. On fungal infections, plaintiffs noted Abbott waited roughly 20 months after a 2008 FDA safety alert before sending warning letters to physicians. Competitor drugs already carried optic neuritis warnings that Humira’s label did not.
The FDA ordered Humira’s black box warning updated for invasive fungal infections in September 2008 after identifying 16 histoplasmosis cases, with Abbott completing the update in November 2009. Optic neuritis was added in March 2011. Current labeling warns of demyelinating diseases and the risk of lymphoma and other malignancies in children and adolescents.
Trial Results
The first injury case to reach trial was Milton Tietz, et al. v. Abbott Laboratories, et al. in April 2013. A jury found Abbott negligent and awarded the plaintiff, who developed disseminated histoplasmosis, $2.24 million. The court ruled that FDA regulatory compliance did not shield Abbott from its ordinary-care duty under state law, and the verdict survived appeal.
Other plaintiffs lost. In Calisi v. Abbott (2013), a federal judge dismissed a lymphoma claim after finding the plaintiff’s expert failed to supply enough scientific data to show the warning label was inadequate. A Tennessee case, Frederick Delano, was dismissed in September 2012. In Maynard v. Abbott Laboratories, a federal court in the Eastern District of Wisconsin denied Abbott’s motion to dismiss a multiple sclerosis failure-to-warn claim, finding a reasonable fact-finder could conclude the company had a duty to warn beyond formal FDA requirements.
AbbVie’s main defenses were federal preemption, arguing state-law failure-to-warn claims were preempted by the Food, Drug, and Cosmetic Act, and the learned intermediary doctrine, which holds that warning the prescribing physician satisfies a manufacturer’s duty.
Where Injury Claims Stand Now
The injury litigation never consolidated into a multidistrict litigation or large mass tort. As of 2026, most attorneys are no longer accepting new Humira failure-to-warn cases, though some firms continue evaluating potential claims involving vision problems and nerve damage.
Antitrust Lawsuits Over the Humira Patent Thicket
A separate and larger body of litigation attacked AbbVie’s patent strategy. Humira’s original U.S. patent expired in 2016, but no biosimilar reached American patients until January 2023. That seven-year gap drove antitrust claims alleging AbbVie had built an impenetrable wall of patents around the drug.
A report by the Initiative for Medicines, Access & Knowledge (I-MAK) counted 247 U.S. patent applications covering Humira, with 89% filed after the drug’s initial 2002 approval. Nearly half were filed after 2014. Critics labeled the practice “evergreening” or “patent layering.” AbbVie filed more than three times as many U.S. patent applications as it did at the European Patent Office, where many similar applications were withdrawn, refused, or revoked. I-MAK estimated the extended U.S. monopoly cost American payers and taxpayers more than $14.4 billion. Medicare and Medicaid spending on Humira rose 266% between 2012 and 2016.
The Consolidated Class Action
Indirect purchasers including the City of Baltimore and employee welfare benefit plans filed a consolidated class action in the Northern District of Illinois: In Re: Humira (Adalimumab) Antitrust Litigation, Case No. 1:2019cv01873. The seven-count complaint alleged violations of Sections 1 and 2 of the Sherman Act and analogous state antitrust laws, targeting both patent accumulation and AbbVie’s settlement agreements with biosimilar makers.
On June 8, 2020, Judge Manish S. Shah granted the defendants’ motion to dismiss without prejudice, finding much of AbbVie’s patent activity was protected under the Noerr-Pennington doctrine, which shields petitioning of government agencies from antitrust liability, and that the plaintiffs’ theory of harm was “too speculative.”
The Seventh Circuit affirmed on August 1, 2022, in an opinion by Judge Easterbrook. The court held that patent law does not cap the number of patents a company may obtain and that AbbVie’s 132 Humira-related patents were presumptively valid. On the biosimilar settlements, the panel rejected the argument that AbbVie had made unlawful reverse payments, concluding the company “did not pay the would-be entrants on either continent” and that the agreements were “a traditional resolution of patent litigation.”
The Biosimilar Settlement Agreements
AbbVie settled patent infringement litigation with at least eight biosimilar makers, granting non-exclusive licenses with staggered U.S. entry dates: Amgen on January 31, 2023; Samsung Bioepis on June 30, 2023; Mylan on July 31, 2023; Sandoz on September 30, 2023; and several others on July 1, 2023. In Europe, where Humira’s composition-of-matter patent expired in 2018, the same companies entered years earlier.
Plaintiffs argued the gap showed AbbVie traded earlier European entry for delayed U.S. entry, functioning as a reverse payment. The Seventh Circuit rejected that framing, noting several companies agreed to 2023 U.S. entry despite having no European plans. Samsung Bioepis owed royalties to AbbVie under its license; AbbVie stated it would make no payments to that company.
FTC Position
The Federal Trade Commission filed an amicus brief in the Seventh Circuit appeal. Without taking a position on the ultimate merits, the FTC argued the district court had misapplied a “scope-of-the-patent” test and had given too much weight to the policy favoring patent settlements at the expense of antitrust scrutiny under FTC v. Actavis, Inc. In May 2021, three House Democrats, including Oversight Chair Carolyn Maloney and Judiciary Chair Jerrold Nadler, formally urged the FTC to investigate whether AbbVie used anticompetitive practices to block Humira biosimilars. No FTC enforcement action specific to Humira has been publicly announced.
The Pricing Fraud Class Action
In April 2023, Hagens Berman filed a class action titled Camargo, et al. v. AbbVie Inc., Case No. 1:23-cv-02589, in the Northern District of Illinois. The lawsuit alleges AbbVie inflated Humira’s price by manipulating the gap between its publicly listed price and the lower prices negotiated with pharmacy benefit managers. The complaint claims this “secret spread” rendered the list price fraudulent and brings 38 counts under Illinois and other state consumer protection laws.
The proposed class covers individuals who purchased Humira since 2013, either at full price or with co-insurance. The complaint notes Humira’s cost rose 470% from its 2003 launch to roughly $77,000 for a year’s supply, while AbbVie reported $16 billion in U.S. net revenue from Humira in 2020 alone.
As of mid-2026, the case is on appeal at the Seventh Circuit under Case No. 26-1543, following a ruling by Judge John Robert Blakey in the district court. The Pharmaceutical Research and Manufacturers of America and the U.S. Chamber of Commerce have filed amicus briefs supporting AbbVie. No settlement has been reached, and no claims process is open for class members.
Marketing and Kickback Settlements
In August 2020, the California Department of Insurance and whistleblower Lazaro Suarez reached a $24 million settlement with AbbVie resolving allegations under California’s Insurance Frauds Prevention Act. Lieff Cabraser represented the whistleblower, with partner Rachel Geman leading the case.
The allegations centered on AbbVie’s “HUMIRA Complete” marketing program. Prosecutors claimed the company gave meals, drinks, and other incentives to physicians to induce Humira prescriptions and sent “Nurse Ambassadors” into patients’ homes who deflected concerns about the drug’s risks and interfered with doctor-patient communications. The California Department of Insurance characterized these practices as kickbacks.
Beyond the payment, AbbVie agreed to significant marketing reforms: disclosing that Ambassadors are AbbVie employees rather than members of a patient’s healthcare team; prohibiting sales representatives from taking prescribers to offsite meals outside approved speaker programs; restricting Ambassadors from patient-specific discussions with prescribing doctors; and barring employees from describing Ambassadors as “extensions of [doctors’] offices.” AbbVie denied all allegations of wrongdoing as part of the settlement.
Separately, in March 2023, AbbVie reached a $2.7 million settlement to resolve a federal whistleblower lawsuit under the False Claims Act. That case alleged the company used unlawful kickbacks to incentivize providers to prescribe Humira.
What the Congressional Investigation Found
The House Committee on Oversight and Reform ran a two-year investigation into AbbVie’s drug pricing, releasing a staff report and holding a hearing on May 18, 2021 at which AbbVie CEO Richard Gonzalez testified.
The committee reported AbbVie had obtained or applied for more than 250 Humira patents, with the last set to expire in 2037. Internal documents showed AbbVie estimated its tactics to delay biosimilar entry from 2017 to 2023 would cost the U.S. healthcare system $19 billion. The committee also alleged AbbVie devoted a significant share of its research budget to a Humira “enhancements” program designed to protect against biosimilar competition rather than develop new treatments, and that executive compensation was tied directly to Humira net revenue during periods of significant price increases. Humira had generated $170 billion in worldwide revenue since 2003, with U.S. prices climbing 470% since launch.
The Dutch Excessive Pricing Case
Humira has also been challenged outside the United States. In the Netherlands, the Pharmaceutical Accountability Foundation brought a collective action against AbbVie in the Amsterdam District Court, alleging the company charged excessive and unlawful prices for Humira between 2004 and 2018. PAF claimed the pricing cost the Dutch healthcare system approximately €1 billion in excess profit, equivalent to nearly 14,000 years of healthy life lost through displaced healthcare resources.
The case was filed under the Dutch Collective Settlement of Mass Damage Act. On July 9, 2025, the Amsterdam District Court declared PAF inadmissible without addressing the substantive merits. PAF has said it is considering an appeal.
The State of Biosimilar Competition
Biosimilar competition, which the antitrust litigation sought to accelerate, began in January 2023 when Amgen launched Amjevita. By mid-2023, at least ten additional biosimilars had entered the U.S. market.
Adoption has been slower than many expected. In the first full year of competition, biosimilars captured less than 2% of total adalimumab prescriptions, according to a study published in JAMA Health Forum in December 2024. By November 2023, written Humira prescriptions still outnumbered biosimilars 46 to 1. The sluggish uptake was largely attributed to pharmacy benefit manager rebate structures that favor Humira’s high list price because it generates larger rebate payments. Humira’s net price fell below that of several biosimilars by late 2023.
The picture has shifted more recently. In April 2024, CVS Caremark removed Humira from its standard commercial formulary in favor of a biosimilar, and other large PBMs followed with similar exclusions in 2024 and 2025. Biosimilar adoption among commercial and employer plans has reached roughly 23%, though government plan uptake remains much lower. A full transition could save the U.S. health system up to $6 billion per year, according to an analysis by the Biosimilars Council.
The financial impact on AbbVie has been substantial. Humira’s global net revenues fell to $4.54 billion in 2025, a nearly 50% decline from the prior year. At its 2021 peak, the drug generated $20.7 billion in annual sales and accounted for more than half of AbbVie’s total revenue.