US court sides with Zantac manufacturers in 75,000 lawsuits

Judge Abigail LeGrow said the trial court erred in applying too lenient a legal standard for admissibility of expert testimony and failed to require the experts to provide "reliable scientific methodologies" to support their conclusions.

LeGrow noted that the trial court did not explain how the experts concluded that ranitidine was linked to cancer. After all, the studies they cited did not examine the effects of the carcinogen N-nitrosodimethylamine (NDMA), which is found in ranitidine, and did not establish a scientifically proven cause-and-effect relationship.

Zantac, first approved by U.S. regulators in 1983, became the world’s best-selling drug in 1988 and one of the first to surpass $1 billion in annual sales. In 2019, Valisure, an independent Connecticut lab, published a study showing that ranitidine can form the probable carcinogen NDMA. Bloomberg later reported that NDMA, once added to rocket fuel, is now used to induce cancer in lab rats. According to the publication, which reviewed GSK documents, the drugmaker knew about the drug’s potential dangers since 1978 but hid it from the FDA.

A few months after the Valisure analysis, manufacturers and health regulators around the world began recalling Zantac and removing it from the market. In October 2021, the Russian Ministry of Health also excluded ranitidine from the list of vital and essential drugs and the minimum pharmacy assortment.

After 2020, lawsuits began to be filed in the United States against companies involved in the sale and production of the drug. The defendants in them were GSK itself, which was the first manufacturer of the drug, as well as Pfizer (a partner of the British pharmaceutical company, sold Zantac in 2000-2006), Haleon (a joint venture of GSK and Pfizer), Sanofi (sold the drug from 2017 to 2019), Boehringer Ingelheim (sold the drug in 2006-2017). Due to the accusations and a large number of lawsuits, the shares of GSK, Sanofi and Haleon fell by 12.5-14.3% in August 2022. According to Bloomberg calculations, the combined capitalization of the companies decreased by $40 billion.

The companies emerged from the scandal using a similar scenario: they denied guilt, but made payments. Thus, in April 2024, it became known that Sanofi would settle 4 thousand lawsuits. As the French company stated, the agreement covers lawsuits filed in most American states, but not in Delaware, where about 20 thousand lawsuits were filed against Sanofi. In 2022, a federal court in Florida ruled that such claims were unfounded and rejected lawsuits from 50 thousand patients. Sanofi itself did not admit guilt and refused to disclose the amount of the deal.

Pfizer agreed in May 2024 to pay $250 million in a settlement in a Delaware lawsuit.

GSK also denied "any allegations of concealment of ranitidine safety data." The company cited the conclusions of the American and European regulators FDA and EMA, as well as 13 independent epidemiological studies. According to them, there is no evidence of a causal relationship between ranitidine therapy and the development of any form of cancer. The FDA found that the level of the carcinogen N-nitrosodimethylamine in ranitidine is no higher than in fried meat. In October 2024, GSK entered into a $2.2 billion settlement for claims in the United States. At the same time, the company maintained its position and did not admit to wrongdoing. The payment, as the company said, will avoid the risk of continued litigation.

The GSK deal resolved 80,000 cases filed in the US, or 93% of the total. The company also paid $70 million to Valisure, which filed a lawsuit in May 2024, emphasizing that GSK had known for 40 years about the risks of developing cancer in patients taking a drug with the active ingredient ranitidine.