The heartburn drug Zantac, once a blockbuster medication, continues to cast a long shadow over the pharmaceutical industry. In a recent development, Pfizer agreed to settle over 10,000 lawsuits in U.S. state courts alleging the drug caused cancer. This follows on the heels of a similar move by Sanofi in March 2024.Zantac, with its active ingredient ranitidine, dominated the heartburn treatment market for decades. Approved in 1983 and reaching peak sales of over $1 billion annually, it revolutionized how people managed heartburn. However, the tide turned in 2019 when independent labs discovered N-Nitrosodimethylamine, commonly known as NDMA, a probable human carcinogen, in ranitidine samples. This revelation prompted the U.S. Food and Drug Administration (FDA) to request the removal of Zantac from the market in 2020.Thousands of lawsuits followed the FDA action, with plaintiffs claiming Zantac use led to various cancers. Facing this legal onslaught, drugmakers have adopted varying approaches. Pfizer, which sold Zantac between 1998 and 2006, maintains the drug is safe and asserts ongoing scientific defense against the lawsuits. However, the recent settlement suggests a strategic shift towards resolving litigation in some jurisdictions.French pharmaceutical giant Sanofi settled approximately 4,000 cases outside Delaware courts for an undisclosed amount in March 2024. The lawsuits specifically centered on claims that Sanofi had failed to adequately disclose risks, leading to adverse health effects.

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“Sanofi is settling these cases, not because we believe the claims have any merit, but rather to avoid the expense and ongoing distraction of the litigation,” a Sanofi spokesperson said at the time.GlaxoSmithKline (GSK), the original manufacturer who received approval for Zantac in 1983, has opted for case-by-case settlements, particularly in California. They dispute any link between Zantac and cancer and are currently facing a jury trial in Illinois alongside Boehringer Ingelheim.“Pfizer continues to vigorously defend against Zantac lawsuits, which we believe are not supported by reliable science," a spokesperson said, adding, "As we have stated previously, Pfizer has explored and will continue to explore opportunistic settlements of certain cases if appropriate and has settled certain cases."A key battleground in the Zantac lawsuits is the scientific evidence. While plaintiffs argue that ranitidine breaks down into NDMA, causing cancer, drug companies maintain the science is flawed. A Florida federal judge bolstered their position in 2022 by dismissing thousands of consolidated cases due to concerns about the scientific basis of the claims. However, a Delaware judge is expected to rule soon on the admissibility of scientific evidence linking Zantac to cancer in state court cases.“The company is confident that its Zantac products, which were reviewed and approved by the FDA, did not cause cancer when used as directed,” Pfizer said.The settlements by Pfizer and Sanofi provide some relief for plaintiffs, but thousands of cases remain outstanding. The upcoming ruling in Delaware and the ongoing Illinois trial are crucial developments to watch. The Zantac saga serves as a stark reminder of the complexities of drug safety and the long legal battles that can erupt after potential health risks come to light.

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Pfizer offers up to $250 mln to settle Zantac cancer lawsuits, FT reportsPfizer moves to settle more than 10,000 Zantac cases in state courts: BloombergPfizer agrees to settle over 10K lawsuits linking Zantac to cancer