GSK settles 4 Zantac cases to head off trial threat

GSK has reached four settlements in the US over claims that heartburn drug Zantac causes cancer, as the UK pharmaceutical group tries to extinguish a legal threat that has hung over the company for more than a year.

The drugmaker said on Wednesday that it had reached a confidential settlement in a case in a California state court, where a trial was due to start next month. It has also settled the three remaining cases over alleged links between Zantac and breast cancer in California.

A handful of the world’s biggest pharmaceutical companies, including GSK, Haleon, Sanofi and Pfizer, had more than £30bn wiped off their market value in August 2022 as investors became increasingly alarmed by the risk of a huge legal bill from the Zantac cases.

The pharma companies, which have all previously marketed Zantac at one point, faced allegations that the medicine causes cancer because it contains small amounts of N-nitrosodimethylamine (NDMA). NDMA is commonly ingested in small amounts but can cause cancer in humans when more is consumed.

GSK settled its first case, which had also been due to go to trial in California, in June. It said on Wednesday that the decision to settle a further four cases reflected the company’s “desire to avoid the distraction related to protracted litigation”.

It did not admit any liability in the settlements and did not give any financial details. The company added that it would continue to “vigorously defend itself based on the facts and the science” in all other Zantac cases.

The next hurdle for GSK will be at a hearing in January over the bulk of the remaining cases, about 73,000 from an outstanding 79,000.

The courts in Delaware adhere to a different standard for evidence than those in California. Delaware’s standard is closer to that of federal courts, which last year dismissed almost 2,500 lawsuits, with the judge saying they were based on flawed science and that the only reliable testing of the blockbuster drug undertaken showed an “unprovable risk of cancer”.

In 2019, French drugmaker Sanofi voluntarily withdrew Zantac from the market when the US Food and Drug Administration started to investigate it. In 2020, the regulator said Zantac appeared to produce unacceptably high levels of NDMA when exposed to heat and requested that it be withdrawn.

A recent independent peer-reviewed paper that studied almost 1.2mn people added to 14 previous research that showed the drug did not increase the risk of cancer. The study, published in the Journal of the American Medicine Association last month, found that Zantac was not associated with an increased risk of 15 types of cancer, compared with people taking other similar drugs, known as histamine H2-receptor antagonists.