GSK et al win another round in Zantac cancer litigation

GSK and other drugmakers fending off litigation claiming that gastrointestinal drug Zantac or a generic caused cancer have won a supreme court ruling in Canada, after also chalking up wins in the US.

The British Columbia Supreme Court has dismissed a proposed class action on behalf of users of ranitidine, who claimed that Zantac and other medicines containing ranitidine feature a carcinogen called N-nitrosodimethylamine (NDMA) that resulted in several forms of cancer and other illnesses.

In its judgment, the court said there was “uncontroverted evidence that neither ranitidine nor NDMA are reliably associated with increased cancer risk”, as well as an “absence of evidence that ranitidine or NDMA cause cancer in humans.”

GSK and around a dozen other companies – including its consumer health spin-off Haleon, Sanofi, Pfizer, and Boehringer Ingelheim – are facing thousands of lawsuits around the world over the issue, with analysts estimating that liability and settlements could end up costing them billions of dollars.

It’s not the end of the matter in Canada, as GSK and its allies still have to defend themselves in proposed class actions by ranitidine users filed in Ontario and Quebec, as well as upwards of 100 individual actions filed by ranitidine users in the country.

GSK said in a statement that since the potential link between ranitidine, NDMA and cancer first emerged in 2019, there have been 13 peer-reviewed epidemiological studies looking at the use of the drug and the “scientific consensus is that there is no consistent or reliable evidence that ranitidine increases the risk for any type of cancer”.

Counsel for the plaintiffs in the lawsuits are claiming that the pharma company knew about the risks of ranitidine for decades but did nothing.

The ruling comes a few months after a US federal court dismissed around 50,000 similar lawsuits, although the defendants did not fare so well at the state level in California, when a judge denied GSK’s attempt to keep experts called by the plaintiffs out of the proceedings.

GSK has said it “respectfully disagrees” with that decision, and will vigorously defend itself in the jury trial, which is due to be heard in July. The first US lawsuit was voluntarily dismissed before it came to trial last year.

Zantac was originated by GSK and launched by the company in the early 1980s, which sold it as a prescription and over-the-counter (OTC) product for indications like heartburn and acid indigestion over the years.

Sanofi had rights to the OTC version of the drug that was recalled in 2019 over possible contamination with the suspected carcinogen NDMA, with the FDA banning sales the following year. It was sold in generic form by several other producers, many of which have also been named in litigation.

Health Canada ordered a stop on sales in 2019 and said the following year that manufacturers had recalled products from some of the manufacturers because it was found they “contained or potentially contained NDMA above acceptable levels.”