GSK disagrees with ranitidine evidence ruling in California

Pharmaceuticals giant GSK responded to a recent ruling in the ongoing legal wranglings over its now-suspended blockbuster heartburn drug Zantac on Friday.

Zantac, or ranitidine, was launched by Glaxo Laboratories in 1981, and was pulled from shelves worldwide in 2019 and 2020 after a probable carcinogen was discovered in ranitidine products from a number of manufacturers.

Tens of thousands of cases are set to be heard before state courts in the US, after a federal judge threw out around 50,000 cases in December after ruling that the expert opinions being relied on by complainants were not scientifically sound.

The first of four bellwether cases in California is being brought by resident James Goetz, who claims to have developed bladder cancer after taking ranitidine.

Since the beginning of March, judge Evelio Grillo has presided over a ‘Sargon’ hearing in the state’s superior court, which is a California-specific case law decision on the admissibility of expert opinion.

GSK said it disagreed with the court's decision that the expert opinion was admissible, postulating that there was no reliable evidence to suggest that the use of ranitidine increased the risk of cancer.

A population-based study published in the International Journal of Environmental Research and Public Health in September, however, found that “ranitidine increased the risk” of liver, lung, gastric and pancreatic cancer.

The court's decision did not mean that it agreed with the complainant’s scientific conclusions or their "litigation-driven science", but rather was only a ruling on a procedural matter.

GSK emphasised that the litigation was still at an early stage, adding that it would continue to press additional defences.

Additionally, the complainant still needed to prove the case at trial.

GSK said it had conducted 13 epidemiological studies looking at human data regarding the use of ranitidine.

The company said the scientific consensus was that there was no consistent or reliable evidence linking ranitidine use to an increased risk of any cancer.

GSK’s ownership of the Zantac brand came from the merger of Glaxo Laboratories and Burroughs in 1995, and then the combination of GlaxoWellcome and SmithKline Beecham in 2000.

Ranitidine came off patent in 1997, and was subsequently marketed under various brand names by a number of pharmaceutical firms worldwide.

At 1045 GMT, shares in GSK were down 3.6% at 1,386p.

Reporting by Josh White for Sharecast.com.