Zantac heartburn pills REUTERS/Brendan McDermid/Illustration

Shares in GSK, Sanofi, Haleon and Pfizer began to recover on Friday (Aug 12) after the companies said that nothing material had changed regarding US litigation focused on heartburn drug Zantac.

The companies’ share prices had fallen sharply last week on investor concern about the litigation over potential cancer-causing impurities that prompted the drug’s withdrawal from markets in 2019 and 2020.

More than 2,000 Zantac-related legal cases have been filed in the United States, analysts say, with the first trial beginning this month.

The prospect of impending Zantac litigation is not new. Among other disclosures, recently listed Haleon had highlighted the risk of such lawsuits in its prospectus.

GSK, Sanofi, Pfizer and Haleon have lost a combined $39 billion from their market value over the past week in the absence of any other particular catalyst, according to Barclays analysts.

Zantac, originally marketed by a forerunner of GSK, has been sold by several companies since the loss of patent exclusivity in the late 1990s, including Pfizer, Boehringer Ingelheim and Sanofi.

Haleon, spun out as an independent company last month, comprises consumer health assets once owned by GSK and Pfizer.

If you want to share your stories and/or experiences with us, please send an email to [email protected]