GSK Faces Whistleblower Suit From Lab That Found Zantac Risk (1)

GSK Plc is facing a whistleblower lawsuit that could potentially cost it billions of dollars from the laboratory that revealed the presence of a probable carcinogen in Zantac, the heartburn medication that the UK drugmaker invented and turned into a blockbuster.

An amended complaint filed Monday contends that GSK hid Zantac’s cancer risks for decades while Medicare, Medicaid and other US government health programs covered prescriptions for the antacid. The lawsuit, which hasn’t been reported before, was brought by Connecticut-based Valisure, the independent lab that raised the alarm about Zantac’s cancer risks in 2019.

Big drugmakers already face some ...