Key Takeaways GSK Plc American depositary receipts (ADRs) sank in intraday trading Monday after a Delaware judge allowed lawsuits to continue claiming the pharmaceutical firm's former heartburn medicine, Zantac, causes cancer. The company denies the accusations, and vows an immediate appeal. GSK said the ruling was inconsistent with one by a federal court in 2022. American depositary receipts (ADRs) of GSK Plc (GSK) tumbled in intraday trading Monday after a Delaware court ruled that lawsuits claiming the d ...