Shares of Pfizer (NYSE: PFE) slipped 3.3% lower as of the market close on Thursday. The decline resulted from investors' concerns about litigation related to Zantac. The U.S. Food and Drug Administration (FDA) called for the heartburn drug to be pulled from the market in 2020 due to safety concerns.
GSK (NYSE: GSK) originally developed Zantac. By 1988, it ranked as the world's best-selling drug. Pfizer marketed an over-the-counter version of Zantac for several years. However, the company sold the U.S. rights to the OTC drug to Sanofi (NASDAQ: SNY) in 2006 and hasn't marketed it since then.
Pfizer does have some legal exposure related to the increased risk of cancer associated with taking Zantac. GSK and Sanofi could be more at risk than Pfizer is because they sold Zantac for longer periods. However, it's too soon to know what the negative impact, if any, will be for any of these companies.
Source Fool.com