The plaintiff in the first lawsuit over the heartburn drug Zantac scheduled to go to trial has agreed to drop his case, according to his attorney and drugmakers named as defendants.

The news on Tuesday came days after shares of GlaxoSmithKline Plc, Sanofi SA, Pfizer Inc and Haleon Plc were hit by investor concerns about thousands of lawsuits claiming the drug, which U.S. regulators pulled from the market in 2020, causes cancer.

The first trial in one of those lawsuits had been scheduled to begin next Monday in Illinois state court. The plaintiff, Joseph Bayer, alleged that he developed esophageal cancer from taking over-the-counter Zantac.

Alexandra Walsh, an attorney for Bayer, said her client could not proceed for "personal health reasons" but had the right to refile his case within a year.

GSK and Boehreinger Ingelheim, which were defendants in the case, both said they were pleased it had been dropped and that scientific evidence showed Zantac was safe.

Zantac, originally marketed by a forerunner of GSK, has been sold by several companies at different times, 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.

The 2020 recall followed an investigation by the U.S. Food and Drug Administration into whether Zantac's active chemical, ranitidine, causes levels of a probable carcinogen N-nitrosodimethylamine (NDMA) to rise in users' bodies.

About 2,000 lawsuits are consolidated in federal court in West Palm Beach, Florida, where a hearing on what expert evidence will be allowed in future trials is scheduled for Sept. 20.

The first federal court trials are expected some time next year, though a highly favorable ruling for the companies on evidence could effectively end the litigation before then.