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June 20 (Reuters) - A bid by GSK and other drugmakers to stop more than 70,000 lawsuits in Delaware over discontinued heartburn drug Zantac has received the backing of leading U.S. industry groups, including the United States Chamber of Commerce and Pharmaceutical Research and Manufacturers of America.
In a friend-of-the-court brief posted to the Delaware Superior Court's docket on Thursday, the groups said that a Delaware judge's recent ruling allowing the lawsuits to proceed jeopardized the state's business-friendly reputation and threatened to turn it into "a hotbed of products-liability and mass-tort litigation."
GSK, Pfizer, Sanofi and Boehringer Ingelheim, which all sold Zantac at times, had asked Judge Vivian Medinilla to bar plaintiffs from offering expert testimony linking Zantac to cancer, arguing that it was not based on sound scientific methods. The plaintiffs' cases depend on that testimony, and cannot go to trial without it.
After the judge refused, the companies petitioned her for leave to appeal directly to the Delaware Supreme Court. The industry groups in Thursday's filing are asking the judge to grant that petition.
The groups, which also include the National Association of Manufacturers and the Biotechnology Innovation Organization, said Medinilla's ruling was at odds with a Florida federal court that in 2022 tossed about 50,000 Zantac claims after rejecting similar evidence as unreliable. Some plaintiffs are appealing that ruling.
If Delaware courts adopted a more relaxed evidence standard for mass tort cases, they said, the state would quickly become a venue of choice for plaintiffs since many U.S. companies are incorporated there.
The groups urged Medinilla to "consider the importance to the business community of clarity, consistency and predictability in Delaware jurisprudence on expert testimony."
A lawyer for the plaintiffs did not immediately respond to a request for comment.
First approved in 1983, Zantac became the world's best-selling medicine in 1988 and one of the first to top $1 billion in annual sales. It was originally marketed by a forerunner of GSK and later sold successively to other companies.
Lawsuits began piling up after the U.S. Food and Drug Administration in 2020 asked manufacturers to pull the drug off the market over concerns that its active ingredient, ranitidine, could degrade into a cancer-causing chemical called NDMA over time or when exposed to heat.
The drugmakers have maintained there is no evidence Zantac exposes users to harmful NDMA levels or causes cancer.
The vast majority of pending cases are in Delaware. Only one case, against GSK and Boehringer Ingelheim in Illinois, has gone to trial, ending in a victory for the companies last month. (Reporting By Brendan Pierson in New York, Editing by Alexia Garamfalvi and Rod Nickel)