WILMINGTON, Del. (Legal Newsline) - Saying it was not her role to “step into the heart of technical debate between opposing scientists,” a Delaware judge refused to exclude plaintiff expert witnesses vital to some 75,000 lawsuits claiming Zantac causes a variety of cancers.
The ruling by Delaware Superior Court Judge Vivian L. Medinilla conflicts with the finding of a federal judge who dismissed 50,000 similar cases for lack of evidence Zantac causes cancer. An Illinois jury also recently rejected a Zantac cancer claim in the first such case to go to trial.
All of the litigation against Zantac manufacturer GSK and others relies in some part on disputed research by Valisure, a New Haven, Conn. laboratory that filed a petition with the Food and Drug Administration in 2019 claiming Zantac, also known as ranitidine, could degrade into cancer-causing NDMA when exposed to heat. The FDA ordered a recall of ranitidine after the report came out, although the agency later criticized Valisure’s methods and the federal judge specifically found the company’s methods unreliable.
Valisure isn’t an expert in the Delaware cases, however, and Judge Medinilla said Delaware law is also looser when it comes to allowing expert witnesses to present their opinions to jurors. Delaware allows experts to change their opinions, doesn’t consider statistical significance necessary to prove causation, doesn’t recognize a “threshold dose” required to cause disease and doesn’t require experts to back up their opinions with epidemiological studies, she said.
“This Court will not inject itself into a dispute over which party has the better science,” she wrote in a May 31 opinion.
The judge lightly criticized GSK’s sole expert on causation, Dr. William C. Zamboni, but refused plaintiff requests to exclude him. The judge also allowed in all of the challenged plaintiff experts including Emery Pharma, a contract lab that has worked with Valisure. GSK argued Emery’s findings that ranitidine could degrade into NDMA should be excluded because it couldn’t replicate some of its own results. Delaware rules of evidence allow experts to change their opinions, the judge said.
“This criticism might carry more weight if Emery were somehow prohibited from updating the report,” the judge wrote. “But many of (GSK’s objections) involve clerical errors; its resolution is fitted for twelve people in the jury box.”
The defense framed the question for the experts is whether ranitidine causes cancer, while the plaintiffs said the question was whether NDMA causes cancer. The judge decided the case revolves around the latter, given evidence from Valisure, Emery and others that ranitidine could degrade into NDMA.
The dispute is similar to the one over whether Johnson & Johnson’s cosmetic talc causes cancer. A small number of plaintiff experts claim the talc contains asbestos, while J&J maintains those experts are confusing jurors by improperly categorizing harmless talc fibers as asbestos. If judges allow the plaintiff experts in, other medical experts can then testify that asbestos causes cancer, without having to opine on whether plaintiffs could have been exposed to asbestos by using talc.