The Wisner Baum law firm in Los Angeles is scheduled next month to bring the first state court lawsuit alleging that the heartburn drug Zantac can cause cancer – a contention that is at the heart of tens of thousands of similar lawsuits filed nationwide.
But the soundness of the science behind these plaintiff claims remains debatable based on the views of expert observers and recent judicial opinions about medical witnesses. Plaintiffs’ attorneys recently received some vindication from a Delaware Superior Court judge, Vivian Medinilla, who in June ruled that plaintiffs’ expert witnesses can testify in court about the relationship between cancer and ranitidine, the generic term for Zantac.
In 2022, however, a federal judge overseeing multidistrict litigation involving Zantac claims in Florida, Robin Rosenberg, dismissed a core compilation of scientific evidence brought by plaintiffs' attorneys in an opinion that spanned more than 300 pages. A central question was under what conditions could the drug degrade into a compound called N-Nitrosodimethylamine (NDMA), which is a likely human carcinogen at certain concentrations.
Rosenberg investigated the strength of lead plaintiffs’ attorneys’ evidence that Zantac, which was voluntarily pulled off the market in 2020, can cause esophageal, bladder, stomach, liver and pancreatic cancers. The allowable NDMA limit in consumer products is 96 nanograms, according to the Food and Drug Administration, but in 2019 private laboratory testing firm Valisure claimed the amount of NDMA it created from ranitidine was more than 3 million nanograms.
The problem was that Valisure heated the drug to 266 degrees Fahrenheit rather than normal storage temperatures for medicines or the 98.6-degree temperature of the human body, according to a paper published last year by Barbara Pfeffer Billauer, a legal and bioethics scholar and professor at the Institute of World Politics. The company also found that it could create a dose of 300,000 nanograms of NDMA from ranitidine at 98.6 degrees – but only when mixed with enough salt to kill a human being.
Rosenberg concluded that under the standard for scientific evidence in the federal court system, the expert testimony failed the requirement to be reliable, relevant and conforming to the facts of the case.
Billauer told the Southern California Record that the 260-plus-degree heating of the drug may have worked for conditions on Mars, but it had no relevance to conditions the drug would have been subjected to under normal human conditions on Earth.
How California judges will approach the Zantac scientific evidence remains to be seen, but judges in the state tend to be more scientifically savvy than jurists in some other states, according to Billauer.
“If the judge goes through it piece by piece by piece, it’s likely (he or she) will toss it,” she said.
Rosenberg chose to look at the scientific studies carefully and fully, according to Billauer.
“You have to really get your hands dirty and look at it,” she said. “... Cherry-picking of evidence (by expert witnesses) causes the downfall of the plaintiffs’ evidence.”
The Zantac cases pending in state courts are concentrated in Delaware, California, Illinois and Pennsylvania, according to the Wisner Baum law firm. Among a handful of cases that went to trial so far in Illinois, juries threw out two cases and a third was a hung jury.
Many of the states where Zantac cases are pending have a rule for scientific evidence known as the Frye standard, which requires evidence to follow the consensus opinion among the community of scientists.
Medinilla’s opinion, which is being appealed to Delaware’s highest court, found that the conclusions of the plaintiffs’ medical witnesses met the burden for discussion in open court.
“In Delaware, our jurisprudence counsels that, subject to earnest deliberation, trial courts entrust questions of science to the scientists,” the judge said in her opinion. “Here, opposing teams of highly educated, skilled expert medical witnesses offer competing opinions. Through well-trained counsel, their efforts only clarify the distinct opposition that defines their respective positions. It would be improper to simply dismiss these experts as ‘poseurs or witnesses for hire.’ They are serious scientists.”