US lab at the centre of legal fight over Zantac and cancer

GSK, Pfizer and several other pharmaceutical companies are taking aim at the credibility of a small independent lab in Connecticut as they defend themselves against thousands of lawsuits claiming a popular heartburn medication can cause cancer.

Valisure, a 20-person operation based in New Haven, caused shockwaves when it said in 2019 that it had found Zantac and generic versions of the drug, which have been sold in the US for more than three decades, contained N-Nitrosodimethylamine, better known as NDMA, which regulators classify as a “probable human carcinogen”.

Since then more than 2,000 personal injury lawsuits have been filed and a further 70,000 claims registered by users of the medication in litigation, which analysts forecast could cost the companies tens of billions of dollars in damages.

As the lawsuits move towards trial, companies who sold branded versions of Zantac over the past 35 years — including GSK, Sanofi, Pfizer and Boehringer Ingelheim Pharmaceuticals — have denied that using Zantac, the brand name for the drug ranitidine, leads to an increased cancer risk.

In mounting their defence they have singled out Valisure, claiming its testing methodology was flawed, biased and undertaken in co-ordination with plaintiffs’ lawyers.

“Valisure’s testing, lobbying, and publicity campaign is the ground zero of this entire litigation,” the pharma groups alleged in court documents filed in litigation overseen by US District Court Judge Robin Rosenberg.

Next month Judge Rosenberg will hold hearings to determine what scientific expert testimony will be admissible in the cases, focusing on testing methods and what levels of NDMA may pose a cancer risk.

Valisure’s research on Zantac has divided scientific experts. US regulators agree that NDMA is not expected to lead to an increase in cancer risk at very low levels, noting it is present in most food and water. However, sustained higher levels of exposure may increase the risk of cancer in humans, they said.

The US Food and Drug Administration previously concluded Valisure’s testing methodology was “inappropriate” and “contributed to or caused the levels of NDMA to be artificially high”. Documents released in response to Freedom of Information Act inquiries, which were first reported by Consumer Reports, also reveal the agency is investigating the lab to ensure its work for companies that seek FDA approval for products complies with the law.

Nevertheless, seven months after Valisure published its own research on Zantac’s NDMA risk, the FDA requested manufacturers to withdraw all their ranitidine drugs from the market, concluding that NDMA levels increase over time even under normal storage conditions.

“This shows the critical importance and impact of independent testing being part of the supply chain.” David Light, co-founder and chief executive of Valisure, told the Financial Times.

The pharma groups have alleged the lab used a testing method that was never validated to test for NDMA in ranitidine, which they said involved “superheating” samples of the drug to produce “artificially high” levels of NDMA.

The companies have also argued that Valisure worked with the plaintiff’s bar to pave the way for the litigation. One of the first lawsuits detailing Zantac’s alleged link with NDMA and cancer was filed by Yitzhak Levin, a lawyer who is a brother-in-law of Light, according to the pharma groups.

Another plaintiff’s lawyer in the Zantac litigation, Gregory Frank, was a “key player in co-ordinating Valisure’s ranitidine testing and citizen petition”, claimed the companies in the court documents.

Neither lawyer responded to a request for comment.

Light said the lab stood by its research methodology and accused pharma groups of attempting to paint Valisure as being behind a “conspiracy”.

“That is absolutely not true at all . . . We are about the science which has been proven right many times and this [screening] is impactful and needs to be better utilised within the industry,” said Light.

He said Valisure was sometimes contracted for consultancy work on behalf of plaintiffs’ lawyers and other groups in relation to its research, but the laboratory was not hired as experts in the Zantac case. Light said a relative of his brother-in-law was prescribed ranitidine, and said he had evidence that it was a problematic drug.

“I think it appropriate that I told him don’t do that [continue to allow his relative to take ranitidine] . . . He’s a litigation lawyer and he filed some of these lawsuits and, you know, that’s his business,” said Light.

Big Pharma’s criticism of the New Haven lab stands in stark contrast to the praise the lab has received from consumer advocates and members of congress for its efforts in highlighting safety concerns about Zantac and other drugs and consumer products.

Valisure is one of only a handful of independent labs in the US, which screen products to ensure they do not contain dangerous substances. Last year it published research showing the presence of benzene, a known human carcinogen, in sunscreen and body sprays leading to numerous product recalls by manufacturers, including Johnson & Johnson.

“There is kind of this big misconception that the FDA is testing everything when the reality is that, you know, the manufacturers self-report the data and the FDA is reviewing the paperwork essentially,” Light said. “There are cracks in the system that are not being well addressed.”