Will the FDA investigate GSK over Zantac? Rosa DeLauro wants to know

Following a report last month that GSK kept quiet for more than four decades about the presence of a potential carcinogen in heartburn drug Zantac, Rep. Rosa DeLauro, D-Connecticut, wants to know whether the FDA plans to investigate.

DeLauro, the ranking member of the House Appropriations Committee, has sent a letter to FDA Commissioner Robert Califf, M.D., asking how the agency will respond, according to Bloomberg. The news outlet has seen the letter, which has yet to be posted to DeLauro's website.

An FDA spokesperson said the agency has received the letter and will respond directly to DeLauro.

"The FDA continues its ongoing review, surveillance, compliance and pharmaceutical quality efforts, and will continue to work with drug manufacturers to ensure safe, effective and high-quality drugs for the American public," the regulator said in a statement.

With GSK already facing tens of thousands of lawsuits alleging Zantac causes cancer, the company was dealt another blow three weeks ago when Bloomberg Businessweek reported that GSK’s own scientists warned of the potential cancer-causing impurity.

GSK responded to the Bloomberg Businessweek story by saying the article "presents an incomplete and biased presentation of the facts surrounding the Zantac (ranitidine) litigation."

"Patient safety is the highest priority for GSK, and the company categorically refutes any allegation of having covered up data regarding the safety of ranitidine," a company spokesperson said.

The FDA took the carcinogen issue into account when it approved Zantac (ranitidine) in 1983, Bloomberg Businessweek reported. But it resurfaced in 2019 when an online pharmacy found high levels of a likely carcinogen in Zantac and its generics. Recalls followed, and the FDA pulled the drug from the market in 2020.

In doing so, the FDA said the amount of the likely carcinogen in the drug, N-Nitrosodimethylamine (NDMA), increases "even under normal storage conditions." The problem is exacerbated by storage at higher temperatures, the FDA said.

GSK's leadership was warned on several occasions about the issue, but the company opted against making any changes to its supply chain or storage procedures, Bloomberg Businessweek reported.

Meanwhile, in the sprawling federal litigation over Zantac, a judge in Florida sided with GSK and other companies late last year. The judge concluded that the plaintiff’s experts utilized “unreliable methodologies” to reach their conclusions and tossed tens of thousands of claims.

Many other companies are still involved in state lawsuits. GSK sold its rights to the drug to Boehringer Ingelheim, which later shuttled it off to Sanofi in an asset swap. Other companies have sold generic versions of the drug as well.

In her 32 years in office, DeLauro has kept a close watch on the FDA. In 2019, when Zantac first came under scrutiny, she urged the regulator for a recall.

It was a company from her district, Valisure, that detected NDMA in Zantac. GSK has criticized the lab’s testing methods. It also has said there is “no consistent or reliable evidence” that Zantac causes cancer.