News from the FDA/CDC

FDA puts hold on esophagitis, H. pylori drug, owing to impurity concerns


The Food and Drug Administration will not act on Phathom Pharmaceutical’s vonoprazan new drug application (NDA) for erosive esophagitis or its postapproval supplement for Helicobacter pylori until the company addresses concerns over the presence of nitrosamine impurities.

The FDA approved the company’s two vonoprazan-based treatments for H. pylori infection, Voquezna Triple Pak (vonoprazan, amoxicillin, clarithromycin) and Voquezna Dual Pak (vonoprazan, amoxicillin), last May.

The target action date of the company’s NDA for vonoprazan for the treatment of erosive esophagitis was Jan. 11, 2023.

In a news release, Phathom said it has received complete response letters from the FDA related to its erosive esophagitis NDA and H. pylori postapproval supplement.

Both letters address specifications and controls for a nitrosamine drug substance–related impurity, N-nitroso-vonoprazan (NVP), which was detected in the initial commercial launch materials of both products.

The FDA letters ask Phathom to provide “additional stability data to demonstrate that levels of the impurity previously found in vonoprazan drug product will remain at or below the daily acceptable intake throughout the proposed shelf life of the product,” Phathom said.

Phathom said it has conducted “extensive root cause investigations regarding the trace levels of the impurity since it was detected and has implemented mitigation measures to control the levels of NVP below the acceptable intake.”

The company expects to meet with the FDA before the end of March to discuss a resubmission plan and a timeline for the vonoprazan products.

Owing to the regulatory delays, Phathom said it no longer expects product launches for H. pylori or erosive esophagitis in the first quarter of 2023.

A version of this article first appeared on

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