Many months after Phathom Pharmaceuticals won FDA approval for vonoprazan as part of two combinations to treat Helicobacter pylori infection, the drugmaker is still unable to launch the product.
Back in the summer of 2022, testing found "trace levels" of a suspected carcinogen in the treatment. Wednesday, Phathom revealed the FDA won't act on the drug's current application in erosive esophagitis by its target decision date of Jan. 11.
Instead, Phathom is working to generate stability data showing that the levels of the suspected carcinogen, N-nitroso-vonoprazan, don't increase beyond acceptable levels during the product's shelf life. Previously, the FDA agreed that an "acceptable daily intake limit" for N-nitroso-vonoprazan is 96 nanograms per day, according to the press release.
With stability testing underway, the company "no longer expects product launches for H. pylori or erosive esophagitis in the first quarter of 2023."
While Phathom is "disappointed" to not launch its product this quarter, it's "otherwise very pleased" with the FDA interactions, CEO Terrie Curran said in the release. As the company works to meet the FDA's stability requirements, Phathom is "maintaining our launch-readiness position," Curran added.
Last May, the Takeda spinout won FDA approval for vonoprazan as a component in two combinations—Voquezna Dual Pak and Voquezna Triple Pak—to treat H. pylori infection.
Shortly after those approvals, the company in August revealed that nitrosamine testing picked up "trace levels" of the impurity in the newly approved product. At the time, the drugmaker said it was working to make the drug available "as soon as possible" and expected a launch in multiple uses in the first quarter of 2023.
Issues with nitrosamines, which are found in everyday items such as water and food, have haunted a large number of drugmakers in recent years. Lab tests have determined that long-term nitrosamine exposure can cause cancer.
Ever since testing found the compounds in popular drugs, the contamination saga has triggered large recalls, shortages and product pulls across the industry.