Phathom Pharmaceuticals is digesting news of an expanded label for its heartburn drug Voquezna.
The FDA on Wednesday afternoon approved the drug for the relief of heartburn associated with non-erosive gastroesophageal reflux disease (GERD) in adults. Reflux happens when the contents in the stomach flow back up into the esophagus. If there’s no tissue damage, the condition is considered non-erosive.
Voquezna is already approved for patients with erosive GERD, but Phathom says the non-erosive market could be even larger. The company estimates that of the 65 million US adults with GERD, 45 million have non-erosive GERD.
“Despite the various treatments available, approximately 15 million non-erosive GERD patients are currently treated with a prescription medication, yet many remain dissatisfied with their therapies and continue to suffer from heartburn symptoms,” a Phathom spokesperson told Endpoints News ahead of the approval.
Most of those patients are on a proton pump inhibitor, or a PPI, according to Martin Gilligan, Phathom’s chief commercial officer. While PPIs have long been the standard of care, Phathom believes Voquezna could offer a more rapid and durable effect.
“We’ll be really focused on patients who are on a PPI and dissatisfied,” he said.
Takeda and Frazier Healthcare Partners launched Phathom in 2019, with Takeda granting the company exclusive rights to Voquezna, or vonoprazan, in the US, Europe and Canada. Takeda markets the drug in countries in Asia and Latin America.
Voquezna is also approved in combination with other products for H. pylori infections in adults. The Voquezna Triple Pak combines vonoprazan with amoxicillin capsules and clarithromycin tablets, while the Voquezna Dual Pak combines vonoprazan and amoxicillin.
The drug hit a roadblock last year, when the FDA rejected it for erosive esophagitis, citing a “nitrosamine drug substance related impurity” detected in samples of the Voquezna Triple Pak and Dual Pak products before their launch. Nitrosamine impurities are known to increase the risk of cancer.
At that time, the FDA requested that Phathom “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.”
As a result, the company did not launch the Triple Pak and Dual Pak products until the concerns raised by the FDA were resolved. It later resubmitted a reformulated version with three months of data “to support the commercial shelf life of vonoprazan.” In October, the FDA approved post-approval supplements for the reformulated versions of the Voquezna Triple Pak and Dual Pak in H. pylori.