The millions of people who regularly suffer from heartburn now have a new FDA-approved treatment option, a Phathom Pharmaceuticals drug with a different mechanism of action than older medications that have been the standard of care for decades.
Phathom drug vonoprazan, brand name Voquezna, is a treatment for gastroesophageal reflux disease, a disorder in which stomach acids flow through a malfunctioning valve and back into the esophagus. The FDA on Thursday approved the Phathom drug as a treatment for non-erosive gastroesophageal reflux disease (GERD) in adults, a form of the chronic condition characterized by the absence of damage to the lining of the esophagus. It’s the most common form of GERD. The new regulatory decision expands on Voquezna’s initial GERD approval last November, which covered use of the product for treating patients who develop damage to the esophagus.
According to Florham Park, New Jersey-based Phathom, about 15 million of the 45 million U.S. adults with non-erosive GERD are treated with a prescription medication. Despite those medications, many of patients continue to experience heartburn symptoms throughout the day and during the night. The longstanding treatments for GERD include proton pump inhibitors, an older class of drugs that work by reducing stomach acid production. Voquezna takes a different approach to reducing stomach acids by blocking an enzyme system involved in secretion of gastric acids. The Phathom drug is a potassium-competitive acid blocker, or PCAB.
Voquezna’s latest approval is based on the results from a Phase 3 study that enrolled 772 adults who experienced four or more days of heartburn per week. Results from the four-week study showed that daily treatment with the drug significantly reduced heartburn compared to the placebo group. The most common adverse reactions reported in the study include abdominal pain, constipation, diarrhea, nausea, and urinary tract infection. Upper respiratory tract infection and sinusitis were also reported in patients who received the study drug in the 20-week extension phase of the clinical trial. The trial results were published in May in the journal Clinical Gastroenterology and Hepatology.
“For decades GERD sufferers had no new class of treatment to turn to in the U.S.,” Phathom President and CEO Terrie Curran said in a prepared statement. “This approval provides patients and healthcare providers with immediate access to the first and only FDA-approved treatment of its kind, from a new class of acid suppression therapy, and the power to help provide complete 24-hour heartburn-free days and nights.”
Vonoprazan was initially developed by Takeda Pharmaceutical, which has commercialized the drug in Asia, Latin America, and Russia. In addition to GERD, the drug is approved, in combination with antibiotics, as a treatment for Helicobacter pylori infection, a type of gastrointestinal infection. In 2019, Takeda and Frazier Healthcare Partners teamed up to form gastrointestinal diseases-focused Phathom. The new company licensed rights to develop and commercialize vonoprazan in the U.S., Europe, and Canada and proceeded to raise $181 million in an IPO. According to the license agreement, Phathom must pay Takeda royalties as well as sales-based milestones that could reach up to $250 million.
In 2022, Phathom won FDA approval for vonoprazan as a treatment for H. pylori infection. The company is exploring additional indications for the drug beyond GERD. In its financial reports, Phathom says a Phase 2 clinical trial is expected to begin later this year evaluating the drug in eosinophilic esophagitis (EoE), an inflammatory condition affecting the esophagus. Corticosteroids are a standard treatment to reduce the inflammation that develops in this disorder. EoE is among the approved indications for the blockbuster Sanofi and Regeneron Pharmaceuticals immunology drug Dupixent. The newest EoE drug is Takeda’s Eohilia, a twice-daily oral suspension formulation of budesonide, a corticosteroid. Eohelia received its FDA approval earlier this year.
Photo: Phathom Pharmaceuticals