Understanding FDA Approval of Vonoprazan-Based Therapies for Helicobacter Pylori

Pharmacy Times (5/4/22): FDA Approves Pair of Vonoprazan Treatments for Helicobacter Pylori Infection

“The (FDA) has approved 2 vonoprazan-based medications for the treatment of Helicobacter pylori (H. pylori) infection.

Phathom Pharmaceuticals announced the approvals of both the Voquezna Triple Pak (vonoprazan, amoxicillin, clarithromycin) and Voquezna Dual Pak (vonoprazan, amoxicillin) based on positive safety and efficacy data from the phase 3 PHALCON-HP trial.”

WD Chey et al. Gastroenterol 2022; 163: 608-619. Open Access! Vonoprazan Triple and Dual Therapy for Helicobacter pylori Infection in the United States and Europe: Randomized Clinical Trial

Key findings from this randomized, controlled trial with treatment-naive 1046 adults:

  • In all patients, vonoprazan triple and dual therapy were superior to lansoprazole triple therapy (80.8% and 77.2%, respectively, vs 68.5% (both superior)
  • In patients with clarithromycin resistance, vonoprazan triple therapy was effective in 65.8%, dual therapy in 69.6%, vs lansoprazole triple therapy 31.9% (both superior)
  • Vonoprazan increases intragastric pH rapidly “and maintains it to a greater degree than PPI; this has been associated with higher H pylori eradication rates” (in prior studies as well)

The associated editorial: CA Fallone (Open Access!) The Current Role of Vonoprazan in Helicobacter pylori Treatment

Based on this new information, the author proposes the treatment algorithm below and notes that “the role of increased acid suppression by PPI substitution with vonoprazan should be examined in other H pylori regimens.” The author favors bismuth quadruple therapy in those with clarithromycin resistance as non-bismuth quadruple therapy utilizes an unnecessary antibiotic (clarithromycin).

Other points:

  • Metronidazole resistance is fairly common, but bismuth quadruple therapy can overcome much of the metronidazole resistance
  • Levofloxacin resistance is quite high in certain regions and should only be used with caution, given recent warnings from the US Food and Drug Administration of aortic rupture in susceptible individuals
  • Rifabutin can cause some bone marrow suppression

My take: With the more widespread availability of susceptiblity testing (beyond clarithromycin), I anticipate more targeted treatments. At the same time, vonoprazan-based treatments are likely to be important in increasing eradication rates.

Related blog posts:

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