Randomised clinical trial: a dose‐ranging study of vonoprazan, a novel potassium‐competitive acid blocker, vs. lansoprazole for the treatment of erosive oesophagitis

BACKGROUND: The potassium‐competitive acid blocker vonoprazan (VPZ) has potent acid‐inhibitory effects and may offer clinical advantages over conventional therapy for acid‐related disorders. AIM: To investigate the efficacy and safety of VPZ in patients with erosive oesophagitis (EO). METHODS: In this multicentre, randomised, double‐blind, parallel‐group, dose‐ranging study, patients ≥20 years with endoscopically confirmed EO [Los Angeles (LA) grades A−D] received VPZ 5, 10, 20 or 40 mg, or lansoprazole (LPZ) 30 mg once daily for 8 weeks. The primary endpoint was the proportion of healed EO subjects as shown by endoscopy at week 4. RESULTS: A total of 732 subjects received VPZ or LPZ. The proportion of healed EO subjects at week 4 was 92.3%, 92.5%, 94.4%, 97.0% and 93.2%, respectively, with VPZ 5, 10, 20 and 40 mg and LPZ 30 mg. All VPZ doses were non‐inferior to LPZ when adjusted for baseline LA grades A/B and C/D. Among those with LA grades C/D, the proportions of healed EO subjects were 87.3%, 86.4%, 100%, 96.0% and 87.0%, respectively, with VPZ 5, 10, 20 and 40 mg and LPZ 30 mg. The incidence of adverse events was similar across the groups. CONCLUSIONS: Vonoprazan was effective and non‐inferior to LPZ in healing EO. VPZ 20 mg or higher was highly efficacious for severe EO (LA grades C/D). VPZ was associated with no safety concern during this 8‐week study, while there was a dose‐dependent increase in serum gastrin. Once‐daily VPZ 20 mg is the recommended clinical dose for treating EO.