Effectiveness and Patient Satisfaction With Zastaprazan in Real-world Practice: A Large-Scale Prospective Observational Study.

BACKGROUND/AIMS: : Gastroesophageal reflux disease (GERD) remains a prevalent condition with unmet therapeutic needs. Zastaprazan is a novel potassium-competitive acid blocker (P-CAB) with potent acid suppression, but real-world evidence is limited. This study assesses symptom improvement and patient satisfaction with zastaprazan in patients with GERD. METHODS: : This multicenter, prospective observational study enrolled adults diagnosed with GERD who received zastaprazan 20 mg daily for 4 weeks. Symptoms were assessed using the Reflux Disease Questionnaire (RDQ). The primary endpoint was the change in the mean GERD score of the RDQ. Secondary endpoints included the mean total RDQ score, patient satisfaction, compliance, and effectiveness stratified by prior medication use and diagnostic method. RESULTS: : Among 5499 participants, the mean GERD score significantly decreased from 2.07 ± 1.12 to 0.44 ± 0.63 at week 4 (change: -1.63 ± 1.07, P < 0.0001). Symptom improvement was observed in treatment-naïve patients (n = 4906, -1.64 ± 1.08, P < 0.0001) and those previously treated with histamine-2 receptor antagonists, proton pump inhibitors, or P-CABs (n = 593, -1.60 ± 1.03, P < 0.0001). The switching group (within 2 days) also showed significant improvement (n = 304, -1.53 ± 1.05, P < 0.0001). Over 90% reported satisfaction, compliance was 93%, and only 2.25% required concomitant medications. Safety was excellent, with only 3 cases of mild adverse reactions (0.05%) and no serious events. CONCLUSION: Zastaprazan was associated with clinically meaningful symptom improvement in GERD patients, regardless of prior medication history, including proton pump inhibitors or other P-CABs, with high patient satisfaction, and a favorable safety profile.