Novel Anaprazole-Based Quadruple Therapy Matches Rabeprazole in H. pylori Eradication Trial

Helicobacter pylori, the Gram-negative bacterium that colonizes the gastric mucosa of roughly half the world’s population, has long been one of medicine’s most stubborn adversaries. It drives chronic gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma, and gastric cancer, and major international guidelines recommend eradication therapy for all infected individuals without competing considerations. In China, a nationwide family-based survey reported an overall infection rate of 40.66 percent, rising to 43.45 percent among adults, making the search for more reliable eradication regimens a public health priority. Now, a prospective, multicenter, randomized controlled trial conducted across four hospitals in Jiangsu Province has tested whether a novel acid suppressant can match the established gold standard, and the results suggest it can.

The trial, published in Frontiers in Cellular and Infection Microbiology, compared bismuth-containing quadruple therapy built around the new proton pump inhibitor anaprazole against the classical second-generation PPI rabeprazole. Both regimens paired their respective PPI with amoxicillin, furazolidone, and colloidal bismuth pectin, given twice daily for 14 days. A total of 320 treatment-naive patients with confirmed H. pylori infection were enrolled between August 2025 and February 2026 and randomly assigned in a 1:1 ratio. Eradication was assessed by the 13C-urea breath test four weeks after therapy completion, an objective endpoint that is unlikely to be swayed by the open-label design.

The choice of antibiotics was deliberate and rooted in regional resistance data. A 2024 meta-analysis in China reported resistance rates of 70.14 percent for metronidazole, 30.72 percent for clarithromycin, and 32.98 percent for levofloxacin, while resistance to amoxicillin, tetracycline, and furazolidone remained strikingly low at 2.41, 2.53, and 1.54 percent respectively. Surveillance from Nanjing confirmed even more extreme figures, with clarithromycin resistance at 50.01 percent and metronidazole resistance at 84.45 percent, while furazolidone and amoxicillin resistance measured just 0.19 and 0.51 percent. The 2022 Chinese national clinical practice guideline explicitly endorses a bismuth quadruple regimen containing amoxicillin and furazolidone in high-resistance regions such as Jiangsu, making this combination the logical backbone for the trial.

But antibiotics alone do not clear the infection. The degree of acid suppression delivered by the PPI is a critical determinant of success, because raising intragastric pH shifts H. pylori from a dormant state into active replication, rendering it vulnerable to bactericidal agents. Amoxicillin is particularly pH-dependent: when intragastric pH rises from 5.5 to 7.5, its minimum inhibitory concentration against the bacterium drops from 0.5 to 0.06 micrograms per milliliter, dramatically amplifying its killing power. Previous work established that successful eradication with bismuth quadruple therapy requires a median 24-hour intragastric pH of 5.7 or higher. The problem is that conventional PPIs are heavily influenced by CYP2C19 genetic polymorphisms, and rapid metabolizers frequently experience treatment failure due to inadequate acid suppression.

This is where anaprazole’s pharmacology becomes compelling. The novel benzimidazole-class PPI, developed domestically in China and approved by the National Medical Products Administration for duodenal ulcers, features a dihydrofuran ring and a modified pyridine core that reshape its metabolic fate. Clearance is split between non-enzymatic pathways, accounting for 49 percent, and the cytochrome P450 system, accounting for 51 percent. Crucially, CYP3A4 is the dominant enzyme at 48.3 percent of metabolism, while CYP2C19 contributes only 3.5 percent. This profile minimizes the impact of CYP2C19 polymorphisms on acid suppression, promises more consistent interindividual efficacy, and lowers the risk of drug-drug interactions. Radiolabel studies showed total cumulative excretion of 93.20 percent, split between urinary and fecal routes, indicating high absorption and extensive metabolism that may reduce renal burden.

The trial’s non-inferiority design set a prespecified margin of minus 10 percent, a threshold the investigators justified on the grounds that both arms received identical antibiotics and bismuth, leaving the PPI as the only variable. A loss exceeding 10 percent would signal clinically inferior acid suppression, while anything within that margin would preserve the regimen’s utility. Sample size calculations assumed a 90 percent eradication rate for both groups, requiring 142 participants per arm for 80 percent power, with 160 per group enrolled to account for attrition. Randomization used block sizes of four generated by a biostatistician with SAS software, and all centers followed standardized operating procedures with the same medication batches and electronic questionnaires to ensure data consistency.

The results were remarkably tight. In the intention-to-treat analysis, eradication rates were 81.9 percent for anaprazole and 80.0 percent for rabeprazole, a difference of 1.9 percent with a confidence interval spanning minus 6.7 to 10.5 percent. Modified intention-to-treat analysis yielded 89.1 versus 88.9 percent, and per-protocol analysis showed 90.9 versus 90.0 percent. In every analysis set, the lower limit of the 95 percent confidence interval sat comfortably above the minus 10 percent non-inferiority margin, with non-inferiority P values below 0.001. The findings align with earlier phase II and III trials demonstrating anaprazole’s non-inferiority to rabeprazole in duodenal ulcer healing, suggesting its acid-suppressive potency is sufficient to support the intragastric pH target required for eradication, though the study did not directly measure gastric pH.

Safety and adherence data reinforced the picture of equivalence. Adverse events occurred in 22.50 percent of the anaprazole group versus 15.00 percent of the rabeprazole group, a numerical difference that did not reach statistical significance. Specific events including nausea and vomiting, diarrhea, abdominal bloating, rash, constipation, abdominal pain, allergic reactions, and drug fever all showed no significant between-group differences, and no serious adverse events were reported. Medication adherence exceeded 87 percent in both arms, attributed to the simple twice-daily 14-day schedule and stringent guidance. Univariate logistic regression found no significant associations between eradication outcome and sex, age, body mass index, comorbidities, smoking, alcohol use, dining habits, or family history of infection, though a history of other or unknown antibiotic use emerged as a significant risk factor for failure with an odds ratio of 3.874.

The study’s limitations are worth noting. Antimicrobial susceptibility testing was not performed, so primary versus secondary resistance could not be disentangled. The sample size was powered for non-inferiority rather than risk factor analysis, and multivariable modeling was not conducted. All four centers were located in Jiangsu Province, which may limit generalizability across China’s vast and heterogeneous resistance landscape. The open-label design, chosen for operational feasibility, may have introduced information bias in self-reported adverse events, though the objective primary endpoint mitigates this concern. A visual-assisted recall method for antibiotic history, while reducing bias compared with unaided questioning, cannot fully eliminate recall error.

Nevertheless, the trial represents the first randomized clinical evaluation of anaprazole-based quadruple therapy for H. pylori eradication, and its conclusion is clear: the anaprazole-containing regimen is non-inferior to the rabeprazole-based standard across efficacy, safety, and adherence. As antimicrobial resistance continues to erode the effectiveness of first-line antibiotics worldwide, the availability of a PPI with more stable, genotype-independent acid suppression offers a meaningful tool for clinicians. Future studies with double-blind designs, broader geographic coverage, and integrated susceptibility testing will be needed to confirm these findings and refine individualized treatment strategies, but for now, anaprazole has earned a place in the conversation about optimizing H. pylori eradication in the resistance era.

Subject of Research: Anaprazole-based versus rabeprazole-based bismuth quadruple therapy for Helicobacter pylori eradication

Article Title: Anaprazole-based versus rabeprazole-based quadruple therapy for Helicobacter pylori eradication: a prospective, multicenter, randomized controlled trial

Article References: Wang, X., Wang, H., Wang, Y., Shen, L., Li, G., Zhu, J., Li, C., Gao, J., & Zhang, Z. (2026). Anaprazole-based versus rabeprazole-based quadruple therapy for Helicobacter pylori eradication: a prospective, multicenter, randomized controlled trial. Frontiers in Cellular and Infection Microbiology, 16, Article 1972507. https://doi.org/10.3389/fcimb.2026.1972507

Image Credits: AI Generated

DOI: 10.3389/fcimb.2026.1972507

Keywords: Helicobacter pylori, anaprazole, rabeprazole, proton pump inhibitor, bismuth quadruple therapy, antibiotic resistance, furazolidone, amoxicillin, eradication therapy, randomized controlled trial, CYP2C19 polymorphism, gastric cancer