Sitafloxacin-based third-line rescue regimens for Helicobacter pylori infection in Japan

Antibacterial Mechanisms and Clinical Impact of Sitafloxacin

Sitafloxacin is a 4th generation fluoroquinolone antibiotic with broad activity against a wide range of Gram-negative and Gram-positive bacteria. It is approved in Japan and used to treat pneumonia and urinary tract infections (UTIs) as well as other upper and lower respiratory infections, genitourinary infections, oral infections and otitis media. Compared to other fluoroquinolones, sitafloxacin displays a low minimal inhibitory concentration (MIC) for many bacterial species but also activity against anaerobes, intracellular bacteria, and persisters. Furthermore, it has also shown strong activity against biofilms of P. aeruginosa and S. aureus in vitro, which was recently validated in vivo with murine models of S. aureus implant-associated bone infection. Although limited in scale at present, the published literature supports the further evaluation of sitafloxacin in implant-related infections and other biofilm-related infections. The aim of this review is to summarize the chemical-positioning-based mechanisms, activity, resistance profile, and future clinical potential of sitafloxacin.

Antibiotic Susceptibility-Guided Concomitant Therapy Regimen with Vonoprazan, High-Dose Amoxicillin, Clarithromycin, and Metronidazole for Helicobacter pylori Eradication as Fourth-Line Regimen: An Interventional Study

This is the first registered intervention study for vonoprazan, high-dose amoxicillin, clarithromycin, and metronidazole 14-day concomitant therapy based on a susceptibility test of Helicobacter pylori. We conducted this study as a fourth-line rescue regimen in Japan.

METHODS

Twenty patients who underwent three rounds of eradication therapies (first- or second-line 7-day triple therapy consisting of amoxicillin and clarithromycin, or metronidazole- and sitafloxacin-based third-line therapy) and had failed eradication based on a urea breath test or fecal antigen test were recruited. All patients underwent endoscopic examination and culture tests before starting eradication therapy. The intervention was concomitant therapy consisting of vonoprazan 20 mg bid, amoxicillin 500 mg qid, clarithromycin 400 mg bid, and metronidazole 250 mg bid for 14 days, which were modified based on the susceptibility test, and the resistant drugs were removed from the regimen. Patients with negative culture results were treated with quadruple therapy. The primary outcome was the eradication rate (UMIN000025765, jRCTs 031180208).

RESULTS

The eradication rate of susceptibility-testing-based fourth-line eradication therapy was 63.2% (95%CI: 38.4-83.7%) in intent-to-treat analysis and 70.6% (95%CI: 44.0-89.7%) in per-protocol analysis. Thirteen patients received quadruple therapy, with eradication rates of 61.5% and 75.0%, respectively. No serious adverse events were reported.

CONCLUSIONS

This vonoprazan-based concomitant therapy modified by the susceptibility test is a potential option as fourth-line eradication after first-line clarithromycin-based 7-day triple, second-line metronidazole-based 7-day triple, and third-line sitafloxacin-based 7-day triple therapy failure.

Third-line and rescue therapy for refractory Helicobacter pylori infection: A systematic review

BACKGROUND

Due to increasing resistance rates of Helicobacter pylori (H. pylori) to different antibiotics, failures in eradication therapies are becoming more frequent. Even though eradication criteria and treatment algorithms for first-line and second-line therapy against H. pylori infection are well-established, there is no clear recommendation for third-line and rescue therapy in refractory H. pylori infection.

AIM

To perform a systematic review evaluating the efficacy and safety of rescue therapies against refractory H. pylori infection.

METHODS

A systematic search of available rescue treatments for refractory H. pylori infection was conducted on the National Library of Medicine’s PubMed search platform based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized or non-randomized clinical trials and observational studies evaluating the effectiveness of H. pylori infection rescue therapies were included.

RESULTS

Twenty-eight studies were included in the analysis of mean eradication rates as rescue therapy, and 21 of these were selected for analysis of mean eradication rate as third-line treatment. For rifabutin-, sitafloxacin-, levofloxacin-, or metronidazole-based triple-therapy as third-line treatment, mean eradication rates of 81.6% and 84.4%, 79.4% and 81.5%, 55.7% and 60.6%, and 62.0% and 63.0% were found in intention-to-treat (ITT) and per-protocol (PP) analysis, respectively. For third-line quadruple therapy, mean eradication rates of 69.2% and 72.1% were found for bismuth quadruple therapy (BQT), 88.9% and 90.9% for bismuth quadruple therapy, three-in-one, Pylera^® (BQT-Pylera), and 61.3% and 64.2% for non-BQT) in ITT and PP analysis, respectively. For rifabutin-, sitafloxacin-, levofloxacin-, or metronidazole-based triple therapy as rescue therapy, mean eradication rates of 75.4% and 78.8%, 79.4 and 81.5%, 55.7% and 60.6%, and 62.0% and 63.0% were found in ITT and PP analysis, respectively. For quadruple therapy as rescue treatment, mean eradication rates of 76.7% and 79.2% for BQT, 84.9% and 87.8% for BQT-Pylera, and 61.3% and 64.2% for non-BQT were found in ITT and PP analysis, respectively. For susceptibility-guided therapy, mean eradication rates as third-line and rescue treatment were 75.0% in ITT and 79.2% in PP analysis.

CONCLUSION

We recommend sitafloxacin-based triple therapy containing vonoprazan in regions with low macrolide resistance profile. In regions with known resistance to macrolides or unavailability of bismuth, rifabutin-based triple therapy is recommended.

Therapeutic Potential of Sitafloxacin as a New Drug Candidate for Helicobacter Eradication in Korea: An In Vitro Culture-Based Study

Background: Increased prevalence of antibiotic resistance to Helicobacter pylori (H. pylori) infection worldwide has driven the search for a new therapeutic candidate. Recently, sitafloxacin, a novel 4-quinolone agent, has emerged as a new therapeutic option for H. pylori eradication, in Japan. However, data on its efficacy for H. pylori eradication in Korea are limited. Therefore, we aimed to investigate the therapeutic potential of sitafloxacin as a first-line treatment for patients with Helicobacter infection through gastric tissue culture-based studies. Materials and Methods: We prospectively enrolled treatment-naïve patients with H. pylori infection who visited the Gil Medical Center between March 2015 and March 2018. After obtaining written informed consent from patients, a total of 121 H. pylori strains were collected. We tested the susceptibility of these strains to sitafloxacin, and other antibiotics for Helicobacter eradication, including clarithromycin (CLR), metronidazole (MTZ), amoxicillin (AMX), tetracycline (TET), levofloxacin (LEV), and ciprofloxacin (CIP) using the agar dilution technique. The minimum inhibitory concentration (MIC) of these antibiotics against H. pylori strains were determined. Results: None of the H. pylori strains obtained were resistant to sitafloxacin (MIC > 1, n = 0), while other conventional eradication drugs including CLR, MTZ, AMX, and TET showed 24.8% (n = 30), 30.6% (n = 37), 5.0% (n = 6), and 0.8% (n = 1) resistance, respectively. Compared to the resistance rates of other quinolones (LEV [36.4%, n = 44] and CIP [37.2%, n = 45]), sitafloxacin showed the best antibiotic performance against Helicobacter strains (0%, n = 0). Furthermore, sitafloxacin also inhibited the growth of 14 H. pylori strains (12.4%), which were resistant to both of clarithromycin, and metronidazole, and 27 strains (22.3%) with multidrug resistance. Conclusions: Sitafloxacin might be a new promising candidate for Helicobacter eradication where antibiotic resistance for Helicobacter is an emerging medical burden, such as in Korea.

Sitafloxacin for Third-Line Helicobacter pylori Eradication: A Systematic Review

BACKGROUND AND AIM

Sitafloxacin-based therapy is a potent candidate for third-line Helicobacter pylori eradication treatment. In this systematic review, we summarise current reports with sitafloxacin-based therapy as a third-line treatment.

METHODS

Clinical studies were systematically searched using PubMed, Cochrane library, Web of Science, and the Igaku-Chuo-Zasshi database. We combined data from clinical studies using a random-effects model and calculated pooled event rates, 95% confidence intervals (CIs), and the pooled odds ratio (OR).

RESULTS

We included twelve clinical studies in the present systematic review. The mean eradication rate for 7-day regimens of either PPI (proton pump inhibitor) or vonoprazan-sitafloxacin-amoxicillin was 80.6% (95% CI, 75.2-85.0). The vonoprazan-sitafloxacin-amoxicillin regimen was significantly superior to the PPI-sitafloxacin-amoxicillin regimen (pooled OR of successful eradication: 6.00; 95% CI: 2.25-15.98, p < 0.001). The PPI-sitafloxacin-amoxicillin regimen was comparable with PPI-sitafloxacin-metronidazole regimens (pooled OR: 1.06; 95% CI: 0.55-2.07, p = 0.86).

CONCLUSIONS

Although the 7-day regimen composed of vonoprazan, sitafloxacin, and amoxicillin is a good option as the third-line Helicobacter pylori eradication treatment in Japan, the extension of treatment duration should be considered to further improve the eradication rate. Considering the safety concern of fluoroquinolones, sitafloxcin should be used after confirming drug susceptibility.

Evidence-based clinical practice guidelines for peptic ulcer disease 2020

The Japanese Society of Gastroenterology (JSGE) revised the third edition of evidence-based clinical practice guidelines for peptic ulcer disease in 2020 and created an English version. The revised guidelines consist of nine items: epidemiology, hemorrhagic gastric and duodenal ulcers, Helicobacter pylori (H. pylori) eradication therapy, non-eradication therapy, drug-induced ulcers, non-H. pylori, and nonsteroidal anti-inflammatory drug (NSAID) ulcers, remnant gastric ulcers, surgical treatment, and conservative therapy for perforation and stenosis. Therapeutic algorithms for the treatment of peptic ulcers differ based on ulcer complications. In patients with NSAID-induced ulcers, NSAIDs are discontinued and anti-ulcer therapy is administered. If NSAIDs cannot be discontinued, the ulcer is treated with proton pump inhibitors (PPIs). Vonoprazan (VPZ) with antibiotics is recommended as the first-line treatment for H. pylori eradication, and PPIs or VPZ with antibiotics is recommended as a second-line therapy. Patients who do not use NSAIDs and are H. pylori negative are considered to have idiopathic peptic ulcers. Algorithms for the prevention of NSAID- and low-dose aspirin (LDA)-related ulcers are presented in this guideline. These algorithms differ based on the concomitant use of LDA or NSAIDs and ulcer history or hemorrhagic ulcer history. In patients with a history of ulcers receiving NSAID therapy, PPIs with or without celecoxib are recommended and the administration of VPZ is suggested for the prevention of ulcer recurrence. In patients with a history of ulcers receiving LDA therapy, PPIs or VPZ are recommended and the administration of a histamine 2-receptor antagonist is suggested for the prevention of ulcer recurrence.

Treatment of Refractory Helicobacter pylori Infection-Tailored or Empirical Therapy

The treatment of refractory Helicobacter pylori remains challenging in clinical practice. Factors that should be considered in the treatment of refractory H. pylori infection include treatment length, dosage of antibiotics and proton pump inhibitors (PPIs), number of drugs, and the selection of appropriate antibiotics. Extending the treatment length of triple therapy and non-bismuth quadruple therapy to 14 days may increase the eradication rate compared with a shorter period (7 or 10 days). The use of a higher dose of PPIs or vonoprazan may also increase the efficacy of triple therapy. Four-drug therapy, including bismuth or non-bismuth quadruple therapies, usually achieve higher eradication rates than triple therapy. The addition of bismuth or metronidazole to levofloxacin-amoxicillin-PPI therapy may also increase the eradication rate. Therefore, four-drug therapies containing a higher dose of PPIs for 14 days are recommended in the third-line treatment setting for refractory H. pylori infection. The selection of appropriate antibiotics may be guided by susceptibility testing or empirically by medication history. Tailored therapy guided by susceptibility testing or genotypic resistance is recommended whenever possible. However, properly designed empirical therapy based on prior medication history (i.e., avoid the reuse of clarithromycin or levofloxacin empirically) is an acceptable alternative to tailored therapy after considering accessibility, cost, and the preference of the patient.

Antofloxacin-based bismuth quadruple therapy is safe and effective in Helicobacter pylori eradication: A prospective, open-label, randomized trial

BACKGROUND AND STUDY AIMS

The present study was designed to evaluate the safety, efficacy, and tolerability of antofloxacin-based bismuth quadruple therapy in Chinese patients with Helicobacter pylori infection.

PATIENTS AND METHODS

Total 290 patients with H. pylori infection were randomly and equally divided into two groups as per different bismuth quadruple therapies for 14 d: colloidal bismuth pectin 200 mg thrice a day, lansoprazole 30 mg twice a day, amoxicillin 1 g twice a day, and antofloxacin 200 mg once a day (ACLA group) or levofloxacin 500 mg once a day (LCLA group). Eradication was assessed with ¹³C-urea breath test 6 wk after treatment completion; the primary endpoint was the eradication rate by intention-to-treat (ITT) and per-protocol (PP) analyses. The minimum inhibitory concentration was measured with the PDM epsilometer test to assess the susceptibility of H. pylori strains on gastric biopsy specimens to antofloxacin and levofloxacin.

RESULTS

The eradication rates of H. pylori in the ACLA group were 93.8% and 97.8% for the ITT and PP analysis, respectively; these rates were significantly higher than those in the LCLA group, at 86.2% and 92.6%, respectively (p = 0.031 and 0.041, respectively). The total incidence of adverse events during the eradication therapy did not significantly differ between the ACLA and LCLA groups (31.7% vs. 37.9%%, p = 0.267), and the two groups displayed similar severity of adverse events (p = 0.156) and compliance rate (100% by ACLA vs. 97.8% by LCLA, p = 0.080). The eradication rate with the antofloxacin susceptible strains in the ACLA group was significantly higher than that with the resistant strains (99.2% vs. 66.7%, p = 0.045). Moreover, the eradication rate with the levofloxacin susceptible strains in the LCLA group was significantly higher than that with the resistant strains (95.3% vs. 80.0%, p = 0.013).

CONCLUSION

Antofloxacin is safe and effective for H. pylori eradication. Antofloxacin-based bismuth quadruple therapy could be an alternative treatment for H. pylori eradication.

Helicobacter pylori rescue treatment with vonoprazan, metronidazole, and sitafloxacin in the presence of penicillin allergy

Background and Aim

To assess the efficacy and safety of 7‐day Helicobacter pylori rescue treatment consisting of a vonoprazan (VPZ), metronidazole (MNZ), and sitafloxacin (STFX) regimen (VPZ‐MNZ‐STFX therapy) in patients with penicillin allergy.

Methods

This was a registered prospective intervention study. Patients with penicillin allergy who were diagnosed with H. pylori infection and had a history of H. pylori eradication were eligible for inclusion. Seventeen patients were prospectively treated with VPZ 20 mg bid, MNZ 250 mg bid, and STFX 100 mg bid for 7 days. Safety was evaluated using a questionnaire on adverse effects.

Results

The eradication rate of 7‐day VPZ‐MNZ‐SFTX therapy was 88.2% (95% confidence interval: 63.6–98.5%; n = 17) in both intention‐to‐treat and per‐protocol analyses. On the questionnaire, 25% of patients reported experiencing diarrhea, with a score of 2 or 3. All patients undergoing VPZ‐MNZ‐STFX therapy completed 100% of their medication course.

Conclusion

Rescue H. pylori eradication with VPZ‐MNZ‐STFX therapy is effective and well tolerated in patients with penicillin allergy (UMIN000016335, jRCTs031180133).

Effect of Antibiotic Susceptibility and CYP3A4/5 and CYP2C19 Genotype on the Outcome of Vonoprazan-Containing Helicobacter pylori Eradication Therapy

Background: Helicobacter pylori eradication containing the potassium-competitive acid blocker, vonoprazan, achieves a higher eradication rate than therapy with proton pump inhibitors (PPIs). Because vonoprazan is mainly metabolized by CYP3A4/5, CYP genotype may affect the eradication rate. We investigated the influence of antibiotic susceptibility and CYP3A4/5 and CYP2C19 genotypes on the eradication rates. Methods: A total of 307 Japanese who were genotyped for CYP3A4 *1/*22, CYP3A5 *1/*3 and CYP2C19 *1/*2/*3/*17, and investigated for susceptibility to antimicrobial agents, received vonoprazan-containing regimens: (1) With amoxicillin and clarithromycin as the first-line treatment; (2) with amoxicillin and metronidazole as the second-line treatment; or (3) with amoxicillin and sitafloxacin as the third-line treatment. Results: The eradication rate was 84.5% (95% confidence interval [CI]: 78.9–89.1%) using first-line, 92.6% (95% CI: 82.1–97.9%) using second-line and 87.5% (95% CI: 73.1–95.8%) using third-line treatment. Infection with clarithromycin-resistant strains was a predictive factor for failed eradication (odds ratio: 5.788, 95% CI: 1.916–17.485, p = 0.002) in multivariate analysis. No significant differences were observed in the eradication rate of regimens among CYP3A4, CYP3A5 and CYP2C19 genotypes. Conclusions: Genotyping for CYP3A4 *1/*22, CYP3A5 *1/*3 and CYP2C19 *1/*2/*3/*17 before vonoprazan-containing eradication treatment may not be useful for predicting clinical outcomes.

Update on quinolone-containing rescue therapies for Helicobacter pylori infection

Third generation of quinolones, such as levofloxacin and moxifloxacin, -containing regimens are often used in second-line or rescue treatment of Helicobacter pylori infection. However, the increasing antibiotic resistance to quinolones affects the efficacies of quinolones-containing therapies in recent years. Therefore, there is a need to enhance the effectiveness of quinolones-containing therapies. Sitafloxacin, a fourth-generation quinolone, and vonoprazan, a novel potassium-competitive acid blocker, are now available as more effective treatment options. The aim of this paper is to summarize the current evidence of quinolone-containing therapies in rescue treatments, and to discuss the importance of drug sensitivity tests or analysis of gyrA mutation before treatments.

Randomized trial of vonoprazan-based versus proton-pump inhibitor-based third-line triple therapy with sitafloxacin for Helicobacter pylori

BACKGROUND AND AIM

This was a prospective, randomized trial of the efficacy of vonoprazan-based and proton-pump inhibitor-based 7-day triple regimens with amoxicillin and sitafloxacin as a third-line therapy for eradicating Helicobacter pylori after failure of clarithromycin-based and metronidazole-based first-line and second-line therapy.

METHODS

We enrolled 63 patients positive for H. pylori in whom first-line and second-line regimens for eradicating failed. Patients were randomized to the V-AS group (vonoprazan 20-mg bid, amoxicillin 750-mg bid, and sitafloxacin 100-mg bid for 7 days) or PPI-AS group (esomeprazole 20-mg bid, rabeprazole 10-mg bid, or lansoprazole 30-mg bid; amoxicillin 750-mg bid; and sitafloxacin 100-mg bid for 7 days). We assessed the outcome of eradication therapy using the ¹³ C-urea breath test. We evaluated safety using patient questionnaires. This study was registered in the UMIN Clinical Trials Registry (UMIN000016336).

RESULTS

The intention-to-treat and per-protocol eradication rates of V-AS were 75.8% (95% confidence interval [CI]: 57.7-88.9%) and 83.3% (95% CI: 65.3-94.4%), respectively. The respective eradication rates of PPI-AS were 53.3% (95% CI: 34.3-71.7%) and 57.1% (95% CI: 37.2-75.5%). In per-protocol analyses, the eradication rate of the V-AS group was significantly higher than that of the PPI-AS group (P = 0.043); however, no significant differences were observed in intention-to-treat analyses (P = 0.071). Questionnaire scores did not differ significantly between the groups.

CONCLUSIONS

The findings suggest that 7-day triple therapy with vonoprazan, amoxicillin, and sitafloxacin is more effective than proton-pump inhibitor, amoxicillin, and sitafloxacin as a third-line regimen for eradicating H. pylori.

Five alternative Helicobacter pylori antibiotics to counter high levofloxacin and metronidazole resistance in the Dominican Republic

The prevalence of Helicobacter pylori resistance to levofloxacin and metronidazole was high in the Dominican Republic. We used two-fold agar dilution method to determine the minimum inhibitory concentration of five alternative antibiotics in 63 Dominican strains. We also assessed the genetic mutations associated with the antibiotic resistance using next-generation sequencing. We revealed that all 63 strains were sensitive towards sitafloxacin, furazolidone, and rifabutin. In contrast, the prevalence of rifaximin and garenoxacin resistance were high (82.5% and 34.9%, respectively). Patients more than or equal to 60 years old had the highest risk of double-antibiotic resistance (7/9, 77.8%, OR = 31.5, P = 0.009) and garenoxacin resistances (8/9, 88.9%, OR = 45.33, P = 0.002) with an increasing risk simultaneously by age (P = 0.004, r = 0.357). Almost all rifaximin resistant strains possessed multiple mutations with more than three mutations within rpoB including the most frequent novel mutations of S352L, I2726L, and V2465A. There was a significant association between vacA genotype and rifaximin resistance (P = 0.042). Among 23 levofloxacin-resistant strains, 82.6% (19/23, P <0.001) were also resistant to garenoxacin, and 39.1% (9/23) had a high minimal inhibitory concentration ≥8 μg/mL with positive trend correlation (P = <0.001, r = 0.84). Among 19 garenoxacin resistant strains, 16 (84.2%) contained mutations at D91 and N87 of gyrA. In conclusion, sitafloxacin, rifabutin, and furazolidone might be considered as alternative antibiotics to be included in H. pylori eradication regimen in regions with high prevalence of levofloxacin and metronidazole resistance, such as the Dominican Republic.

Role of Vonoprazan in Helicobacter pylori Eradication Therapy in Japan

Complete eradication of Helicobacter pylori is important for preventing the development of gastric cancer. The outcome of H. pylori eradication therapy is mainly dependent on bacterial susceptibility to antimicrobial agents and potent neutralization of intragastric pH across 24 h, especially when using acid-sensitive antimicrobial agents such as clarithromycin (CLR), amoxicillin and sitafloxacin. However, conventional regimens comprising twice-daily doses (bid) of proton pump inhibitors (PPIs) are generally insufficient for maintaining the required gastric acid secretion for 24 h for successful eradication in all H. pylori-positive patients. Further, the increasing prevalence of CLR-resistant strains with each year has led to a decrease in eradication rates of first-line PPI- and CLR-containing therapies in developed countries, including Japan. In 2015, the potassium-competitive acid blocker vonoprazan (VPZ) became clinically available in Japan. VPZ competitively inhibits H⁺/K⁺-ATPase activity more potently than PPIs (e.g., omeprazole, lansoprazole, rabeprazole, pantoprazole, and esomeprazole). Therefore, a VPZ-containing H. pylori eradication regimen is expected to increase the eradication rate compared with conventional regimens containing a standard dose of PPI. In fact, a recent meta-analysis that investigated the efficacy of first-line eradication therapy showed that a VPZ-containing regimen achieved a higher eradication rate than a PPI-containing regimen. While the Maastricht V/Florence Consensus Report recommends selecting a bismuth or non-bismuth quadruple therapy and concomitant therapy for patients living in areas with high prevalence of CLR resistance, a VPZ-containing regimen demonstrates effectiveness for patients infected with CLR-resistant strains and patients living in areas where the prevalence of CLR-resistant strains is >15%. As a next step, studies are needed to determine the factors affecting the clinical outcome of VPZ-containing therapy and optimal VPZ-containing alternative regimens for tailored treatments. In this review, we summarize the advantages and disadvantages of VPZ in H. pylori eradication therapy.

In Vitro Activity of Diphenyleneiodonium toward Multidrug-Resistant Helicobacter pylori Strains

Background/Aims

The increased resistance of Helicobacter pylori to antibiotics has increased the need to develop new treatments for this bacterium. The aim of our study was to identify new drugs with anti-H. pylori activity.

Methods

We screened a small molecule library—the library of pharmacologically active compounds (LOPAC), which includes 1,280 pharmacologically active compounds—to identify inhibitors of H. pylori growth. The minimal inhibitory concentrations (MICs) of antibiotics against multidrug-resistant H. pylori strains were determined using the agar dilution method.

Results

We identified diphenyleneiodonium (DPI) as a novel anti-H. pylori agent. The MIC values for DPI were <0.03 μg/mL against all tested H. pylori strains. DPI also exhibited strong antibacterial activity against common gram-negative and gram-positive pathogenic bacteria.

Conclusions

DPI may be a candidate anti-H. pylori drug for future development.

First-Line Helicobacter pylori Eradication with Vonoprazan, Clarithromycin, and Metronidazole in Patients Allergic to Penicillin

AIM

To assess the efficacy of 7-day first-line Helicobacter pylori eradication with vonoprazan (VPZ), clarithromycin (CAM), and metronidazole (MNZ) in patients with penicillin allergy.

METHODS

Patients with penicillin allergy, diagnosed with Helicobacter pylori infection and did not have history of Helicobacter pylori eradication, were eligible for the study. Twenty patients were prospectively treated with 20 mg VPZ twice daily, 200 or 400 mg CAM twice daily, and 250 mg MNZ twice daily for 7 days. We also collected the data from 30 patients retrospectively treated with proton pump inhibitor (PPI), CAM, and MNZ. Safety was evaluated in patients completing an adverse effect questionnaire.

RESULTS

Both the intention-to-treat and per-protocol effectiveness of VPZ-based eradication were 100% (95% CI: 86.1-100%; n = 20). The eradication rates of PPI-based regimen were 83.3% (95% CI: 65.3-94.4%) in the ITT and 82.7% (95% CI: 64.2-94.2%) in the PP analyses. Abdominal fullness was more frequent in VCM compared to PCM. However, all patients with VCM regimen had taken 100% of their course of medication.

CONCLUSION

Triple therapy with VPZ, CAM, and MNZ is well tolerated and effective for eradicating Helicobacter pylori in patients allergic to penicillin. This study was registered in the UMIN Clinical Trials Registry as UMIN000016335.

Four-times-daily Dosing of Rabeprazole with Sitafloxacin, High-Dose Amoxicillin, or Both for Metronidazole-Resistant Infection with Helicobacter pylori in Japan

BACKGROUND

The bacterial resistance of Helicobacter pylori to antimicrobial agents such as clarithromycin and metronidazole has been increasing worldwide, leading to the failure of eradication treatment. Here, we present an eradication regimen consisting of four-times-daily dosing (q.i.d.) of rabeprazole with potent acid inhibition.

AIM

To investigate the efficacy of eradication therapy with rabeprazole q.i.d. and amoxicillin or sitafloxacin in Japanese infected with a metronidazole-resistant strain.

METHODS

We retrospectively investigated the efficacy of eradication regimens with rabeprazole q.i.d. for 7 days in 111 Japanese pooled patients infected with a metronidazole-resistant strain of H. pylori at Hamamatsu University School of Medicine Hospital or the Shiga University of Medical Science Hospital: 1, with sitafloxacin 100 mg twice daily (b.i.d.) (n = 82); 2, with amoxicillin 500 mg q.i.d. (n = 15); and 3, with amoxicillin q.i.d. and sitafloxacin b.i.d.-combined regimen (n = 14). Eradication status was assessed at 8 weeks via a ¹³ C-urea breath test.

RESULTS

Eradication rate on intention-to-treat analysis was 93.7% (95% confidence interval: 87.4-97.4%, 104/111), irrespective of the high prevalence of strains resistant to clarithromycin (81.1%, 90/111) and levofloxacin (42.3%, 47/111). No significant differences in eradication rates were observed among the different treatment regimens (p = .408), eradication history (p = .096) and different CYP2C19 genotypes (p = .789). On multivariate analysis, no significant risk factor for eradication failure by therapy with potent acid inhibition was seen.

CONCLUSION

In Japanese patients infected with metronidazole-resistant strains of H. pylori, eradication rates exceeding 90% can be achieved using appropriate dosing of antibiotic agents with strain susceptibility (amoxicillin q.i.d. and/or sitafloxacin b.i.d.) together with acid inhibition for a full 24 h and rabeprazole 10 mg q.i.d. These findings may be further evidence for dual therapy with rabeprazole q.i.d. and an antibiotic agent (amoxicillin q.i.d. or sitafloxacin b.i.d.) in Japanese patients with metronidazole-resistant strains.

Antibiotic resistance and gyrA mutation affect the efficacy of 10-day sitafloxacin-metronidazole-esomeprazole therapy for Helicobacter pylori in penicillin allergic patients

BACKGROUND AND AIM

Helicobacter pylori (H. pylori) eradication regimen has not been standardized for patients with penicillin allergy. We investigated the association between the efficacy of a 10-day sitafloxacin, metronidazole, and esomeprazole triple regimen and antibiotic resistance, in patients with penicillin allergy.

METHODS

Penicillin-allergic patients infected with H. pylori were enrolled between March 2014 and November 2015. The minimum inhibitory concentrations (MICs) of sitafloxacin and metronidazole, and the gyrA mutation status of the H. pylori strains were determined before treatment. The cut-off points for antimicrobial resistance were defined as 8.0 µg/ml for metronidazole and 0.12 µg/ml for sitafloxacin. The patients received the triple therapy (20 mg esomeprazole, bid; 250 mg metronidazole, bid; and 100 mg sitafloxacin, bid) for 10 days. Successful eradication was evaluated using the [¹³C] urea breath test or the H. pylori stool antigen test.

RESULTS

Fifty-seven patients were analyzed, and the overall eradication rate was 89.5%. The eradication rate in cases of double antibiotic resistance to metronidazole and sitafloxacin was 40.0%, whereas for other combinations of resistance, this was above 90.0%. Finally, the eradication rate of gyrA mutation-negative strains was 96.2%, whereas for gyrA mutation-positive strains, it was 83.9%. Adverse events were reported in 31.6% of cases, all of which were mild and tolerable.

CONCLUSION

Ten days of sitafloxacin and metronidazole triple therapy was safe and highly effective in eradicating H. pylori in penicillin-allergic patients. Double resistance to metronidazole and sitafloxacin was an important predicting factor for eradication failure. However, 10 days of the sitafloxacin and metronidazole triple therapy was highly effective if the strain was susceptible to either sitafloxacin or metronidazole.

Efficacy of triple therapy with esomeprazole, amoxicillin, and sitafloxacin as a third-line Helicobacter pylori eradication regimen

OBJECTIVE

To examine the efficacy of third-line Helicobacter pylori eradication therapy with esomeprazole, amoxicillin, and sitafloxacin for patients with clarithromycin- and metronidazole-based first- and second-line therapy failure.

METHODS

Thirty patients with first- and second-line H. pylori eradication failure were treated prospectively with esomeprazole 20mg twice daily, amoxicillin 750mg twice daily, and sitafloxacin 100mg twice daily for 7 days. After 8-12 weeks, the outcome of eradication therapy was assessed by ¹³C-urea breath test or stool antigen test.

RESULTS

All 30 patients completed the study. Eradication was successful in 25 patients and the eradication rate was 83% in the intention-to-treat and per-protocol analyses. No specific or significant adverse events were recorded in the 30 patients. Patient characteristics such as sex, body mass index, and pepsinogen I/II ratio did not differ between patients who were treated successfully and those who were not treated successfully.

CONCLUSIONS

Third-line H. pylori eradication therapy with esomeprazole, amoxicillin, and sitafloxacin is as safe and effective as previously reported sitafloxacin-based triple therapy.

Efficacy of 10-day Sitafloxacin-Containing Third-Line Rescue Therapies for Helicobacter pylori Strains Containing the gyrA Mutation

BACKGROUND AND AIM

Sitafloxacin-containing Helicobacter pylori eradication therapy is a promising third-line therapeutic approach, but there is no previous studies between gyrA mutation status of H. pylori strains and the efficacy of 10-day sitafloxacin-containing regimens. Here, we assessed the efficacy of 2 different 10-day sitafloxacin-containing rescue regimens.

METHODS

Patients who failed first- and second-line eradication therapies were enrolled. The minimum inhibitory concentrations (MICs) of sitafloxacin, amoxicillin, and metronidazole and the gyrA mutation status of the H. pylori strains were determined before treatment. The patients were randomized to receive a 10-day triple therapy containing either esomeprazole (20 mg, b.i.d.), amoxicillin (500 mg, q.i.d.), and sitafloxacin (100 mg, b.i.d.) (EAS regimen) or esomeprazole (20 mg, b.i.d.), metronidazole (250 mg, b.i.d.), and sitafloxacin (100 mg, b.i.d.) (EMS regimen). Eradication rates were evaluated by the [13C] urea breath test or the H. pylori stool antigen test.

RESULTS

All patients with gyrA mutation-negative strains (24 in EAS and 16 in EMS) showed successful eradication, irrespective of the regimen they received. In patients with gyrA mutation-positive strains, we found eradication rates of 70.3% (26/37) and 66.7% (26/39) in the EAS and EMS groups in per-protocol population, respectively (p = .81). According to logistic regression analyses, the MICs of sitafloxacin, which were strongly associated with gyrA mutation status, were independently associated with successful eradication in both groups. This study was registered in the UMIN Clinical Trials Registry as UMIN000006483.

CONCLUSION

There is no significant difference in the eradication rates between EAS and EMS, regardless of the gyrA mutation status of the H. pylori strains. GyrA mutation status was an important factor in predicting successful eradication with sitafloxacin-containing rescue therapies.

Quinolone-based first, second and third-line therapies for Helicobacter pylori

Helicobacter pylori (H. pylori) is a very common bacterium that infects about 50% of the world population in urban areas and over 90% of people living in rural and developing countries. Fluoroquinolones, a class of antimicrobials, have been extensively used in eradication regimens for H. pylori. Levofloxacin is the most commonly used, and in second-line regimens, is one of the most effective options. However, an increasing resistance rate of H. pylori to fluoroquinolones is being observed, that will likely affect their effectiveness in the near future. Other novel fluoroquinolone molecules, such as moxifloxacin, sitafloxacin, gatifloxacin and gemifloxacin, have been proposed and showed encouraging results in vitro, although data on their clinical use are still limited. Further studies in large sample trials are needed to confirm their safety and efficacy profile in clinical practice.

Antibiotic treatment for Helicobacter pylori: Is the end coming?

Infection with the Gram-negative pathogen Helicobacter pylori (H. pylori) has been associated with gastro-duodenal disease and the importance of H. pylori eradication is underscored by its designation as a group I carcinogen. The standard triple therapy consists of a proton pump inhibitor, amoxicillin and clarithromycin, although many other regimens are used, including quadruple, sequential and concomitant therapy regimens supplemented with metronidazole, clarithromycin and levofloxacin. Despite these efforts, current therapeutic regimens lack efficacy in eradication due to antibiotic resistance, drug compliance and antibiotic degradation by the acidic stomach environment. Antibiotic resistance to clarithromycin and metronidazole is particularly problematic and several approaches have been proposed to overcome this issue, such as complementary probiotic therapy with Lactobacillus. Other studies have identified novel molecules with an anti-H. pylori effect, as well as tailored therapy and nanotechnology as viable alternative eradication strategies. This review discusses current antibiotic therapy for H. pylori infections, limitations of this type of therapy and predicts the availability of newly developed therapies for H. pylori eradication.

High Efficacy of Finafloxacin on Helicobacter pylori Isolates at pH 5.0 Compared with That of Other Fluoroquinolones

Finafloxacin is a novel fluoroquinolone with improved antimicrobial efficacy, especially in an acidic environment. The efficacy of finafloxacin for the inhibition of Helicobacter pylori infection was compared with the efficacies of levofloxacin and moxifloxacin at neutral and acidic pH. The impacts of gyrA point mutation on the efficacy of those three fluoroquinolones were also investigated. A total of 128 clinical H. pylori strains were utilized. MICs of levofloxacin, moxifloxacin, and finafloxacin were determined at pH 5.0 and pH 7.0 by the agar dilution method. The impact of gyrA point mutations that are responsible for fluoroquinolone resistance was analyzed; the results showed 50 strains with an Asn-87 point mutation, 48 strains with an Asp-91 point mutation, and the remaining 30 strains with no gyrA mutations. The use of finafloxacin led to MIC values at pH 5.0 that were lower than the values seen at pH 7.0 for 112 strains (112/128, 87.5%), and this proportion was higher than that seen with moxifloxacin (21/128, 16.4%, P < 0.001). Finafloxacin also demonstrated a rate of susceptibility (MIC, <1 μg/ml) (37.5%, 48/128) at pH 5.0 that was higher than that seen with moxifloxacin (2.3%, 3/128) (P < 0.001). The trends were similar regardless of which of the Asn-87, Asp-91, and A2143 point mutations were present. In conclusion, the superior antimicrobial efficacy of finafloxacin against H. pylori in an acidic environment suggests the possible use of finafloxacin for treatment of H. pylori infection, as has been proposed by its developer, Merlion Pharma.

High Helicobacter pylori cure rate with sitafloxacin-based triple therapy

BACKGROUND

Bacterial resistance of Helicobacter pylori to antibiotics is increasing and it often leads to failure of antibiotic treatment. A new sitafloxacin-based triple therapy was developed to counter this situation; the fluoroquinolone sitafloxacin has a low minimum inhibitory concentration for H. pylori.

AIM

To investigate the efficacy in Japanese patients of sitafloxacin-based triple therapy and document its efficacy in relation to anti-microbial susceptibility.

METHODS

We investigated the efficacy of a 1-week sitafloxicin-based regimen of rabeprazole 10 mg four times daily (q.d.s.), metronidazole 250 mg twice daily (b.d.) and sitafloxacin 100 mg b.d. in 180 H. pylori-positive Japanese patients (first-line treatment: n = 45, second-line; n = 41, third-line: n = 94). At 8 weeks, patients were given the (13) C-urea breath test to assess eradication status.

RESULTS

Eradication rate was 92.2% [95% confidence interval (CI): 87.3-95.7%, 166/180] in intention-to-treat analysis. Although the eradication rate was higher in patients treated with first-line therapy [45/45 (100%, 95% CI: 83.4-100%)] than in those with second- [38/41 (92.7%, 80.1-98.5%)] or third-line therapy [83/94 (88.3%, 80.0-94.0%)], no significant differences were noted with respect to the number of previous therapy attempts (P = 0.054). Eradication rates in patients infected with sensitive- and resistant strains to metronidazole were 96.6% (28/29) and 96.3% (77/80) (P = 0.941), respectively, while rates were 98.4% (60/61) in sitafloxacin-sensitive and 50.0% (1/2) in sitafloxacin resistant strains (P < 0.001).

CONCLUSION

Sitofloxacin-based triple therapy with metronidazole b.d. and rabeprazole q.d.s. achieved an eradication rate exceeding 88%, irrespective of eradication history, CYP2C19 genotype, or metronidazole resistance status.

Diagnosis of Helicobacter pylori using the rapid urease test

Helicobacter pylori (H. pylori) is a major human pathogen which causes progressive gastroduodenal damage. Guidelines recommend that, unless there are compelling reasons to delay, treatment is indicated for all patients in whom the infection is diagnosed. The rapid urease test (RUT) is a popular diagnostic test in that it is a rapid, cheap and simple test that detects the presence of urease in or on the gastric mucosa. The sensitivity and specificity are generally high and many versions have been approved for use in humans. Best results are obtained if biopsies are obtained from both the antrum and corpus. The tissue sample embedded in the RUT gel can also be utilized for other tests such as for molecular based tests of microbial susceptibility or for host factors. False-positive results are rare if the RUT contains an antibacterial agent to prevent growth of urease-containing contaminants and the tests are discarded at 24 hours. The use of antimicrobial drugs and proton pump inhibitors as well as the presence of intestinal metaplasia may result in false-negative results. A negative test should not be used as the criteria for cure or in cases where accuracy is important for patient management such as in upper gastrointestinal bleeding. Interpretation of the test should take into account the pretest probability and the prevalence of H. pylori in the population. The test can also be used to provide an informal assessment of the accuracy of the histopathology result and discrepancies should prompt a review of the histopathology and discussions with the pathologist.

Treatment of Helicobacter pylori infection 2014

This review summarizes important studies regarding H.pylori therapy published from April 2013 to April 2014. The main themes that emerge are assessing the efficacy of standard triple therapy, as well as exploring new first-line treatments, predominantly optimized triple therapies and non-bismuth quadruple schemes. Regarding newer non-bismuth quadruple regimens, the compliance and tolerance seem to be similar for sequential and concomitant regimens. Notably, no study yet has demonstrated a clear statistical superiority for either, and a systematic review and meta-analysis may be warranted. Other studies examined the role of levofloxacin and bismuth based therapies in H. pylori eradication. The efficacy of bismuth as a second-line after sequential therapy was particularly noteworthy. Levofloxacin-based therapies also appear to be useful and versatile as part of different antibiotic combinations and in first-, second-, and third-line therapies. The emerging problem of quinolone resistance remains a worry. Individualized therapy, based on factors such as antimicrobial information, resistance data, and CYP2C19 metabolism, may well be the most notable future trend to emerge this year.

Helicobacter pylori eradication with moxifloxacin-containing therapy following failed first-line therapies in South Korea

AIM: To investigate moxifloxacin-containing triple therapy as second-line treatment for Helicobacter pylori (H. pylori) infection following failed first-line treatment.

METHODS: The sample included 312 patients for whom first-line treatment failed between January 2008 and May 2013; 27 patients were excluded, and a total of 285 patients received 7- or 14-d moxifloxacin-containing triple therapy as second-line treatment for H. pylori infection. First line regimens included 7-d standard triple (n = 172), 10-d bismuth-containing quadruple (n = 28), 14-d concomitant (n = 37), or 14-d sequential (n = 48) therapy. H. pylori status was evaluated using ¹³C-urea breath testing 4 wk later, after completion of the treatment. The primary outcome was the H. pylori eradication rate analyzed using intention-to-treat (ITT) and per protocol (PP) analyses. The secondary outcome was the occurrence of serious adverse events. Demographic and clinical factors were analyzed using Student’s t-tests and Pearson’s χ² tests according to first- and second-line regimens. A P value of less than 0.05 was considered statistically significant.

RESULTS: The eradication rate of moxifloxacin-containing triple therapy was 68.4% (ITT; 95%CI: 62.8-73.5) and 73.9% (PP; 95%CI: 68.3-78.8). The eradication rate was significantly higher with 14 d compared to 7 d of treatment (77.5% vs 62.5%, P = 0.017). Peptic ulcer patients had a higher eradication rate than the patients without ulcers (82.9% vs 70.6%, P = 0.046). The demographic and clinical characteristics were not significantly different between the groups according to first-line therapies. ITT and PP analyses of the moxifloxacin-containing triple therapy indicated the following eradication rates: 70.9% (95%CI: 63.8-77.2) and 77.2% (95%CI: 70.1-83.1) for standard triple; 67.9% (95%CI: 51.5-84.2) and 67.9% (95%CI: 51.5-84.2) for bismuth-containing quadruple; 60.4% (95%CI: 46.3-73.0) and 70.7% (95%CI: 54.0-80.9) for sequential; and 67.6% (95%CI: 51.5-80.4) and 67.6%(95%CI: 51.5-80.4) for concomitant therapy. There were no statistically significant differences in the efficacy of the first-line regimens (P = 0.492). The most common adverse event was diarrhea. There were no serious adverse events and no significant differences in the frequency of side effects between the first- and second-line regimens (28.7% vs 26.1%, respectively).

CONCLUSION: Moxifloxacin-containing triple therapy as second-line treatment resulted in low eradication rates. There were no differences in the efficacy between the first-line regimens in South Korea.