Value elements and methods of value-based pricing for drugs in Japan: a systematic review.

INTRODUCTION: Value-based pricing (VBP) can be a promising tool for optimizing drug prices. However, there is no consensus on the specific value elements and pricing method that should be used for VBP. AREAS COVERED: We performed a systematic review and narrative synthesis to investigate the value elements and pricing method for VBP. The main inclusion criterion was that value elements, VBP method, and estimated prices for actual drugs were reported. We performed a search in MEDLINE and ICHUSHI Web. Eight articles met the selection criteria. Four studies adopted the cost-effectiveness analysis (CEA) approach and the others used different approaches. The CEA approach included the value elements of productivity, value of hope, real option value, disease severity, insurance value in addition to costs and quality-adjusted life years. The other approaches used efficacy, toxicity, novelty, rarity, research and development costs, prognosis, population health burden, unmet needs, and effectiveness. Each study used individual methods to quantify these broader value elements. EXPERT OPINION: Both conventional and broader value elements are used for VBP. To allow VBP to be widely applied to various diseases, a simple, versatile method is preferable. Further research is needed to establish VBP method which enables to incorporate broader values.

Cost-Effectiveness of Vonoprazan Compared With Proton Pump Inhibitors in Patients Taking Low-Dose Aspirin for Secondary Prevention of Cardiovascular Events in Japan.

BACKGROUND: Low-dose aspirin (LDA) is used to prevent recurrent cardiovascular (CV) events, but is associated with upper gastrointestinal (GI) bleeding; concomitant use of a proton pump inhibitor (PPI) reduces this risk. This study aimed to assess the cost-effectiveness of vonoprazan compared with PPIs (lansoprazole and esomeprazole) in patients taking LDA for secondary prevention of CV events.Methods and Results: A Markov simulation model was developed to predict the number of GI bleeding and acute CV events using 3 strategies (vonoprazan+LDA, esomeprazole+LDA, and lansoprazole+LDA), which were translated into quality-adjusted life-years (QALYs) and costs. Transition probabilities and utilities were derived from the results of published literature, and medical costs were based on the Japanese National Health Insurance fee table and claims databases in 2020. Outcomes were projected over 30 years starting at age 65 years and discounted at 2% annually. Expected costs with esomeprazole 20 mg, lansoprazole 15 mg and vonoprazan 10 mg were JPY 1,225,657, JPY 943,930, and JPY 1,059,510, respectively. The QALY gain for vonoprazan vs. esomeprazole was 0.35, thus vonoprazan was dominant against esomeprazole. The QALY gain for vonoprazan vs. lansoprazole was 0.29 and the incremental cost-effectiveness ratio (ICER) was JPY 398,551, thus, vonoprazan was more cost-effective than lansoprazole. CONCLUSIONS: Vonoprazan is dominant or cost-effective compared with esomeprazole and lansoprazole in patients taking LDA for secondary prevention of CV events.

Network Meta-analysis Comparing Vonoprazan and Proton Pump Inhibitors for Heartburn Symptoms in Erosive Esophagitis.

GOALS: This systematic review and network meta-analysis aimed to assess the relative efficacy of vonoprazan and proton pump inhibitors (PPIs) on early heartburn symptom resolution in patients with erosive esophagitis. BACKGROUND: Limited available data directly compare the efficacy of vonoprazan, a first-in-class potassium-competitive acid blocker, with PPIs in erosive esophagitis. STUDY: We conducted a systematic literature review (in MEDLINE and CENTRAL) and subsequent network meta-analysis according to Cochrane and PRISMA guidelines. Double-blind, randomized controlled trials in adults with erosive esophagitis treated with vonoprazan or a PPI were included in the analysis. Primary outcomes were heartburn symptom resolution rate on Day 1 and Day 7. The study was performed with all available data, using a random effects model within a Bayesian framework. RESULTS: Overall, 10 randomized controlled trials were included in the network meta-analysis. For heartburn resolution rate on Day 1 (9 of 10 trials), vonoprazan 20 mg once daily (QD) was superior to placebo (median odds ratio=16.75, 95% credible interval: 2.16-207.80). Point estimates numerically favored vonoprazan 20 mg QD over other comparators. For heartburn resolution rate on Day 7 (10 of 10 trials), vonoprazan 20 mg QD was superior to placebo and other comparators except rabeprazole 20 mg QD. Point estimates numerically favored vonoprazan 20 mg QD over rabeprazole 20 mg QD. CONCLUSIONS: In this study, vonoprazan 20 mg QD was equally effective in heartburn resolution on Day 1, and equally or more effective on Day 7 versus PPIs in adults with erosive esophagitis.

Impact of Vonoprazan Triple-Drug Blister Packs on H. pylori Eradication Rates in Japan: Interrupted Time Series Analysis.

INTRODUCTION: Helicobacter pylori eradication therapy requires a complex prescribing schedule combining clarithromycin, amoxicillin, and a proton-pump inhibitor (PPI) or potassium-competitive acid blocker (P-CAB, vonoprazan). To reduce the burden of complex prescribing and increase adherence, a vonoprazan triple-drug blister pack comprising all three medications was launched in June 2016. This study aimed to assess the impact of the combination blister pack on eradication success rate in Japan immediately after launch. METHODS: We performed an interrupted time series analysis using a large administrative claims database of 7,300,000 insured individuals. We identified 36,570 patients who received first-line clarithromycin triple therapy from June 2015 to May 2016 (prelaunch) and 35,721 who received the same therapy from July 2016 to June 2017 (post-launch). The primary outcome was the success rate of clarithromycin triple therapy and the secondary outcomes were proportion of vonoprazan use and proportion of combination blister pack use. RESULTS: The success rate of clarithromycin triple therapy increased by 2.44% (95% confidence interval [CI] 1.36-3.52; P < 0.0001) after the launch of the vonoprazan triple-drug blister pack. The proportion of vonoprazan use and proportion of combination blister pack use increased by 12.7% (95% CI 10.0-15.3; P < 0.0001) and 29.2% (95% CI 25.4-32.9; P < 0.0001), respectively. CONCLUSIONS: Launch of the vonoprazan triple-drug blister pack had a significant impact on the success rate of clarithromycin triple therapy, with greater proportions of vonoprazan and combination blister pack use. Introducing an easy-to-use formulation may be effective in changing prescribing practice and subsequent patient outcomes.

Upper gastrointestinal bleeding in Japanese patients with ischemic heart disease receiving vonoprazan or a proton pump inhibitor with multiple antithrombotic agents: A nationwide database study.

BACKGROUND: Vonoprazan has been launched as an alternative to proton-pump inhibitors (PPIs). This was the first study to compare the occurrence of upper gastrointestinal bleeding (UGIB) with vonoprazan treatment to that with PPI treatment in patients with ischemic heart disease (IHD) taking ≥2 antithrombotic agents, including those receiving dual antiplatelet therapy (DAPT). METHODS: Using Japanese Diagnosis Procedure Combination data from 2016 to 2017, we identified 16,415 patients with IHD who were prescribed ≥2 antithrombotic agents, including new antiplatelet medication with concurrent vonoprazan (n = 2226 or PPIs n = 14,189). UGIB occurrence was analyzed using an inverse probability-weighted Cox proportional hazards model. Non-inferiority of vonoprazan to PPI treatment for UGIB occurrence was assessed. RESULTS: Six-month incidence of UGIB in patients treated with vonoprazan and PPIs was 3.14% 70/2226 and 4.17% (591/14,189), respectively. The adjusted hazard ratio (aHR) of 0.84 was significantly below the non-inferiority margin (HR 2.06) (p < 0.0001), and thus demonstrated that vonoprazan treatment was non-inferior to PPIs in terms of occurrence of UGIB events. The difference between the 2 treatments was also not statistically significant [aHR 0.84; 95% confidence interval (CI): 0.65-1.07; p = 0.154). In a subgroup analysis, UGIB occurrence with vonoprazan and other PPI treatment in patients receiving DAPT was 2.82% (22/779) and 3.96% (209/5276) respectively; a non-significant difference (aHR 0.74; 95% CI: 0.48-1.16; p = 0.189) that demonstrated non-inferiority (p < 0.0001). CONCLUSIONS: Vonoprazan was non-inferior to PPIs in terms of UGIB occurrence over 6 months in patients with IHD receiving ≥2 antithrombotic agents, including new antiplatelet medication.

Current Status of Helicobacter pylori Diagnosis and Eradication Therapy in Japan Using a Nationwide Database.

BACKGROUND: Helicobacter pylori infection increases the risk of stomach cancer; therefore, eradication therapy is recommended for infected individuals. Although several methods are recommended for the diagnosis and therapy of H. pylori infection, their frequency and effectiveness have not been fully investigated in Japan. METHODS: A nationwide claims database including >1.6 million patients (April 2008 - -October 2016) in Japan was utilized. We analyzed the distribution of methods for H. pylori diagnosis and therapy, waiting period between eradication and diagnostic test, and success rate of primary therapy. RESULTS: Data for 481,041 patients were extracted. After primary eradication therapy, urea breath test was used for >80% of diagnoses, and antibody measurement for 0.7%. The success rate of primary eradication was >80% for most diagnostic methods and 69.0% for antibody measurement; inappropriately-timed antibody measurement may have contributed to this disparity. The overall success rate of eradication therapy decreased from 2011 to 2014, but increased from 2015, coinciding with launch of the potassium-competitive acid blocker vonoprazan, which showed a higher success rate of eradication than proton-pump inhibitors. CONCLUSIONS: Diagnostic tests of H. pylori infection mostly followed Japanese Society for Helicobacter Research guidance, although some antibody measurements were timed inappropriately. Vonoprazan appears to increase the success rate of primary therapy.

Cost-utility analysis of a 'vonoprazan-first' strategy versus 'esomeprazole- or rabeprazole-first' strategy in GERD.

BACKGROUND: Gastroesophageal reflux disease (GERD) can be treated using a vonoprazan-first strategy (first-line treatment with vonoprazan), or esomeprazole-first/rabeprazole-first strategies (first-line treatment with proton-pump inhibitors [PPIs], esomeprazole/rabeprazole, followed by a switch to vonoprazan). This cost-utility analysis used long-term simulation modeling to evaluate the cost-effectiveness of a vonoprazan-first strategy compared with the esomeprazole-first and rabeprazole-first strategies. METHODS: A Markov simulation model was developed to evaluate the cost-effectiveness of vonoprazan-first, esomeprazole-first, and rabeprazole-first strategies, comprising healing and maintenance therapies, over 5 years (4-week cycles). Healing therapy began with the administration of a normal dose of drug per real-world practice. If patients were not healed endoscopically, either a longer duration of healing therapy was provided (vonoprazan), the dose was increased (rabeprazole), or patients were switched to vonoprazan (immediately for esomeprazole, and after dose-escalation for rabeprazole, respectively). Healed patients received maintenance (lower/same dose as healing therapy). Recurrence resulted in re-challenge with healing therapy. Transition probabilities were derived from the results of indirect comparisons (network meta-analysis) and costs calculated from the Japanese payer perspective. Outcomes were defined as quality-adjusted life years (QALYs), with utilities based on published values. RESULTS: Expected costs of the vonoprazan-, esomeprazole-, and rabeprazole-first strategies were ¥36,194, ¥76,719, and ¥41,105, respectively, over 5 years. QALY gains for vonoprazan-first strategy versus the esomeprazole- and rabeprazole-first strategies were 0.014 and 0.003, respectively. Both estimated incremental cost-effectiveness ratios were dominant and robust to two sensitivity analyses. CONCLUSIONS: Vonoprazan-first strategy increased QALYs and appeared to be cost-effective for GERD patients compared with the esomeprazole- or rabeprazole-first strategies.

Association between parental history of Helicobacter pylori treatment failure and treatment failure in the offspring.

BACKGROUND AND AIM: Both clarithromycin-resistant Helicobacter pylori and CYP2C19 polymorphisms may be passed down for generations and are known risk factors for the failure of H. pylori eradication therapy. However, no study has evaluated the risk of clarithromycin triple therapy failure in patients with a parental history of such failure. This study investigated the association between a history of clarithromycin triple therapy failure in parents and clarithromycin triple therapy failure in the offspring. METHODS: This cross-sectional study was conducted using a large administrative claims database of 3 100 000 insured individuals. We identified 404 patients who had both personal and parental records of prescriptions for first-line clarithromycin triple therapy between January 2005 and February 2018. Failure of clarithromycin triple therapy was defined as treatment with second-line therapy after having received first-line clarithromycin triple therapy. A parental history of clarithromycin triple therapy failure was defined as failure of clarithromycin triple therapy by either the father or the mother. Odds ratios were estimated using logistic regression models adjusted for age, sex, diabetes mellitus, and peptic ulcer. RESULTS: The incidence of clarithromycin triple therapy failure was 22.5% (91/404). Based on univariate analysis (odds ratio [95% confidence interval], 1.90 [1.10-3.29]) and multivariable analysis (odds ratio [95% confidence interval], 1.93 [1.10-3.39]), parental history of clarithromycin triple therapy failure was associated with failure of clarithromycin triple therapy in the offspring. CONCLUSION: A parental history of clarithromycin triple therapy failure is a risk factor for failure of clarithromycin triple therapy in the offspring.

Vonoprazan versus proton-pump inhibitors for healing gastroesophageal reflux disease: A systematic review.

BACKGROUND AND AIM: Gastroesophageal reflux disease (GERD) is a common disease caused by reflux of gastric contents to the esophagus. Proton-pump inhibitors (PPIs) are recommended as a first-line therapy to treat GERD. Recently, a new potassium-competitive acid blocker, vonoprazan, was launched in Japan. We aimed to evaluate the comparative efficacy of vonoprazan and other PPIs in healing GERD. METHODS: We used MEDLINE and the Cochrane Central Register of Controlled Trials to search the literature. Double-blind randomized controlled trials for PPIs and/or vonoprazan that were published in English or Japanese and assessed healing effects in adult GERD patients were included. To estimate the comparative efficacy of treatments, we performed a Bayesian network meta-analysis to assess the consistency assumption. RESULTS: Of 4001 articles identified in the database, 42 studies were eligible. One study was hand-searched and added to the analysis. For the main analysis of healing effects at 8 weeks, odds ratios (ORs) of vonoprazan (20 mg daily) to esomeprazole (20 mg), rabeprazole (20 mg), lansoprazole (30 mg), and omeprazole (20 mg) were 2.29 (95% credible interval, 0.79-7.06), 3.94 (1.15-14.03), 2.40 (0.90-6.77), and 2.71 (0.98-7.90), respectively. Subgroup analysis for patients with severe esophagitis at baseline showed significantly higher ORs for vonoprazan versus most of the comparator PPIs. CONCLUSIONS: This analysis shows that the GERD healing effect of vonoprazan is higher than that of rabeprazole (20 mg) but not higher than other PPIs. Subgroup analysis indicated that vonoprazan is more effective than most PPIs for patients with severe erosive esophagitis.

Systematic review with network meta-analysis: indirect comparison of the efficacy of vonoprazan and proton-pump inhibitors for maintenance treatment of gastroesophageal reflux disease.

BACKGROUND: Long-term maintenance treatment of gastroesophageal reflux disease (GERD) is important to prevent relapse. Proton-pump inhibitors (PPIs) are used for both treatment and maintenance therapy of GERD. Recently, a potassium-competitive acid blocker vonoprazan was launched in Japan. We evaluated the comparative efficacy of vonoprazan and other PPIs for GERD maintenance. METHODS: A systematic literature search was performed using MEDLINE and Cochrane Central Register of Controlled Trials. Double-blind randomized controlled trials (RCTs) of PPIs, vonoprazan, and placebo for GERD maintenance published in English or Japanese were selected. Among them, studies conducted at the recommended dose and for the recommended use, and containing information on maintenance rate based on endoscopic assessment, were included. The comparative efficacies of treatments were estimated by performing a Bayesian network meta-analysis, which assessed the consistency assumption. Outcomes were number or rate of patients who maintained remission. RESULTS: Of 4001 articles identified, 22 RCTs were eligible for analysis. One study published as an abstract was hand-searched and added. The consistency hypothesis was not rejected for the analysis. The odds ratio of vonoprazan 10 mg to each PPI was 13.92 (95% credible interval [CI] 1.70-114.21) to esomeprazole 10 mg; 5.75 (95% CI 0.59-51.57) to rabeprazole 10 mg; 3.74 (95% CI 0.70-19.99) to lansoprazole 15 mg; and 9.23 (95% CI 1.17-68.72) to omeprazole 10 mg. CONCLUSIONS: The efficacy of vonoprazan in GERD maintenance treatment may be higher than that of some PPIs. However, a direct comparison of vonoprazan and PPIs is required to confirm these effects.

Nitroxides prevent exacerbation of indomethacin-induced gastric damage in adjuvant arthritis rats.

Nonsteroidal anti-inflammatory drugs are the drugs of choice in the treatment of rheumatoid arthritis (RA) because of their rapid analgesic effect. However, they induce severe gastric damage in RA patients and animals by a process mediated by reactive oxygen species (ROS). Nitroxides (nitroxyl radicals) are widely used as imaging agents and antioxidants to explore the role of ROS generation in the pathogenesis of disease. In this study, the effectiveness of the newly synthesized nitroxides 8-aza-7,7,9,9-tetramethyl-1,4-dioxaspiro[4.5]undecan-8-oxyl (compound 1) and 4-oxo-2,2,6,6-tetraethylpiperidine-1-oxyl (compound 2) in the prevention of gastric ulcers in adjuvant arthritis rats treated with indomethacin was evaluated by monitoring the reaction of reactive oxygen species in gastric tissue with Overhauser-enhanced magnetic resonance imaging (OMRI). Pretreatment with all tested nitroxides suppressed the ulcers induced by indomethacin treatment in arthritic rats. OMRI using compounds 1 and 2 as well as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL) demonstrated a redox imbalance in the stomach of these rats. Lipid peroxide and interleukin (IL)-1ß levels in the gastric mucosa were significantly suppressed by compound 1 and TEMPOL, whereas CINC/gro, a member of the IL-8 family, was significantly suppressed by compound 1 only. These results suggest that the preventive effects of nitroxides on gastric ulcers may operate by different mechanisms.

In vivo evaluation of novel nitroxyl radicals with reduction stability.

Nitroxyl radicals (nitroxide) have great potential advantages as spin probes, antioxidants, contrast agents, and radiation-protecting agents. However, they are readily reduced by reductants in cells and lose their paramagnetic nature. Recently, tetraethyl-substituted nitroxyl radicals have been reported to have high stability toward reduction by ascorbic acid (AsA). We report the general considerations of tetraethyl nitroxyl radicals for in vivo application. The reason for the low reactivity to AsA reduction was the positive value of Gibbs energy between the tetraethyl nitroxyl radical and AsA. Further, these compounds had an inhibitory effect on lipid peroxidation despite having AsA resistance. They had low antiproliferative effects in HepG2 cells and HUVECs and did not have a lowering effect on blood pressure in animals. Further, after intravenous injection, the ESR signal intensities of tetraethyl-substituted piperidine nitroxyl radicals were very stable in mice over 20 min. These results suggest that tetraethyl-substituted nitroxyl radicals have stability against bioreduction with reductants such as AsA and confer onto them features as antioxidants and paramagnetic tracers/contrast agents. Hence, they will be useful in identifying the foci of oxidative stress in vivo using redox-based imaging approaches.