Comparing the acid-suppressive effects of three brands of generic lansoprazole with the original: pharmacokinetic bioequivalence tests do not necessarily guarantee pharmacodynamic equivalence

Treatment strategies for reflux esophagitis including a potassium-competitive acid blocker: A cost-effectiveness analysis in Japan

INTRODUCTION

Gastroesophageal reflux disease is a common condition, and proton pump inhibitors (PPIs) are the mainstays of treatment. However, concerns have been raised about the safety of PPIs. A potassium-competitive acid blocker (P-CAB), vonoprazan (VPZ), was recently introduced, which may provide clinical benefits. This study was performed to investigate the cost-effectiveness of alternative long-term strategies including continuous and discontinuous treatment with VPZ for the management of reflux esophagitis in Japan.

METHODS

A health state transition model was developed to capture the long-term management of reflux esophagitis. Four different strategies were compared: (a) intermittent PPI using lansoprazole (LPZ); (b) intermittent P-CAB; (c) maintenance PPI using LPZ; and (d) maintenance P-CAB.

RESULTS

Intermittent P-CAB was the most cost-effective, and the number of days for which medication was required with this strategy was fewest. Maintenance PPI was more efficacious, but more costly than intermittent P-CAB. Maintenance P-CAB was more efficacious, but more costly than maintenance PPI. Co-payments were higher for maintenance PPI than for intermittent P-CAB, and for maintenance P-CAB than for maintenance PPI, which were considered reasonable for the majority of patients to improve symptoms.

CONCLUSIONS

Intermittent P-CAB appears to be the strategy of choice for the majority of reflux esophagitis patients in clinical practice. If a patient is not satisfied with the symptom control of the current strategy, switching to a more effective strategy appears to be a reasonable option for the majority of patients.

Vonoprazan versus Lansoprazole for the Initial Treatment of Reflux Esophagitis: A Cost-effectiveness Analysis in Japan

Objective Gastroesophageal reflux disease (GERD) is a highly prevalent disorder that negatively affects patients' quality of life and reduces their work productivity. The medical expenses associated with the treatment of GERD are the highest among all digestive diseases. Current guidelines recommend the administration of a standard dose of proton pump inhibitor (PPI) for eight weeks as an initial GERD treatment. However, there is growing concern regarding the safety of PPI treatment. Recently, a novel potassium-competitive acid blocker (P-CAB), vonoprazan (VPZ), was approved for the treatment of reflux esophagitis in Japan and may provide clinical benefits in GERD treatment. This study was conducted to evaluate the cost-effectiveness of a P-CAB, VPZ vs. a PPI, lansoprazole (LPZ), for the acute medical treatment of reflux esophagitis. Methods A clinical decision analysis was performed using a Markov chain approach to compare VPZ to LPZ in the acute treatment of reflux esophagitis in Japan. Results The P-CAB strategy was superior to the PPI strategy in terms of cost-effectiveness (direct cost per patient to achieve clinical success) and the number of days for which medication was required. Sensitivity analyses revealed that this superiority was robust within the plausible range of probabilities. This remained true even when the healing rates in cases of mild esophagitis were applied. Conclusion The P-CAB strategy was consistently superior to the conventional PPI strategy using the original LPZ in terms of cost-effectiveness and the number of days for which medication was required. Thus, VPZ appears to be the drug of choice for the acute medical treatment of reflux esophagitis.

Inhibition of Gastric H+,K+-ATPase Activity in Vitro by Dissolution Media of Original Brand-Name and Generic Tablets of Lansoprazole, a Proton Pump Inhibitor

To investigate the inhibitory effect of a commercial proton pump inhibitor (lansoprazole) on the gastric proton pump H⁺,K⁺-ATPase in vitro, we used orally disintegrating (OD) tablets including original brand-name and generic tablets. In the course of the development of generic products, dissolution and clinical tests are necessary to ensure their bioequivalence to the original brand-name products; by contrast, there is almost no opportunity to demonstrate their activity in vitro. This study initially compared the similarity of the dissolution of test generic tablets with that of the original brand-name tablets. The dissolution tests for 15 and 30-mg lansoprazole tablets found their dissolution properties were similar. Subsequently, the dissolution media were sampled and then their effects on the H⁺,K⁺-ATPase activity were measured using tubulovesicles prepared from the gastric mucosa of hogs. We confirmed that the inhibitory effects of the generic tablets on H⁺,K⁺-ATPase activity were consistent with those of the original brand-name tablets. Furthermore, lansoprazole contents in each tablet estimated from their inhibitory effects were in good agreement with their active pharmaceutical ingredient content. To our knowledge, this is the first technical report to compare the in vitro biochemical activity of lansoprazole OD tablets between the original brand-name and generic commercial products.

Calculation of direct antiretroviral treatment costs and potential cost savings by using generics in the German HIV ClinSurv cohort

Background/Aim of the Study

The study aimed to determine the cost impacts of antiretroviral drugs by analysing a long-term follow-up of direct costs for combined antiretroviral therapy, cART,-regimens in the nationwide long-term observational multi-centre German HIV ClinSurv Cohort. The second aim was to develop potential cost saving strategies by modelling different treatment scenarios.

Methods

Antiretroviral regimens (ART) from 10,190 HIV-infected patients from 11 participating ClinSurv study centres have been investigated since 1996. Biannual data cART,-initiation, cART-changes, surrogate markers, clinical events and the Centre of Disease Control- (CDC)-stage of HIV disease are reported. Treatment duration was calculated on a daily basis via the documented dates for the beginning and end of each antiretroviral drug treatment. Prices were calculated for each individual regimen based on actual office sales prices of the branded pharmaceuticals distributed by the license holder including German taxes.

Results

During the 13-year follow-up period, 21,387,427 treatment days were covered. Cumulative direct costs for antiretroviral drugs of €812,877,356 were determined according to an average of €42.08 per day (€7.52 to € 217.70). Since cART is widely used in Germany, the costs for an entire regimen increased by 13.5%. Regimens are more expensive in the advanced stages of HIV disease. The potential for cost savings was calculated using non-nucleotide-reverse-transcriptase-inhibitor, NNRTI, more frequently instead of ritonavir-boosted protease inhibitor, PI/r, in first line therapy. This calculation revealed cumulative savings of 10.9% to 19.8% of daily treatment costs (50% and 90% substitution of PI/r, respectively). Substituting certain branded drugs by generic drugs showed potential cost savings of between 1.6% and 31.8%.

Conclusions

Analysis of the data of this nationwide study reflects disease-specific health services research and will give insights into the cost impacts of antiretroviral therapy, and might allow a more rational allocation of resources within the German health care system.