Cost-effectiveness of olanzapine in the first-line treatment of schizophrenia in China

Cost-effectiveness of rezvilutamide versus bicalutamide and androgen-deprivation therapy in patients with highvolume, metastatic, hormone-sensitive prostate cancer

Background: Rezvilutamide, a novel androgen-receptor inhibitor with limited blood-brain barrier penetration, exhibits significant antitumour activity against highvolume, metastatic, hormone-sensitive prostate cancer (mHSPC). In this study, we aimed to compare the cost-effectiveness of rezvilutamide and bicalutamide as first-line treatments for untreated prostate cancer among Chinese patients, in order to evaluate the efficacy of rezvilutamide. Methods: In this study, we utilized partition survival model to assess the cost-effectiveness of rezvilutamide and bicalutamide treatments for highvolume mHSPC. The model was developed using TreeAge Pro 2022 software and relied on clinical data obtained from the CHART trial. Transition probabilities were estimated from the reported survival probabilities in trials using parametric survival modeling. From the perspective of the Chinese healthcare system, we calculated quality-adjusted life years (QALYs), incremental cost-effectiveness ratio (ICER), and lifetime cost. A lifetime horizon and an annual discount rate of 5% were employed. To address modeling uncertainties, we conducted one-way sensitivity analysis and probabilistic sensitivity analysis. Results: The cost of rezvilutamide versus bicalutamide were $62700 and $13200. Rezvilutamide had an ICER of $41900 per additional QALYs gained compared with bicalutamide. Research indicated that rezvilutamide achieved at least an 28.20% probability of cost-effectiveness at the threshold of $38223.34/QALY. One-way sensitivity analysis revealed that the results were sensitive to utility of PD. Scenario analysis showed that rezvilutamide was cost-effectiveness if its price was reduced by more than 10%. Conclusion: Based on the analysis at the current price, rezvilutamide was found to be less cost-effective for patients with highvolume mHSPC compared to bicalutamide in China.

Effect of Co-Treatment of Olanzapine with SEP-363856 in Mice Models of Schizophrenia

Olanzapine is a commonly used drug in the treatment of schizophrenia, but its clinical application has been restricted by metabolic-related side effects. In order to mitigate the weight gain side effects caused by olanzapine, other drugs with different targets were selected for combined use and evaluated in animal models of schizophrenia. SEP-363856 is a novel psychotropic agent which is under phase III clinical trials for schizophrenia treatment. The aim of the research was to evaluate whether co-administration of olanzapine and SEP-363856 exerts synergistic anti-schizophrenic effects in the apomorphine (APO)-induced climbing test, the MK-801-induced hyperactivity test, and the Morris water maze test, and therefore reduces the weight gain side effects induced by olanzapine. Through isobolographic analysis, the results showed a synergistic interaction in the climbing test; the experimental ED30 (3 mg/kg) was significantly smaller (p < 0.05) than the theoretical ED30 (5 mg/kg). Additionally, such potentiating effects appeared additive in the MK-801 challenge experiment. Co-treatment with an effective dose of olanzapine and a low dose of SEP-363856 reversed MK-801-induced cognitive impairment symptoms in mice. Moreover, combination treatment with olanzapine and SEP-363856 controls sustained weight gain in mice with chronic exposure to olanzapine. These results support further clinical trials to test the effectiveness of co-treatment of olanzapine and SEP-363856 for controlling symptoms and weight gain in patients with schizophrenia during antipsychotic treatments.

A Systematic Review of Methods and Study Quality of Economic Evaluations for the Treatment of Schizophrenia

Background: Schizophrenia is a severe and complex disease with substantial economic and social burdens. Despite multiple treatment choices, adverse events, and impaired social functions are still challenges in clinical therapy. Pharmacoeconomic evaluations could provide evidence to help decision makers improve the utilization of scarce resources. However, there remains some challenges especially in modeling due to uncertainties in progression of schizophrenia. There are limited summaries about the overall methodologies of schizophrenia economic evaluations.

Objective: The aim of this study is to review the existing economic evaluations of antipsychotics for the treatment of schizophrenia and summarize the evidence and methods applied.

Methods: An electronic literature search was performed in PubMed, Web of Science, EBSCO host, The Cochrane Library and ScienceDirect from January 2014 to December 2020. Search terms included “schizophrenia,” “schizophrenic,” “pharmacoeconomic,” “economic evaluation,” “cost-effectiveness,” and “cost-utility.” The Literature was screened and extracted by two researchers independently and assessed with the Quality of Health Economic Studies (QHES) List and Consolidated Health Economic Evaluation Reporting Standards (CHEERS) Statement.

Results: A total of 25 studies were included in the review. The regions included Europe, North America, Asia and Africa. Most of the studies chose second-generation antipsychotics as comparators and integrated treatment sequences. Time horizons varied from 1 year to lifetime. The healthcare sector was the most common perspective, accordingly, most of the evaluations considered only direct medical costs. The Markov model and decision tree model were the most common choices. Adverse events, compliance and persistence were considered important parameters. Quality-adjusted life-years were the major outcomes applied to the economic evaluations. All utilities for health states and adverse events were collected from published literature. All of the studies applied uncertainty analysis to explore the robustness of the results. The quality of the studies was generally satisfactory. However, improvements were needed in the choice of time horizons, the measurements of outcomes and the descriptions of assumptions.

Conclusions: This study highlights the methodology of economic evaluation of schizophrenia. Recommendations for modeling method and future study are provided.

Olanzapine induced reproductive toxicity in male rats

Although it is reported that olanzapine (OLZ), which is an atypical antipsychotic drug, causes sexual dysfunction in men, it is noteworthy that there is not any study evaluating the toxic effects of OLZ on the male reproductive system. In the scope of this research, it was aimed to assess the reproductive toxic effects of OLZ by oral administration of 2.5, 5, or 10 mg/kg of it to male rats for 28 days. For this purpose, sperm concentration, motility and morphology, and DNA damage were determined, and histopathological examination of testis tissue was carried out in rats. Also, the levels of serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone, which play roles in the regulation of reproductive functions, and the levels of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) which play roles in reproductive pathologies as oxidative stress biomarkers, were determined. According to the results, normal sperm morphology was decreased in 5 ve 10 mg/kg OLZ-administered groups, and pathological findings were evident in the testicular structure of the OLZ-administered group when compared with the control group. It was determined that serum LH, FSH, and testosterone levels were decreased in the OLZ-administered group. Also, decreases of GSH levels in testis tissue were determined and evaluated as the markers of the oxidative stress induced by OLZ in the testis. In conclusion, it was determined that reproductive toxic effects were induced in rats by OLZ administration. This pathology was accompanied by alterations of the hormone levels and testicular oxidative stress.

Cost-effectiveness of aripiprazole orally disintegrating tablets in the treatment of schizophrenia in China

BACKGROUND

Orally disintegrating tablet (ODT) formulation of antipsychotics is one of the innovative drug delivery systems developed to improve medication adherence. We aimed to evaluate the cost-effectiveness of aripiprazole ODT vs. aripiprazole standard oral tablet (SOT), as well as olanzapine SOT in China.

METHODS

We developed a discrete event simulation model from government payers' perspective. On the entry, 100,000 patients in each group were simulated for relapse, adverse events, changing adherence level, medication discontinuation, switching or quitting in response to three different medication adherence levels. The model projected quality adjusted life years (QALYs) and treatment costs over a 1-year time horizon. Parameter uncertainties were assessed through sensitivity analyses.

RESULTS

The QALYs per patient over 1-year treatment with aripiprazole ODT, aripiprazole SOT, or olanzapine SOT, were 0.7282, 0.7112, and 0.7218, respectively. The corresponding costs were $1,423, $2,215, and $1,493. In both comparisons, aripiprazole ODT was dominant. Compared with aripiprazole SOT and olanzapine SOT, the likelihood of aripiprazole ODT being cost-effective was 99.2% and 69.2%, respectively, using 3 times per capita GDP per QALY as willingness-to-pay threshold.

CONCLUSIONS

The aripiprazole ODT is associated with more QALYs at lower costs compared with both aripiprazole SOT and olanzapine SOT in treating schizophrenia in China.

A Systematic Review of Economic Models Across the Entire Schizophrenia Pathway

BACKGROUND

Schizophrenia is associated with a high economic burden. Economic models can help to inform resource allocation decisions to maximise benefits to patients.

OBJECTIVES

This systematic review aims to assess the availability, quality and consistency of conclusions of health economic models evaluating the cost effectiveness of interventions for schizophrenia.

METHODS

An electronic search was performed on multiple databases (MEDLINE, EMBASE, PsycINFO, Cochrane database of systematic reviews, NHS Economic Evaluation Database and Health Technology Assessment database) to identify economic models of interventions for schizophrenia published between 2005 and 2020. Two independent reviewers selected studies for inclusion. Study quality was assessed using the National Institute for Health and Care Excellence (NICE) checklist and the Cooper hierarchy. Model characteristics and conclusions were descriptively summarised.

RESULTS

Seventy-three models met inclusion criteria. Seventy-eight percent of existing models assessed antipsychotics; however, due to inconsistent conclusions reported by different studies, no antipsychotic can be considered clearly cost effective compared with the others. A very limited number of models suggest that the following non-pharmacological interventions might be cost effective: psychosocial interventions, stratified tests, employment intervention and intensive intervention to improve liaison between primary and secondary care. The quality of included models is generally low due to use of a short time horizon, omission of adverse events of interventions, poor data quality and potential conflicts of interest.

CONCLUSIONS

This review highlights a lack of models for non-pharmacological interventions, and limitations of the existing models, including low quality and inconsistency in conclusions. Recommendations on future modelling approaches for schizophrenia are provided.

Open-Label, Randomized, Single-Dose, 2-Period, 2-Sequence Crossover, Comparative Pharmacokinetic Study to Evaluate Bioequivalence of 2 Oral Formulations of Olanzapine Under Fasting and Fed Conditions

Olanzapine, a second-generation atypical antipsychotic drug, is widely used for schizophrenia and moderate to severe mania associated with bipolar disorders. This open-label, randomized, single-dose, 2-sequence, 2-period crossover, comparative pharmacokinetic study assessed the bioequivalence of 5 mg of olanzapine administered in tablet (R) or disintegrating tablet (T) formulation in healthy Chinese volunteers under both fasting and fed conditions. Numbers of enrolled subjects were 30 and 24 for fasting and fed treatments, respectively. Blood samples were drawn and collected predose as well as up to 144 hours postdose. The plasma concentration of olanzapine was quantitated by a robust, rapid, and sensitive liquid chromatography-tandem mass spectrometry method. The R was bioequivalent to T formulation under either fasting or fed conditions. The 90%CI for ratios of the geometric means observed maximum plasma concentration, area under the curve from time 0 extrapolated to last time point, and area under the curve from time 0 extrapolated to infinity were all within the allowed limit (80.0% to 125.0%). The pharmacokinetic profiles of T and R formulations were similar under fasting and fed conditions. Both formulations were well tolerated, with a similar incidence of treatment-emergent adverse events under fasting and fed conditions.

Optimized UPLC-MS/MS method for the quantitation of olanzapine in human plasma: application to a bioequivalence study

Aim: Olanzapine (OLZ) is the first-line, cost-effectiveness treatment for schizophrenia in China. A quantitative ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determination of OLZ in human plasma was developed. Results: LC separation was achieved on Waters XBrige C₁₈ column. ESI⁺ was involved and multiple reaction monitoring transitions were at m/z 313.2→256.1 for OLZ and m/z 316.2→256.1 IS (d3-OLZ). The linear range was 0.1-20 ng/ml with LLOQ of 0.1 ng/ml. Accuracy and precision were within 10%. The validated method was successfully applied to a bioequivalence study of OLZ disintegrating tablets at dose of 5 mg with 100% reproducibility evaluated by incurred sample reanalysis. Conclusion: A robust validated method was developed for quantitation of OLZ in human plasma.