A retrospective investigation of HLA-B*5801 in hyperuricemia patients in a Han population of China.

BACKGROUND: Hyperuricemia and gout have become increasingly prevalent in China. Allopurinol is an effective urate-lowering therapy, but it has severe side effects. HLA-B*5801 is highly associated with the allopurinol-induced toxic epidermal necrolysis and Stevens-Johnson syndrome. PATIENTS AND METHODS: In this retrospective report, we had genotyped HLA-B*5801 in 253 cases of hyperuricemia and gout patients in a Han population in Shenzhen and analyzed the clinical management of medications. RESULTS: We found 30 carriers of the HLA-B*5801 allele in 253 cases of hyperuricemia or gout patients in the population (11.9%). Allopurinol was prescribed in both HLA-B*5801-positive and HLA-B*5801-negative groups. The evaluation of four models with or without genetic screening and management of allopurinol or febuxostat indicated that the HLA-B*5801 screening had significant cost benefit for clinical management. CONCLUSION: For appropriate management and cost-effectiveness, the HLA-B*5801 allele should be screened in all patients with hyperuricemia and gout in the Chinese population.

Impact of Non-Adherence and Flare Resolution on the Cost-Effectiveness of Treatments for Gout: Application of a Linked Pharmacometric/Pharmacoeconomic Model.

BACKGROUND: Dual urate-lowering therapy (ULT) with lesinurad in combination with either allopurinol or febuxostat is an option for patients with gout unsuccessfully treated on either monotherapy. Treatment failure is often a result of poor medication adherence. Imperfect adherence in clinical trials may lead to biased estimates of treatment effect and confound the results of cost-effectiveness analyses. OBJECTIVES: To estimate the impact of varying medication adherence on the cost effectiveness of lesinurad dual therapy and estimate the value-based price of lesinurad at which the incremental cost-effectiveness ratio is equal to £20,000 per quality-adjusted life-year (QALY). METHODS: Treatment effect was simulated using published pharmacokinetic-pharmacodynamic models and scenarios representing adherence in clinical trials, routine practice, and perfect use. The subsequent cost and health impacts, over the lifetime of a patient cohort, were estimated using a bespoke pharmacoeconomic model. RESULTS: The base-case incremental cost-effectiveness ratios comparing lesinurad dual ULT with monotherapy ranged from £39,184 to £78,350/QALY gained using allopurinol and £31,901 to £124,212/QALY gained using febuxostat, depending on the assumed medication adherence. Results assuming perfect medication adherence imply a per-quarter value-based price of lesinurad of £45.14 when used in dual ULT compared with allopurinol alone and £57.75 compared with febuxostat alone, falling to £25.41 and £3.49, respectively, in simulations of worsening medication adherence. CONCLUSIONS: The estimated value-based prices of lesinurad only exceeded that which has been proposed in the United Kingdom when assuming both perfect drug adherence and the eradication of gout flares in sustained treatment responders.

Combining Model-Based Clinical Trial Simulation, Pharmacoeconomics, and Value of Information to Optimize Trial Design.

The Bayesian decision-analytic approach to trial design uses prior distributions for treatment effects, updated with likelihoods for proposed trial data. Prior distributions for treatment effects based on previous trial results risks sample selection bias and difficulties when a proposed trial differs in terms of patient characteristics, medication adherence, or treatment doses and regimens. The aim of this study was to demonstrate the utility of using pharmacometric-based clinical trial simulation (CTS) to generate prior distributions for use in Bayesian decision-theoretic trial design. The methods consisted of four principal stages: a CTS to predict the distribution of treatment response for a range of trial designs; Bayesian updating for a proposed sample size; a pharmacoeconomic model to represent the perspective of a reimbursement authority in which price is contingent on trial outcome; and a model of the pharmaceutical company return on investment linking drug prices to sales revenue. We used a case study of febuxostat versus allopurinol for the treatment of hyperuricemia in patients with gout. Trial design scenarios studied included alternative treatment doses, inclusion criteria, input uncertainty, and sample size. Optimal trial sample sizes varied depending on the uncertainty of model inputs, trial inclusion criteria, and treatment doses. This interdisciplinary framework for trial design and sample size calculation may have value in supporting decisions during later phases of drug development and in identifying costly sources of uncertainty, and thus inform future research and development strategies.

Cost-effectiveness of sequential urate lowering therapies for the management of gout in Singapore.

Aims: Allopurinol is the most common urate lowering therapy (ULT) used to treat gout but may cause life-threatening severe cutaneous adverse reactions (SCAR) in a small number of patients. Risk of SCAR is increased for patients with the HLA-B*58:01 genotype. When alternative ULT is required, febuxostat or probenecid are recommended. The aim of this study was to conduct a cost-utility analysis of sequential ULT treatment strategies for gout, including strategies with and without HLA-B*58:01 genotyping prior to treatment initiation, with a view to inform optimal gout management in Singapore.Materials and methods: A Markov model was developed from the Singapore healthcare payer perspective. Reflecting local practice, 12 different treatment strategies containing at least one ULT (allopurinol, febuxostat, probenecid) were evaluated in adults with gout. Response rates (SUA < 6mg/dL) were derived from an in-house network meta-analysis and from published literature. Incremental cost-effectiveness ratios (ICERs) were calculated over a 30-year time horizon, with costs and benefits discounted at 3% per annum. Sensitivity analyses were conducted to explore uncertainties.Results: Sequential treatment of allopurinol 300 mg/day-allopurinol 600 mg/day-probenecid ("standard of care") was cost-effective compared to no ULT, with an ICER of SGD1,584/QALY. Allopurinol300-allopurinol600-probenecid-febuxostat sequence compared to allopurinol300-allopurinol600-probenecid had an ICER of SGD11,400/QALY. All other treatment strategies were dominated by preceding strategies. Treatment strategies incorporating HLA-B*58:01 genotyping before ULT use were dominated by the corresponding non-genotyping strategy.Conclusions: Current standard of care (allopurinol300-allopurinol 600-probenecid) for gout is cost-effective compared with no ULT in the local context. Febuxostat is unlikely to be cost-effective in Singapore at current prices unless it is used last-line.

The impact of adoption of a new urate-lowering agent on trends in utilization and cost in practice.

OBJECTIVES: Changes in treatment choice of therapy and size of treated population that can lead to under- or overestimate of payer's budget are less likely to be reassured after reimbursement adoption of a new drug. The aim of this study was to evaluate the effects of febuxostat introduction and the modifications in its insurance coverage on the utilization and expenditure of urate-lowering therapy (ULT). METHODS: Electronic medical records for adults patients prescribed any ULT during 2010-2015 was derived from the largest medical organization in Taiwan. Aggregated estimates of ULT use and costs were assessed per 3-month and per patient per month (PPPM). Factors associated with total ULT expenditure were assessed using a time series design with factored Autoregressive Integrated Moving Average (ARIMA) models. RESULTS: ULT prevalent users increased 34.1% from 2010 to 2015 and a 123% increase in total ULT expenditure. Numbers on allopurinol and sulfinpyrazone both declined 31%, and on benzbromarone and febuxostat gradually increased to 38.21% and 22.89% of all users in 2015. Insurance payments PPPM ($4.44 to $9.22) and total monthly ULT cost ($32,946 to $ 85,732) growth more than doubled in 6 years, trend changes generated mostly by individuals switching to febuxostat. CONCLUSIONS: ULT use moved to favor benzbromarone and febuxostat; greater expensive uptake for febuxostat led to a rapid rise in ULT cost. Marginal values of increasing access to febuxostat for asymptomatic hyperuricemia should be focus on future studies to facilitate drug prices negotiation and ensure appropriate ULT use.

Second-line treatment with lesinurad and allopurinol versus febuxostat for management of hyperuricemia: a cost-effectiveness analysis for Spanish patients.

INTRODUCTION/OBJECTIVES: Lesinurad, in combination with allopurinol, has been approved for treatment of patients with gout which do not reach therapeutic serum urate target with xanthine oxidase inhibitors monotherapy. The study aimed to assess the incremental cost-effectiveness ratio of adding lesinurad to allopurinol as second-line therapy, compared to febuxostat for patients with gout in Spain. METHOD: A Markov model representing disease evolution was used to estimate the lifetime accumulated cost and benefits in terms of quality-adjusted-life-year (QALY). Patients could either continue with second-line treatment with lesinurad (200 mg/daily) plus allopurinol (400 mg/daily) or febuxostat (80 mg/daily) switch to allopurinol monotherapy (271 mg/daily) in case of intolerance or discontinue treatment. The treatment's efficacy captured in the transition probabilities between health states were derived from CLEAR and EXCEL trials. Quality of life related to gout severity and flare frequency was considered by means of utilities. The total cost estimation (€, 2019) included drug acquisition cost, disease monitoring, and flare management cost. Unitary local costs derived from databases and literature. A 3% annual discount rate was applied for cost and outcomes. RESULTS: Lesinurad plus allopurinol provided higher QALYs (14.79) than febuxostat (14.69). Total accrued cost/patient was lower with lesinurad and allopurinol (€50,631.51) versus febuxostat (€56,698.64). Lesinurad plus allopurinol resulted more effective and less costly (dominant option) versus febuxostat. CONCLUSIONS: Lesinurad plus allopurinol therapy compared with febuxostat seems an effective option for the management of hyperuricemia in patients who did not reach serum urate target to previous allopurinol monotherapy, associated to cost-savings for the Spanish Health System.Key Points• Lesinurad, in combination with allopurinol, has been recently authorized as second-line treatment of hyperuricemia in gout patients.• Lesinurad plus allopurinol provided higher effectiveness in terms of quality-adjusted-life-years (14.79) than febuxostat (14.69).• Lesinurad plus allopurinol resulted less costly (total cost/per patient) compared with febuxostat.• Lesinurad plus allopurinol resulted a dominant option compared with febuxostat.

Integration of Pharmacometrics and Pharmacoeconomics to Quantify the Value of Improved Forgiveness to Nonadherence: A Case Study of Novel Xanthine Oxidase Inhibitors for Gout.

Linked pharmacometric and pharmacoeconomic models provide a structured approach for assessing the value of candidate drugs in development. The aim of this study was to assess the utility of such an approach for identifying the properties of xanthine oxidase inhibitors (XOi) providing improved forgiveness to nonadherence and estimate the maximum reimbursement price. The pharmacometric and pharmacoeconomic models were used to simulate the time course of serum uric acid concentrations and estimate quality-adjusted life years and costs for the XOi febuxostat and a range of hypothetical analogues. Compounds with reduced clearance or increased potency were more forgiving to missed doses, however, even following relatively large changes in these properties the predicted maximum reimbursement prices represented an increase of only 19% above febuxostat 80 mg. Linked pharmacometric and pharmacoeconomic modeling methods have the potential to inform early drug development by providing an indication of pricing options that may permit reimbursement.

Cost-Effectiveness Analysis of Lesinurad/Allopurinol Versus Febuxostat for the Management of Gout/Hyperuricemia in Italy.

BACKGROUND: Until very recently the only therapeutic alternative for the management of patients affected by gout/hyperuricemia that did not respond to a first-line treatment based on allopurinol alone or who cannot tolerate allopurinol was febuxostat, a xanthine oxidase non-purine-selective inhibitor. Lately, however, a new therapeutic alternative has become available for the management of this pathology: lesinurad, a urate transporter inhibitor. OBJECTIVE: To objective of this study was to evaluate the cost effectiveness of lesinurad/allopurinol in comparison with febuxostat as a second-line therapeutic strategy for the management of patients affected by gout and hyperuricemia that did not respond to a first-line therapy based on allopurinol alone. METHODS: A Markov model was built based on the natural history of the pathology; patients entered the model according to their level of serum uric acid concentration and flowed across it according to their response to the therapy. The analysis was carried out considering the perspective of the Italian National Health Service on a lifetime horizon and 6-month cycles. Costs and quality-adjusted life-years (QALYs) were discounted at a 3.5% yearly rate. The results of the model were expressed in terms of incremental cost-effectiveness ratio (ICER). Both a one-way and a multi-way Monte-Carlo analysis were carried out in order to check the robustness of the results achieved. RESULTS: The ICER derived from the comparison was equal to €77.53/QALY on the lifetime horizon, as there was a higher level of costs associated with the combination as compared with febuxostat (€10,658.27 vs. €10,645.87, for a differential of €12.40) and a higher level of QALYs achieved (7.77 vs. 7.61, for a differential of 0.16). CONCLUSIONS: The lesinurad/allopurinol combination is recommended for the treatment of patients affected by gout/hyperuricemia in the Italian Health System as it appears to be cost effective and thus sustainable for the Italian healthcare sector.

Cost-effectiveness analysis of febuxostat in patients with gout in Spain.

UNLABELLED: Objectives Cost-effectiveness of febuxostat compared with allopurinol in the treatment of hyperuricemia in patients with gout. Methods Costs, clinical outcomes, and QALYs were estimated using a Markov model. Febuxostat 80 mg and 120 mg sequentially, used as first line and second line therapy, was compared with allopurinol 300 mg. Patients switched to the next treatment in the sequence according to a dichotomous response vs no response (target serum urate level < 6 mg/dl outcome) after 3 months of active treatment. A 3% discount rate and 5-year time horizon were applied. PERSPECTIVE: National Health System. Results The addition of febuxostat to any therapeutic strategy was an efficient option, with incremental cost-effectiveness ratios (ICER) compared with allopurinol 300 mg ranging from €5268-€9737. Conclusions Febuxostat is a cost-effective treatment in Spain for the management of hyperuricemia in gout patients, with ICERs far below accepted Spanish efficiency thresholds (30 000€/QALY).

Febuxostat in the management of gout: a cost-effectiveness analysis.

OBJECTIVE: To determine the cost-effectiveness of febuxostat vs allopurinol for the management of gout. METHODS: A stochastic microsimulation cost-effectiveness model with a US private-payer perspective and 5-year time horizon was developed. Model flow based on guideline and real-world treatment paradigms incorporated gout flare, serum uric acid (sUA) testing, treatment titration, discontinuation, and adverse events, chronic kidney disease (CKD) incidence and progression, and type 2 diabetes mellitus (T2DM) incidence. Outcomes were estimated for the general gout population and for gout patients with CKD stages 3/4. Modeled treatment interventions were daily oral febuxostat 40-80 mg and allopurinol 100-300 mg. Baseline patient characteristics were taken from epidemiologic studies, efficacy data from randomized controlled trials, adverse event rates from package inserts, and costs from the literature, government sources, and expert opinion. Eight clinically-relevant incremental cost-effectiveness ratios were estimated: per patient reaching target sUA, per flare avoided, per CKD incidence, progression, stages 3/4 progression, and stage 5 progression avoided, per incident T2DM avoided, and per death avoided. RESULTS: Five-year incremental cost-effectiveness ratios for the general gout population were $5377 per patient reaching target sUA, $1773 per flare avoided, $221,795 per incident CKD avoided, $29,063 per CKD progression avoided, $36,018 per progression to CKD 3/4 avoided, $71,426 per progression to CKD 5 avoided, $214,277 per incident T2DM avoided, and $217,971 per death avoided. In patients with CKD 3/4, febuxostat dominated allopurinol for all cost-effectiveness outcome measures. CONCLUSIONS: Febuxostat may be a cost-effective alternative to allopurinol, especially for patients with CKD stages 3 or 4.

Cost Comparison of Urate-Lowering Therapies in Patients with Gout and Moderate-to-Severe Chronic Kidney Disease.

BACKGROUND: Patients with chronic kidney disease (CKD) are at increased risk for developing gout and having refractory disease. Gout flare prevention relies heavily on urate-lowering therapies such as allopurinol and febuxostat, but clinical decision making in patients with moderate-to-severe CKD is complicated by significant comorbidity and the scarcity of real-world cost-effectiveness studies. OBJECTIVE: To compare total and disease-specific health care expenditures by line of therapy in allopurinol and febuxostat initiators after diagnosis with gout and moderate-to-severe CKD. METHODS: A retrospective observational cohort study was conducted to compare mean monthly health care cost (in 2012 U.S. dollars) among gout patients with CKD (stage 3 or 4) who initiated allopurinol or febuxostat. The primary outcome was total mean monthly health care expenditures, and the secondary outcome was disease-specific (gout, diabetes, renal, and cardiovascular disease [CVD]) expenditures. Gout patients (ICD-9-CM 274.xx) aged ≥ 18 years with concurrent CKD (stage 3 or 4) were selected from the MarketScan databases (January 2009-June 2012) upon allopurinol or febuxostat initiation. Patients were followed until disenrollment, discontinuation of the qualifying study agent, or use of the alternate study agent. Patients initiating allopurinol were subsequently propensity score-matched (1:1) to patients initiating febuxostat. Five generalized linear models (GLMs) were developed, each controlling for propensity score, to identify the incremental costs (vs. allopurinol) associated with febuxostat initiation in first-line (without prior allopurinol exposure) and second-line (with prior allopurinol exposure) settings. RESULTS: Propensity score matching yielded 2 cohorts, each with 1,486 patients (64.6% male, mean [SD] age 67.4 [12.8] years). Post-match, 74.6% of patients had stage 3 CKD; 82.9% had CVD; and 42.1% had diabetes. The post-match sample was well balanced on numerous comorbidities and medication exposures with the following exception: 50.0% of febuxostat initiators were treated in the second-line setting; that is, they had baseline exposure to allopurinol, whereas only 4.2% of allopurinol initiators had baseline exposure to febuxostat. Unadjusted mean monthly cost was $1,490 allopurinol and $1,525 febuxostat (P = 0.809). GLM results suggest that first-line febuxostat users incurred significantly (P = 0.009) lower cost than allopurinol users ($1,299 vs. $1,487), whereas second-line febuxostat initiators incurred significantly (P = 0.001) higher cost ($1,751 vs. $1,487). Febuxostat initiators in both settings had significantly (P < 0.001) higher gout-specific cost, due to higher febuxostat acquisition cost. Increased gout-specific cost in the first-line febuxostat cohort was offset by significantly (P < 0.001) lower CVD ($288 vs. $459) and renal-related cost ($86 vs. $216). There were no significant differences in either renal or CVD costs (adjusted) between allopurinol initiators treated almost exclusively in the first-line setting and second-line febuxostat patients. CONCLUSIONS: Gout patients with concurrent CKD, initiating treatment with febuxostat in a first-line setting, incurred significantly less total cost than patients initiating allopurinol during the first exposure to each agent. Conversely, patients treated with second-line febuxostat following allopurinol incurred significantly higher total cost than patients initiating allopurinol. There was no significant difference in total cost between the agents across line of therapy. Although study findings suggest the potential for CVD and renal-related savings to offset febuxostat's higher acquisition cost in gout patients with moderate-to-severe CKD, this is the first such retrospective evaluation. Future research is warranted to both demonstrate the durability of study findings and to better elucidate the mechanism by which associated cost offsets occur. DISCLOSURES: No outside funding supported this study. Turpin is an employee of Takeda Pharmaceuticals U.S.A. Mitri and Wittbrodt were employees of Takeda Pharmaceuticals U.S.A. at the time of this study. Tidwell and Schulman are employees of Outcomes Research Solutions, consultants to Takeda Pharmaceuticals U.S.A. All authors contributed to the design of the study and to the writing and review of the manuscript. All authors read and approved the final manuscript. Tidwell and Schulman collected the data, and all authors participated in data interpretation.