Cabazitaxel for the second-line treatment of metastatic hormone-refractory prostate cancer: a NICE single technology appraisal

Dynamic and Flexible Survival Models for Extrapolation of Relative Survival: A Case Study and Simulation Study

BACKGROUND

Extrapolation of survival data is a key task in health technology assessments (HTAs), which may be improved by incorporating general population mortality data via relative survival models. Dynamic survival models are a promising method for extrapolation that may be expanded to dynamic relative survival models (DRSMs), a novel development presented here. There are currently neither examples of dynamic models in HTA nor comparisons of DRSMs with other relative survival models when used for survival extrapolation.

METHODS

An existing appraisal, for which there had been disagreement over the approach to survival extrapolation, was chosen and the health economic model recreated. The sensitivity of estimates of cost-effectiveness to different model choices (standard survival models, DSMs, and DRSMs) and specifications was examined. The appraisal informed a simulation study to evaluate DRSMs with relative survival models based on both standard and spline-based (flexible) models.

RESULTS

Dynamic models provided insight into the behavior of the trend in the hazard function and how it may vary during the extrapolated phase. DRSMs led to extrapolations with improved plausibility for which model choice may be based on clinical input. In the simulation study, the flexible and dynamic relative survival models performed similarly and provided highly variable extrapolations.

LIMITATIONS

Further experience with these models is required to identify settings when they are most useful, and they provide sufficiently accurate extrapolations.

CONCLUSIONS

Dynamic models provide a flexible and attractive method for extrapolating survival data and facilitate the use of clinical input for model choice. Flexible and dynamic relative survival models make few structural assumptions and can improve extrapolation plausibility, but further research is required into methods for reducing the variability in extrapolations.

How Uncertain is the Survival Extrapolation? A Study of the Impact of Different Parametric Survival Models on Extrapolated Uncertainty About Hazard Functions, Lifetime Mean Survival and Cost Effectiveness

BACKGROUND AND OBJECTIVE

The extrapolation of estimated hazard functions can be an important part of cost-effectiveness analyses. Given limited follow-up time in the sample data, it may be expected that the uncertainty in estimates of hazards increases the further into the future they are extrapolated. The objective of this study was to illustrate how the choice of parametric survival model impacts on estimates of uncertainty about extrapolated hazard functions and lifetime mean survival.

METHODS

We examined seven commonly used parametric survival models and described analytical expressions and approximation methods (delta and multivariate normal) for estimating uncertainty. We illustrate the multivariate normal method using case studies based on four representative hypothetical datasets reflecting hazard functions commonly encountered in clinical practice (constant, increasing, decreasing, or unimodal), along with a hypothetical cost-effectiveness analysis.

RESULTS

Depending on the survival model chosen, the uncertainty in extrapolated hazard functions could be constant, increasing or decreasing over time for the case studies. Estimates of uncertainty in mean survival showed a large variation (up to sevenfold) for each case study. The magnitude of uncertainty in estimates of cost effectiveness, as measured using the incremental cost per quality-adjusted life-year gained, varied threefold across plausible models. Differences in estimates of uncertainty were observed even when models provided near-identical point estimates.

CONCLUSIONS

Survival model choice can have a significant impact on estimates of uncertainty of extrapolated hazard functions, mean survival and cost effectiveness, even when point estimates were similar. We provide good practice recommendations for analysts and decision makers, emphasizing the importance of considering the plausibility of estimates of uncertainty in the extrapolated period as a complementary part of the model selection process.

A Review of Survival Analysis Methods Used in NICE Technology Appraisals of Cancer Treatments: Consistency, Limitations, and Areas for Improvement

Objectives. In June 2011, the National Institute for Health and Care Excellence (NICE) Decision Support Unit published a Technical Support Document (TSD) providing recommendations on survival analysis for NICE technology appraisals (TAs). Survival analysis outputs are influential inputs into economic models estimating the cost-effectiveness of new cancer treatments. Hence, it is important that systematic and justifiable model selection approaches are used. This study investigates the extent to which the TSD recommendations have been followed since its publication. Methods. We reviewed NICE cancer TAs completed between July 2011 and July 2017. Information on survival analyses undertaken and associated critiques for overall survival (OS) and progression-free survival were extracted from the company submissions, Evidence Review Group (ERG) reports, and final appraisal determination documents. Results. Information was extracted from 58 TAs. Only 4 (7%) followed all TSD recommendations for OS outcomes. The vast majority (91%) compared a range of common parametric models and assessed their fit to the data (86%). Only a minority of TAs included an assessment of the shape of the hazard function (38%) or proportional hazards assumption (40%). Validation of the extrapolated portion of the survival function using external data was attempted in a minority of TAs (40%). Extrapolated survival functions were frequently criticized by ERGs (71%). Conclusions. Survival analysis within NICE TAs remains suboptimal, despite publication of the TSD. Model selection is not undertaken in a systematic way, resulting in inconsistencies between TAs. More attention needs to be given to assessing hazard functions and validation of extrapolated survival functions. Novel methods not described in the TSD have been used, particularly in the context of immuno-oncology, suggesting that an updated TSD may be of value.

Multiple Criteria Decision Analysis for HTA across four EU Member States: Piloting the Advance Value Framework

Multiple Criteria Decision Analysis (MCDA) has emerged as a methodology for Health Technology Assessment (HTA). However, limited empirical evidence is available on its use by decision-makers; where available, it only comes from single-setting exercises, while cross-country comparative studies are unavailable. This study applies the Advance Value Framework (AVF), an MCDA methodology for HTA based on multi-attribute value theory, through a series of case studies with decision-makers in four countries, to explore its feasibility and compare decision-makers' value preferences and results. The AVF was applied in the evaluation of three drugs for metastatic, castrate resistant, prostate cancer (abiraterone, cabazitaxel and enzalutamide) in the post-chemotherapy indication. Decision conferences were organised in four European countries in collaboration with their HTA or health insurance organisations by involving relevant assessors and experts: Sweden (TLV), Andalusia/Spain (AETSA), Poland (AOTMiT) and Belgium (INAMI-RIZIV). Participants' value preferences, including performance scoring and criteria weighting, were elicited through a facilitated decision-analysis modelling approach using the MACBETH technique. Between 6 and 11 criteria were included in each jurisdiction's value model, allocated across four criteria domains; Therapeutic Benefit criteria consistently ranked first in relative importance across all countries. Consistent drug rankings were observed in all settings, with enzalutamide generating the highest overall weighted preference value (WPV) score, followed by abiraterone and cabazitaxel. Dividing drugs' overall WPV scores by their costs produced the lowest "cost per unit of value" for enzalutamide, followed by abiraterone and cabazitaxel. These results come in contrast with the actual country HTA recommendations and pricing decisions. Overall, although some differences in value preferences were observed between countries, drug rankings remained the same. The MCDA methodology employed could act as a decision support tool in HTA, due to the transparency in the construction of value preferences in a collaborative manner.

Cost-effectiveness analyses and cost analyses in castration-resistant prostate cancer: A systematic review

Background

Treatment of metastatic prostate cancer is associated with high personal and economic burden. Recently, new treatment options for castration-resistant prostate cancer became available with promising survival advantages. However, cost-effectiveness of those new treatment options is sometimes ambiguous or given only under certain circumstances. The aim of this study was to systematically review studies on the cost-effectiveness of treatments and costs of castration-resistant prostate cancer (CRPC) and metastasizing castration-resistant prostate cancer (mCRPC) on their methodological quality and the risk of bias.

Methods

A systematic literature search was performed in the databases PubMed, CINAHL Complete, the Cochrane Library and Web of Science Core Collection for costs-effectiveness analyses, model-based economic evaluations, cost-of-illness analyses and budget impact analyses. Reported costs were inflated to 2015 US$ purchasing power parities. Quality assessment and risk of bias assessment was performed using the Consolidated Health Economic Evaluation Reporting Standards checklist and the Bias in Economic Evaluations checklist, respectively.

Results

In total, 38 articles were identified by the systematic literature search. The methodological quality of the included studies varied widely, and there was considerable risk of bias. The cost-effectiveness treatments for CRPC and mCRPC was assessed with incremental cost-effectiveness ratios ranging from dominance for mitoxantrone to $562,328 per quality-adjusted life year gained for sipuleucel-T compared with prednisone alone. Annual costs for the treatment of castration-resistant prostate cancer ranged from $3,067 to $77,725.

Conclusion

The cost-effectiveness of treatments of CRPC strongly depended on the willingness to pay per quality-adjusted life year gained/life-year saved throughout all included costs-effectiveness analyses and model-based economic evaluations. High-quality cost-effectiveness analyses based on randomized controlled trials are needed in order to make informed decisions on the management of castration-resistant prostate cancer and the resulting financial impact on the healthcare system.

Current therapeutic options in metastatic castration-resistant prostate cancer

BACKGROUND

The tumors of many patients with prostate cancer eventually become refractory to androgen deprivation therapy with progression to metastatic castration-resistant disease. Significant advances in the treatment of metastatic castration-resistant prostate cancer (mCRPC) have been made in recent years, and new treatment strategies have recently been made available. The aim of this report was to schematically review all the approved pharmacologic treatment options for patients with mCRPC through 2018, analyzing the efficacy and possible side effects of each therapy to assist clinicians in reaching an appropriate treatment decision. New biomarkers potentially of aid in the choice of treatment in this setting are also briefly reviewed.

METHODS

We performed a literature search of clinical trials of new drugs and treatments for patients diagnosed with mCRPC published through 2018.

RESULTS

Two new hormonal drugs, abiraterone acetate and enzalutamide have been approved by FDA in 2011 and 2012, respectively for the treatment of patients with mCRPC and have undergone extensive testing. While these treatments have shown a benefit in progression-free and overall survival, the appropriate sequencing must still be determined so that treatment decisions can be made based on their specific clinical profile. Cabazitaxel has been shown to be an efficient therapeutic option in a postdocetaxel setting, while its role in chemotherapy-naïve patients must still be determined. Sipuleucel-T and radium-223 have been studied in patients without visceral metastases and have achieved overall survival benefits with good safety profiles. The feasibility and efficacy of combinations of new treatments with other known therapies such as chemotherapy are currently under investigation.

CONCLUSIONS

Drug development efforts continue to attempt to prolong survival and improve quality of life in the mCRPC setting, with several therapeutic options available. Ongoing and future trials are needed to further assess the efficacy and safety of these new drugs and their interactions, along with the most appropriate sequencing.

Evaluating the Benefits of New Drugs in Health Technology Assessment Using Multiple Criteria Decision Analysis: A Case Study on Metastatic Prostate Cancer With the Dental and Pharmaceuticals Benefits Agency (TLV) in Sweden

Background. Multiple criteria decision analysis (MCDA) has been identified as a prospective methodology for assisting decision makers in evaluating the benefits of new medicines in health technology assessment (HTA); however, limited empirical evidence exists from real-world applications. Objective. To test in practice a recently developed MCDA methodological framework for HTA, the Advance Value Framework, in a proof-of-concept case study with decision makers. Methods. A multi-attribute value theory methodology was adopted applying the MACBETH questioning protocol through a facilitated decision-analysis modelling approach as part of a decision conference with four experts. Settings. The remit of the Swedish Dental and Pharmaceutical Benefits Agency (Tandvårds- och läkemedelsförmånsverket [TLV]) was adopted but in addition supplementary value dimensions were considered. Patients. Metastatic castrate-resistant prostate cancer patients were considered having received prior chemotherapy. Interventions. Abiraterone, cabazitaxel, and enzalutamide were evaluated as third-line treatments. Measurements. Participants’ value preferences were elicited involving criteria selection, options scoring, criteria weighting, and their aggregation. Results. Eight criteria attributes were finally included in the model relating to therapeutic impact, safety profile, socioeconomic impact, and innovation level with relative importance weights 44.5%, 33.3%, 14.8%, and 7.4% per cluster, respectively. Enzalutamide scored the highest overall weighted preference value score, followed by abiraterone and cabazitaxel. Dividing treatments’ overall weighted preference value scores by their costs derived “costs per unit of value” for ranking the treatments based on value-for-money grounds. Limitations. Study limitations included lack of comparative clinical effects across treatments and the small sample of participants. Conclusion. The Advance Value Framework has the prospects of facilitating the evaluation process in HTA and health care decision making; additional research is recommended to address technical challenges and optimize the use of MCDA for policy making.

A New Approach for Sampling Ordered Parameters in Probabilistic Sensitivity Analysis

BACKGROUND

Probabilistic sensitivity analysis (PSA) in cost-effectiveness analysis involves sampling a large number of realisations of an economic model. For some parameters, we may be uncertain around the true mean values of the variables, but the ordering of the values is known. Typical sampling approaches lack either statistical or clinical validity. For example, sampling using a common number generator results in extreme dependence, and independent sampling can lead to realisations with incorrect ordering.

METHODS

We propose a new sampling approach for ordered parameters, the difference method (DM) approach, which samples the parameters of interest via a difference parameter. If the parameters of interest are bounded, it involves transforming the variables so that they are unbounded and then sampling via the difference parameter. We have provided a Microsoft Excel workbook to implement the method. The proposed approach is illustrated with an example sampling ordered parameters for utility and cost.

RESULTS

The DM approach has a number of advantages when comparing with the typical approaches used in practice. It generates PSA samples that have similar summary statistics as the given values in our examples, while maintaining the constraint that one value was greater than another. The method also implies plausible positive correlation between the two ordered variables.

CONCLUSIONS

Both clinical and statistical validity should be checked when producing PSA samples. The DM approach should be considered as a solution to potential problems in generating PSA samples for ordered parameters.

Treatments for Metastatic Prostate Cancer (mPC): A Review of Costing Evidence

BACKGROUND

Prostate cancer (PC) is the most common cancer in Western countries. More than one third of PC patients develop metastatic disease, and the 5-year expected survival in distant disease is about 35%. During the last few years, new treatments have been launched for metastatic castrate-resistant prostate cancer (mCRPC).

OBJECTIVES

We aimed to review the current literature on health economic analysis on the treatment of metastatic prostate cancer (mPC), compare the studies, summarize the findings and make the results available to administrators and decision makers.

METHODS

A systematic literature search was done for economic evaluations (cost-minimization, cost-effectiveness, cost-utility, cost-of-illness, cost-of-drug, and cost-benefit analyses). We employed the PubMed^® search engine and searched for publications published between 2012 and 2016. The terms used were "prostate cancer", "metastatic" and "cost". An initial screening of all headlines was performed, selected abstracts were analysed, and finally the full papers investigated. Study characteristics, treatment and comparator, country, type of evaluation, perspective, year of value, time horizon, efficacy data, discount rate, total costs and sensitivity analysis were analysed. The quality was assessed using the Quality of Health Economic Studies (QHES) instrument.

RESULTS

A total of 227 publications were detected and screened, 58 selected for full-text assessment and 31 included in the final analyses. Despite the significant international literature on the treatment of mCRPC, there were only 15 studies focusing on cost-effectiveness analysis (CEA). Medical treatment constituted two thirds of the selected studies. Significant costs in the treatment of mCRPC were disclosed. In the pre-docetaxel setting, both abiraterone acetate (AA) and enzalutamide were concluded beyond accepted cost/quality-adjusted life year limits. In the docetaxel refractory setting, most studies concluded that enzalutamide was cost-effective and superior to AA. In most studies, cabazitaxel was not recommended, because of high cost. Looking at bone-targeting drugs, generic zoledronic acid (ZA) was recommended. External beam radiotherapy (EBRT) was analysed in three studies, and single fraction radiotherapy was concluded to be cost saving. Radium-223 was documented as beneficial, but costly. The quality of the studies was generally good, but sensitivity analyses, discounting and the measurement of health outcomes were present in less than two thirds of the selected studies.

CONCLUSIONS

The treatment of mCRPC was associated with significant cost. In the post-docetaxel setting, single fraction radiotherapy and enzalutamide were considered cost-effective in most studies. Generic ZA was the recommended bone-targeting therapy.

Cabazitaxel for Hormone-Relapsed Metastatic Prostate Cancer Previously Treated With a Docetaxel-Containing Regimen: An Evidence Review Group Perspective of a NICE Single Technology Appraisal

As part of its single technology appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited the company that manufactures cabazitaxel (Jevtana^®, Sanofi, UK) to submit evidence for the clinical and cost effectiveness of cabazitaxel for treatment of patients with metastatic hormone-relapsed prostate cancer (mHRPC) previously treated with a docetaxel-containing regimen. The School of Health and Related Research Technology Appraisal Group at the University of Sheffield was commissioned to act as the independent Evidence Review Group (ERG). The ERG produced a critical review of the evidence for the clinical and cost effectiveness of the technology based upon the company's submission to NICE. Clinical evidence for cabazitaxel was derived from a multinational randomised open-label phase III trial (TROPIC) of cabazitaxel plus prednisone or prednisolone compared with mitoxantrone plus prednisone or prednisolone, which was assumed to represent best supportive care. The NICE final scope identified a further three comparators: abiraterone in combination with prednisone or prednisolone; enzalutamide; and radium-223 dichloride for the subgroup of people with bone metastasis only (no visceral metastasis). The company did not consider radium-223 dichloride to be a relevant comparator. Neither abiraterone nor enzalutamide has been directly compared in a trial with cabazitaxel. Instead, clinical evidence was synthesised within a network meta-analysis (NMA). Results from TROPIC showed that cabazitaxel was associated with a statistically significant improvement in both overall survival and progression-free survival compared with mitoxantrone. Results from a random-effects NMA, as conducted by the company and updated by the ERG, indicated that there was no statistically significant difference between the three active treatments for both overall survival and progression-free survival. Utility data were not collected as part of the TROPIC trial, and were instead taken from the company's UK early access programme. Evidence on resource use came from the TROPIC trial, supplemented by both expert clinical opinion and a UK clinical audit. List prices were used for mitoxantrone, abiraterone and enzalutamide as directed by NICE, although commercial in-confidence patient-access schemes (PASs) are in place for abiraterone and enzalutamide. The confidential PAS was used for cabazitaxel. Sequential use of the advanced hormonal therapies (abiraterone and enzalutamide) does not usually occur in clinical practice in the UK. Hence, cabazitaxel could be used within two pathways of care: either when an advanced hormonal therapy was used pre-docetaxel, or when one was used post-docetaxel. The company believed that the former pathway was more likely to represent standard National Health Service (NHS) practice, and so their main comparison was between cabazitaxel and mitoxantrone, with effectiveness data from the TROPIC trial. Results of the company's updated cost-effectiveness analysis estimated a probabilistic incremental cost-effectiveness ratio (ICER) of £45,982 per quality-adjusted life-year (QALY) gained, which the committee considered to be the most plausible value for this comparison. Cabazitaxel was estimated to be both cheaper and more effective than abiraterone. Cabazitaxel was estimated to be cheaper but less effective than enzalutamide, resulting in an ICER of £212,038 per QALY gained for enzalutamide compared with cabazitaxel. The ERG noted that radium-223 is a valid comparator (for the indicated sub-group), and that it may be used in either of the two care pathways. Hence, its exclusion leads to uncertainty in the cost-effectiveness results. In addition, the company assumed that there would be no drug wastage when cabazitaxel was used, with cost-effectiveness results being sensitive to this assumption: modelling drug wastage increased the ICER comparing cabazitaxel with mitoxantrone to over £55,000 per QALY gained. The ERG updated the company's NMA and used a random effects model to perform a fully incremental analysis between cabazitaxel, abiraterone, enzalutamide and best supportive care using PASs for abiraterone and enzalutamide. Results showed that both cabazitaxel and abiraterone were extendedly dominated by the combination of best supportive care and enzalutamide. Preliminary guidance from the committee, which included wastage of cabazitaxel, did not recommend its use. In response, the company provided both a further discount to the confidential PAS for cabazitaxel and confirmation from NHS England that it is appropriate to supply and purchase cabazitaxel in pre-prepared intravenous-infusion bags, which would remove the cost of drug wastage. As a result, the committee recommended use of cabazitaxel as a treatment option in people with an Eastern Cooperative Oncology Group performance status of 0 or 1 whose disease had progressed during or after treatment with at least 225 mg/m² of docetaxel, as long as it was provided at the discount agreed in the PAS and purchased in either pre-prepared intravenous-infusion bags or in vials at a reduced price to reflect the average per-patient drug wastage.

Prostate cancer

Much progress has been made in research for prostate cancer in the past decade. There is now greater understanding for the genetic basis of familial prostate cancer with identification of rare but high-risk mutations (eg, BRCA2, HOXB13) and low-risk but common alleles (77 identified so far by genome-wide association studies) that could lead to targeted screening of patients at risk. This is especially important because screening for prostate cancer based on prostate-specific antigen remains controversial due to the high rate of overdiagnosis and unnecessary prostate biopsies, despite evidence that it reduces mortality. Classification of prostate cancer into distinct molecular subtypes, including mutually exclusive ETS-gene-fusion-positive and SPINK1-overexpressing, CHD1-loss cancers, could allow stratification of patients for different management strategies. Presently, men with localised disease can have very different prognoses and treatment options, ranging from observation alone through to radical surgery, with few good-quality randomised trials to inform on the best approach for an individual patient. The survival of patients with metastatic prostate cancer progressing on androgen-deprivation therapy (castration-resistant prostate cancer) has improved substantially. In addition to docetaxel, which has been used for more than a decade, in the past 4 years five new drugs have shown efficacy with improvements in overall survival leading to licensing for the treatment of metastatic castration-resistant prostate cancer. Because of this rapid change in the therapeutic landscape, no robust data exist to inform on the selection of patients for a specific treatment for castration-resistant prostate cancer or the best sequence of administration. Moreover, the high cost of the newer drugs limits their widespread use in several countries. Data from continuing clinical and translational research are urgently needed to improve, and, crucially, to personalise management.

LG308, a Novel Synthetic Compound with Antimicrotubule Activity in Prostate Cancer Cells, Exerts Effective Antitumor Activity

Microtubule plays many different essential roles in the process of tumorigenesis in many eukaryotes, and targeting mitotic progression by disturbing microtubule dynamics is used as a common strategy for cancer treatment. Microtubule-targeted drugs, including paclitaxel and Vinca alkaloids, were previously considered to work primarily by increasing or decreasing the cellular microtubule mass. The tubulin/microtubule system, which is an integral component of the cytoskeleton, is a therapeutic target for prostate cancer. In this study, we found a novel synthetic compound, 8-fluoro-N-phenylacetyl-1, 3, 4, 9-tetrahydro-β-carboline (LG308), which disrupted the microtubule organization via inhibiting the polymerization of microtubule in PC-3M and LNCaP prostate cancer cell lines. Further study proved that LG308 induced mitotic phase arrest and inhibited G2/M progression significantly in LNCaP and PC-3M cell lines in a dose-dependent manner, and these were associated with the upregulation of cyclin B1 and mitotic marker MPM-2 and the dephosphorylation of cdc2. Besides, the cell proliferation and colony formation of PC-3M and LNCaP cells were effectively inhibited by LG308. Furthermore, LG308 induced apoptosis and cell death in PC-3M and LNCaP cell lines in vitro. In vivo, LG308 dramatically suppressed the growth and metastasis of prostate cancer in both xenograft and orthotopic models. All these data indicate that LG308 is a promising anticancer candidate with antimitotic activity for the treatment of prostate cancer.

Rituximab in combination with corticosteroids for the treatment of anti-neutrophil cytoplasmic antibody-associated vasculitis: a NICE single technology appraisal

As part of its single technology appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited the manufacturer of rituximab (Roche Products) to submit evidence of the clinical and cost effectiveness of rituximab in combination with corticosteroids for treatment of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The School of Health and Related Research Technology Appraisal Group at the University of Sheffield was commissioned to act as the independent Evidence Review Group (ERG). The ERG produced a critical review of the evidence for the clinical and cost effectiveness of the technology, based upon the manufacturer's submission to NICE. The evidence was derived mainly from a double-blind, phase III, placebo-controlled trial of rituximab in patients with new or relapsed 'severe' AAV, which compared a rituximab treatment regimen with an oral cyclophosphamide treatment regimen. Intravenous cyclophosphamide is also commonly used but was not included in the pivotal trial. The evidence showed that rituximab is noninferior to oral cyclophosphamide in terms of induction of remission in adults with AAV and de novo disease, and is superior to oral cyclophosphamide in terms of remission in adults who have relapsed once on cyclophosphamide. The ERG concluded that the results of the manufacturer's economic evaluation could not be considered robust, because of errors and because the full range of relevant treatment sequences were not modelled. The ERG amended the manufacturer's model and demonstrated that rituximab was likely to represent a cost-effective addition to the treatment sequence if given after cyclophosphamide treatment.

Economic evaluation of sipuleucel-T immunotherapy in castration-resistant prostate cancer

The objective is to examine the cost-utility of sipuleucel-T immunotherapy in asymptomatic or minimally symptomatic castration-resistant prostate cancer patients. The addition of sipuleucel-T immunotherapy to standard treatment led to a gain of 0.37 quality-adjusted life-year (QALY) at an additional cost of US$104,536. The incremental cost-utility ratio was US$283,000 per QALY saved. Threshold sensitivity analyses indicated that a price reduction of at least 53%, or application in a group of patients resulting in the relative reduction in the mortality rate of at least 39%, ought to augment the economic value of this regimen. Sipuleucel-T immunotherapy treatment at the current price with 96.5% certainty is not cost-effective. The specific group of patients who will benefit more from the treatment should be revealed and treated, or the cost of the vaccine should be lowered significantly to increase its economic value. Accounting for crossover treatment in control patients improves sipuleucel-T's value (US$132,000 per QALY saved) although further investigation is necessary.

Aripiprazole for the treatment and prevention of acute manic and mixed episodes in bipolar I disorder in children and adolescents: a NICE single technology appraisal

As part of its single technology process, the National Institute for Health and Care Excellence (NICE) invited the manufacturers of aripiprazole (Otsuka Pharmaceutical Co. and Bristol Myers Squibb) to submit evidence of the clinical and cost effectiveness of aripiprazole for the treatment and prevention of acute manic and mixed episodes in bipolar I disorder in children and adolescents. The School of Health and Related Research Technology Appraisal Group at the University of Sheffield was commissioned to act as the independent Evidence Review Group (ERG). The ERG produced a critical review of the evidence for the clinical and cost effectiveness of the technology, based upon the manufacturers' submission to NICE. The evidence, which was derived mainly from a double-blind, phase III, placebo-controlled trial of aripiprazole in patients aged 10-17 years, showed that aripiprazole performed significantly better than placebo in reducing mania according to the primary outcome measurement (the Young Mania Rating Scale at 4 weeks). Safety outcomes indicated that aripiprazole was significantly more likely to cause extrapyramidal symptoms and somnolence than placebo. The manufacturers also presented a network meta-analysis of aripiprazole versus other atypical antipsychotics commonly used to treat manic episodes (olanzapine, quetiapine and risperidone) to show that aripiprazole performed similarly to the comparator drugs in terms of efficacy and safety. Aripiprazole was demonstrated to perform better in safety outcomes of (1) less weight gain than olanzapine and quetiapine; and (2) less prolactin increase than olanzapine, quetiapine and risperidone. Results from the manufacturers' economic evaluation showed that use of aripiprazole second-line dominated all of the other treatment strategies that were considered. However, there was considerable uncertainty in this result, and clinical advisors indicated that the actual treatment strategy employed in practice is likely to be dependent upon the patient's characteristics. The ERG demonstrated that if this personalised medicine resulted in improved cost effectiveness for any of the other treatment strategies, then they had the potential to dominate use of aripiprazole second-line. In conclusion, whilst a strategy including aripiprazole appeared to be cost effective relative to a strategy without it, there was not robust enough evidence to recommend a specific place for aripiprazole within the treatment pathway.

Ruxolitinib for the treatment of myelofibrosis: a NICE single technology appraisal

The National Institute for Health and Care Excellence (NICE) invited the manufacturer of ruxolitinib (Novartis) to submit clinical and cost-effectiveness evidence for ruxolitinib within its licensed indication (the treatment of disease-related splenomegaly or symptoms in adult patients with myelofibrosis), according to the Institute's Single Technology Appraisal process. The Centre for Reviews and Dissemination and Centre for Health Economics at the University of York were commissioned to act as the independent Evidence Review Group (ERG). This article provides a description of the company submission, the ERG review and the resulting NICE guidance TA289 issued in June 2013. The ERG critically reviewed the evidence presented in the manufacturer's submission and identified areas requiring clarification, for which the manufacturer provided additional evidence. The main clinical effectiveness data were derived from two phase III, multicentre, randomised controlled trials (RCTs): Controlled myelofibrosis study with oral JAK inhibitor treatment (COMFORT)-II compared ruxolitinib with best available therapy (BAT), and COMFORT-I compared ruxolitinib with placebo. These RCTs demonstrated that ruxolitinib confers significant benefits in terms of spleen size reduction and improvement in symptom burden. In the COMFORT-II trial, a reduction in spleen volume of ≥35 % was achieved in 28 % of ruxolitinib-treated patients compared with 0 % of patients in the BAT group (p < 0.001) at 48 weeks, and there was a mean change in spleen volume of -30.1 versus +7.3 % (p < 0.001). Ruxolitinib also provided significant improvements in myelofibrosis-associated symptoms and health-related quality-of-life compared with BAT and placebo. The ERG concluded that ruxolitinib appears to reduce splenomegaly and its associated symptoms, but that there was considerable uncertainty surrounding the manufacturer's cost-effectiveness estimates due to limitations in the manufacturer's model. The manufacturer's model did not allow for disease progression, did not accurately capture symptomatic relief, had several implausible or unjustified assumptions, and there were several parameter choices that the ERG found sub-optimal. ERG sensitivity analyses found that nearly all plausible adjustments to the model reduced the cost effectiveness of ruxolitinib. It is very likely that the base-case incremental cost-effectiveness ratio of £73,980/quality-adjusted life-year presented by the manufacturer represents a best-case scenario. The NICE Appraisal Committee concluded that ruxolitinib was clinically effective, but could not be considered a cost effective use of National Health Service (NHS) resources for treating disease-related splenomegaly or symptoms in adults with myelofibrosis. Ruxolitinib is not recommended for the treatment of disease-related splenomegaly or symptoms in adult patients with primary myelofibrosis (also known as chronic idiopathic myelofibrosis), post-polycythaemia vera myelofibrosis and post-essential thrombocythaemia myelofibrosis in NICE TA289.

Recent progress in pharmaceutical therapies for castration-resistant prostate cancer

Since 2010, six drugs have been approved for the treatment of castration-resistant prostate cancer, i.e., CYP17 inhibitor Abiraterone, androgen receptor antagonist Enzalutamide, cytotoxic agent Cabazitaxel, vaccine Sipuleucel-T, antibody Denosumab against receptor activator of nuclear factor kappa B ligand and radiopharmaceutical Alpharadin. All these drugs demonstrate improvement on overall survival, expect for Denosumab, which increases the bone mineral density of patients under androgen deprivation therapy and prolongs bone-metastasis-free survival. Besides further CYP17 inhibitors (Orteronel, Galeterone, VT-464 and CFG920), androgen receptor antagonists (ARN-509, ODM-201, AZD-3514 and EZN-4176) and vaccine Prostvac, more drug candidates with various mechanisms or new indications of launched drugs are currently under evaluation in different stages of clinical trials, including various kinase inhibitors and platinum complexes. Some novel strategies have also been proposed aimed at further potentiation of antitumor effects or reduction of side effects and complications related to treatments. Under these flourishing circumstances, more investigations should be performed on the optimal combination or the sequence of treatments needed to delay or reverse possible resistance and thus maximize the clinical benefits for the patients.

Trabectedin for the treatment of advanced metastatic soft tissue sarcoma: a NICE single technology appraisal

The National Institute for Health and Clinical Excellence (NICE) invited the manufacturer of trabectedin (PharmaMar) to submit evidence for the clinical and cost effectiveness of this drug for the treatment of advanced metastatic soft tissue sarcoma (aMSTS), as part of the Institute's single technology appraisal (STA) process. The School of Health and Related Research (ScHARR) was commissioned to act as the Evidence Review Group (ERG). This paper provides a description of the company submission, the ERG review and NICE's subsequent decisions. The ERG produced a review of the evidence for the clinical and cost effectiveness of the technology contained within the manufacturer's submission to NICE. The ERG also independently modified the manufacturer's decision analytic model to examine the impact of altering some of the key assumptions. The main evidence was derived from a single phase II randomized controlled trial (RCT) conducted in liposarcoma and leiomyosarcoma only, in which the licensed dose of trabectedin was compared with a different dose of trabectedin. Additional data were also presented from three uncontrolled phase II trials. Supplementary studies were used to represent best supportive care (BSC). The median overall survival (OS) was 13.9 months for the licensed dose of trabectedin in the main randomized controlled trial (RCT) and ranged from 9.2 months to 12.8 months in the other studies included. Supplementary studies supplied by the manufacturer, and assumed to represent BSC, had median OS of 5.9-6.6 months. The progression-free survival (PFS) rates at 6 months for trabectedin were 35.5 % in the main RCT and 24.4-29 % in the other studies included. The PFS rates at 6 months were 8-14 % for BSC. In the manufacturer's original submission to NICE, the base-case incremental cost-effectiveness ratio (ICER) of trabectedin compared with BSC was approximately £44,000 per QALY gained. After amendment of errors identified by the ERG, the ICER reported by the manufacturer increased to approximately £61,000. The ERG concluded that, despite clarifications from the manufacturer and the revisions made to the model, there was still considerable uncertainty in the ICER. The NICE Appraisal Committee (AC) gave a negative initial recommendation, although indicated that trabectedin in aMSTS met the end-of-life criteria. Subsequently, the manufacturer submitted a patient access scheme (PAS) where any cycles beyond the fifth were provided at no cost by the manufacturer. This improved the ICER to approximately £34,000 per QALY gained. The AC gave a positive recommendation, subject to the implementation of the PAS.

Golimumab for the treatment of ankylosing spondylitis: a NICE single technology appraisal

As part of the National Institute for Health and Clinical Excellence (NICE) single technology appraisal (STA) process, the Evidence Review Group (ERG) produced a report to comment on the clinical and cost effectiveness of golimumab (Simponi(®), Merck Sharp & Dohme) for the treatment of ankylosing spondylitis (AS) relative to other comparators as presented in the manufacturer's submission (MS) to NICE. The population was those with active disease who had not responded to conventional therapy. The specified comparators were conventional care and two other tumour necrosis factor alpha (TNF-α) inhibitors (adalimumab and etanercept). Outcomes to be considered were disease activity, functional capacity, disease progression, adverse effects of treatment and health-related quality of life (HR-QOL). There were no head-to-head trials comparing TNF-α inhibitors. The submission included one trial of golimumab versus placebo (the GO-RAISE trial) and additionally seven placebo-controlled randomized controlled trials (RCTs) of other TNF-α inhibitor agents (five with etanercept, and two with adalimumab). The results of these trials were generally a statistically significant improvement from each of the TNF-α inhibitors. A Bayesian mixed treatment comparison (MTC) showed there was generally overlap in the 95 % credible intervals (CrIs) between the TNF-α inhibitors. Exceptions included a greater risk of discontinuation of treatment for golimumab than for etanercept (relative risk [RR] 4.30; 95 % CrI 1.01-18.50). The cost-effectiveness analysis (CEA) compared all of these TNF-α inhibitors. Relative effectiveness was informed only by RR of response (proportion achieving at least a 50 % improvement in Bath AS Disease Activity Index [BASDAI] score; BASDAI50) from the MTC. In the base-case analysis, the incremental cost-effectiveness ratio (ICER) of golimumab versus conventional care was £26,597 and adalimumab and etanercept were extendedly dominated by golimumab. The manufacturer concluded that golimumab is a cost-effective treatment option. Generally, the ERG agreed with the MTC analyses. The main problem was that the MS used data from one trial, which included a period of cross-over. The ERG found some problems with the CEA model, mainly that it did not allow for comparison of TNF-α inhibitor sequences and did not use MTC estimates for treatment discontinuation or adverse events (AEs). The ERG could not correct the sequencing problem, but re-ran the CEA with discontinuations and AEs estimated from the MTC and using the correct trial data. The results of the ERG analysis were that golimumab was extendedly dominated by etanercept, and the preferred treatment was either conventional treatment or etanercept, depending on the ICER threshold. Uncertainty was also substantial. NICE issued guidance (technology appraisal [TA] 233), which recommended golimumab according to the indications described in TA143 for etanercept and adalimumab, i.e. as first-line therapy among the TNF-α inhibitors unless patients are intolerant to one or both alternatives. Given the factors cited by NICE for their decision, the ERG recommends that there should be greater clarity in the NICE methods guidance on handling uncertainty in CEAs as well as the incorporation of benefit from process of care.

Rituximab for the first-line maintenance treatment of follicular non-Hodgkin's lymphoma : a NICE single technology appraisal

The National Institute for Health and Clinical Excellence (NICE) invited the manufacturer of rituximab (RTX) [Roche] to submit evidence for the clinical and cost effectiveness of RTX as first-line maintenance treatment for patients with follicular non-Hodgkin's lymphoma (fNHL) whose disease has responded to induction therapy with RTX plus cytotoxic chemotherapy (R-CTX) in accordance with the Institute's Single Technology Appraisal (STA) process. The Liverpool Reviews and Implementation Group (LRiG) at the University of Liverpool was commissioned to act as the Evidence Review Group (ERG). This article summarizes the ERG's review of the evidence submitted by the manufacturer and provides a summary of the Appraisal Committee's (AC) decision. The clinical evidence was derived from a multi-centred, open-label, randomized phase III study (PRIMA) comparing first-line maintenance treatment with RTX with observation only in 1,018 patients with previously untreated advanced fNHL. Median time to event (MTE) for the primary endpoint of progression-free survival (PFS) in the RTX arm was not estimable due to data immaturity; median PFS in the observation arm was 48.36 months. A statistically significant benefit of RTX maintenance therapy for PFS was reported (hazard ratio [HR] 0.55, 95 % CI 0.44-0.68; p < 0.0001). Statistically significant differences in favour of RTX were also reported for a range of secondary endpoints. Assessment of overall survival benefit could be not made due to insufficient events. The ERG's main concern with the clinical-effectiveness data presented was their lack of maturity. The submitted incremental cost-effectiveness ratio was within the NICE threshold. The ERG questioned the model on a number of grounds, particularly the use of Markov methodology rather than patient simulations, the impact of patient age on the outcome and the projective PFS modelling. The ERG considered it impossible to draw firm conclusions regarding the clinical or cost effectiveness of the intervention as the dataset was as yet too immature. At a third meeting, the AC concluded that RTX could be recommended as first-line maintenance treatment for patients with fNHL whose disease has responded to induction R-CTX.