The Effects of Model Misspecification in Unanchored Matching-Adjusted Indirect Comparison: Results of a Simulation Study.

OBJECTIVES: To assess the performance of unanchored matching-adjusted indirect comparison (MAIC) by matching on first moments or higher moments in a cross-study comparisons under a variety of conditions. A secondary objective was to gauge the performance of the method relative to propensity score weighting (PSW). METHODS: A simulation study was designed based on an oncology example, where MAIC was used to account for differences between a contemporary trial in which patients had more favorable characteristics and a historical control. A variety of scenarios were then tested varying the setup of the simulation study, including violating the implicit or explicit assumptions of MAIC. RESULTS: Under ideal conditions and under a variety of scenarios, MAIC performed well (shown by a low mean absolute error [MAE]) and was unbiased (shown by a mean error [ME] of about zero). The performance of the method deteriorated where the matched characteristics had low explanatory power or there was poor overlap between studies. Only when important characteristics are not included in the matching did the method become biased (nonzero ME). Where the method showed poor performance, this was exaggerated if matching was also performed on the variance (ie, higher moments). Relative to PSW, MAIC provided similar results in most circumstances, although it exhibited slightly higher MAE and a higher chance of exaggerating bias. CONCLUSIONS: MAIC appears well suited to adjust for cross-trial comparisons provided the assumptions underpinning the model are met, with relatively little efficiency loss compared with PSW.

Evaluation of survival extrapolation in immuno-oncology using multiple pre-planned data cuts: learnings to aid in model selection.

BACKGROUND: Due to limited duration of follow up in clinical trials of cancer treatments, estimates of lifetime survival benefits are typically derived using statistical extrapolation methods. To justify the method used, a range of approaches have been proposed including statistical goodness-of-fit tests and comparing estimates against a previous data cut (i.e. interim data collected). In this study, we extend these approaches by presenting a range of extrapolations fitted to four pre-planned data cuts from the JAVELIN Merkel 200 (JM200) trial. By comparing different estimates of survival and goodness-of-fit as JM200 data mature, we undertook an iterative process of fitting and re-fitting survival models to retrospectively identify early indications of likely long-term survival. METHODS: Standard and spline-based parametric models were fitted to overall survival data from each JM200 data cut. Goodness-of-fit was determined using an assessment of the estimated hazard function, information theory-based methods and objective comparisons of estimation accuracy. Best-fitting extrapolations were compared to establish which one provided the most accurate estimation, and how statistical goodness-of-fit differed. RESULTS: Spline-based models provided the closest fit to the final JM200 data cut, though all extrapolation methods based on the earliest data cut underestimated the 'true' long-term survival (difference in restricted mean survival time [RMST] at 36 months: - 1.1 to - 0.5 months). Goodness-of-fit scores illustrated that an increasingly flexible model was favored as data matured. Given an early data cut, a more flexible model better aligned with clinical expectations could be reasonably justified using a range of metrics, including RMST and goodness-of-fit scores (which were typically within a 2-point range of the statistically 'best-fitting' model). CONCLUSIONS: Survival estimates from the spline-based models are more aligned with clinical expectation and provided a better fit to the JM200 data, despite not exhibiting the definitively 'best' statistical goodness-of-fit. Longer-term data are required to further validate extrapolations, though this study illustrates the importance of clinical plausibility when selecting the most appropriate model. In addition, hazard-based plots and goodness-of-fit tests from multiple data cuts present useful approaches to identify when a more flexible model may be advantageous. TRIAL REGISTRATION: JAVELIN Merkel 200 was registered with ClinicalTrials.gov as NCT02155647 on June 4, 2014.

Cost-Effectiveness Analysis of Recombinant Factor VIII Fc-Fusion Protein (rFVIIIFc) for the Treatment of Severe Hemophilia A in Italy Incorporating Real-World Dosing and Joint Health Data.

BACKGROUND: Patients with severe hemophilia A (SHA) in Italy are routinely treated with standard half-life recombinant factor VIII (rFVIII) products. rFVIII Fc-fusion protein (rFVIIIFc) is an extended half-life rFVIII product that enables less frequent administration than rFVIII, which may support improved adherence. Available data indicate low breakthrough bleed rates and potentially improved long-term joint health for patients treated with rFVIIIFc prophylaxis. OBJECTIVE: This study assessed the cost effectiveness of rFVIIIFc versus rFVIII from an Italian healthcare perspective. METHODS: A Semi-Markov model was constructed to assess the lifetime costs and benefits of rFVIII and rFVIIIFc prophylaxis. rFVIII product acquisition costs from a published Italian database were included for both prophylaxis and the resolution of breakthrough bleeding. Clinical outcomes within the model were determined based on published annualized bleeding rates and literature regarding the development of target joints (TJs) as the incidence of bleeds and TJs is associated with impaired health-related quality of life. Cost effectiveness was assessed using cost per quality-adjusted life-year (QALY) gained. RESULTS: Compared with rFVIII, rFVIIIFc was associated with a per-patient cost saving of approximately €1.3 million and QALY gains of 0.39 over a lifetime horizon. Sensitivity analyses considering alternative efficacy, dosing, and structural assumptions each showed that rFVIIIFc dominated rFVIII (i.e., provided more QALYs at a reduced cost). CONCLUSIONS: This cost-effectiveness analysis demonstrated that rFVIIIFc may offer a cost-effective treatment option for patients with SHA in Italy.

NICE, in Confidence: An Assessment of Redaction to Obscure Confidential Information in Single Technology Appraisals by the National Institute for Health and Care Excellence.

INTRODUCTION: Health technology assessment (HTA) aims to provide a transparent framework within which normative judgements can be applied for decision making. Such transparency enables the public to understand the rationale for decision making, but conflicts with companies being able to offer commercially sensitive discounts. We investigated how to balance these conflicting ideals. METHODS: National Institute for Health and Care Excellence (NICE) submissions were reviewed for products with an approved, simple Patient Access Scheme (PAS) discount. The approach to censoring was noted (e.g. total cost and clinical outcomes redacted). Submissions were then assessed for transparency (i.e. whether the decision appeared justifiable given the available information) and confidentiality (i.e. whether the PAS discount could be 'back calculated'). RESULTS: One hundred and eighteen products have an approved commercial arrangement, of which 110 have simple PAS discounts considered within the NICE Single Technology Appraisal programme. A definitive incremental cost-effectiveness ratio was presented within final NICE guidance in only 20 appraisals. Documentation for seven appraisals allowed for the straightforward 'back calculation' of PAS discounts. Furthermore, a large amount of information was censored as academic-in-confidence and remains so many years later. CONCLUSION: Appropriate redaction ensures discounts remain confidential, yet maintains the transparency of the HTA decisions made. Complete redaction does not allow for transparent, justifiable decision making. However, redacting 'enough' information to preclude direct estimation of discounts provides a means of maintaining both transparency and confidentiality. This study demonstrates a lack of consensus regarding presentation of results, and the importance of appropriate redaction.

Cost-effectiveness of Trifluridine/tipiracil for Previously Treated Metastatic Colorectal Cancer in England and Wales.

BACKGROUND: Treatment options at third-line and beyond for patients with late-line metastatic colorectal cancer (mCRC) are limited, and outcomes are poor with best supportive care (BSC). This study investigated the cost-effectiveness of trifluridine/tipiracil and regorafenib relative to BSC alone in patients with mCRC who have been previously treated with, or are not considered candidates for, standard chemotherapies. MATERIALS AND METHODS: A partitioned survival model was constructed to assess the lifetime costs and benefits accrued by patients. Clinical data were derived from the pivotal phase III (Randomized, Double-Blind, Phase 3 Study of TAS-102 plus Best Supportive Care [BSC] versus Placebo plus BSC in Patients with Metastatic Colorectal Cancer Refractory to Standard Chemotherapies [RECOURSE]) and supporting phase II (J003-10040030) randomized controlled trial of trifluridine/tipiracil + BSC versus placebo + BSC, as well as the phase III Colorectal Cancer Treated With Regorafenib or Placebo After Failure of Standard Therapy (CORRECT) randomized controlled trial of regorafenib, and were extrapolated to estimate lifetime outcomes. Costs were taken from published sources, and health effects sourced from previous mCRC studies. RESULTS: Trifluridine/tipiracil was associated with a 0.27 incremental life year versus BSC alone, which corresponds to a 0.17 quality-adjusted life year gain. The incremental cost of treatment with trifluridine/tipiracil was £8,479, resulting in an incremental cost-effectiveness ratio of £51,194 per quality-adjusted life year gained. Trifluridine/tipiracil was shown to dominate regorafenib (improve outcomes with reduced costs). Sensitivity analyses showed principal areas of uncertainty were survival estimates and patient utility. CONCLUSIONS: The results show that trifluridine/tipiracil is more clinically and cost-effective than regorafenib, with clinical outcomes greatly exceeding those for patients treated with BSC alone. Based on the results of the analysis, trifluridine/tipiracil offers an important new treatment option for patients with mCRC maintaining good performance status at the end of life.

How do we avoid disaster when exiting the European Medicines Agency? Making the most of Brexit in pharmaceutical regulation.

As the UK prepares to leave the EU, it must decide what path it is to take with a large number of regulatory and technical agencies who provide collaboration at the European level. In the case of pharmaceuticals, the European Medicines Agency (EMA) provides pan-European licencing for novel pharmaceuticals. Should the UK depart from the EMA system, this article highlights the loss to patients immediately (slower access to novel treatments), and in the long term by having no access to some novel products as companies choose not to launch in the UK. The lack of access then may also preclude the access to these treatments as generic medicines, causing harm far into the future. The other costs considered are the cost for duplicating the functions of the EMA, or the alternative of using the decisions of other regulators without input to decisions made. An alternative is then set out, of how the UK can prosper under 'Brexit', by remaining a member of the EMA, but accepting the decisions without political oversight (as currently happens with the European Commission). Additional freedom could be given to a UK regulator to accept decisions (where appropriate) from other agencies such as the Food & Drug Administration-further speeding access and making the UK a more attractive market. Such an arrangement would put the UK in a better position than the good position it is in currently. This would give patients (both now and in the future) the best access to treatment possible, and promote/attract an industry which employs (directly and indirectly) 500,000 jobs.

Measuring quality of life in opioid-induced constipation: mapping EQ-5D-3 L and PAC-QOL.

BACKGROUND: In health economic evaluations, quality of life should be measured with preference-based utilities, such as the EuroQol 5 Dimension 3-level (EQ-5D-3 L). Non-preference-based instruments (often disease-specific questionnaires) are commonly mapped to utilities. We investigated if the relationship observed between the Patient Assessment of Constipation Quality of Life (PAC-QOL) and the EQ-5D-3 L in patients with chronic idiopathic constipation (CIC) also applies in opioid-induced constipation (OIC). METHODS: EQ-5D-3 L patient-level data from a clinical study of lubiprostone in OIC (n = 439) were scored using the UK tariff. A published mapping between the PAC-QOL and the EQ-5D-3 L was tested using these data. New mapping formulas were analysed, including PAC-QOL total and subscale scores. The root mean square error (RMSE), the adjusted R(2) and predicted/observed plots were used to test the fit. RESULTS: The utility measured with the EQ-5D-3 L was 0.450 ± 0.329, with a distinctly bimodal distribution. This significantly improved if patients responded to treatment (defined as an increase of three spontaneous bowel movements per week, with no rescue medication taken). The published mapping in CIC performed poorly in this OIC population, and the PAC-QOL could not be reliably mapped on to the EQ-5D-3 L even when re-estimating coefficients. This was shown in our two mappings (using PAC-QOL total score, and subscale scores) by a high RMSE (0.317 and 0.314) and a low R(2) (0.068 and 0.080), with high utilities underestimated and low utilities overestimated. CONCLUSIONS: Patients with OIC have a low quality of life which does improve with the resolution of symptoms. However the PAC-QOL cannot be used to estimate the EQ-5D-3 L utility - potentially as the PAC-QOL does not capture the all relevant aspects of the patients quality of life (for example the cause of the opioid use).