The results of Randomized Controlled Trials (RCTs) on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio. These do not constitute the sufficient ...statistics required for meta-analysis or cost-effectiveness analysis, and their use in secondary analyses requires strong assumptions that may not have been adequately tested. In order to enhance the quality of secondary data analyses, we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated.
We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations, using where available information on number of events and numbers at risk. The reproducibility and accuracy of survival probabilities, median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics (survival probabilities, medians and hazard ratios) with statistics based on repeated reconstructions by multiple observers.
The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics. Accuracy was excellent for survival probabilities and medians, for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported.
The algorithm is a reliable tool for meta-analysis and cost-effectiveness analyses of RCTs reporting time-to-event data. It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves.
Background
Standard parametric survival models are commonly used to estimate long-term survival in oncology health technology assessments; however, they can inadequately represent the complex pattern ...of hazard functions or underlying mechanism of action (MoA) of immuno-oncology (IO) treatments.
Objective
The aim of this study was to explore methods for extrapolating overall survival (OS) and provide insights on model selection in the context of the underlying MoA of IO treatments.
Methods
Standard parametric, flexible parametric, cure, parametric mixture and landmark models were applied to data from ATLANTIC (NCT02087423; data cut-off DCO 3 June 2016). The goodness of fit of each model was compared using the observed survival and hazard functions, together with the plausibility of corresponding model extrapolation beyond the trial period. Extrapolations were compared with updated data from ATLANTIC (DCO 7 November 2017) for validation.
Results
A close fit to the observed OS was seen with all models; however, projections beyond the trial period differed. Estimated mean OS differed substantially across models. The cure models provided the best fit for the new DCO.
Conclusions
Standard parametric models fitted to the initial ATLANTIC DCO generally underestimated longer-term OS, compared with the later DCO. Cure, parametric mixture and response-based landmark models predicted that larger proportions of patients with metastatic non-small cell lung cancer receiving IO treatments may experience long-term survival, which was more in keeping with the observed data. Further research using more mature OS data for IO treatments is needed.
This study aimed to compare 6-month adherence to therapy with exenatide once weekly (Bydureon(®)) vs liraglutide once daily (Victoza(®)) in patients with type 2 diabetes under primary care in ...Germany.
A nationwide longitudinal prescription database (LRx), (between January 2011 and September 2014) was used to analyze adherence to therapy. The proportion of days covered (PDC) by prescription was used as a measure of adherence in the 6-month postindex period. Logistic regression analyses were performed to investigate the associations between glucagon-like peptide-1 receptor agonist therapy adjusting for age, sex, and cotherapy.
Therapy was initiated in 5,449 patients with exenatide once weekly (age: 59.7±11.8 years; 51.4% were male) and in 24,648 patients with liraglutide once daily (age: 59.4±11.4 years; 49.7% were male). The median PDC was 0.88 for exenatide once weekly and 0.77 for liraglutide once daily (P<0.05). Once-weekly exenatide was associated with significantly higher adherence. Odds ratio (95% confidence interval) for having a PDC of ≥0.80 was 1.78 (1.62-1.96) for exenatide once weekly compared with liraglutide once daily after adjusting for age, sex, and cotherapy.
Adherence to treatment with exenatide once weekly was significantly increased compared to that with liraglutide once daily over 6 months in patients with type 2 diabetes.
Stakeholders in healthcare are increasingly turning to real world evidence (RWE) to inform their decisions, alongside evidence from randomized controlled trials. RWE is generated by analysing data ...gathered from routine clinical practice, and can be used across the product lifecycle, providing insights into areas including disease epidemiology, treatment effectiveness and safety, and health economic value and impact. Recently, the US Food and Drug Administration and the European Medicines Agency have stated their ambition for greater use of RWE to support applications for new indications, and are now consulting with their stakeholders to formalize standards and expected methods for generating RWE.
Pharmaceutical companies are responding to the increasing demands for RWE by developing standards and processes for each stage of the evidence generation pathway. Some conventions are already in place for assuring quality, whereas other processes are specific to the research question and data sources available. As evidence generation increasingly becomes a core role of medical affairs divisions in large pharmaceutical companies, standards of rigour will continue to evolve and improve. Senior pharmaceutical leaders can drive this change by making RWE a core element of their corporate strategy, providing top-level direction on how their respective companies should approach RWE for maximum quality.
Here, we describe the current and future areas of RWE application within the pharmaceutical industry, necessary access to data to generate RWE, and the challenges in communicating RWE. Supporting and building on viewpoints from industry and publicly funded research, our perspective is that at each stage of RWE generation, quality will be critical to the impact that RWE has on healthcare decision-makers; not only where RWE is an established and evolving tool, but also in new areas that have the potential to disrupt and to improve drug development pathways.
Abstract Purpose Each year in France, varicella and zoster affect large numbers of children and adults, resulting in medical visits, hospitalizations for varicella- and zoster-related complications, ...and societal costs. Disease prevention by varicella vaccination is feasible, wherein a plausible option involves replacing the combined measles, mumps, and rubella (MMR) vaccine with the combined MMR and varicella (MMRV) vaccine. This study aimed to: (1) assess the cost-effectiveness of adding routine varicella vaccination through MMRV, using different vaccination strategies in France; and (2) address key uncertainties, such as the economic consequences of breakthrough varicella cases, the waning of vaccine-conferred protection, vaccination coverage, and indirect costs. Methods Based on the outputs of a dynamic transmission model that used data on epidemiology and costs from France, a cost-effectiveness model was built. A conservative approach was taken regarding the impact of varicella vaccination on zoster incidence by assuming the validity of the hypothesis of an age-specific boosting of immunity against varicella. Findings The model determined that routine MMRV vaccination is expected to be a cost-effective option, considering a cost-effectiveness threshold of €20,000 per quality-adjusted life-year saved; routine vaccination was cost-saving from the societal perspective. Results were driven by a large decrease in varicella incidence despite a temporary initial increase in the number of zoster cases due to the assumption of exogenous boosting. In the scenario analyses, despite moderate changes in assumptions about incidence and costs, varicella vaccination remained a cost-effective option for France. Implications Routine vaccination with MMRV was associated with high gains in quality-adjusted life-years, substantial reduction in the occurrences of varicella- and zoster-related complications, and few deaths due to varicella. Routine MMRV vaccination is also expected to provide reductions in costs related to hospitalizations, medication use, and general-practitioner visits, as well as indirect costs, and it is expected to be a cost-effective intervention in France (GSK study identifier: HO-12-6924).
Abstract Purpose Varicella has a high incidence affecting the vast majority of the population in France and can lead to severe complications. Almost every individual infected by varicella becomes ...susceptible to herpes zoster later in life due to reactivation of the latent virus. Zoster is characterized by pain that can be long-lasting in some cases and has no satisfactory treatment. Routine varicella vaccination can prevent varicella. The vaccination strategy of replacing both doses of measles, mumps, and rubella (MMR) with a combined MMR and varicella (MMRV) vaccine is a means of reaching high vaccination coverage for varicella immunization. The objective of this analysis was to assess the impact of routine varicella vaccination, with MMRV in place of MMR, on the incidence of varicella and zoster diseases in France and to assess the impact of exogenous boosting of zoster incidence, age shift in varicella cases, and other possible indirect effects. Methods A dynamic transmission population-based model was developed using epidemiological data for France to determine the force of infection, as well as an empirically derived contact matrix to reduce assumptions underlying these key drivers of dynamic models. Scenario analyses tested assumptions regarding exogenous boosting, vaccine waning, vaccination coverage, risk of complications, and contact matrices. Findings The model provides a good estimate of the incidence before varicella vaccination implementation in France. When routine varicella vaccination is introduced with French current coverage levels, varicella incidence is predicted to decrease by 57%, and related complications are expected to decrease by 76% over time. After vaccination, it is observed that exogenous boosting is the main driver of change in zoster incidence. When exogenous boosting is assumed, there is a temporary increase in zoster incidence before it gradually decreases, whereas without exogenous boosting, varicella vaccination leads to a gradual decrease in zoster incidence. Changing vaccine efficacy waning levels and coverage assumptions are still predicted to result in overall benefits with varicella vaccination. Implications In conclusion, the model predicted that MMRV vaccination can significantly reduce varicella incidence. With suboptimal coverage, a limited age shift of varicella cases is predicted to occur post-vaccination with MMRV. However, it does not result in an increase in the number of complications. GSK study identifier: HO-12-6924.
Abstract Background Ouwens et al. and Jansen have presented methods for (network) meta-analysis of survival data by using a multidimensional treatment effect as an alternative to the synthesis of ...constant hazards ratios, which allow for a better fit to the data and the expected survival of competing interventions for cost-effectiveness analysis. However, results may be sensitive to the assumed underlying survival function. Objective To estimate the expected progression-free survival (PFS) for fulvestrant 500 mg versus alternative hormonal therapies for postmenopausal women with advanced breast cancer who relapsed previously by means of a network meta-analysis of currently available randomized controlled trials using alternative underlying survival functions. Methods Eleven randomized controlled trials were included that evaluated fulvestrant 500 mg (n = 3), fulvestrant 250 mg (n = 5), fulvestrant 250 mg loading dose (n = 3), anastrozole 1 mg (n = 3), megestrol acetate (n = 4), letrozole 2.5 mg (n = 3), letrozole 0.5 mg (n = 3), and exemestane (n = 2). PFS percentages and numbers at risk were derived from Kaplan-Meier curves and combined by means of Bayesian network meta-analysis on the basis of the difference in the shape and scale parameters of the Weibull, log-normal, and log-logistic parametric survival functions. Results The log-normal distribution provided the best fit, suggesting that the proportional hazard assumption was not valid. Based on the difference in expected PFS, it was found that fulvestrant 500 mg is more efficacious than fulvestrant 250 mg, megestrol acetate, and anastrozole (−5.73 months; 95% credible interval CrI−10.67,−1.67). Expected PFS for fulvestrant 500 mg ranged from 10.87 (95% CrI 9.21, 13.07) to 17.02 (95% CrI 13.33, 22.02) months for the Weibull versus log-logistic distribution. Conclusions Fulvestrant 500 mg is expected to be more efficacious than fulvestrant 250 mg, megestrol acetate, and anastrozole 1 mg and at least as efficacious as exemestane and letrozole 2.5 mg in terms of PFS among postmenopausal women with advanced breast cancer after failure on endocrine therapy. The findings were not sensitive to the distribution, although the expected PFS varied substantially, emphasizing the importance of performing sensitivity analyses.
The major drivers of cost-effectiveness for chronic obstructive pulmonary disease (COPD) therapies are the occurrence of exacerbations and deaths. Exacerbations, including acute and long-term events, ...can cause worsening of COPD and lead to an increased risk of further exacerbations, and ultimately may elevate the risk of death. In contrast to this, health economic models are based on COPD severity progression. In this post hoc analysis of the ETHOS study, we focus on the progression of COPD due to exacerbations and deaths.
We fitted semi-parametric and fully parametric multi-state Markov models with the following five progressive states: State 1, no exacerbation; State 2, 1 moderate exacerbation; State 3, ≥ 2 moderate exacerbations; State 4, ≥ 1 severe exacerbations; State 5, death. The models only allowed a patient to transition to a worsened health state, and transitions did not necessarily have to be to the next adjacent state. We used the multi-state models to analyse data from ETHOS, a phase III, 52-week study assessing the efficacy and safety of triple therapy with budesonide/glycopyrronium/formoterol fumarate dihydrate in moderate-to-very severe COPD.
The Weibull multi-state Markov model showed good fit of the data. In line with clinical evidence, we found a higher mortality risk after a severe exacerbation (11.4-fold relative ratio increase 95% CI, 7.7-17.0, 6.4-fold increase 95% CI, 3.8-10.8 and 5.4-fold increase 95% CI, 2.9-10.3 relative to no exacerbations, 1 moderate exacerbation or ≥ 2 moderate exacerbations, respectively). One moderate exacerbation increased mortality risk 1.8-fold (95% CI, 1.1-2.9) vs no exacerbations. We also found a higher risk of severe exacerbation and mortality following ≥ 2 moderate exacerbations.
Multi-state modelling of patients with COPD in ETHOS found an acute and chronic effect of severe exacerbations on mortality risk. Risk was also increased after a moderate exacerbation. Clinical management with effective pharmacotherapies should be optimised to avoid even moderate exacerbations. Modelling with exacerbations could be an alternative to current COPD models focused on disease progression.
NCT02465567.
Whether 30-day modified Rankin Scale (mRS) scores can predict 90-day scores is unclear. This study derived and validated a model to predict ordinal 90-day mRS score in an intracerebral hemorrhage ...(ICH) population using 30-day mRS values and routinely available baseline variables. Adults enrolled in the Antihypertensive Treatment of Acute Cerebral Hemorrhage-2 (ATACH-2) trial between May 2011 and September 2015 with acute ICH, who were alive at 30 days and had mRS scores reported at both 30 and 90 days were included in this post-hoc analysis. A proportional odds regression model for predicting ordinal 90-day mRS scores was developed and internally validated using bootstrapping. Variables in the model included: mRS score at 30 days, age (years), hematoma volume (cm3), hematoma location (deep basal ganglia, thalamus, lobar, or infratentorial), presence of intraventricular hemorrhage (IVH), baseline Glasgow Coma Scale (GCS) score, and National Institutes of Health Stroke Scale (NIHSS) score at randomization. We assessed model fit, calibration, discrimination, and agreement (ordinal, dichotomized functional independence), and EuroQol-5D (EQ-5D utility weighted) between predicted and observed 90-day mRS. A total of 898/1000 participants were included. Following bootstrap internal validation, our model (calibration slope = 0.967) had an optimism-corrected c-index of 0.884 (95% CI = 0.873-0.896) and R2 = 0.712 for 90-day mRS score. The weighted ĸ for agreement between observed and predicted ordinal 90-day mRS score was 0.811 (95% CI = 0.787-0.834). Agreement between observed and predicted functional independence (mRS score of 0-2) at 90 days was 74.3% (95% CI = 69.9-78.7%). The mean ± SD absolute difference between predicted and observed EQ-5D-weighted mRS score was negligible (0.005 ± 0.145). This tool allows practitioners and researchers to utilize clinically available information along with the mRS score 30 days after ICH to reliably predict the mRS score at 90 days.
Background
In the phase III PACIFIC study, durvalumab improved survival versus placebo in patients with unresectable stage III non-small-cell lung cancer (NSCLC) whose disease had not progressed ...after platinum-based concurrent chemoradiotherapy. The appraisal by the UK’s National Institute for Health and Care Excellence (NICE) included a cost-effectiveness analysis based on an early data readout from PACIFIC March 2018 data cut-off (DCO); median follow-up duration 25.2 months; range 0.2–43.1. Uncertainties regarding long-term survival outcomes with durvalumab led to some challenges in estimating the cost effectiveness of this therapy.
Objective
Here, we validate the survival extrapolations used in the original company base-case analysis by benchmarking them against updated survival data from the 4-year follow-up analysis of PACIFIC (i.e. approximately 4 years after the last patient was randomised; March 2020 DCO; median follow-up duration 34.2 months; range 0.2–64.9). Moreover, we update the original analysis with these more mature survival data to examine the consistency of key economic outputs with the original analysis.
Methods
The original analysis used a semi-Markov (state-transition) approach and was based on patients whose tumours expressed programmed cell death-ligand 1 on ≥ 1% of cells (to reflect the European licence for durvalumab). We benchmarked the survival extrapolations used in the original company base-case analysis against survival data from the 4-year follow-up of PACIFIC and updated the cost-effectiveness analysis with these more mature survival data. Early deaths avoided by the adoption of durvalumab into the UK Cancer Drugs Fund (CDF) in March 2019 were estimated using the 4-year follow-up survival data and an assumed uptake of 125 patients/year (lower estimate) and 367 patients/year (higher estimate).
Results
The original company base-case analysis had a good visual fit with the observed overall survival (OS) distribution for the durvalumab arm and accurately predicted the 48-month OS rate (predicted 55%; observed 55%); by comparison, the fit was less precise for the placebo arm, for which the analysis underestimated the 48-month OS rate (predicted 32%; observed 38%). In the updated company base-case analysis, durvalumab yielded 2.51 incremental quality-adjusted life-years (QALYs) (− 0.43 vs. the original company base-case analysis), corresponding to an incremental cost-effectiveness ratio of £22,665/QALY (+£3298 vs. the original analysis), which falls within the upper bound of NICE’s willingness-to-pay threshold (£30,000/QALY gained). We estimate that between 31 and 91 early patient deaths may have been avoided by the adoption of durvalumab into the CDF.
Conclusions
These findings reinforce the patient benefit observed with durvalumab in unresectable stage III NSCLC, support the routine use and cost effectiveness of this therapy, and demonstrate how appropriate modelling can inform the early adoption of therapies by payers to achieve patient benefit.
Plain Language Summary
Based on the results of a clinical trial, the European Medicines Agency approved durvalumab for the treatment of adults with a specific type of advanced lung cancer whose tumours cannot be removed surgically and whose disease has not progressed after chemotherapy and radiotherapy. The UK’s National Institute for Health and Care Excellence (NICE) invites companies to submit cost-effectiveness analyses to help with decision making about adopting new therapies. The company included an analysis based on early trial data that suggested durvalumab was cost effective compared with other previous treatments. As patients in the study at the time of the initial submission to NICE were only followed for approximately 2 years, the long-term survival benefit that could be achieved with durvalumab was uncertain. Therefore, NICE recommended durvalumab for use within the Cancer Drugs Fund (CDF) to allow patients to access the drug while more data were being collected. Here, we demonstrate that the original cost-effectiveness model accurately predicted the rates of long-term survival for patients receiving durvalumab and that durvalumab remains a cost-effective use of healthcare resources based on recently published data from the trial (which added approximately 2 further years of follow-up). Moreover, we estimate that adopting durvalumab into the CDF may have avoided 31–91 early patient deaths from lung cancer. These findings support NICE’s early decision to make durvalumab available within the CDF and the adoption of durvalumab for routine use within the UK national health service.
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