Quality adjusted survival analysis

Cost-effectiveness analysis of atezolizumab plus bevacizumab and chemotherapy for the treatment of metastatic, persistent, or recurrent cervical cancer (BEATcc)

BACKGROUND

The addition of atezolizumab to bevacizumab plus platinum regimen has demonstrated notable improvements in treating metastatic, persistent, or recurrent cervical cancer, but its cost-effectiveness requires further investigation. From a US payer perspective, we aimed to evaluate the cost-effectiveness of atezolizumab plus bevacizumab and chemotherapy vs. standard chemotherapy as a first-line treatment for metastatic, persistent, or recurrent cervical cancer.

METHODS

A partitioned survival model based on the data from the BEATcc trial was used to calculate the incremental cost-effectiveness ratio (ICER), using cost and health utility information obtained from literature and publicly accessible databases. One-way and probabilistic sensitivity analyses were performed to evaluate the model's responsiveness to variations in parameters.

RESULTS

The addition of atezolizumab resulted in an additional 0.839 quality-adjusted life years (QALY) at an additional cost of $458,237, leading to an ICER of $545,943/QALY. One-way sensitivity analysis indicated that the cost of atezolizumab had the greatest impact on the ICER, followed by the utility value of progression-free survival (PFS) and follow-up costs. Probabilistic sensitivity analysis showed a 0% cost-effectiveness probability at the current willingness-to-pay (WTP) threshold of $150,000 per QALY.

CONCLUSION

Adding atezolizumab to chemotherapy is cost-prohibitive in the US and may not be cost-effective for patients.

Estimands and Cumulative Incidence Function Regression in Clinical Trials: Some New Results on Interpretability and Robustness

Regression analyses based on transformations of cumulative incidence functions are often adopted when modeling and testing for treatment effects in clinical trial settings involving competing and semi-competing risks. Common frameworks include the Fine-Gray model and models based on direct binomial regression. Using large sample theory we derive the limiting values of treatment effect estimators based on such models when the data are generated according to multiplicative intensity-based models, and show that the estimand is sensitive to several process features. The rejection rates of hypothesis tests based on cumulative incidence function regression models are also examined for null hypotheses of different types, based on which a robustness property is established. In such settings supportive secondary analyses of treatment effects are essential to ensure a full understanding of the nature of treatment effects. An application to a palliative study of individuals with breast cancer metastatic to bone is provided for illustration.

Estimands in clinical trials of complex disease processes

Clinical trials with random assignment of treatment provide evidence about causal effects of an experimental treatment compared to standard care. However, when disease processes involve multiple types of possibly semi-competing events, specification of target estimands and causal inferences can be challenging. Intercurrent events such as study withdrawal, the introduction of rescue medication, and death further complicate matters. There has been much discussion about these issues in recent years, but guidance remains ambiguous. Some recommended approaches are formulated in terms of hypothetical settings that have little bearing in the real world. We discuss issues in formulating estimands, beginning with intercurrent events in the context of a linear model and then move on to more complex disease history processes amenable to multistate modeling. We elucidate the meaning of estimands implicit in some recommended approaches for dealing with intercurrent events and highlight the disconnect between estimands formulated in terms of potential outcomes and the real world.

Scaling and interpreting treatment effects in clinical trials using restricted mean survival time

BACKGROUND

Restricted mean survival time is the expected duration of survival up to a chosen time of restriction τ . For comparison studies, the difference in restricted mean survival times between two groups provides a summary measure of the treatment effect that is free of assumptions regarding the relative shape of the two survival curves, such as proportional hazards. However, it can be difficult to judge the magnitude of the effect from a comparison of restricted means due to the truncation of observation at time τ .

METHODS

In this article, we describe additional ways of expressing the treatment effect based on restricted means that can be helpful in this regard. These include the ratio of restricted means, the ratio of life-years (or time) lost, and the average integrated difference between the survival curves, equal to the difference in restricted means divided by τ . These alternative metrics are straightforward to calculate and provide a means for scaling the effect size as an aid to interpretation. Examples from two randomized, multicenter clinical trials in prostate cancer, NRG/RTOG 0521 and NRG/RTOG 0534, with primary endpoints of overall survival and biochemical/radiological progression-free survival, respectively, are presented to illustrate the ideas.

RESULTS

The four effect measures (restricted mean survival time difference, restricted mean survival time ratio, time lost ratio, and average survival rate difference) were 0.45 years, 1.05, 0.81, and 0.038 for RTOG 0521 and 1.36 years, 1.17, 0.56, and 0.12 for RTOG 0534 with τ  = 12 and 11 years, respectively. Thus, for example, the 0.45-year difference in the first trial translates into a 19% reduction in time lost and a 3.8% average absolute difference between the survival curves over the 12-year horizon, a modest effect size, whereas the 1.36-year difference in the second trial corresponds to a 44% reduction in time lost and a 12% absolute survival difference, a rather large effect.

CONCLUSIONS

In addition to the difference in restricted mean survival times, these alternative measures can be helpful in determining whether the magnitude of the treatment effect is clinically meaningful.

RETRACTED: Cost-effectiveness of chemotherapy and dostarlimab for advanced or recurrent endometrial cancer

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the Authors. The authors have independently identified an error in the formula that was utilized to calculate the Quality Adjusted Life Years which invalidates the data and the conclusion of the paper. The authors have contacted the journal requesting to retract the article. Apologies are offered to the readers of the journal for any confusion or inconvenience that may have resulted from the publication of this article.

Joint inference for competing risks data using multiple endpoints

Competing risks data are commonly encountered in randomized clinical trials and observational studies. This paper considers the situation where the ending statuses of competing events have different clinical interpretations and/or are of simultaneous interest. In clinical trials, often more than one competing event has meaningful clinical interpretations even though the trial effects of different events could be different or even opposite to each other. In this paper, we develop estimation procedures and inferential properties for the joint use of multiple cumulative incidence functions (CIFs). Additionally, by incorporating longitudinal marker information, we develop estimation and inference procedures for weighted CIFs and related metrics. The proposed methods are applied to a COVID-19 in-patient treatment clinical trial, where the outcomes of COVID-19 hospitalization are either death or discharge from the hospital, two competing events with completely different clinical implications.

Cost Effectiveness of CDK4/6 Inhibitors in the First-Line Treatment of HR+/HER2- Metastatic Breast Cancer in Postmenopausal Women in the USA

BACKGROUND AND OBJECTIVE

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors improve progression-free survival when combined with endocrine therapies in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer. However, the comparative cost effectiveness of utilizing three US Food and Drug Administration-approved CDK4/6 inhibitors is unknown. Therefore, we aimed to evaluate the cost effectiveness of individual CDK4/6 inhibitors (palbociclib, ribociclib, abemaciclib) with letrozole versus letrozole monotherapy in the first-line treatment of hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer in the USA.

METHODS

We constructed a Markov-based decision-analytic model to evaluate the cost effectiveness of CDK4/6 inhibitors plus endocrine therapies over a 40-year lifetime from a third-party payer perspective. The model incorporated health states (progression-free disease, progressive disease, and death), major adverse events (neutropenia), and cancer-specific and all-cause mortality. Using clinical efficacy and quality-of-life scores (utility) data from clinical trials, we estimated quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios using Medicare charges reported in US dollars per 2022 valuation and a discount rate of 3% applied to costs and outcomes. We performed deterministic and probabilistic sensitivity analyses to evaluate parametric and decision uncertainty.

RESULTS

Compared to letrozole, the model estimated an increase of 5.72, 5.87, and 6.39 in QALYs and costs of $799,178, $788,168, and $741,102 in combining palbociclib, ribociclib, and abemaciclib plus letrozole, respectively. Palbociclib or ribociclib plus letrozole were dominated by abemaciclib plus letrozole. Compared with letrozole, abemaciclib plus letrozole resulted in an incremental cost-effectiveness ratio of $457,538 per QALY with an incremental cost of $553,621 and an incremental QALY gain of 1.21. The results were sensitive to the cost of abemaciclib, disease progression utility, and patients' age.

CONCLUSIONS

At a willingness to pay of $100,000/QALY gained, our model predicts that combining CDK4/6 inhibitors plus letrozole is not cost effective with a marginal increase in QALYs at a high cost. Lowering the cost of these drugs or identifying patients who can receive maximal benefit from CDK4/6 inhibitors would improve the value of this regimen in patients.

Q-TWiST analysis of pembrolizumab combined with chemotherapy as first-line treatment of metastatic triple-negative breast cancer that expresses PD-L1

OBJECTIVE

In the KEYNOTE-355 (KN355) trial, pembrolizumab in combination with chemotherapy demonstrated superior efficacy and manageable safety compared with chemotherapy alone in patients with previously untreated locally recurrent inoperable and metastatic triple-negative breast cancer (mTNBC) with PD-L1 positive (Combined Positive Score [CPS]≥ 10) tumours. This study aimed to evaluate the clinical benefits and risks of pembrolizumab measured by quality-adjusted survival in the trial population.

METHODS

The study used data from the final analysis of KN355. The Quality-adjusted Time Without Symptoms of disease progression or Toxicity of treatment (Q-TWiST) analysis was used to compare treatments of pembrolizumab plus chemotherapy versus chemotherapy alone. Patients' survival time was partitioned into three health states - toxicity before disease progression (TOX), time without symptoms or toxicity before disease progression (TWiST), and relapse (REL). Utilities for these health states were estimated using EuroQol-5 Dimensions, 3 Levels (EQ-5D-3L) data collected in KN355. Q-TWiST was derived as the utility-weighted sum of the mean health state durations.

RESULTS

Patients randomised to pembrolizumab plus chemotherapy had 3.7 months greater Q-TWiST (relative gain of 18%; P = 0.003) compared to those randomised to chemotherapy at the median follow-up of 44 months, and 4.3 months greater Q-TWiST (relative gain of 20%; P = 0.004) at the maximum follow-up of 52 months. The Q-TWiST gain increased with longer follow-up time.

CONCLUSIONS

Pembrolizumab plus chemotherapy was associated with statistically significant and clinically important improvement in Q-TWiST compared to chemotherapy in previously untreated PD-L1-positive mTNBC.

Who really benefits from intraperitoneal chemotherapy for advanced ovarian cancer? A treatment-free survival analysis of the AICE trial

OBJECTIVE

To investigate whether peritoneal disease extent can predict the survival benefit of intraperitoneal/intravenous (IP/IV) chemotherapy in ovarian cancer.

DESIGN

A treatment-free survival (TFS) analysis.

SETTING

Five-centre trial.

POPULATION

An extended follow-up of the Additional Intraperitoneal Cisplatin and Etoposide in ovarian cancer (AICE) trial (NCT01669226), with data cut-off on 27 August 2020. Patients were categorised into subgroups with high tumour burden (HTB) and low tumour burden (LTB).

METHODS

Overall survival (OS) was divided into time on protocol treatment exposure (T), time free of subsequent treatment or death (TFS) and time after the first subsequent therapy (REL). TFS analyses and quality-adjusted OS were calculated by multiplying the mean time in each health state by its assigned utility: quality-adjusted OS = u_t  × T + TFS + u_rel  × REL.

MAIN OUTCOME MEASURES

The area under each Kaplan-Meier curve was estimated using the 96-month restricted mean time, with threshold utility analyses used to illustrate quality-adjusted OS comparisons.

RESULTS

In the HTB subgroup, the restricted mean TFS was 33.9 months and 18.7 months in the IP/IV and IV groups, respectively (p = 0.005), with a significant quality-adjusted OS gain (13.2-16.0 months). In the LTB subgroup, IP/IV therapy yielded no survival benefit in either TFS (p = 0.268) or quality-adjusted OS (range: 1.4-6.3 months).

CONCLUSIONS

Both TFS and quality-adjusted OS was longer across all utility weight values with IP/IV than with standard IV therapy in the HTB subgroup, whereas patients in the LTB subgroup did not benefit from the therapy. The tumour burden of ovarian cancer should be assessed before deciding on IP/IV versus IV treatment.

Quantifying Treatment Effects in Trials with Multiple Event-Time Outcomes

BACKGROUND

Data on the occurrence times of multiple outcomes, reflecting the temporal profile of disease burden/progression, have been used to estimate treatment effects in various recent randomized trials. Most procedures for analyzing these data require specific model assumptions. When the assumptions are not met, the results may be misleading. Robust, model-free procedures for study design and analysis that enable clinically meaningful interpretations are warranted.

METHODS

For each treatment group, we constructed and summarized the estimated mean cumulative count of events over time by the area under the curve (AUC), which can be interpreted as the mean total event-free time lost from multiple undesirable outcomes. A higher curve, and resulting larger AUC, implies a worse treatment. The treatment effect is quantified by the ratio and/or difference of AUCs. The timing and occurrence of recurrent heart failure hospitalizations (HFHs) and cardiovascular (CV) death from Prospective Comparison of ARNI with ARB Global Outcomes in HF with Preserved Ejection Fraction (PARAGON-HF), comparing sacubitril/valsartan with valsartan, are presented for illustration. We also discuss the design of future studies on the basis of the proposed method.

RESULTS

With 48 months of follow-up, estimated AUCs, representing the total event-free time lost to HFHs and CV death, were 11.3 and 13.1 event-months for sacubitril/valsartan and valsartan, respectively. The ratio of these AUCs was 0.86 (95% confidence interval, 0.75 to 1.00; P=0.049), a 14% reduction of disease burden favoring combination therapy. A future study, similar to PARAGON-HF, designed using the new proposal would require fewer patients would than a conventional time-to-first-event analysis.

CONCLUSIONS

The proposed method is robust and model-free and provides a clinically interpretable, time-scale summary of the treatment effect. (Funded by National Institutes of Health.).

Net-benefit regression with censored cost-effectiveness data from randomized or observational studies

Cost-effectiveness analysis is an essential part of the evaluation of new medical interventions. While in many studies both costs and effectiveness (eg, survival time) are censored, standard survival analysis techniques are often invalid due to the induced dependent censoring problem. We propose methods for censored cost-effectiveness data using the net-benefit regression framework, which allow covariate-adjustment and subgroup identification when comparing two intervention groups. The methods provide a straightforward way to construct cost-effectiveness acceptability curves with censored data. We also propose a more efficient doubly robust estimator of average causal incremental net benefit, which increases the likelihood that the results will represent a valid inference in observational studies. Lastly, we conduct extensive numerical studies to examine the finite-sample performance of the proposed methods, and illustrate the proposed methods with a real data example using both survival time and quality-adjusted survival time as the measures of effectiveness.

The Cost Effectiveness of Axicabtagene Ciloleucel Versus Best Supportive Care in the Treatment of Adult Patients with Relapsed or Refractory Large B-Cell Lymphoma (LBCL) After Two or More Lines of Systemic Therapy in Canada

BACKGROUND AND OBJECTIVE

Axicabtagene ciloleucel (axi-cel) received marketing authorisation in Canada for the treatment of relapsed or refractory large B-cell lymphoma after two or more lines of systemic therapy, and the clinical and economic value of axi-cel to patients and the healthcare system should be examined. The objective of this analysis is to determine, from societal and public healthcare payer perspectives, the cost effectiveness of axi-cel versus best supportive care for patients with relapsed or refractory large B-cell lymphoma in Canada.

METHODS

A pharmacoeconomic model was developed and populated with clinical data derived from the ZUMA-1 and SCHOLAR-1 studies using a propensity score-matched comparison. A partitioned survival mixture-cure modelling approach was taken to characterise the potential curative effect of axi-cel therapy in large B-cell lymphoma. Healthcare resource utilisation and adverse event data were based on results from ZUMA-1, and utility values were derived from ZUMA-1 data supplemented with published literature. Costs (in 2021 Canadian dollars) were taken from publicly available Canadian cost databases and published literature. Benefits and costs were discounted at 1.5% per year, and sensitivity analyses were conducted to assess the robustness of the results.

RESULTS

In the base case, axi-cel generated an incremental 6.2 life-years compared to best supportive care, corresponding to 4.6 additional quality-adjusted life-years, and was associated with $606,010 in additional costs. The incremental cost-utility ratio was $132,747 per quality-adjusted life-year gained compared with best supportive care from a societal perspective ($106,392 per quality-adjusted life-year gained from a public healthcare payer perspective). Key drivers of the analysis included progression-free survival and overall survival values for axi-cel.

CONCLUSIONS

The results of this analysis suggest that axi-cel may be considered a cost-effective allocation of resources compared with best supportive care for the treatment of adult patients with relapsed or refractory large B-cell lymphoma in Canada.

Cost-Effectiveness of Apatinib and Cabozantinib for the Treatment of Radioiodine-Refractory Differentiated Thyroid Cancer

Background: The effectiveness of apatinib and cabozantinib for the treatment of radioactive iodine–refractory differentiated thyroid cancer (RAIR-DTC) has been demonstrated recently. We aimed to evaluate the cost-effectiveness of these treatments from the Chinese healthcare system perspective.

Methods: Two partitioned survival models over a 10-year horizon were built to compare the cost and effectiveness of apatinib vs. placebo and cabozantinib vs. placebo based on the clinical data from the phase 3 randomized REALITY and COSMIC-311 trials. Costs and utility data were obtained from the literature and institutional database. The incremental cost-effectiveness ratio (ICER) was calculated. One-way and probabilistic sensitivity analysis was performed to test the robustness of the conclusion.

Results: Apatinib yielded an additional quality-adjusted life-year (QALY) of 0.74 at an additional cost of Chinese Renminbi ¥44,077. The ICER was ¥93,460 (US dollar $13545)/QALY and it was below the current willingness-to-pay (WTP) threshold of ¥217341/QALY. Cabozantinib was associated with an additional QALY of 0.79 at an extra cost of ¥3,55,614 when compared with placebo, and the ICER was ¥4,52,325 ($65,554)/QALY, which was above the WTP threshold. The conclusion were robust under one-way and probabilistic sensitivity analysis. The price of cabozantinib has to drop to ¥5.87/mg (39% of the current price) for it has a 50% likelihood of being cost-effective.

Conclusion: Apatinib is cost-effective for RAIR-DTC when compared with placebo from the perspective of Chinese healthcare system. However, based on the current evidence, cabozantinib might not be cost-effective and a reduction of price is warranted.

Cost-effectiveness analysis of Ado-trastuzumab emtansine for the treatment of residual invasive HER2-positive breast cancer

Objective

Methods

Results

Conclusion

Utility based approach in individualized optimal dose selection using machine learning methods

The goal in personalized medicine is to individualize treatment using patient characteristics and improve health outcomes. Selection of optimal dose must balance the effect of dose on both treatment efficacy and toxicity outcomes. We consider a setting with one binary efficacy and one binary toxicity outcome. The goal is to find the optimal dose for each patient using clinical features and biomarkers from available dataset. We propose to use flexible machine learning methods such as random forest and Gaussian process models to build models for efficacy and toxicity depending on dose and biomarkers. A copula is used to model the joint distribution of the two outcomes and the estimates are constrained to have non‐decreasing dose‐efficacy and dose‐toxicity relationships. Numerical utilities are elicited from clinicians for each potential bivariate outcome. For each patient, the optimal dose is chosen to maximize the posterior mean of the utility function. We also propose alternative approaches to optimal dose selection by adding additional toxicity based constraints and an approach taking into account the uncertainty in the estimation of the utility function. The proposed methods are evaluated in a simulation study to compare expected utility outcomes under various estimated optimal dose rules. Gaussian process models tended to have better performance than random forest. Enforcing monotonicity during modeling provided small benefits. Whether and how, correlation between efficacy and toxicity, was modeled, had little effect on performance. The proposed methods are illustrated with a study of patients with liver cancer treated with stereotactic body radiation therapy.

Poly(ADP-ribose) polymerase (PARP) inhibitors for the treatment of ovarian cancer

BACKGROUND

Ovarian cancer is the sixth most common cancer in women world-wide. Epithelial ovarian cancer (EOC) is the most common; three-quarters of women present when disease has spread outside the pelvis (stage III or IV). Treatment consists of a combination of  surgery and platinum-based chemotherapy. Although initial responses to chemotherapy are good, most women with advanced disease will relapse. PARP (poly (ADP-ribose) polymerase) inhibitors (PARPi), are a type of anticancer treatment that works by preventing cancer cells from repairing DNA damage, especially in those with breast cancer susceptibility gene (BRCA) variants. PARPi offer a different mechanism of anticancer treatment from conventional chemotherapy.

OBJECTIVES

To determine the benefits and risks of poly (ADP-ribose) polymerase) inhibitors (PARPi) for the treatment of epithelial ovarian cancer (EOC).

SEARCH METHODS

We identified randomised controlled trials (RCTs) by searching the Cochrane Central Register of Controlled Trials (Central 2020, Issue 10), Cochrane Gynaecological Cancer Group Trial Register, MEDLINE (1990 to October 2020), Embase (1990 to October 2020), ongoing trials on www.controlled-trials.com/rct, www.clinicaltrials.gov, www.cancer.gov/clinicaltrials, the National Research Register (NRR), FDA database and pharmaceutical industry biomedical literature.

SELECTION CRITERIA

We included trials that randomised women with EOC to PARPi with no treatment, or PARPi versus conventional chemotherapy, or PARPi together with conventional chemotherapy versus conventional chemotherapy alone.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. Two review authors independently assessed whether studies met the inclusion criteria. We contacted investigators for additional data. Outcomes included overall survival (OS), objective response rate (ORR), quality of life (QoL) and rate of adverse events.

MAIN RESULTS

We included 15 studies (6109 participants); four (3070 participants) with newly-diagnosed, advanced EOC and 11 (3039 participants) with recurrent EOC. The studies varied in types of comparisons and evaluated PARPi. Eight studies were judged as at low risk of bias in most of the domains. Quality of life data were generally poorly reported. Below we present six key comparisons.  The majority of participants had BRCA mutations, either in their tumour (sBRCAmut) and/or germline (gBRCAmut), or homologous recombination deficiencies (HRD) in their tumours. Newly diagnosed EOC Overall, four studies evaluated the effect of PARPi in newly-diagnosed, advanced EOC. Two compared PARPi with chemotherapy and chemotherapy alone. OS data were not reported. The combination of PARPi with chemotherapy may have little to no difference in progression-free survival (PFS) (two studies, 1564 participants; hazard ratio (HR) 0.82, 95% confidence interval (CI 0).49 to 1.38; very low-certainty evidence)(no evidence of disease progression at 12 months' 63% with PARPi versus 69% for placebo).  PARPi with chemotherapy likely increases any severe adverse event (SevAE) (grade 3 or higher) slightly (45%) compared with chemotherapy alone (51%) (two studies, 1549 participants, risk ratio (RR) 1.13, 95% CI 1.07 to 1.20; high-certainty evidence). PARPi combined with chemotherapy compared with chemotherapy alone likely results in little to no difference in the QoL (one study; 744 participants, MD 1.56 95% CI -0.42 to 3.54; moderate-certainty evidence).  Two studies compared PARPi monotherapy with placebo as maintenance after first-line chemotherapy in newly diagnosed EOC. PARPi probably results in little to no difference in OS (two studies, 1124 participants; HR 0.81, 95%CI 0.59 to 1.13; moderate-certainty evidence) (alive at 12 months 68% with PARPi versus 62% for placebo). However, PARPi may increase PFS (two studies, 1124 participants; HR 0.42, 95% CI 0.19 to 0.92; low-certainty evidence) (no evidence of disease progression at 12 months' 55% with PARPi versus 24% for placebo). There may be an increase in the risk of experiencing any SevAE (grade 3 or higher) with PARPi (54%) compared with placebo (19%)(two studies, 1118 participants, RR 2.87, 95% CI 1.65 to 4.99; very low-certainty evidence), but the evidence is very uncertain. There is probably a slight reduction in QoL with PARPi, although this may not be clinically significant (one study, 362 participants; MD -3.00, 95%CI -4.48 to -1.52; moderate-certainty evidence).  Recurrent, platinum-sensitive EOC Overall, 10 studies evaluated the effect of PARPi in recurrent platinum-sensitive EOC. Three studies compared PARPi monotherapy with chemotherapy alone. PARPi may result in little to no difference in OS (two studies, 331 participants; HR 0.95, 95%CI 0.62 to 1.47; low-certainty evidence) (percentage alive at 36 months 18% with PARPi versus 17% for placebo). Evidence is very uncertain about the effect of PARPi on PFS (three studies, 739 participants; HR 0.88, 95%CI 0.56 to 1.38; very low-certainty evidence)(no evidence of disease progression at 12 months 26% with PARPi versus 22% for placebo). There may be little to no difference in rates of any SevAE (grade 3 or higher) with PARPi (50%) than chemotherapy alone (47%) (one study, 254 participants; RR 1.06, 95%CI 0.80 to 1.39; low-certainty evidence). Four studies compared PARPi monotherapy as maintenance with placebo. PARPi may result in little to no difference in OS (two studies, 560 participants; HR 0.88, 95%CI 0.65 to 1.20; moderate-certainty evidence)(percentage alive at 36 months 21% with PARPi versus 17% for placebo). However, evidence suggests that PARPi as maintenance therapy results in a large PFS (four studies, 1677 participants; HR 0.34, 95% CI 0.28 to 0.42; high-certainty evidence)(no evidence of disease progression at 12 months 37% with PARPi versus 5.5% for placebo). PARPi maintenance therapy may result in a large increase in any SevAE (51%) (grade 3 or higher) than placebo (19%)(four studies, 1665 participants, RR 2.62, 95%CI 1.85 to 3.72; low-certainty evidence). PARPi compared with chemotherapy may result in little or no change in QoL (one study, 229 participants, MD 1.20, 95%CI -1.75 to 4.16; low-certainty evidence). Recurrent, platinum-resistant EOC Two studies compared PARPi with chemotherapy. The certainty of evidence in both studies was graded as very low. Overall, there was minimal information on the QoL and adverse events.

AUTHORS' CONCLUSIONS

PARPi maintenance treatment after chemotherapy may improve PFS in women with newly-diagnosed and recurrent platinum-sensitive EOC; there may be little to no effect on OS, although OS data are immature. Overall, this is likely at the expense of an increase in SevAE. It is  disappointing that data on quality of life outcomes  are relatively sparse. More research is needed to determine whether PARPi have a role to play in platinum-resistant disease.

Implementation and prospective evaluation of the Country Heart Attack Prevention model of care to improve attendance and completion of cardiac rehabilitation for patients with cardiovascular diseases living in rural Australia: a study protocol

INTRODUCTION

Despite extensive evidence of its benefits and recommendation by guidelines, cardiac rehabilitation (CR) remains highly underused with only 20%-50% of eligible patients participating. We aim to implement and evaluate the Country Heart Attack Prevention (CHAP) model of care to improve CR attendance and completion for rural and remote participants.

METHODS AND ANALYSIS

CHAP will apply the model for large-scale knowledge translation to develop and implement a model of care to CR in rural Australia. Partnering with patients, clinicians and health service managers, we will codevelop new approaches and refine/expand existing ones to address known barriers to CR attendance. CHAP will codesign a web-based CR programme with patients expanding their choices to CR attendance. To increase referral rates, CHAP will promote endorsement of CR among clinicians and develop an electronic system that automatises referrals of in-hospital eligible patients to CR. A business model that includes reimbursement of CR delivered in primary care by Medicare will enable sustainable access to CR. To promote CR quality improvement, professional development interventions and an accreditation programme of CR services and programmes will be developed. To evaluate 12-month CR attendance/completion (primary outcome), clinical and cost-effectiveness (secondary outcomes) between patients exposed (n=1223) and not exposed (n=3669) to CHAP, we will apply a multidesign approach that encompasses a prospective cohort study, a pre-post study and a comprehensive economic evaluation.

ETHICS AND DISSEMINATION

This study was approved by the Southern Adelaide Clinical Human Research Ethics Committee (HREC/20/SAC/78) and by the Department for Health and Wellbeing Human Research Ethics Committee (2021/HRE00270), which approved a waiver of informed consent. Findings and dissemination to patients and clinicians will be through a public website, online educational sessions and scientific publications. Deidentified data will be available from the corresponding author on reasonable request.

TRIAL REGISTRATION NUMBER

ACTRN12621000222842.

Modelled Economic Analysis for Dacomitinib-A Cost Effectiveness Analysis in Treating Patients With EGFR-Mutation-Positive Non-Small Cell Lung Cancer in China

Objectives

To establish the cost-effectiveness of dacomitinib compared to gefitinib from the Chinese healthcare system perspective.

Patients

Advanced non-small cell lung cancer (NSCLC) harbouring epidermal growth factor receptor (EGFR) mutations.

Methods

Partitioned survival analysis was undertaken to examine the cost-effectiveness of dacomitinib utilising individual patient data (IPD) from the pivotal randomised controlled trial (RCT) (ARCHER 1050). The three health states modelled were progression-free, post-progression, and death. Parametric survival distributions were fitted to IPD against the Kaplan-Meier survival curves corresponding to progression-free survival (PFS) and overall survival (OS) outcomes by randomised groups. Costs included drug acquisition and administration, outpatient management (outpatient consultation and examinations), and best supportive care costs. Utility weights were sourced from the pivotal trial and other published literature. The incremental cost-effectiveness ratio (ICER) was calculated with costs and quality-adjusted life years (QALYs) discounted at an annual rate of 5%. Both deterministic and probabilistic sensitivity analyses were undertaken.

Results

In the base case, dacomitinib (CNY 265,512 and 1.95 QALY) was associated with higher costs and QALY gains compared to gefitinib (CNY 247,048 and 1.61 QALYs), resulting in an ICER of CNY 58,947/QALY. Using the empirical WTP/QALY threshold, dacomitinib is a cost-effective treatment strategy for patients with EGFR-mutation-positive advanced NSCLC. The probabilistic sensitivity analysis suggested that dacomitinib had a 97% probability of being cost-effective.

Conclusions

Dacomitinib is a cost-effective treatment strategy in treating patients with EGFR-mutation-positive NSCLC from the Chinese healthcare system perspective. The uncertainty around the cost-effectiveness of dacomitinib could be reduced if long-term survival data become available.

Clinical Trial Registration

NCT01024413

Quality of life and Q-TWiST were not adversely affected in Ewing sarcoma patients treated with combined anlotinib, irinotecan, and vincristine: (Peking University People's Hospital Ewing sarcoma trial-02, PKUPH-EWS-02)

BACKGROUND

Combined treatment with anlotinib, irinotecan, as well as vincristine for advanced Ewing sarcoma (EWS) has been verified been effective in the prospective trial of Peking University People's Hospital EWS trial-02. We aimed to assess the dynamic changes in health-related quality of life (QoL) and the benefit-risk in quality-adjusted survival in current study.

METHODS

Twelve "pediatric" patients and 23 "adult" patients were enrolled. QoL was assessed with the EORTC QLQ-C30 for adults and PedsQL 3.0 Cancer Module for children and adolescents. The quality-adjusted time without symptoms of disease progression or toxicity of treatment (Q-TWiST) analysis was used to describe treatment results.

RESULTS

Progression-free survival was not accompanied by diminished QoL. Differences in scores on the QoL global health status and specific functioning before, during, and after treatment were not significantly different with time (P = .14 for adults and .91 for children). During treatment, there was a statistically insignificant trend towards improved QoL with reduced tumor burden (P = .14 for adults and .10 for children), but QoL significantly declined with progression of disease (P = .05 for adults and .04 for children). The most common adverse events were neutropenia (12.1%), leukopenia (16.6%), anemia (12.7%), and diarrhea (4.93%). Results across the trial analyses showed that the median time of Q-TWiST was 0.73 (interquartile range, 0-1.57) months, whereas the median time with toxicity before disease progression was 3.9 (interquartile range, 2.3, 6.1).

CONCLUSION

QoL exhibited a trend towards improvement in accordance with high objective response in this trial with the receipt of combination therapy of anlotinib, vinsristine, and irinotecan for advanced EWS. The toxicity profile did not translate into significantly worse overall scores during treatment.

Cost-effectiveness analysis of pembrolizumab for treatment of US patients with persistent, recurrent, or metastatic cervical cancer

OBJECTIVE

The effectiveness of pembrolizumab for persistent, recurrent, or metastatic cervical cancer has been demonstrated. We aimed to evaluate its cost-effectiveness from the United States (US) healthcare payers perspective.

METHODS

A partitioned survival model over a 30-year lifetime horizon was developed to compare the cost and effectiveness of pembrolizumab versus placebo based on clinical data from the KEYNOTE-826 phase 3 randomized trial. Costs and health state utilities were obtained from literature and publicly available databases. The incremental cost-effectiveness ratio (ICER) was measured. One-way and probabilistic sensitivity analyses were conducted.

RESULTS

For the Intention-to-Treat patients, pembrolizumab was associated with an additional 0.74 quality-adjusted life-year (QALY) at an additional cost of $182,271 when compared with placebo. The ICER was $247,663/QALY. For patients with a programmed death-ligand 1 combined positive score ≥ 1 and 10, the ICER was $253,322/QALY and $214,212/QALY, respectively. One-way sensitivity analyses showed that pembrolizumab had the greatest impact on the ICER. Probabilistic sensitivity analyses showed that the probability of pembrolizumab being cost-effective was zero at the current willingness-to-pay threshold of $150,000/QALY. The price of pembrolizumab had to reduce at least to $28.336 (55.8% of the current price) for it to be cost-effective in a 50% of chance.

CONCLUSION

The addition of pembrolizumab to chemotherapy is costly and might not be cost-effective for persistent, recurrent, or metastatic cervical cancer at the current price in the US.

A Bayesian Framework for Patient-Level Partitioned Survival Cost-Utility Analysis

Patient-level health economic data collected alongside clinical trials are an important component of the process of technology appraisal. For end-of-life treatments, the modeling of cost-effectiveness data may involve some form of partitioned survival analysis, in which measures of quality of life and survival for pre- and postprogression periods are combined to generate aggregate measures of clinical benefits (e.g., quality-adjusted survival). In addition, resource use data are often collected and costs are calculated for each type of health service (e.g., treatment, hospital, or adverse events costs). A critical problem in these analyses is that effectiveness and cost data present some complexities, such as nonnormality, spikes, and missingness, which should be addressed using appropriate methods to avoid biased results. This article proposes a general Bayesian framework that takes into account the complexities of trial-based partitioned survival cost-utility data to provide more adequate evidence for policy makers. Our approach is motivated by, and applied to, a working example based on data from a trial assessing the cost-effectiveness of a new treatment for patients with advanced non-small-cell lung cancer.[Box: see text].

Economic Evaluation of Sacituzumab Govitecan for the Treatment of Metastatic Triple-Negative Breast Cancer in China and the US

BACKGROUND

The effectiveness of Sacituzumab Govitecan (SG) for metastatic triple-negative breast cancer (mTNBC) has been demonstrated. We aimed to evaluate its cost-effectiveness on mTNBC from the Chinese and United States (US) perspective.

METHODS

A partitioned survival model was developed to compare the cost and effectiveness of SG versus single-agent chemotherapy based on clinical data from the ASCENT phase 3 randomized trial. Cost and utility data were obtained from the literature. The incremental cost-effectiveness ratio (ICER) was measured, and one-way and probabilistic sensitivity analyses (PSA) were performed to observe model stability. A Markov model was constructed to validate the results.

RESULTS

In China, SG yielded an additional 0.35 quality-adjusted life-year (QALY) at an additional cost of Chinese Renminbi ¥2257842. The ICER was ¥6375856 ($924037)/QALY. In the US, SG yielded the same additional QALY at an extra cost of $175393 and the ICER was $494479/QALY. Similar results were obtained from the Markov model. One-way sensitivity analyses showed that SG price had the greatest impact on the ICER. PSA showed the probability of SG to be cost-effective when compared with chemotherapy was zero at the current willing-to-pay threshold of ¥217341/QALY and $150000/QALY in China and the US, respectively. The probability of cost-effectiveness of SG would approximate 50% if its price was reduced to ¥10.44/mg in China and $3.65/mg in the US.

CONCLUSION

SG is unlikely to be a cost-effective treatment of mTNBC at the current price both in China and the US.

Window mean survival time

We propose a class of alternative estimates and tests to restricted mean survival time (RMST) which improves power in numerous survival scenarios while maintaining a level of interpretability. The industry standards for interpretable hypothesis tests in survival analysis, RMST and logrank tests (LRTs), can suffer from low power in cases where the proportional hazards assumption fails. In particular, when late differences occur between survival curves, our proposed estimate and class of tests, window mean survival time (WMST), outperforms both RMST and LRT without sacrificing interpretability, unlike weighted rank tests (WRTs). WMST has the added advantage of maintaining high power when the proportional hazards assumption is met, while WRTs do not. With testing methods often being chosen in advance of data collection, WMST can ensure adequate power without distributional assumptions and is robust to the choice of its restriction parameters. Functions for performing WMST analysis are provided in the survWM2 package in R.

Comparison of Duration of Response vs Conventional Response Rates and Progression-Free Survival as Efficacy End Points in Simulated Immuno-oncology Clinical Trials

IMPORTANCE

Phase 2 trials and early efficacy end points play a crucial role in informing decisions about whether to continue to phase 3 trials. Conventional end points, such as objective response rate (ORR) and progression-free survival (PFS), have demonstrated inconsistent associations with overall survival (OS) benefits in immune checkpoint inhibitor (ICI) trials. Restricted mean duration of response (DOR) is a rigorous metric that combines both response status and duration information. However, its utility in clinical development has not been comprehensively explored.

OBJECTIVE

To determine whether using restricted mean DOR in phase 2 trials can advance promising regimens to phase 3 trials sooner and eliminate unfavorable regimens earlier and with a higher degree of confidence compared with PFS and ORR.

DESIGN, SETTING, AND PARTICIPANTS

This simulated modeling study randomized phase 2 screening trials by resampling 1376 patients from 2 completed randomized phase 3 trials of ICIs. Data were analyzed from August 2019 to July 2020.

EXPOSURES

Use of ICIs.

MAIN OUTCOMES AND MEASURES

Restricted mean DOR, PFS, ORR, and OS were estimated and compared between groups. Three scenarios were considered: (1) significant differences in OS, PFS, and ORR; (2) significant differences in OS and noticeable differences in ORR but not PFS; and (3) no differences in OS, PFS, or ORR. For each setting, 5000 randomized phase 2 trials with different sample sizes were simulated, with additional censoring applied to mimic staggered accruals and ensure fair comparisons between different analysis methods. Probabilities of concluding positive phase 2 trials using PFS, ORR, and DOR were summarized and compared.

RESULTS

The restricted mean DOR difference correctly estimated a positive OS benefit more frequently than did the ORR or PFS tests, across different sample sizes, significance levels, and censoring levels evaluated. When both OS and PFS differed, the ranges of true-positive or power rates were 79.2% to 98.7% for DOR, 56.3% to 93.2% for PFS, and 67.0% to 96.0% for ORR. When OS differed but PFS did not, the ranges of power rates were 24.0% to 76.0% for DOR, 3.0% to 19.0% for PFS, and 10.5% to 38.0% for ORR. When OS was similar, the false-positive rate of restricted mean DOR test was close to the chosen significance level.

CONCLUSIONS AND RELEVANCE

These findings suggest that restricted mean DOR in randomized phase 2 trials is potentially more sensitive and useful than PFS and ORR in estimating the subsequent phase 3 conclusions and, thus, may be considered to complementarily facilitate decision-making in future clinical development.

Cost-Utility Analysis of Continuation Versus Discontinuation of First-Line Chemotherapy in Patients With Metastatic Squamous-Cell Esophageal Cancer: Economic Evaluation Alongside the E-DIS Trial

OBJECTIVES

Continuous chemotherapy has been used to treat patients with metastatic esophageal squamous cell carcinoma (mESCC), despite weak evidence supporting a clinical benefit, associated side effects for the patients, and unjustified medical costs. In the French setting, we conducted a cost-utility analysis alongside the randomized E-DIS trial (NCT01248299), which compared first-line fluorouracil/platinum-based chemotherapy continuation (CT-CONT) to CT discontinuation (CT-DISC) in progressive-free patients after an initial 6-week treatment phase.

METHODS

A partitioned survival analysis was performed using patient-level data collected during the trial for survival outcomes, quality of life (EQ-5D-3L), and medical costs. The mean quality-adjusted life-years (QALYs) and medical costs were estimated over an 18-month period to assess the incremental net monetary benefit and incremental cost-effectiveness ratio. Uncertainty was handled using the nonparametric bootstrap and univariate analysis. Sixty-seven patients with mESCC were randomized and included in the cost-utility analysis.

RESULTS

On average, CT-CONT slightly decreased the number of QALYs (-0.038) and increased the cost per patient (+ €1177). At a willingness-to-pay threshold of €50 000/QALY, the incremental net monetary benefit was negative (-€3077 [95% confidence interval: -6564; 4359]), and the incremental cost-effectiveness ratio was -30 958€/QALY (CT-CONT dominated). The probability of the CT-CONT treatment option being cost-effective at a willingness-to-pay threshold of €50 000/QALY, compared to CT-DISC, was 29%.

CONCLUSIONS

CT-DISC may be considered as an alternative therapeutic option to CT-CONT in patients with mESCC who have stable disease after an initial chemotherapy treatment phase. A continuous chemotherapy could indeed reduce the number of QALYs because of the disutility associated with the continuous treatment.

Balancing efficacy and quality of life measurements among metastatic renal cell carcinoma (RCC) studies

Metastatic renal cell carcinoma (mRCC) treatments have rapidly evolved in the last few years. While vascular endothelial growth factor (VEGF) inhibition had previously been the mainstay of treatment for first-line advanced RCC therapy in the past decade, it has now rapidly changed into combination checkpoint inhibitors with or without VEGF TKIs, although there remains a role for VEGF tyrosine kinase inhibitor monotherapy for patients with favorable-risk disease and for those with intermediate and poor-risk disease with the use of cabozantinib. Perspectives on the Quality-adjusted survival Time without Symptoms of disease or Toxicity (Q-TWiST) analysis for the CABOSUN trial, as well as different aspects of efficacy regarding different first-line therapy for advanced or metastatic RCC are discussed herein.

Cost-effectiveness of Osimertinib vs Docetaxel-bevacizumab in Third-line Treatment in EGFR T790M Resistance Mutation Advanced Non-Small Cell Lung Cancer in China

PURPOSE

This study aimed to evaluate the cost-effectiveness of osimertinib vs docetaxel and bevacizumab in third-line treatment in EGFR T790M resistance mutation advanced non-small cell lung cancer in China from the perspective of the health care system.

METHODS

To explore modeling uncertainty, 2 different model methods (a Markov model and a partitioned survival [PS] model) were developed to simulate costs and health outcomes during a lifetime. Both models consisted of 3 health states: progression-free survival, postprogression survival, and death. Efficacy and safety data of osimertinib vs docetaxel and bevacizumab in patients who had acquired EGFR T790M resistance mutation were derived from a key head-to-head clinical trial. Cost and utility values were derived from local charges, the literature, the China Drug Bidding Database, and patients' health care documents. Two scenario analyses and sensitivity analyses were performed to explore the robustness of the results.

FINDINGS

In the Markov model, compared with docetaxel and bevacizumab, osimertinib yielded 0.69 additional quality-adjusted life-years (QALYs) at an additional cost (in US dollars) of $17,311 for an incremental cost-utility ratio (ICUR) of $25,463 per QALY. In the PS model, osimertinib yielded an additional 0.69 QALYs with an incremental cost of $17,827 for an ICUR of $25,951 per QALY. From the Markov model, the ICUR was $29,416 per QALY in scenario 1 and $25,543 per QALY in scenario 2. From the PS model, the ICUR was $30,264 per QALY and $25,947 per QALY for scenarios 1 and 2, respectively. In the probabilistic sensitivity analysis, osimertinib treatment had a 21%-63% probability of being cost-effective at a willingness-to-pay threshold of $9777 to $29,330 per QALY (1-3 times the gross domestic product per capita).

IMPLICATIONS

The findings from the present analysis suggest that osimertinib could be cost-effective vs docetaxel and bevacizumab in third-line treatment in EGFR T790M resistance mutation advanced non-small cell lung cancer in China.

Economic Evaluation of Cisplatin Plus Gemcitabine Versus Paclitaxel Plus Gemcitabine for the Treatment of First-Line Advanced Metastatic Triple-Negative Breast Cancer in China: Using Markov Model and Partitioned Survival Model

INTRODUCTION

This study aimed to evaluate the cost-effectiveness of cisplatin plus gemcitabine vs. paclitaxel plus gemcitabine as a first-line treatment for metastatic triple-negative breast cancer in China.

METHODS

The Markov model and partitioned survival (PS) model were used, and the study included three health states over the period of a lifetime. Transition probabilities and safety data were derived from the CBCSG006 trial (cisplatin plus gemcitabine vs. paclitaxel plus gemcitabine in patients who had acquired metastatic triple-negative breast cancer). Cost and utility values were derived from previous studies, the Chinese Drug Bidding Database, and healthcare documents. Sensitivity analyses were performed to observe model stability.

RESULTS

In the Markov model, compared with paclitaxel plus gemcitabine, cisplatin plus gemcitabine yielded an additional 0.15 QALYs, with an incremental cost of 1976.33 USD. The incremental cost-utility ratio (ICUR) was 12,826.98 USD/QALY (quality-adjusted life year). In the PS model, cisplatin plus gemcitabine yielded an additional 0.17 QALYs with an incremental cost of 2384.63 USD; the incremental cost-utility ratio (ICUR) was 13,867.7 USD/QALY. In the first scenario analysis, in which the 3-year time horizon was used in both arms, the total QALYs in the cisplatin plus gemcitabine group were larger and the costs were lower, indicating that cisplatin plus gemcitabine was superior to paclitaxel plus gemcitabine. In the second scenario, in which the progression-free (PF) utility (during chemotherapy) was 0.76, the PF utility was 0.96, and the post-progression (PP) utility was 0.55, the result obtained with the Markov model showed that the ICUR was 11,063.68 USD/QALY. In the probabilistic sensitivity analysis (PSA) on the Markov model, the probabilities that cisplatin plus gemcitabine would be cost-effective were 48.94-78.72% if the willingness-to-pay threshold was 9776.8 to 29,330.4 USD/QALY.

CONCLUSIONS

The findings of the present analysis suggest that cisplatin plus gemcitabine might be much more cost-effective than paclitaxel plus gemcitabine in patients receiving first-line treatment for metastatic triple-negative breast cancer in China.

The Potential Long-Term Comparative Effectiveness of Larotrectinib and Entrectinib for Second-Line Treatment of TRK Fusion-Positive Metastatic Lung Cancer

BACKGROUND

Larotrectinib and entrectinib are FDA-approved therapies for patients with non-small cell lung cancer (NSCLC) with neurotrophic receptor tyrosine kinase gene fusion (TRK fusion-positive) whose cancer has metastasized and progressed. Early evidence indicates that these targeted therapies may offer dramatic survival benefits versus traditional cytotoxic regimens, but it remains uncertain how larotrectinib and entrectinib compare with each other.

OBJECTIVE

To simulate and compare expected life-years and quality-adjusted life-years (QALYs) for both TRK inhibitors.

METHODS

We developed a partitioned survival model to project the long-term comparative effectiveness of larotrectinib versus entrectinib in second-line treatment of metastatic NSCLC. Larotrectinib survival data were derived from a 13-month follow-up of 12 patients with TRK fusion-positive NSCLC in the NCT02122913 (phase 1) and NCT02576431 (NAVIGATE) trials. Entrectinib survival data were derived from a 13-month follow-up of 10 patients with TRK fusion-positive NSCLC in the ALKA-372-001, STARTRK-1, and STARTRK-2 trials. For larotrectinib and entrectinib progression-free survival and overall survival (OS), in-trial survival was extrapolated using parametric curve fits. Exponential fits were selected for all survival models based on minimal Bayesian information criteria and clinical plausibility. Lifetime survival curves were used to estimate expected mean/median survival. QALYs were estimated by applying preprogression and postprogression health state utilities derived from the literature.

RESULTS

In the base case, treatment with larotrectinib and entrectinib resulted in 5.4 and 1.2 median preprogression life-years and 7.0 and 1.8 median total life-years, respectively. Mean preprogression life-years (QALYs) were 7.5 (5.0) and 1.9 (1.2), and mean total life-years (QALYs) were 9.2 (5.8) and 4.4 (2.4), respectively.

CONCLUSIONS

Among TRK inhibitors for metastatic NSCLC, larotrectinib is estimated to provide improved life-year and QALY outcomes versus entrectinib based on parametric extrapolations of in-trial survival data. Our analysis is limited by lack of NSCLC-specific data on entrectinib OS, the small samples of patients with NSCLC in the trials, and a cross-trial comparison. Future studies should re-evaluate the comparative effectiveness of larotrectinib versus entrectinib as more patients are treated and as long-term survival data mature.

DISCLOSURES

Funding for this study was contributed by Bayer Healthcare, which reviewed the manuscript drafts, and employees contributed to the manuscript as coauthors. Xia and Williamson are employees of Bayer Healthcare. Roth, Carlson, and Sullivan are consultants to Bayer Healthcare and retain rights to all final revisions to the manuscript. Carlson also reports fees from Adaptive Biotechnologies, unrelated to this work. Roth reports consulting fees from BMS, unrelated to this work.

Estimating the quantile medical cost under time-dependent covariates and right censored time-to-event variable based on a state process

Estimating the medical costs from disease diagnosis to a terminal event is of immense interest to researchers. However, most of existing literature on such research focused on the estimation of cumulative mean function (CMF) for history process. In this paper, the combined scheme of both inverse probability of censoring weighting (IPCW) technique and longitudinal quantile regression model is used to develop a novel procedure to the estimation of cumulative quantile function (CQF) based on history process with time-dependent covariates and right censored time-to-event variable. The consistency of proposed estimator is derived. The extensive simulation study is conducted to investigate the performance of the estimator given in this paper. A medical cost data from a multicenter automatic defibrillator implantation trial (MADIT) is analyzed to illustrate the application of developed method.

Estimation of Quality-Adjusted Life Expectancy of Patients With Oral Cancer: Integration of Lifetime Survival With Repeated Quality-of-Life Measurements

BACKGROUND

Quality-adjusted life year is widely applied nowadays, which consider both survival and quality of life (QoL). When most diseases are becoming chronic, it is imperative to quantify the overall health impact of a disease in lifetime perspective.

OBJECTIVE

The purpose of this study is to introduce methods for estimating quality-adjusted life expectancy (QALE) and loss of QALE in patients with a disease or specific conditions.

METHODS

The QALE of an index cohort can be represented as the integration of the product of lifetime survival function and mean QoL function. We introduce a robust extrapolation approach for estimating lifetime survival function and propose an approach for estimating lifetime mean QoL function for studies with limited follow-up. The best part of the proposed method is that the survival data and QoL data can be collected separately. A cohort of patients with a specific condition can be identified by databases that regularly collect data for the control of diseases, and their survival status is verified by linking to a mortality registry. Although nationwide QoL data are not available, researchers can implement a relative short-term follow-up interview on a random sample of patients to collect QoL data. For demonstration, we applied the proposed methods to estimate QALE and loss of QALE of oral cancer patients.

RESULTS

The estimates (95% confidence interval) of QALE for oral cancer patients were 11.0 (10.5-11.6) and 14.2 (12.7-15.5) quality-adjusted life years (QALYs) for men and women, respectively. The estimates of loss of QALE for the male and female patients with oral cancer were 14.4 (13.8-14.9) and 7.5 (6.2-9.0) QALYs, respectively.

CONCLUSIONS

The methods for estimating QALE and loss of QALE can be applied to economic evaluation of cancer control, including screening.

A Q-TWiST Analysis Comparing Nivolumab and Therapy of Investigator's Choice in Patients with Recurrent/Metastatic Platinum-Refractory Squamous Cell Carcinoma of the Head and Neck

OBJECTIVES

In the CheckMate 141 trial (NCT02105636), nivolumab demonstrated survival, health-related quality of life, and healthcare resource utilization benefits vs single-agent therapy of investigator's choice (IC) (methotrexate, docetaxel or cetuximab) in patients with platinum-refractory recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). We assessed between-treatment differences in quality-adjusted time without symptoms of disease progression or toxicity (Q-TWiST).

METHODS

Survival data from CheckMate 141 (nivolumab, n = 240; IC, n = 121) was partitioned into toxicity (TOX), time without symptoms or toxicity (TWiST), and relapse (REL). TOX was defined as time spent with all-cause grade 3-4 adverse events after randomization, before disease progression. TWiST was defined as time not in TOX or REL. REL was defined as time between disease progression and death. Utility values derived from three-level EuroQol five-dimensional questionnaire data from CheckMate 141 were used to calculate Q-TWiST as the utility-weighted sum of the mean duration in each health state.

RESULTS

The between-group difference in Q-TWiST score was 1.23 months (95% confidence interval 1.17-1.29) favoring nivolumab (p < 0.001). The nivolumab group experienced significantly longer mean time in TWiST (3.82 vs 2.78 months) and REL (4.02 vs 3.30 months) compared with the IC group (p < 0.001). Mean time in TOX was lower for nivolumab vs IC (0.30 vs 0.37 months, p < 0.001).

CONCLUSIONS

In CheckMate 141, nivolumab resulted in statistically significant and clinically meaningful gains (relative difference > 10%) in quality-adjusted survival vs standard of care in patients with R/M SCCHN.

R You Still Using Excel? The Advantages of Modern Software Tools for Health Technology Assessment

Economic models are used in health technology assessments (HTAs) to evaluate the cost-effectiveness of competing medical technologies and inform the efficient use of healthcare resources. Historically, these models have been developed with specialized commercial software (such as TreeAge) or more commonly with spreadsheet software (almost always Microsoft Excel). Although these tools may be sufficient for relatively simple analyses, they put unnecessary constraints on the analysis that may ultimately limit its credibility and relevance. In contrast, modern programming languages such as R, Python, Matlab, and Julia facilitate the development of models that are (i) clinically realistic, (ii) capable of quantifying decision uncertainty, (iii) transparent and reproducible, and (iv) reusable and adaptable. An HTA environment that encourages use of modern software can therefore help ensure that coverage and pricing decisions confer greatest possible benefit and capture all scientific uncertainty, thus enabling correct prioritization of future research.

The appropriateness of coronary investigation in myocardial injury and type 2 myocardial infarction (ACT-2): A randomized trial design

BACKGROUND

Elevated troponin level findings among patients presenting with suspected acute coronary syndrome (ACS) or another intercurrent illness undeniably identifies patients at increased risk of mortality. Whilst enhancing our capacity to discriminate risk, the use of high-sensitivity troponin assays frequently identifies patients with myocardial injury (i.e. troponin rise without acute signs of myocardial ischemia) or type 2 myocardial infarction (T2MI; oxygen supply-demand imbalance). This leads to the clinically challenging task of distinguishing type 1 myocardial infarction (T1MI; coronary plaque rupture) from myocardial injury and T2MI in the context of concurrent acute illness. Diagnostic discernment in this context is crucial because MI classification has implications for further investigation and care. Early invasive management is of well-established benefit among patients with T1MI. However, the appropriateness of this investigation in the heterogeneous context of T2MI, where there is high competing mortality risk, remains unknown. Although coronary angiography in T2MI is advocated by some, there is insufficient evidence in existing literature to support this opinion as highlighted by current national guidelines.

OBJECTIVE

The objective is to evaluate the clinical and economic impact of early invasive management with coronary angiography in T2MI in terms of all-cause mortality and cost effectiveness.

DESIGN

This prospective, pragmatic, multicenter, randomized trial among patients with suspected supply demand ischemia leading to troponin elevation (n=1,800; T2MI [1,500], chronic myocardial injury [300]) compares the impact of invasive angiography (or computed tomography angiography as per local preference) within 5 days of randomization versus conservative management (with or without functional testing at clinician discretion) on all-cause mortality by 2 years. Randomized treatment allocation will be stratified by baseline estimated risk of mortality using the Acute Physiology, Age, and Chronic Health Evaluation (APACHE) III risk score. Cost-effectiveness will be evaluated by follow-up on clinical events, quality of life, and resource utilization over 24 months.

SUMMARY

Ascertaining the most appropriate first-line investigative strategy for these commonly encountered high-risk T2MI patients in a randomized comparative study will be pivotal in informing evidence-based guidelines that lead to better patient and health care outcomes.

Patient-centered simulations to assess the usefulness of the 70-gene signature for adjuvant chemotherapy administration in early-stage breast cancer

PURPOSE

From the MINDACT trial, Cardoso et al. did not demonstrate a significant efficacy for adjuvant chemotherapy (CT) for women with early-stage breast cancer presenting high clinical and low genomic risks. Our objective was to assess the usefulness of the 70-gene signature in this population by using an alternative endpoint: the number of Quality-Adjusted Life-Years (QALYs), i.e., a synthetic measure of quantity and quality of life.

METHODS

Based on the results of the MINDACT trial, we simulated a randomized clinical trial consisting of 1497 women with early-stage breast cancer presenting high clinical and low genomic risks. The individual preferences for the different health states and corresponding decrements were obtained from the literature.

RESULTS

The gain in terms of 5-year disease-free survival was 2.8% (95% CI from - 0.1 to 5.7%, from 90.4% for women without CT to 93.3% for women with CT). In contrast, due to the associated side effects, CT significantly reduced the number of QALYs by 62 days (95% CI from 55 to 70 days, from 4.13 years for women without CT to 3.96 years for women with CT).

CONCLUSION

Our results support the conclusions published by Cardoso et al. by providing additional evidence that the 70-gene signature can be used to avoid overtreatment by CT for women with high clinical risk but low genomic risk.

Q-TWiST Analysis to Assess Benefit-Risk of Pembrolizumab in Patients with PD-L1-Positive Advanced or Metastatic Non-small Cell Lung Cancer

OBJECTIVES

Pembrolizumab monotherapy showed significantly longer overall survival and fewer treatment-related adverse events compared to chemotherapy in patients with advanced or metastatic non-small cell lung cancer (NSCLC) with programmed death ligand-1 (PD-L1)-positive tumors in the first-line setting in KEYNOTE (KN)-024 and in those previously treated in KN010. The objective of this analysis was to assess the benefit-risk of pembrolizumab in terms of quality-adjusted survival amongst patients in these trials.

METHODS

The Quality-adjusted Time Without Symptoms of disease progression or Toxicity of treatment (Q-TWiST) analysis was used to compare treatments. Survival time was partitioned into three health states: with toxicity before disease progression, without toxicity before disease progression, and disease progression until death. Health state utilities were estimated using EuroQol-5 Dimensions, 3 Levels (EQ-5D-3L) data collected in the trials. Q-TWiST was calculated as the utility-weighted sum of the mean health state durations. Trial data analyzed included the primary analysis and subsequent data cutoffs. The base-case analysis was based on the most recent analysis of the trials.

RESULTS

Patients randomized to pembrolizumab had 2.49 months greater Q-TWiST (P value < 0.001) compared to those randomized to platinum-based chemotherapy at a follow-up of 24 months in KN024, and 2.29 months greater Q-TWiST (P value < 0.001) compared to docetaxel over 30 months follow-up in KN010. Results across the trial analyses showed an increase in trend for the Q-TWiST improvement of pembrolizumab over time.

CONCLUSIONS

Pembrolizumab showed significant improvement in Q-TWiST compared to chemotherapy in advanced or metastatic NSCLC in both previously untreated and treated patients. The benefits of pembrolizumab continued to accrue with longer follow-ups.

Progression-free survival as a surrogate endpoint for overall survival in modern ovarian cancer trials: a meta-analysis

Background

Progression-free survival (PFS) has been adopted as the primary endpoint in many randomized controlled trials, and can be determined much earlier than overall survival (OS). We investigated whether PFS is a good surrogate endpoint for OS in trials of first-line treatment for epithelial ovarian cancer (EOC), and whether this relationship has changed with the introduction of new treatment types.

Methods

In a meta-analysis, we identified summary data [hazard ratio (HR) and median time] from published randomized controlled trials. Linear regression was used to assess the association between treatment effects on PFS and OS overall, and for subgroups defined by treatment type, postprogression survival (PPS) and established prognostic factors.

Results

Correlation between HRs for PFS and OS, in 26 trials with 30 treatment comparisons comprising 24,870 patients, was modest (r² = 0.52, weighted by trial sample size). The correlation diminished with recency: preplatinum/paclitaxel era, r²= 0.66; platinum/paclitaxel, r²= 0.44; triplet combinations, r²= 0.22; biologicals, r²= 0.30. The median PPS increased over time for the experimental (P_trend = 0.03) and control arms (P_trend = 0.003). The difference in median PPS between treatment arms strongly correlated with the difference in median OS (r² = 0.83). In trials where the control therapy had median PPS of less than 18 months, correlation between PFS and OS was stronger (r² = 0.64) than where the median PPS was longer (r² = 0.48).

Conclusions

In EOC, correlation in the relative treatment effect between PFS and OS in first-line platinum-based chemotherapy randomized controlled trials is moderate and has weakened with increasing availability of effective salvage therapies.

Quantifying the totality of treatment effect with multiple event-time observations in the presence of a terminal event from a comparative clinical study

To evaluate the totality of one treatment's benefit/risk profile relative to an alternative treatment via a longitudinal comparative clinical study, the timing and occurrence of multiple clinical events are typically collected during the patient's follow-up. These multiple observations reflect the patient's disease progression/burden over time. The standard practice is to create a composite endpoint from the multiple outcomes, the timing of the occurrence of the first clinical event, to evaluate the treatment via the standard survival analysis techniques. By ignoring all events after the composite outcome, this type of assessment may not be ideal. Various parametric or semiparametric procedures have been extensively discussed in the literature for the purposes of analyzing multiple event-time data. Many existing methods were developed based on extensive model assumptions. When the model assumptions are not plausible, the resulting inferences for the treatment effect may be misleading. In this article, we propose a simple, nonparametric inference procedure to quantify the treatment effect, which has an intuitive clinically meaningful interpretation. We use the data from a cardiovascular clinical trial for heart failure to illustrate the procedure. A simulation study is also conducted to evaluate the performance of the new proposal.

Nonparametric Two-Sample Tests of the Marginal Mark Distribution with Censored Marks

Occasionally, investigators collect auxiliary marks at the time of failure in a clinical study. Because the failure event may be censored at the end of the follow-up period, these marked endpoints are subject to induced censoring. We propose two new families of two-sample tests for the null hypothesis of no difference in mark-scale distribution that allows for arbitrary associations between mark and time. One family of proposed tests is a nonparametric extension of an existing semi-parametric linear test of the same null hypothesis while a second family of tests is based on novel marked rank processes. Simulation studies indicate that the proposed tests have the desired size and possess adequate statistical power to reject the null hypothesis under a simple change of location in the marginal mark distribution. When the marginal mark distribution has heavy tails, the proposed rank-based tests can be nearly twice as powerful as linear tests.

Cost-Effectiveness of Ribociclib plus Letrozole Versus Palbociclib plus Letrozole and Letrozole Monotherapy in the First-Line Treatment of Postmenopausal Women with HR+/HER2- Advanced or Metastatic Breast Cancer: A U.S. Payer Perspective

BACKGROUND

U.S. regulatory approvals of the cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitors ribociclib and palbociclib as add-ons to letrozole greatly enhance the prospects for treating postmenopausal women with hormone receptor-positive (HR+)/human epidermal receptor 2-negative (HER2-) advanced or metastatic breast cancer. Clinical trials have established that the combination of a CDK 4/6 inhibitor with letrozole can significantly improve progression-free survival (PFS) versus letrozole monotherapy and is safe and well tolerated. Cost-effectiveness studies are required to inform payers and clinical decision makers on the money value of combination treatment in clinical practice.

OBJECTIVE

To evaluate the cost-effectiveness of ribociclib plus letrozole versus palbociclib plus letrozole and versus letrozole monotherapy in the first-line treatment of postmenopausal women with HR+/HER2- advanced or metastatic breast cancer from a U.S. private third-party payer perspective.

METHODS

A partitioned survival model including 3 health states (progression free, with either overall response or stable disease; progressed disease; and death) simulated lifetime costs and outcomes over a 40-year lifetime horizon with a 1-month cycle length. Clinical efficacy data (PFS and overall survival [OS]) were derived from a phase III trial of ribociclib plus letrozole (MONALEESA-2; NCT01958021), a phase II trial of palbociclib plus letrozole (PALOMA-1; NCT00721409), and a Bayesian network meta-analysis. Health care costs included drug acquisition and monitoring, disease management, subsequent therapies, and serious drug-related adverse events. Effectiveness was measured in life-years, derived from survival projections, and in quality-adjusted life-years (QALYs), calculated from time spent in each state combined with health-state utility values. A one-way deterministic sensitivity analysis explored the impact of uncertainty in key model parameters on results, and probabilistic uncertainty was assessed through a Monte Carlo probabilistic sensitivity analysis.

RESULTS

Ribociclib plus letrozole was dominant versus palbociclib plus letrozole, with a cost saving of $43,037 and a gain of 0.086 QALYs. Compared with letrozole monotherapy, ribociclib plus letrozole was associated with an incremental cost of $144,915 and an incremental QALY of 0.689, equating to an incremental cost-effectiveness ratio of $210,369 per QALY. Key model drivers included OS HRs for palbociclib plus letrozole versus letrozole and for ribociclib plus letrozole versus letrozole, the PFS HR for palbociclib plus letrozole versus letrozole, PD health-state costs, utility of response, and cost discount rate. The probabilities that ribociclib plus letrozole was cost-effective versus letrozole at thresholds of $50,000, $100,000 and $200,000 per QALY gained were 1.6%, 6.3%, and 50.5%, respectively.

CONCLUSIONS

In the United States, ribociclib plus letrozole is a cost-effective alternative to palbociclib plus letrozole for the first-line treatment of postmenopausal women with HR+/HER2- advanced or metastatic breast cancer. Ribociclib plus letrozole is also cost-effective versus letrozole monotherapy at willingness-to-pay thresholds greater than $198,000 per QALY (for probabilistic analysis).

DISCLOSURES

Funding for this study was provided by Novartis, which manufactures ribociclib and provided input on the study design and data collection, analysis, and interpretation. Mistry, May, Suri, and Young are employees of PAREXEL. Tang, Mishra, D. Bhattacharyya, and Dalal are employees of Novartis. S. Bhattacharyya was an employee of Novartis during the study period. Tang and Dalal hold stock in Novartis. Brixner, Oderda, and Biskupiak were paid by Millcreek Outcomes Group as consultants for work on this project. Brixner has also consulted for AstraZeneca, UCB, Regeneron, and Abbott.

Infliximab versus ciclosporin for steroid-resistant acute severe ulcerative colitis (CONSTRUCT): a mixed methods, open-label, pragmatic randomised trial

Background

Infliximab and ciclosporin are of similar efficacy in treating acute severe ulcerative colitis, but there has been no comparative evaluation of their relative clinical effectiveness and cost-effectiveness.

Methods

In this mixed methods, open-label, pragmatic randomised trial, we recruited consenting patients aged 18 years or older at 52 district general and teaching hospitals in England, Scotland, and Wales who had been admitted, unscheduled, with severe ulcerative colitis and failed to respond to intravenous hydrocortisone within about 5 days. Patients were randomly allocated (1:1) to receive either infliximab (5 mg/kg intravenous infusion given over 2 h at baseline, and again at 2 weeks and 6 weeks after the first infusion) or ciclosporin (2 mg/kg per day by continuous infusion for up to 7 days, followed by twice-daily tablets delivering 5·5 mg/kg per day for 12 weeks). Randomisation used a web-based password-protected site, with a dynamic algorithm to generate allocations on request, thus protecting against investigator preference or other subversion, while ensuring that each trial group was balanced by centre, which was the only stratification used. Local investigators and participants were aware of the treatment allocated, but the chief investigator and analysts were masked. Analysis was by treatment allocated. The primary outcome was quality-adjusted survival—ie, the area under the curve (AUC) of scores from the Crohn's and Ulcerative Colitis Questionnaire (CUCQ) completed by participants at baseline, 3 months, and 6 months, then every 6 months from 1 year to 3 years. This trial is registered with the ISRCTN Registry, number ISRCTN22663589.

Findings

Between June 17, 2010, and Feb 26, 2013, 270 patients were recruited. 135 patients were allocated to the infliximab group and 135 to the ciclosporin group. 121 (90%) patients in each group were included in the analysis of the primary outcome. There was no significant difference between groups in quality-adjusted survival (mean AUC 564·0 [SD 241·9] in the infliximab group vs 587·0 [226·2] in the ciclosporin group; mean adjusted difference 7·9 [95% CI −22·0 to 37·8]; p=0·603). Likewise, there were no significant differences between groups in the secondary outcomes of CUCQ scores, EQ-5D, or SF-6D scores; frequency of colectomy (55 [41%] of 135 patients in the infliximab group vs 65 [48%] of 135 patients in the ciclosporin group; p=0·223); or mean time to colectomy (811 [95% CI 707–912] days in the infliximab group vs 744 [638–850] days in the ciclosporin group; p=0·251). There were no differences in serious adverse reactions (16 reactions in 14 participants receiving infliximab vs ten in nine patients receiving ciclosporin); serious adverse events (21 in 16 patients vs 25 in 17 patients); or deaths (three in the infliximab group vs none in the ciclosporin group).

Interpretation

There was no significant difference between ciclosporin and infliximab in clinical effectiveness.

Funding

NIHR Health Technology Assessment programme.

Comparison Of iNfliximab and ciclosporin in STeroid Resistant Ulcerative Colitis: pragmatic randomised Trial and economic evaluation (CONSTRUCT)

BACKGROUND

The efficacy of infliximab and ciclosporin in treating severe ulcerative colitis (UC) is proven, but there has been no comparative evaluation of effectiveness.

OBJECTIVE

To compare the clinical effectiveness and cost-effectiveness of infliximab and ciclosporin in treating steroid-resistant acute severe UC.

METHOD

Between May 2010 and February 2013 we recruited 270 participants from 52 hospitals in England, Scotland and Wales to an open-label parallel-group, pragmatic randomised trial. Consented patients admitted with severe colitis completed baseline quality-of-life questionnaires before receiving intravenous hydrocortisone. If they failed to respond within about 5 days, and met other inclusion criteria, we invited them to participate and used a web-based adaptive randomisation algorithm to allocate them in equal proportions between 5 mg/kg of intravenous infliximab at 0, 2 and 6 weeks or 2 mg/kg/day of intravenous ciclosporin for 7 days followed by 5.5 mg/kg/day of oral ciclosporin until 12 weeks from randomisation. Further treatment was at the discretion of physicians responsible for clinical management. The primary outcome was quality-adjusted survival (QAS): the area under the curve (AUC) of scores derived from Crohn's and Ulcerative Colitis Questionnaires completed by participants at 3 and 6 months, and then 6-monthly over 1-3 years, more frequently after surgery. Secondary outcomes collected simultaneously included European Quality of Life-5 Dimensions (EQ-5D) scores and NHS resource use to estimate cost-effectiveness. Blinding was possible only for data analysts. We interviewed 20 trial participants and 23 participating professionals. Funded data collection finished in March 2014. Most participants consented to complete annual questionnaires and for us to analyse their routinely collected health data over 10 years.

RESULTS

The 135 participants in each group were well matched at baseline. In 121 participants analysed in each group, we found no significant difference between infliximab and ciclosporin in QAS [mean difference in AUC/day 0.0297 favouring ciclosporin, 95% confidence interval (CI) -0.0088 to 0.0682; p = 0.129]; EQ-5D scores (quality-adjusted life-year mean difference 0.021 favouring ciclosporin, 95% CI -0.032 to 0.096; p = 0.350); Short Form questionnaire-6 Dimensions scores (mean difference 0.0051 favouring ciclosporin, 95% CI -0.0250 to 0.0353; p = 0.737). There was no statistically significant difference in colectomy rates [odds ratio (OR) 1.350 favouring infliximab, 95% CI 0.832 to 2.188; p = 0.223]; numbers of serious adverse reactions (event ratio = 0.938 favouring ciclosporin, 95% CI 0.590 to 1.493; p = 0.788); participants with serious adverse reactions (OR 0.660 favouring ciclosporin, 95% CI 0.282 to 1.546; p = 0.338); numbers of serious adverse events (event ratio 1.075 favouring infliximab, 95% CI 0.603 to 1.917; p = 0.807); participants with serious adverse events (OR 0.999 favouring infliximab, 95% CI 0.473 to 2.114; p = 0.998); deaths (all three who died received infliximab; p = 0.247) or concomitant use of immunosuppressants. The lower cost of ciclosporin led to lower total NHS costs (mean difference -£5632, 95% CI -£8305 to -£2773; p < 0.001). Interviews highlighted the debilitating effect of UC; participants were more positive about infliximab than ciclosporin. Professionals reported advantages and disadvantages with both drugs, but nurses disliked the intravenous ciclosporin.

CONCLUSIONS

Total cost to the NHS was considerably higher for infliximab than ciclosporin. Nevertheless, there was no significant difference between the two drugs in clinical effectiveness, colectomy rates, incidence of SAEs or reactions, or mortality, when measured 1-3 years post treatment. To assess long-term outcome participants will be followed up for 10 years post randomisation, using questionnaires and routinely collected data. Further studies will be needed to evaluate the efficacy and effectiveness of new anti-tumour necrosis factor drugs and formulations of ciclosporin.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN22663589.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 44. See the NIHR Journals Library website for further project information.

Oncology Modeling for Fun and Profit! Key Steps for Busy Analysts in Health Technology Assessment

In evaluating new oncology medicines, two common modeling approaches are state transition (e.g., Markov and semi-Markov) and partitioned survival. Partitioned survival models have become more prominent in oncology health technology assessment processes in recent years. Our experience in conducting and evaluating models for economic evaluation has highlighted many important and practical pitfalls. As there is little guidance available on best practices for those who wish to conduct them, we provide guidance in the form of 'Key steps for busy analysts,' who may have very little time and require highly favorable results. Our guidance highlights the continued need for rigorous conduct and transparent reporting of economic evaluations regardless of the modeling approach taken, and the importance of modeling that better reflects reality, which includes better approaches to considering plausibility, estimating relative treatment effects, dealing with post-progression effects, and appropriate characterization of the uncertainty from modeling itself.

QTWiST analysis of the RECOURSE trial of trifluridine/tipiracil in metastatic colorectal cancer

Purpose

A Quality-adjusted Time WIthout Symptoms of disease or Toxicity (QTWiST) analysis was carried out to assess quality-adjusted survival time in the RECOURSE trial of trifluridine/tipiracil versus placebo in pretreated metastatic colorectal cancer (mCRC).

Methods

Duration of overall survival in the RECOURSE trial (n=798 patients) was partitioned into three discrete health states: toxicity (TOX), time without symptoms or toxicity (TWIST) and relapse (REL). TOX was defined as time spent with grade 3 or 4 treatment-related adverse events (AEs) after randomisation and before progression or censoring. AEs were limited to those related to trifluridine/tipiracil and known to affect quality of life (QoL) (ie, nausea, vomiting, diarrhoea, fatigue/asthaenia, anorexia and febrile neutropaenia). The estimated mean duration of each state, weighted by a utility coefficient representing QoL, was combined into a global QTWiST score.

Results

In the RECOURSE trial, overall survival was 7.1 months with trifluridine/tipiracil versus 5.3 months with placebo. Patients receiving trifluridine/tipiracil spent longer in each health state than placebo recipients. Using assumed utility coefficients of 1 for TWIST and 0.5 for TOX and REL, the QTWiST was 5.48 months for the trifluridine/tipiracil group and 3.98 months for the placebo group, a difference of 1.5 (95% CI 1.49 to 1.52) months in favour of trifluridine/tipiracil. A sensitivity analysis using large variations in utility coefficients for TOX and REL produced a range of only approximately 0.5 months from minimum to maximum QTWiST.

Conclusions

Quality-adjusted survival, as measured by QTWiST, shows clinically meaningful improvements in patients treated with trifluridine/tipiracil versus placebo in pretreated mCRC.