Network meta-analysis of survival data with fractional polynomials

Comparative efficacy of later-line therapies for metastatic colorectal cancer: a network meta-analysis of survival curves

INTRODUCTION

We evaluated the comparative efficacy of six later-line (≥3) therapies for metastatic colorectal cancer (mCRC) over placebo. We applied a novel statistical method of reconstructing pseudo-patient-level data (pseudo-IPD) to inform a network meta-analysis of survival curves that considers shape in addition to scale parameters.

METHODS

A literature search yielded 10 phase II/III trials. We digitized all survival curves and applied a novel method incorporating curve coordinates, patients-at-risk, and events reported to generate pseudo-IPD. Using fitted random effects lognormal distributions, we estimated the survival proportions and HRs (95CrI) of progression-free (PFS) and overall survival (OS) over 12 months of follow-up.

RESULTS

Compared to placebo, in ascending order, 12-month OS HRs were 0.50 (95% CrI = 0.35, 0.69; PFS = 0.11 (95% CrI = 0.06, 0.14)) for TAS+bevacizumab; 0.71 (95% CrI = 0.51, 0.97; PFS = 0.26 (95% CrI = 0.16, 0.41)) for regorafenib; 0.75 (95% CrI = 0.61, 0.91; (PFS = 0.24 (95% CrI = 0.17, 0.31)) for TAS-102; 0.80 (95% CrI = 0.79, 0.90; PFS = 0.18 (95% CrI = 0.13, 0.24)) for fruquintinib; 0.83 (95% CrI = 0.50, 0.99; PFS = 0.42 (95% CrI = 0.20, 0.75)) for atezolizumab+cobimetinib; and 1.03 (95% CrI = 0.55, 1.65; PFS = 0.67 (95% CrI = 0.29, 1.01)) for atezolizumab.

CONCLUSION

In this independent NMA of survival data, all later-line mCRC therapies but atezolizumab monotherapy exhibited superiority in 12-month PFS and OS over placebo. TAS+bevacizumab emerged as the most dominant option and may be the preferred choice, with fruquintinib, regorafenib, and TAS-102 monotherapy showing statistically significant but lower PFS and OS benefits.

REGISTRATION

PROSPERO: CRD42022371953.

Predicting Treatment Effects from Surrogate Endpoints in Historical Trials in First-Line Metastatic Castration-Resistant Prostate Cancer

Surrogate endpoints are becoming increasingly important in health technology assessment, where decisions are based on complex cost-effectiveness models (CEMs) that require numerous input parameters. Daniels and Hughes Surrogate Model was used to predict missing effect estimates in randomized controlled trials (RCTs) evaluating first-line treatments in metastatic castration-resistant prostate cancer (mCRPC) patients. Network meta-analyses (NMAs) were conducted to assess the comparative efficacy of these treatments. Databases were searched (inception to October 2022) using Ovid®. Several grey literature searches were also conducted (PROSPERO: CRD42021283512). Available trial data for radiographic progression-free survival (rPFS) and overall survival (OS) were used to predict the unreported effect of rPFS or OS for relevant comparator treatments. Bayesian NMAs were conducted using observed and predicted treatment effects. Effect estimates and 95% credible intervals were calculated for each comparison. Mean ranks and the probability of being best (p-best) were obtained. Twenty-five RCTs met the eligibility criteria and of these, 8 reported jointly rPFS and OS; while rPFS was predicted for 12 RCTs and 10 comparators, and OS was predicted for 5 RCTs and 6 comparators. A nonstandard dose of docetaxel (docetaxel 50 mg/m2 every 2 weeks) had the highest probability of being the most effective for rPFS (p-best: 59%) and OS (p-best: 48%), followed by talazoparib plus enzalutamide (13% and 19%, respectively). Advanced surrogate modelling techniques allowed obtaining relevant parameter and indirect estimates of previously unavailable data and may be used to populate future CEMs requiring rPFS and OS in first-line mCRPC.

Overall survival with non-proportional hazards in first-line treatment for patients with metastatic colorectal cancer: Systematic review and network meta-analysis

This study aimed to identify the most effective first-line treatment for patients with metastatic colorectal cancer based on overall survival, identify the most commonly used treatment, and generate a meaningful ranking among all available treatments based on their relative effectiveness. Researchers used the ANOVA parametrization method to fit the second-order fractional polynomial network meta-analysis with a random-effect model. Using a non-proportional hazards network meta-analysis, 46 treatments were compared by considering a combination of direct and indirect evidence extracted from clinical trial studies. Included in the review were 46 trials involving 21350 patients. Between January 2000 and January 2023, researchers conducted a thorough search through Embase, PubMed/Medline, and Scopus. To undertake a secondary analysis of this data, we recreate individual patient data from published Kaplan-Meier (K-M) survival curves and assess the accuracy of that reconstruction. A random-effects model was used to evaluate the pooled overall survival and hazard ratio with a 95 percent confidence interval. The predicted survival curves for the network meta-analysis showed that GOLFIG and FOLFOX + Cetuximab treatments have higher survival, respectively. Our results provide moderate quality evidence and comparative effective estimates for various available first-line treatments for metastasis colorectal cancer based on network meta-analysis.

Comparative Cost-Effectiveness of Gemcitabine and Cisplatin in Combination with S-1, Durvalumab, or Pembrolizumab as First-Line Triple Treatment for Advanced Biliary Tract Cancer

PURPOSE

The clinical effectiveness of triple chemotherapy consisting of gemcitabine, cisplatin plus either S-1 (GCS), durvalumab (DGC), or pembrolizumab (PGC) as first-line treatment for advanced biliary tract cancer (BTC) has been reported. However, their comparative cost-effectiveness is unclear. We conducted a model-based cost-effectiveness analysis from the perspective of Japanese healthcare payer.

METHODS

A 10-year partitioned survival model was constructed by comparing the time-dependent hazards of the KHBO1401-MITSUBA, TOPAZ-1, and KEYNOTE-966 trials. The cost and utility came from previously published reports. Quality-adjusted life years (QALY) were used to measure the effects on health. Costs for direct medical care were taken into account. There was a one-way analysis and a probability sensitivity analysis. A willingness-to-pay threshold of 7.5 million yen (57,034 USD) per QALY was defined.

RESULTS

The incremental costs per QALY for GCS, DGC, and PGC in the base case study were 3,779,374 JPY (28,740 USD), 86,058,056 JPY (65,4434 USD), and 28,982,059 JPY (220,396 USD), respectively. No parameter had an influence beyond the threshold in a one-way sensitivity analysis. A probabilistic sensitivity analysis revealed that the probability of GCS, DGC, and PGC being cost-effective at the threshold was 85.6%, 0%, and 0%, respectively.

CONCLUSION

Given the current circumstances, it is probable that triple therapy utilizing GCS will emerge as a plausible and efficient primary chemotherapy strategy for patients with advanced BTC in the Japanese healthcare system, as opposed to DGC and PGC.

Confirming the efficacy and safety of CDK4/6 inhibitors in the first-line treatment of HR+ advanced breast cancer: a systematic review and meta-analysis

Objective: Cyclin-dependent kinase (CDK) 4 and 6 inhibitors (abemaciclib, palbociclib and ribociclib) have been recommended in the first-line treatment of hormone receptor-positive (HR+) breast cancer in China. Our study aims to evaluate the efficacy and safety of CDK4/6 inhibitors by processing survival data using fractional polynomial modeling methods. Methods: Phase II or III randomized controlled trials in treatment-naive HR + patients with advanced breast cancer were systematically searched through the preset search strategy. The fractional polynomial (FP) model was used to relax the proportional hazard assumption and obtain time-varying hazard ratio (HR). Progression-free life years (PFLYs) and life years (LYs) were calculated from the area under curve (AUC) of the predicted progression-free survival (PFS) and overall survival (OS) curves to evaluate the long-term efficacy benefit. Odds ratio (OR) of grade≥3 adverse events were analyzed for safety outcomes. Results: 6 randomized controlled trials with 2,638 patients were included. The first-order FP model (p = -1) and the first-order FP model (p = 1) were used to calculate the time-varying HR of PFS and OS, respectively. Extrapolating to 240 months, abemaciclib obtained a PFS benefit of 3.059 PFLYs and 6.275 LYs by calculating the AUC of the PFS and OS curves. Palbociclib obtained 2.302 PFLYs and 6.351 LYs. Ribociclib obtained 2.636 PFLYs and 6.543 LYs. In terms of safety, the use of CDK4/6 inhibitors resulted in a higher risk of adverse events (OR = 9.84, 95% CI: 8.13-11.95), especially for palbociclib (OR = 14.04, 95% CI: 10.52-18.90). Conclusion: The use of CDK4/6 inhibitors in treatment-naive patients with HR + advanced breast cancer significantly improves survival, but also increases the risk of adverse events. Abemaciclib and ribociclib may be the best options for prolonging PFS and OS in treatment-naïve patients, respectively.

Lenvatinib plus pembrolizumab for untreated advanced renal cell carcinoma: a systematic review and cost-effectiveness analysis

Background

Renal cell carcinoma is the most common type of kidney cancer, comprising approximately 85% of all renal malignancies. Patients with advanced renal cell carcinoma are the focus of this National Institute for Health and Care Excellence multiple technology appraisal. A patient's risk of disease progression depends on a number of prognostic risk factors; patients are categorised as having intermediate/poor risk or favourable risk of disease progression.

Objectives

The objectives of this multiple technology appraisal were to appraise the clinical effectiveness and cost-effectiveness of lenvatinib plus pembrolizumab versus relevant comparators listed in the final scope issued by the National Institute for Health and Care Excellence: sunitinib, pazopanib, tivozanib, cabozantinib and nivolumab plus ipilimumab.

Methods

The assessment group carried out clinical and economic systematic reviews and assessed the clinical and cost-effectiveness evidence submitted by Eisai, Hatfield, Hertfordshire, UK (the manufacturer of lenvatinib) and Merck Sharp & Dohme, Whitehouse Station, NJ, USA (the manufacturer of pembrolizumab). The assessment group carried out fixed-effects network meta-analyses using a Bayesian framework to generate evidence for clinical effectiveness. As convergence issues occurred due to sparse data, random-effects network meta-analysis results were unusable. The assessment group did not develop a de novo economic model, but instead modified the partitioned survival model provided by Merck Sharp & Dohme.

Results

The assessment group clinical systematic review identified one relevant randomised controlled trial (CLEAR trial). The CLEAR trial is a good-quality, phase III, multicentre, open-label trial that provided evidence for the efficacy and safety of lenvatinib plus pembrolizumab compared with sunitinib. The assessment group progression-free survival network meta-analysis results for all three risk groups should not be used to infer any statistically significant difference (or lack of statistically significant difference) for any of the treatment comparisons owing to within-trial proportional hazards violations or uncertainty regarding the validity of the proportional hazards assumption. The assessment group overall survival network meta-analysis results for the intermediate-/poor-risk subgroup suggested that there was a numerical, but not statistically significant, improvement in the overall survival for patients treated with lenvatinib plus pembrolizumab compared with patients treated with cabozantinib or nivolumab plus ipilimumab. Because of within-trial proportional hazards violations or uncertainty regarding the validity of the proportional hazards assumption, the assessment group overall survival network meta-analysis results for the favourable-risk subgroup and the all-risk population should not be used to infer any statistically significant difference (or lack of statistically significant difference) for any of the treatment comparisons. Only one cost-effectiveness study was included in the assessment group review of cost-effectiveness evidence. The study was limited to the all-risk population, undertaken from the perspective of the US healthcare system and included comparators that are not recommended by the National Institute for Health and Care Excellence for patients with untreated advanced renal cell carcinoma. Therefore, the extent to which resource use and results are generalisable to the NHS is unclear. The assessment group cost-effectiveness results from the modified partitioned survival model focused on the intermediate-/poor-risk and favourable-risk subgroups. The assessment group cost-effectiveness results, generated using list prices for all drugs, showed that, for all comparisons in the favourable-risk subgroup, treatment with lenvatinib plus pembrolizumab costs more and generated fewer benefits than all other treatments available to NHS patients. For the intermediate-/poor-risk subgroup, treatment with lenvatinib plus pembrolizumab costs more and generated more benefits than treatment with cabozantinib and nivolumab plus ipilimumab.

Conclusions

Good-quality clinical effectiveness evidence for the comparison of lenvatinib plus pembrolizumab with sunitinib is available from the CLEAR trial. For most of the assessment group Bayesian hazard ratio network meta-analysis comparisons, it is difficult to reach conclusions due to within-trial proportional hazards violations or uncertainty regarding the validity of the proportional hazards assumption. However, the data (clinical effectiveness and cost-effectiveness) used to populate the economic model are relevant to NHS clinical practice and can be used to inform National Institute for Health and Care Excellence decision-making. The assessment group cost-effectiveness results, generated using list prices for all drugs, show that lenvatinib plus pembrolizumab is less cost-effective than all other treatment options.

Study registration

This study is registered as PROSPERO CRD4202128587.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Evidence Synthesis Programme (NIHR award ref: NIHR134985) and is published in full in Health Technology Assessment; Vol. 28, No. 49. See the NIHR Funding and Awards website for further award information.

Reply to "Matters arising: cost-effectiveness of first-line immunotherapy combinations with or without chemotherapy for advanced non-small cell lung cancer: a modelling approach"

In this article, we read with great attention the correspondence by Bullement et al., regarding our published study on cost-effectiveness of first-line immunotherapy combinations with or without chemotherapy for advanced non-small cell lung cancer. We referred to a few the most important comments from Bullement et al. in our opinion, including proportional hazard (PH) assumption, accelerated failure time (AFT) model, and health utility, and made some explanations.

Time-dependent efficacy analysis of first-line immunotherapies for advanced non-small cell lung cancer

BACKGROUND

Many randomized controlled trials (RCTs) and network meta-analyses have demonstrated that the progression-free survival (PFS) and overall survival (OS) of advanced non-small cell lung cancer (NSCLC) patients can be improved through combination immunotherapy or monotherapies. However, time-dependent analysis of the treatment effect is currently lacking. Thus, we aimed to evaluate the efficacy of first-line immunotherapy, and establish a hazard ratio function to reflect the time-varying progression or mortality risk of patients with NSCLC.

METHODS

Seventeen clinical trials were selected based on search strategy. Baseline characteristics, including the age, sex, smoking status, geographical region, and Eastern Cooperative Oncology Group (ECOG) performance status of patients, were balanced, resulting in ten immunotherapies from nine appropriate clinical trials to conduct treatment effect comparison.

RESULTS

We found that nivolumab plus ipilimumab (nivo + ipi) improved the PFS and OS over time. The hazard ratio of nivo + ipi, relative to that of pembrolizumab, decreased from 1.11 to 0.36 for PFS, and from 0.93 to 0.49 for OS over a 10-year period. In terms of the response to immunotherapy in patients with different PD-L1 expression levels, patients with PD-L1 > = 50% experienced lower rates of progression and a reduced mortality risk over time. The hazard ratio of patients with PD-L1 > = 50% relative to all of the patients decreased from 0.73 to 0.69 for PFS, and from 0.78 to 0.67 for OS.

CONCLUSIONS

Based on the fact that time-dependent progression and mortality risk existed during the treatment duration, physicians should select a suitable treatment regimen for patients based on the hazard ratio.

Cost-effectiveness analysis of PD-1 inhibitors as second-line therapy for advanced or metastatic esophageal squamous cell carcinoma in China: an economic evaluation based on network meta-analysis

BACKGROUND

Several economic studies have assessed the cost-effectiveness of programmed cell death protein-1 (PD-1) inhibitors compared to second-line chemotherapy in treating esophageal squamous cell carcinoma (ESCC). However, there is a lack of economic comparisons among the different PD-1 inhibitors.

AIM

This study aimed to assess the cost-effectiveness of PD-1 inhibitors (nivolumab, pembrolizumab, camrelizumab, and tislelizumab) in second-line treatment for advanced or metastatic ESCC within the Chinese healthcare system.

METHOD

The clinical trials were systematically retrieved from PubMed, Embase, Web of Science, and the Cochrane Library. We established a fractional polynomials model to conduct a network meta-analysis, enabling the calculation of hazard ratios and expected survival rates. Economic outcomes were estimated using a partitioned survival model. The costs and utilities were gathered from published sources. The threshold for willingness-to-pay (WTP) for a quality-adjusted life year (QALY) was set at three times China's per capita gross domestic product in 2022. Sensitivity analyses (SA) were performed to address uncertainties in the model.

RESULTS

Four phase III randomized controlled trials were included, evaluating the cost-effectiveness of four PD-1 inhibitors, camrelizumab, nivolumab, tislelizumab, and pembrolizumab, compared to chemotherapy for the second-line treatment of advanced or metastatic ESCC. For camrelizumab, nivolumab, tislelizumab, and pembrolizumab, the corresponding incremental cost-effectiveness ratios were $27,375.43/QALY, $205,312.19/QALY, $9,266.73/QALY, and $220,368.10/QALY, respectively. The SA results indicated the robustness of the base analysis findings.

CONCLUSION

From the Chinese healthcare system, under the WTP of $38,253.48/QALY, tislelizumab is a cost-effective treatment option for the second-line treatment of advanced or metastatic ESCC.

Cost-effectiveness analysis of immune checkpoint inhibitors as first-line therapy in advanced biliary tract cancer

Aim: To assess the cost-effectiveness of immune checkpoint inhibitors as first-line treatments for advanced biliary tract cancer (BTC).Methods: This pharmacoeconomic evaluation employed the fractional polynomial network meta-analysis and partitioned survival model. Costs and utilities were collected from the literature and databases. Sensitivity analyses were used to examine uncertainties.Results: The incremental cost-effectiveness ratios (ICERs) of first-line treatment strategies were $761,371.37 per quality-adjusted life-year (QALY) or $206,222.53/QALY in the US and $354,678.79 /QALY or $213,874.22/QALY in China, respectively. The sensitivity analysis results were largely consistent with the base case.Conclusion: From the US and Chinese payer perspectives, adding durvalumab or pembrolizumab to chemotherapy is unlikely to be cost effective in the first-line setting for advanced BTC.

Bayesian pairwise meta-analysis of time-to-event outcomes in the presence of non-proportional hazards: A simulation study of flexible parametric, piecewise exponential and fractional polynomial models

BACKGROUND

Traditionally, meta-analysis of time-to-event outcomes reports a single pooled hazard ratio assuming proportional hazards (PH). For health technology assessment evaluations, hazard ratios are frequently extrapolated across a lifetime horizon. However, when treatment effects vary over time, an assumption of PH is not always valid. The Royston-Parmar (RP), piecewise exponential (PE), and fractional polynomial (FP) models can accommodate non-PH and provide plausible extrapolations of survival curves beyond observed data.

METHODS

Simulation study to assess and compare the performance of RP, PE, and FP models in a Bayesian framework estimating restricted mean survival time difference (RMSTD) at 50 years from a pairwise meta-analysis with evidence of non-PH. Individual patient data were generated from a mixture Weibull distribution. Twelve scenarios were considered varying the amount of follow-up data, number of trials in a meta-analysis, non-PH interaction coefficient, and prior distributions. Performance was assessed through bias and mean squared error. Models were applied to a metastatic breast cancer example.

RESULTS

FP models performed best when the non-PH interaction coefficient was 0.2. RP models performed best in scenarios with complete follow-up data. PE models performed well on average across all scenarios. In the metastatic breast cancer example, RMSTD at 50-years ranged from -14.6 to 8.48 months.

CONCLUSIONS

Synthesis of time-to-event outcomes and estimation of RMSTD in the presence of non-PH can be challenging and computationally intensive. Different approaches make different assumptions regarding extrapolation and sensitivity analyses varying key assumptions are essential to check the robustness of conclusions to different assumptions for the underlying survival function.

Twenty years of network meta-analysis: Continuing controversies and recent developments

Network meta-analysis (NMA) is an extension of pairwise meta-analysis (PMA) which combines evidence from trials on multiple treatments in connected networks. NMA delivers internally consistent estimates of relative treatment efficacy, needed for rational decision making. Over its first 20 years NMA's use has grown exponentially, with applications in both health technology assessment (HTA), primarily re-imbursement decisions and clinical guideline development, and clinical research publications. This has been a period of transition in meta-analysis, first from its roots in educational and social psychology, where large heterogeneous datasets could be explored to find effect modifiers, to smaller pairwise meta-analyses in clinical medicine on average with less than six studies. This has been followed by narrowly-focused estimation of the effects of specific treatments at specific doses in specific populations in sparse networks, where direct comparisons are unavailable or informed by only one or two studies. NMA is a powerful and well-established technique but, in spite of the exponential increase in applications, doubts about the reliability and validity of NMA persist. Here we outline the continuing controversies, and review some recent developments. We suggest that heterogeneity should be minimized, as it poses a threat to the reliability of NMA which has not been fully appreciated, perhaps because it has not been seen as a problem in PMA. More research is needed on the extent of heterogeneity and inconsistency in datasets used for decision making, on formal methods for making recommendations based on NMA, and on the further development of multi-level network meta-regression.

Sharing Medical Big Data While Preserving Patient Confidentiality in Innovative Medicines Initiative: A Summary and Case Report from BigData@Heart

Sharing individual patient data (IPD) is a simple concept but complex to achieve due to data privacy and data security concerns, underdeveloped guidelines, and legal barriers. Sharing IPD is additionally difficult in big data-driven collaborations such as Bigdata@Heart in the Innovative Medicines Initiative, due to competing interests between diverse consortium members. One project within BigData@Heart, case study 1, needed to pool data from seven heterogeneous data sets: five randomized controlled trials from three different industry partners, and two disease registries. Sharing IPD was not considered feasible due to legal requirements and the sensitive medical nature of these data. In addition, harmonizing the data sets for a federated data analysis was difficult due to capacity constraints and the heterogeneity of the data sets. An alternative option was to share summary statistics through contingency tables. Here it is demonstrated that this method along with anonymization methods to ensure patient anonymity had minimal loss of information. Although sharing IPD should continue to be encouraged and strived for, our approach achieved a good balance between data transparency while protecting patient privacy. It also allowed a successful collaboration between industry and academia.

survextrap: a package for flexible and transparent survival extrapolation

BACKGROUND

Health policy decisions are often informed by estimates of long-term survival based primarily on short-term data. A range of methods are available to include longer-term information, but there has previously been no comprehensive and accessible tool for implementing these.

RESULTS

This paper introduces a novel model and software package for parametric survival modelling of individual-level, right-censored data, optionally combined with summary survival data on one or more time periods. It could be used to estimate long-term survival based on short-term data from a clinical trial, combined with longer-term disease registry or population data, or elicited judgements. All data sources are represented jointly in a Bayesian model. The hazard is modelled as an M-spline function, which can represent potential changes in the hazard trajectory at any time. Through Bayesian estimation, the model automatically adapts to fit the available data, and acknowledges uncertainty where the data are weak. Therefore long-term estimates are only confident if there are strong long-term data, and inferences do not rely on extrapolating parametric functions learned from short-term data. The effects of treatment or other explanatory variables can be estimated through proportional hazards or with a flexible non-proportional hazards model. Some commonly-used mechanisms for survival can also be assumed: cure models, additive hazards models with known background mortality, and models where the effect of a treatment wanes over time. All of these features are provided for the first time in an R package, survextrap, in which models can be fitted using standard R survival modelling syntax. This paper explains the model, and demonstrates the use of the package to fit a range of models to common forms of survival data used in health technology assessments.

CONCLUSIONS

This paper has provided a tool that makes comprehensive and principled methods for survival extrapolation easily usable.

Model-based meta-analysis of non-small cell lung cancer with standard of care PD-1 inhibitors and chemotherapy for early development decision making

Single-arm cohorts/trials are often used in early phase oncology programs to support preliminary clinical activity assessments for investigational products, administered alone or in combination with standard of care (SOC) agents. Benchmarking clinical activity of those combinations against other treatments, including SOC, requires indirect comparisons against external trials, which presents challenges including cross-study differences in trial populations/other factors. To facilitate such nonrandomized comparisons, we developed a comprehensive model-based meta-analysis (MBMA) framework to quantitatively adjust for factors related to efficacy in metastatic non-small cell lung cancer (mNSCLC). Data were derived from 15 published studies assessing key programmed cell death protein-1 (PD-1) inhibitors pembrolizumab (n = 8) and nivolumab (n = 7), representing current SOC in mNSCLC. In the first stage, a mixed-effects logistic regression model for overall response rate (ORR) was developed accounting for effects of various population covariates on ORR. The ORR model results indicated an odds ratio (OR) of 1.02 for squamous versus non-squamous histology and OR of 1.20 for PD-ligand 1 tumor proportion score (TPS) per every 10% increase of TPS level. Next, a nonparametric mixed-effects model for overall survival (OS) was developed with ORR/other clinical covariates as input. Subsequently, MBMA simulations of relevant hypothetical scenarios involving single-arm trial design predicted OS hazard ratios as a function of ORR with matched patient characteristics. Findings from this MBMA and derived parameter estimates can be generally applied by the reader as a framework for interpreting efficacy data from early phase trials to support ORR-based go/no-go decisions and futility rules, illustrated through examples in this report.

Multi-state network meta-analysis of progression and survival data

Multiple randomized controlled trials, each comparing a subset of competing interventions, can be synthesized by means of a network meta-analysis to estimate relative treatment effects between all interventions in the evidence base. Here we focus on estimating relative treatment effects for time-to-event outcomes. Cancer treatment effectiveness is frequently quantified by analyzing overall survival (OS) and progression-free survival (PFS). We introduce a method for the joint network meta-analysis of PFS and OS that is based on a time-inhomogeneous tri-state (stable, progression, and death) Markov model where time-varying transition rates and relative treatment effects are modeled with parametric survival functions or fractional polynomials. The data needed to run these analyses can be extracted directly from published survival curves. We demonstrate use by applying the methodology to a network of trials for the treatment of non-small-cell lung cancer. The proposed approach allows the joint synthesis of OS and PFS, relaxes the proportional hazards assumption, extends to a network of more than two treatments, and simplifies the parameterization of decision and cost-effectiveness analyses.

Challenges in conducting fractional polynomial and standard parametric network meta-analyses of immune checkpoint inhibitors for first-line advanced renal cell carcinoma

Aim: Network meta-analyses (NMAs) increasingly feature time-varying hazards to account for non-proportional hazards between different drug classes. This paper outlines an algorithm for selecting clinically plausible fractional polynomial NMA models. Methods: The NMA of four immune checkpoint inhibitors (ICIs) + tyrosine kinase inhibitors (TKIs) and one TKI therapy for renal cell carcinoma (RCC) served as case study. Overall survival (OS) and progression free survival (PFS) data were reconstructed from the literature, 46 models were fitted. The algorithm entailed a-priori face validity criteria for survival and hazards, based on clinical expert input, and predictive accuracy against trial data. Selected models were compared with statistically best-fitting models. Results: Three valid PFS and two OS models were identified. All models overestimated PFS, the OS model featured crossing ICI + TKI versus TKI curves as per expert opinion. Conventionally selected models showed implausible survival. Conclusion: The selection algorithm considering face validity, predictive accuracy, and expert opinion improved the clinical plausibility of first-line RCC survival models.

Using individual participant data to improve network meta-analysis projects

A network meta-analysis combines the evidence from existing randomised trials about the comparative efficacy of multiple treatments. It allows direct and indirect evidence about each comparison to be included in the same analysis, and provides a coherent framework to compare and rank treatments. A traditional network meta-analysis uses aggregate data (eg, treatment effect estimates and standard errors) obtained from publications or trial investigators. An alternative approach is to obtain, check, harmonise and meta-analyse the individual participant data (IPD) from each trial. In this article, we describe potential advantages of IPD for network meta-analysis projects, emphasising five key benefits: (1) improving the quality and scope of information available for inclusion in the meta-analysis, (2) examining and plotting distributions of covariates across trials (eg, for potential effect modifiers), (3) standardising and improving the analysis of each trial, (4) adjusting for prognostic factors to allow a network meta-analysis of conditional treatment effects and (5) including treatment-covariate interactions (effect modifiers) to allow relative treatment effects to vary by participant-level covariate values (eg, age, baseline depression score). A running theme of all these benefits is that they help examine and reduce heterogeneity (differences in the true treatment effect between trials) and inconsistency (differences in the true treatment effect between direct and indirect evidence) in the network. As a consequence, an IPD network meta-analysis has the potential for more precise, reliable and informative results for clinical practice and even allows treatment comparisons to be made for individual patients and targeted populations conditional on their particular characteristics.

Indirect treatment comparison of lurbinectedin versus other second-line treatments for small-cell lung cancer

Aim: Compare lurbinectedin versus other second-line (2L) small-cell lung cancer (SCLC) treatments. Methods: An unanchored matching-adjusted indirect comparison connected the platinum-sensitive SCLC cohort of a single-arm lurbinectedin trial to a network of three randomized controlled trials (oral and intravenous [IV] topotecan, and platinum re-challenge) identified by systematic literature review. Network meta-analysis methods estimated relative treatment effects. Results: In platinum-sensitive patients, lurbinectedin demonstrated a survival benefit and favorable safety profile versus oral and IV topotecan and platinum re-challenge (overall survival, hazard ratio [HR]: 0.43; 95% credible interval [CrI]: 0.27, 0.67; HR: 0.43; 95% CrI: 0.26, 0.70; HR: 0.42; 95% CrI: 0.30, 0.58 respectively). Conclusion: Lurbinectedin showed a robust survival benefit and favorable safety versus other SCLC treatments in 2L platinum-sensitive SCLC.

A Comparison of Alternative Network Meta-Analysis Methods in the Presence of Nonproportional Hazards: A Case Study in First-Line Advanced or Metastatic Renal Cell Carcinoma

OBJECTIVES

Network meta-analysis (NMA) of time-to-event outcomes based on constant hazard ratios can result in biased findings when the proportional hazards (PHs) assumption does not hold in a subset of trials. We aimed to summarize the published non-PH NMA methods for time-to-event outcomes, demonstrate their application, and compare their results.

METHODS

The following non-PH NMA methods were compared through an illustrative case study in oncology of 4 randomized controlled trials in terms of progression-free survival and overall survival: (1) 1-step or (2) 2-step multivariate NMAs based on traditional survival distributions or fractional polynomials, (3) NMAs with restricted cubic splines for baseline hazard, and (4) restricted mean survival NMA.

RESULTS

For progression-free survival, the PH assumption did not hold across trials and non-PH NMA methods better reflected the relative treatment effects over time. The most flexible models (fractional polynomials and restricted cubic splines) fit better to the data than the other approaches. Estimated hazard ratios obtained with different non-PH NMA methods were similar at 5 years of follow-up but differed thereafter in the extrapolations. Although there was no strong evidence of PH violation for overall survival, non-PH NMA methods captured this uncertainty in the relative treatment effects over time.

CONCLUSIONS

When the PH assumption is questionable in a subset of the randomized controlled trials, we recommend assessing alternative non-PH NMA methods to estimate relative treatment effects for time-to-event outcomes. We propose a transparent and explicit stepwise model selection process considering model fit, external constraints, and clinical validity. Given inherent uncertainty, sensitivity analyses are suggested.

Left Upper Lobe Multi-Segmentectomy Vs Lobectomy for Early-Stage Lung Cancer: A Meta-Analysis

INTRODUCTION

The left upper lobe (LUL) has unique hilar anatomy, and LUL multi-segmentectomy (apical trisegmentectomy and lingulectomy) may result in different outcomes than both single anatomical segmentectomy and left upper lobectomy in the management of early-stage primary lung cancer; however no meta-analyses have been performed. The aim of this meta-analysis is to determine if LUL multi-segmentectomy is non-inferior to left upper lobectomy for long-term survival outcomes, or superior for in-hospital outcomes.

METHODS

Electronic databases searches were performed on PubMed, Embase, and the Cochrane Library to identify studies comparing outcomes in LUL multi-segmentectomy vs left upper lobectomy in early-stage lung cancer (clinical stage T2 N0 or less). Long-term postoperative overall and disease-free survival were assessed via reconstruction of Kaplan-Meier survival curves. In-hospital complications and length of stay, as well as long term recurrence were analysed via random effects models.

RESULTS

Five relevant studies were identified, including 1,196 patients. Overall survival did not differ at 5 years (multi-segmentectomy 92.6% vs lobectomy 89.3%, P=0.188), but patients undergoing LUL multi-segmentectomy had better disease-free survival at 5 years (93.1% vs 88.4%, P=0.041). Patients undergoing LUL multi-segmentectomy had a shorter mean length of hospital stay (mean difference -0.26 days, 95% CI; -0.39 to 0.14, P<0.01, I²=0.00%). There was no difference in combined in-hospital complications (P=0.14), local recurrence (P=0.35), distant recurrence (P=0.23), or overall recurrence (P=0.39).

CONCLUSION

LUL multi-segmentectomy is associated with reduced hospital length of stay, but no difference in long-term overall survival compared with left upper lobectomy in the management of early-stage primary lung cancer.

Economic evaluation of five first-line PD-(L)1 inhibitors for treating non-squamous non-small cell lung cancer in China: A cost-effectiveness analysis based on network meta-analysis

Background and objective: Non-small cell lung cancer (NSCLC) is one of the most malignant cancer types that causes substantial economic burden in China. This study aimed to evaluate the cost-effectiveness of five first-line anti-PD-(L)1 treatments, including sintilimab, camrelizumab, atezolizumab, pembrolizumab and sugemalimab with each combined with chemotherapy, for treating advanced non-squamous NSCLC (nsq-NSCLC) from Chinese healthcare system perspective. Methods: Clinical data were obtained from the following clinical trials, namely, ORIENT-11, CameL, IMpower132, KEYNOTE-189 and GEMSTONE-302. A network meta-analysis was performed based on fractional polynomial models. We constructed a partitioned survival model with a three-week cycle length and a lifetime horizon to derive the incremental cost-effectiveness ratio (ICER). We performed one-way sensitivity analysis and probablistic sensitivity analysis to test the robustness. Additionally, two scenario analyses were undertaken to investigate the impact of Patient Assistant Program on the economic conclusion and to explore potential uncertainty associated with population representativeness of the global trial. Results: Compared with camrelizumab + chemotherapy, sugemalimab + chemotherapy and atezolizumab + chemotherapy were dominated, and the ICERs generated from sintilimab + chemotherapy and pembrolizumab + chemotherapy were $15,280.83/QALY and $159,784.76/QALY, respectively. Deterministic sensitivity analysis showed that uncertainty around ICERs was mainly driven by HR related parameters derived from NMA and drug price. The probablistic sensitivity analysis suggested that camrelizumab treatment was cost-effective at a willingness-to-pay threshold of 1-time GDP per capita. When the threshold was set as 3-time GDP per capita, sintilimab strategy demonstrated the excellent cost-effective advantage. Sensitivity analysis proved the reliability of base-case results. Results from two scenario analyses indicated that the primary finding was robust. Conclusion: In current context of Chinese healthcare system, sintilimab + chemotherapy appeared to be cost-effective for the treatment of nsq-NSCLC compared with sugemalimab, camrelizumab, pembrolizumab as well as atezolizumab combined with chemotherapy.

Sintilimab plus chemotherapy for first-line treatment of advanced or metastatic nonsquamous non-small-cell lung cancer: network meta-analysis

Aim: This systematic literature review and network meta-analysis evaluated the efficacy and safety of sintilimab + pemetrexed + platinum versus US FDA-approved/National Comprehensive Cancer Network-recommended immune checkpoint inhibitor (ICI) combination therapies for untreated advanced/metastatic non-squamous non-small-cell lung cancer without EGFR/ALK aberrations. Methods: Bayesian network meta-analysis was the base-case analysis and included assessment of fixed and random effects, and independent and simultaneous models, adjusting for baseline risk (placebo response). Chemotherapy was the common comparator. Results: Sintilimab + pemetrexed + platinum was associated with significantly longer progression-free survival than atezolizumab + platinum + nab-paclitaxel (hazard ratio [HR]: 0.57; 95% credible interval [CrI]: 0.40-0.82) and nivolumab + ipilimumab + pemetrexed + platinum (HR: 0.66; 95% CrI: 0.48-0.92). Sintilimab + pemetrexed + platinum and pembrolizumab + pemetrexed + platinum showed comparable progression-free survival (HR: 0.96; 95% CrI: 0.71-1.30). There was no significant difference in overall survival (HR range: 0.61-0.81) or overall response rates (odds ratio [OR] range: 0.29-0.75) between sintilimab + pemetrexed + platinum and the other ICI combinations. The incidence of high-grade adverse events was higher with sintilimab + pemetrexed + platinum than with nivolumab + ipilimumab (OR: 0.46; 95% CrI: 0.33-0.64) or without chemotherapy (OR: 0.25; 95% CrI: 0.19-0.34), with no significant difference between sintilimab + pemetrexed + platinum and the other ICI combinations. Conclusion: Sintilimab + pemetrexed + platinum showed comparable efficacy and safety versus US standard-of-care first-line ICI combinations for advanced/metastatic non-squamous non-small-cell lung cancer.

Bayesian hierarchical model-based network meta-analysis to overcome survival extrapolation challenges caused by data immaturity

Aim: This research evaluated standard Weibull mixture cure (WMC) network meta-analysis (NMA) with Bayesian hierarchical (BH) WMC NMA to inform long-term survival of therapies. Materials & methods: Four trials in previously treated metastatic non-small-cell lung cancer with PD-L1 >1% were used comparing docetaxel with nivolumab, pembrolizumab and atezolizumab. Cure parameters related to a certain treatment class were assumed to share a common distribution. Results: Standard WMC NMA predicted cure rates were 0.03 (0.01; 0.07), 0.18 (0.12; 0.24), 0.07 (0.02; 0.15) and 0.03 (0.00; 0.09) for docetaxel, nivolumab, pembrolizumab and atezolizumab, respectively, with corresponding incremental life years (LY) of 3.11 (1.65; 4.66), 1.06 (0.41; 2.37) and 0.42 (-0.57; 1.68). The Bayesian hierarchical-WMC-NMA rates were 0.06 (0.03; 0.10), 0.17 (0.11; 0.23), 0.12 (0.05; 0.20) and 0.12 (0.03; 0.23), respectively, with incremental LY of 2.35 (1.04; 3.93), 1.67 (0.68; 2.96) and 1.36 (-0.05; 3.64). Conclusion: BH-WMC-NMA impacts incremental mean LYs and cost-effectiveness ratios, potentially affecting reimbursement decisions.

Efficacy and safety of treatments for advanced thymic carcinoma after failure of first-line platinum-based chemotherapy: A systematic literature review and meta-analysis

Thymic carcinoma (TC) is a rare cancer and patients failing initial chemotherapy (relapse/refractory) face limited therapeutic options given no approved options or consensus standard of care. This study aimed to identify and summarize clinical outcomes of all regimens evaluated in clinical trials of relapsed or refractory patients. Interventional trials enrolling advanced TC patients who failed first-line chemotherapy and reported outcomes in this group were eligible for inclusion in our systemic literature review (SLR). Between-study heterogeneity was assessed to determine the feasibility of pooling specific studies and treatments. Objective response rate (ORR), overall survival (OS), progression-free survival (PFS), and duration of response (DOR) endpoints were of interest for meta-analysis. Nineteen trials were identified in the SLR. Three trials with one or two TC patients were removed from our assessment to reduce publication bias. Response rates among studies with at least ten TC patients varied from 9 % to 38 %. Pooled ORRs in patients receiving S-1 (46 patients), sunitinib (46 patients), or pembrolizumab (66 patients) were 28 %, 24 %, and 21 %, respectively. Prolonged duration of response with pembrolizumab was observed with a pooled median of 23.8 months (95 % confidence interval [CI]: 12, not reached). Median PFS of five months or greater was reported in patients treated with sunitinib, lenvatinib, pembrolizumab, capecitabine + gemcitabine, everolimus, or S-1. Median OS of 20 months or greater was reported in trials evaluating S-1 or pembrolizumab; this endpoint was not reached in trials evaluating lenvatinib, regorafenib, or sunitinib. Generalizability of treatment effects is challenging in the research of rare diseases and meta-analysis of clinical outcomes may help to increase precision and relevance of results to the larger TC population. Our study found limited treatment options upon relapse, demonstrating a need for further investigations into novel therapeutics and well-powered clinical trials to better inform on optimal treatments.

A network meta-analysis of immunotherapy-based treatments for advanced nonsquamous non-small cell lung cancer

Introduction: In the absence of head-to-head trials comparing immunotherapies for advanced nonsquamous non-small-cell lung cancer (NsqNSCLC), a network meta-analysis (NMA) was conducted to compare the relative efficacy of these treatments. Materials & methods: A systematic literature review of randomized controlled trials evaluating first-line-to-progression and second-line treatments for advanced NsqNSCLC informed Bayesian NMAs for overall survival (OS) and progression-free survival (PFS) end points. Results: Among first-line-to-progression treatments, pembrolizumab + pemetrexed + platinum showed the greatest OS benefit versus other regimens and a PFS benefit versus all but three regimens. Among second-line treatments, an OS benefit was seen for atezolizumab, nivolumab and pembrolizumab versus docetaxel. Conclusion: Pembrolizumab + pemetrexed + platinum showed the maximum OS benefit in the first-line setting. In the second-line setting, anti-PD-1/anti-PD-L1 monotherapies were better than docetaxel.

Clinical outcomes in patients relapsed/refractory after ≥2 prior lines of therapy for follicular lymphoma: a systematic literature review and meta-analysis

BACKGROUND

Patients with follicular lymphoma (FL) can have high response rates to early lines of treatment. However, among FL patients relapsed/refractory (r/r) after ≥2 prior lines of therapy (LOT), remission tends to be shorter and there is limited treatment guidance. This study sought to evaluate the clinical outcomes for r/r FL after ≥2 prior LOT identified through systematic literature review.

METHODS

Eligible studies included comparative or non-comparative interventional or observational studies of systemic therapies among adults with FL r/r after ≥2 prior LOT published prior to 31st May 2021. Prior LOT must have included an anti-CD20 monoclonal antibody and an alkylating agent, in combination or separately. Overall response rate (ORR) and complete response (CR) were estimated using inverse-variance weighting with Freeman-Tukey double-arcsine transformations. Kaplan-Meier (KM) curves for progression-free survival (PFS) and overall survival (OS) estimated by reconstructing digitized curves using the Guyot algorithm, and survival analyses were conducted, stratified by ≥2 prior LOT and ≥ 3 prior LOT groups (as defined in the source material). Restricting the analyses to the observational cohorts was investigated as a sensitivity analysis.

RESULTS

The analysis-set included 20 studies published between 2014 and 2021. Studies were primarily US and/or European based, with the few exceptions using treatments approved in US/Europe. The estimated ORR was 58.47% (95% confidence interval [CI]: 51.13-65.62) and proportion of patients with CR was 19.63% (95% CI: 15.02-24.68). The median OS among those ≥2 prior LOT was 56.57 months (95% CI: 47.8-68.78) and median PFS was 9.78 months (95% CI: 9.01-10.63). The 24-month OS decreased from 66.50% in the ≥2 prior LOT group to 59.51% in the ≥3 prior LOT group, with a similar trend in PFS at 24-month (28.42% vs 24.13%).

CONCLUSIONS

This study found that few r/r FL patients with ≥2 prior LOT achieve CR, and despite some benefit, approximately 1/3 of treated patients die within 24 months. The shorter median PFS with increasing prior LOT suggest treatment durability is suboptimal in later LOT. These findings indicate that patients are underserved by treatments currently available in the US and Europe.

Effectiveness and cost-effectiveness analysis of 11 treatment paths, seven first-line and three second-line treatments for Chinese patients with advanced wild-type squamous non-small cell lung cancer: A sequential model

Background

A total of 11 treatment sequences for advanced wild-type squamous non-small cell lung cancer are recommended by Chinese Society of Clinical Oncology Guidelines, consisting of seven first-line and three second-line treatments. Five of these treatments were newly approved in China between 2021 and 2022. We evaluated the effectiveness and cost-effectiveness of these strategies from the Chinese healthcare system perspective.

Methods

Network meta-analysis with non-proportional hazards was used to calculate the relative efficacy between interventions. A sequential model was developed to estimate costs and quality-adjusted life years (QALY) for treatment sequences with first-line platinum- and paclitaxel-based chemotherapy (SC) with or without nedaplatin, tislelizumab, camrelizumab, sintilimab, sugemalimab or pembrolizumab, followed by second-line docetaxel, tislelizumab or nivolumab. SC and docetaxel were used as comparators for first-line and second-line treatments, respectively. QALY and incremental cost-effectiveness ratio (ICER) were used to evaluate effectiveness and cost-effectiveness, respectively. Cost-effective threshold was set as USD 19,091. Subgroup analysis was conducted to determine the best first-line and second-line therapy.

Results

Pembrolizumab + SC, followed by docetaxel (PED) was the most effective treatment sequence. QALYs for patients received SC, nedaplatin + SC, tislelizumab + SC, sintilimab + SC, camrelizumab + SC, sugemalimab + SC, pembrolizumab + SC followed by docetaxel were 0.866, 0.906, 1.179, 1.266, 1.179, 1.266, 1.603, 1.721, 1.807; QALYs for SC, nedaplatin + SC followed by tislelizumab were 1.283, 1.301; QALYs for SC, nedaplatin + SC followed by nivolumab were 1.353, 1.389. Camrelizumab + SC, followed by docetaxel (CAD) was the most cost-effective. Compared to SC with or without nedaplatin, tislelizumab, or sintilimab followed by docetaxel, ICERs of CAD were USD 12,276, 13,210, 6,974, 9,421/QALY, respectively. Compared with nedaplatin or SC followed by tislelizumab, the ICERs of CAD were USD 4,183, 2,804/QALY; CAD was dominant compared with nedaplatin or SC followed by nivolumab; The ICER of sugemalimab + SC followed by docetaxel and PED were USD 522,023, 481,639/QALY compared with CAD. Pembrolizumab + SC and camrelizumab + SC were the most effective and cost-effective first-line options, respectively; tislelizumab was the most effective and cost-effective second-line therapy. Tislelizumab used in second-line was more effective than first-line, no significant differences between their cost-effectiveness. Sensitivity and scenario analysis confirmed robustness of the results.

Conclusions

PED and CAD are the most effective and cost-effective treatment sequence, respectively; pembrolizumab + SC and camrelizumab + SC are the most effective and cost-effective first-line choice, respectively; tislelizumab is the most effective and cost-effective second-line choice.

A meta-analytic framework to adjust for bias in external control studies

While randomized controlled trials (RCTs) are the gold standard for estimating treatment effects in medical research, there is increasing use of and interest in using real-world data for drug development. One such use case is the construction of external control arms for evaluation of efficacy in single-arm trials, particularly in cases where randomization is either infeasible or unethical. However, it is well known that treated patients in non-randomized studies may not be comparable to control patients-on either measured or unmeasured variables-and that the underlying population differences between the two groups may result in biased treatment effect estimates as well as increased variability in estimation. To address these challenges for analyses of time-to-event outcomes, we developed a meta-analytic framework that uses historical reference studies to adjust a log hazard ratio estimate in a new external control study for its additional bias and variability. The set of historical studies is formed by constructing external control arms for historical RCTs, and a meta-analysis compares the trial controls to the external control arms. Importantly, a prospective external control study can be performed independently of the meta-analysis using standard causal inference techniques for observational data. We illustrate our approach with a simulation study and an empirical example based on reference studies for advanced non-small cell lung cancer. In our empirical analysis, external control patients had lower survival than trial controls (hazard ratio: 0.907), but our methodology is able to correct for this bias. An implementation of our approach is available in the R package ecmeta.

Cost-Effectiveness and Economic Burden Analyses on All First-Line Treatments of Chronic Lymphocytic Leukemia

OBJECTIVES

Several chemoimmunotherapy and targeted treatment regimens are approved as front-line therapies in chronic lymphocytic leukemia. We estimated for the 10-year cost-effectiveness of these treatment regimens and the economic burden of following the estimated risk-stratified 21 040 patients with chronic lymphocytic leukemia diagnosed in 2020 for 10 years.

METHODS

A Markov model with 7 exclusive health states was specified over a 10-year time horizon. Treatment effectiveness inputs were obtained from a novel network meta-analysis on the progression-free survival, overall survival curves, and time to next treatment. Costs and utilities inputs were included for each health state for each treatment and discounted at 3.0%/year. Life-years (LYs) and quality-adjusted LYs (QALYs) for each treatment were determined. Using the lowest cost regimen as reference, the incremental cost-effectiveness ratio (ICER) and incremental cost-utility ratio (ICUR) were estimated. The 10-year per-patient cost was determined by risk status and by initial treatment.

RESULTS

Venetoclax-plus-obinutuzumab was the lowest cost regimen, hence the reference. Superior in effectiveness to all chemoimmunotherapies, it was cost saving. With the highest effectiveness gains at 6.26 LYs and 5.01 QALYs and despite being the most expensive regimen ($1 298 638 per patient), acalabrutinib-plus-obinutuzumab yielded the best ICER ($409 343/LY gained) and ICUR ($501 236/QALY gained). The remaining ICERs of targeted therapies ranged from $512 101/LY gained to $793 236/LY gained and the ICURs from $579 737/QALY gained to $869 300/QALY gained. The 10-year postdiagnosis low/high (venetoclax-plus-obinutuzumab/acalabrutinib-plus-obinutuzumab) economic burden ranges were $42 690 to $98 665 for low-risk, $141 339 to $326 660 for intermediate-risk, and $273 650 to $632 453 for high-risk patients.

CONCLUSIONS

Compared with venetoclax-plus-obinutuzumab, chemoimmunotherapies are associated with less health benefits at higher cost. The targeted therapies achieve greater benefits at higher cost.

Network Meta-analysis on Disconnected Evidence Networks When Only Aggregate Data Are Available: Modified Methods to Include Disconnected Trials and Single-Arm Studies while Minimizing Bias

BACKGROUND

Network meta-analysis (NMA) requires a connected network of randomized controlled trials (RCTs) and cannot include single-arm studies. Regulators or academics often have only aggregate data. Two aggregate data methods for analyzing disconnected networks are random effects on baseline and aggregate-level matching (ALM). ALM has been used only for single-arm studies, and both methods may bias effect estimates.

METHODS

We modified random effects on baseline to separate RCTs connected to and disconnected from the reference and any single-arm studies, minimizing the introduction of bias. We term our modified method reference prediction. We similarly modified ALM and extended it to include RCTs disconnected from the reference. We tested these methods using constructed data and a simulation study.

RESULTS

In simulations, bias for connected treatments for ALM ranged from -0.0158 to 0.051 and for reference prediction from -0.0107 to 0.083. These were low compared with the true mean effect of 0.5. Coverage ranged from 0.92 to 1.00. In disconnected treatments, bias of ALM ranged from -0.16 to 0.392 and of reference prediction from -0.102 to 0.40, whereas coverage of ALM ranged from 0.30 to 0.82 and of reference prediction from 0.64 to 0.94. Under fixed study effects for disconnected evidence, bias was similar, but coverage was 0.81 to 1.00 for reference prediction and 0.18 to 0.76 for ALM. Trends of similar bias but greater coverage for reference prediction with random study effects were repeated in constructed data.

CONCLUSIONS

Both methods with random study effects seem to minimize bias in treatment connected to the reference. They can estimate treatment effects for disconnected treatments but may be biased. Reference prediction has greater coverage and may be recommended overall.

HIGHLIGHTS

Two methods were modified for network meta-analysis on disconnected networks and for including single-arm observational or interventional studies in network meta-analysis using only aggregate data and for minimizing the bias of effect estimates for treatments only in trials connected to the reference.Reference prediction was developed as a modification of random effects on baseline that keeps analyses of trials connected to the reference separately from those disconnected from the reference and from single-arm studies. The method was further modified to account for correlation in trials with more than 2 arms and, under random study effects, to estimate variance in heterogeneity separately in connected and disconnected evidence.Aggregate-level matching was extended to include trials disconnected from the reference, rather than only single-arm studies. The method was further modified to separately estimate treatment effects and heterogeneity variance in the connected and disconnected evidence and to account for the correlation between arms in trials with more than 2 arms.Performance was assessed using a constructed data example and simulation study.The methods were found to have similar, and sometimes low, bias when estimating the relative effects for disconnected treatments, but reference prediction with random study effects had the greatest coverage.The use of reference prediction with random study effects for disconnected networks is recommended if no individual patient data or alternative real-world evidence is available.

Identifying optimal PD-1/PD-L1 inhibitors in first-line treatment of patients with advanced squamous non-small cell lung cancer in China: Updated systematic review and network meta-analysis

Objective: After Gemstone-302 was published in Lancet in January 2022, seven PD-(L)1 inhibitors launched or about to be launched in China, but there are no head-to-head RCTs reporting the comparative efficacy for squamous non-small cell lung cancer (sq-NSCLC). Therefore, we aimed to indirectly compare the efficacy of these treatments to provide evidence for clinical decision and Chinese national reimbursement drug listing.

Methods: We collected phase III clinical trials targeted on stage IIIB–IV patients for first-line immunotherapy of sq-NSCLC by systematically searching databases. Relative effects of competing treatments were assessed by Bayesian network meta-analysis and non-parametric restricted mean survival time (RMST) model. Hazard ratio (HR), severe adverse events (SAEs, grade 3–5), progression-free survival (PFS) and overall survival (OS) years were the outcomes. Subgroup analysis was done according to PD-(L)1 expression, smoking, gender, Eastern Cooperative Oncology Group performance status, age and disease stage. Sensitivity analysis using the range of parameters distribution as well as different comparison methods was performed to test the robustness of the results.

Results: A total of 7 clinical trials with 2,640 patients were included. For OS, the efficiency (HR, 95%CI) ranks from high to low were sugemalimab (0.48, 0.32–0.73), camrelizumab (0.55, 0.40–0.76), sintilimab (0.56, 0.35–0.90), pembrolizumab (0.71, 0.58–0.87) and atezolizumab (0.88, 0.73–1.05). For PFS, the efficiency ranks from high to low were sugemalimab (0.33, 0.24–0.45), camrelizumab (0.37, 0.30–0.46), tislelizumab (0.53, 0.36–0.79), sintilimab (0.54, 0.42–0.69), toripalimab (0.56, 0.38–0.83), pembrolizumab (0.57, 0.47–0.70) and atezolizumab (0.71, 0.59–0.85). Proportional hazard models and non-proportional hazard models showed consistent efficiency ranks. When extrapolated to long-term survival benefit, under non-proportional hazard ratio, sugemalimab achieved the highest PFS benefit (lifeyears, LYs) in 2 years (1.323), with camrelizumab (1.320), sintilimab (1.243), tislelizumab (1.189), pembrolizumab (0.990) and atezolizumab (0.947) ranking in order; Camrelizumab achieved the highest OS benefit (LYs) in 10 years (2.723), with atezolizumab (2.445) and pembrolizumab (2.397) ranking in order. RMST model showed similar results. In terms of safety, PD-(L)1 inhibitors increased the incidence of SAEs when combined with chemotherapy, sugemalimab and camrelizumab was the safest drugs.

Conclusion: Sugemalimab is superior both in HR and long-term survival benefit for Chinese patients with advanced sq-NSCLC.

A comparison of neoadjuvant therapies for gastroesophageal and gastric cancer on tumour resection rate: A network meta-analysis

Background

Gastric cancer is one of the most common malignancies around the world, and a variety of neoadjuvant chemotherapies with different drug combinations are available for the treatment. R0 resection refers to a microscopically negative margin on resection, where no gross or microscopic tumour remains in the primary tumour. We aimed to find evidence on the relative effectiveness of neoadjuvant therapies for patients with advanced gastroesophageal and gastric cancer on the R0 resection rate.

Methods

Relevant randomised controlled trials were searched using appropriate keywords in health-related databases. We performed network meta-analysis within a frequentist framework. The endpoint assessed was the R0 resection rate. We assessed consistency and transitivity assumptions that are necessary for network meta-analysis. This study only used data from published studies. The need for consent from participants was waived by the Ethics Review Committee of the International Medical University in Malaysia.

Results

Six randomised controlled trials involving 1700 patients were identified. A network plot was formed with five neoadjuvant regimens [DLX (pyrimidine analogue + platinum compounds + chemoradiotherapy), DELX (pyrimidine analogue + epipodophylllotoxins/etoposide + platinum compounds + chemoradiotherapy), ADL (anthracycline + pyrimidine analogue + platinum compounds), ADM (anthracycline+ pyrimidine analogue + anti-folate compounds) and LTX (platinum compounds + taxane + chemoradiotherapy)] and surgery alone for management of patients with advanced gastroesophageal and gastric cancer. Assumptions required for a network meta-analysis such as consistency ((global test: Chi2 (1): 3.71; p:0.054)), and the transitivity in accord to the characteristics of interventions considered in this review were not violated. In the network comparison, surgery alone has a lower R0 resection rate compared with LTX (OR 0.2, 95%CI:0.01, 0.38) or DLX (OR 0.48, 95%CI: 0.29, 0.79). LTX has higher resection rate compared with DLX (OR 2.47, 95%CI: 1.08 to 5.63), DELX (OR 106.0, 95%CI: 25.29 to 444.21), ADM (OR 5.41, 95%CI: 1.56 to 18.78) or ADL (OR 3.12, 95%CI: 1.27 to 7.67). There were wide or very wide CIs in many of these comparisons. Overall certainty of the evidence was low or very low. Further research in this field is very likely to have an important impact on our confidence in the R0 resection rates between LTX versus other neoadjuvant chemotherapy is likely to change the estimate.

Conclusions

Findings suggest that overall quality of evidence on the relative effectiveness of neoadjuvant chemotherapies was low to very low level. Therefore, we are very uncertain about the true effect of neoadjuvant therapies in the R0 resection rate in patients with gastroesophageal and gastric cancer. Future well-designed large trials are needed. To recruit large samples in this field, multicountry trials are recommended. Future trials also need to assess treatment-related adverse events, and patients-centered outcomes such as health‐related quality of life.

Novel and existing flexible survival methods for network meta-analyses

Aim: Technical Support Document 21 discusses trial-based, flexible relative survival models. The authors generalized flexible relative survival models to the network meta-analysis (NMA) setting while accounting for different treatment-effect specifications. Methods: The authors compared the standard parametric model with mixture, mixture cure and nonmixture cure, piecewise, splines and fractional polynomial models. The optimal treatment-effect parametrization was defined in two steps. First, all models were run with treatment effects on all parameters and subsequently the optimal model was defined by removing uncertain treatment effects, for which the parameter was smaller than its standard deviation. The authors used a network in previously treated advanced non-small-cell lung cancer. Results: Flexible model-based NMAs impact fit and incremental mean survival and they increase corresponding uncertainty. Treatment-effect specification impacts incremental survival, reduces uncertainty and improves the fit statistic. Conclusion: Extrapolation techniques already available for individual trials can now be used for NMAs to ensure that the most plausible extrapolations are being used for health technology assessment submissions.

Switch from Hemodialysis to Peritoneal Dialysis: Does the Time Spent on Hemodialysis Impact Outcomes in Peritoneal Dialysis?

INTRODUCTION

Switch from hemodialysis (HD) to peritoneal dialysis (PD) is unfrequent, but incentive strategies to perform PD can lead to an increase of these transitions. However, data on transitioning from HD to PD are scarce. We hypothesized that time spent on HD before transfer to PD would impact PD outcomes.

METHODS

This registry-based, nationwide study analyzed patients transferred from HD to PD. Patients who began HD between January 2008 and December 2016 were included. Cox and Fine and Gray regression models were used to explore the relationship between time spent on HD before PD and outcomes in PD: PD cessation for death or retransfer to HD (composite endpoint); for death; and for retransfer to HD.

RESULTS

Over the study period, 1,985 of the 77,587 HD starters (3%) were transferred to PD. The median time spent on HD before transfer to PD was 1.94 months (interquartile range [IQR] 1.02-4.01). The median survival time on PD after this transition was 20 months (IQR 18-21). Time spent on HD before PD was associated with increased risk of death or retransfer to HD (cause-specific hazard ratio [cs-HR] 1.01, 95% confidence interval [CI]: 1-1.02 for a 1-month increase) and death (cs-HR 1.02, 95% CI: 1.01-1.03) but not with retransfer to HD censored on death (cs-HR 1.00, 95% CI: 0.99-1.01). The results were similar when considering competing events.

DISCUSSION/CONCLUSION

Switch from HD to PD is rare in France. Time spent on HD before transfer is associated with patient survival but not with retransfer to HD.

Challenges of modelling approaches for network meta-analysis of time-to-event outcomes in the presence of non-proportional hazards to aid decision making: Application to a melanoma network

BACKGROUND

Synthesis of clinical effectiveness from multiple trials is a well-established component of decision-making. Time-to-event outcomes are often synthesised using the Cox proportional hazards model assuming a constant hazard ratio over time. However, with an increasing proportion of trials reporting treatment effects where hazard ratios vary over time and with differing lengths of follow-up across trials, alternative synthesis methods are needed.

OBJECTIVES

To compare and contrast five modelling approaches for synthesis of time-to-event outcomes and provide guidance on key considerations for choosing between the modelling approaches.

METHODS

The Cox proportional hazards model and five other methods of estimating treatment effects from time-to-event outcomes, which relax the proportional hazards assumption, were applied to a network of melanoma trials reporting overall survival: restricted mean survival time, generalised gamma, piecewise exponential, fractional polynomial and Royston-Parmar models.

RESULTS

All models fitted the melanoma network acceptably well. However, there were important differences in extrapolations of the survival curve and interpretability of the modelling constraints demonstrating the potential for different conclusions from different modelling approaches.

CONCLUSION

The restricted mean survival time, generalised gamma, piecewise exponential, fractional polynomial and Royston-Parmar models can accommodate non-proportional hazards and differing lengths of trial follow-up within a network meta-analysis of time-to-event outcomes. We recommend that model choice is informed using available and relevant prior knowledge, model transparency, graphically comparing survival curves alongside observed data to aid consideration of the reliability of the survival estimates, and consideration of how the treatment effect estimates can be incorporated within a decision model.

Cost-Effectiveness Analysis of Five Systemic Treatments for Unresectable Hepatocellular Carcinoma in China: An Economic Evaluation Based on Network Meta-Analysis

Background and Objective

Unresectable hepatocellular carcinoma (uHCC) is the main histological subtype of liver cancer and causes a great disease burden in China. We aimed to evaluate the cost-effectiveness of five first-line systemic treatments newly approved in the Chinese market for the treatment of uHCC, namely, sorafenib, lenvatinib, donafenib, sintilimab plus bevacizumab (D + A), and atezolizumab plus bevacizumab (T + A) from the perspective of China's healthcare system, to provide a basis for decision-making.

Methods

We constructed a network meta-analysis of 4 clinical trials and used fractional polynomial models to indirectly compare the effectiveness of treatments. The partitioned survival model was used for cost-effectiveness analysis. Primary model outcomes included the costs in US dollars and health outcomes in quality-adjusted life-years (QALYs) and the incremental cost-effectiveness ratio (ICER) under a willingness-to-pay threshold of $33,521 (3 times the per capita gross domestic product in China) per QALY. We performed deterministic and probabilistic sensitivity analyses to investigate the robustness. To test the effect of active treatment duration on the conclusions, we performed a scenario analysis.

Results

Compared with sorafenib, lenvatinib, donafenib, D + A, and T + A regimens, it yielded an increase of 0.25, 0.30, 0.95, and 1.46 life-years, respectively. Correspondingly, these four therapies yielded an additional 0.16, 0.19, 0.51, and 0.86 QALYs and all four ICERs, $40,667.92/QALY gained, $27,630.63/QALY gained, $51,877.36/QALY gained, and $130,508.44/QALY gained, were higher than $33,521 except for donafenib. T + A was the most effective treatment and donafenib was the most economical option. Sensitivity and scenario analysis results showed that the base-case analysis was highly reliable.

Conclusion

Although combination therapy could greatly improve patients with uHCC survival benefits, under the current WTP, donafenib is still the most economical option.

Systematic literature review and network meta-analysis of pembrolizumab versus other interventions for previously untreated, unresectable or metastatic, microsatellite instability-high or mismatch repair-deficient colorectal cancer

Aim: To compare pembrolizumab with competing interventions for previously untreated, unresectable or metastatic microsatellite instability-high or mismatch repair-deficient colorectal cancer. Method: Trials were identified via a systematic literature review and synthesized using a Bayesian network meta-analysis with time-varying hazard ratios (HRs). Results: Using intention-to-treat data, HRs for overall survival were generally in favor of pembrolizumab but not statistically significant; however, statistical significance was reached versus all comparators by month 16 when accounting for crossover. Estimated HRs for progression-free survival significantly favored pembrolizumab versus all comparators by month 12. Pembrolizumab was also superior to all comparators in terms of grade ≥3 adverse events. Conclusion: These analyses suggest that pembrolizumab is a highly efficacious and safe treatment in this population.

Out of Date or Best Before? A Commentary on the Relevance of Economic Evaluations Over Time

The impact of time on the applicability and relevance of historical economic evaluations can be considerable. Ignoring this may lead to the use of weak or invalid evidence to inform important research questions or resource allocation decisions, as historical economic evaluations may have reached different conclusions compared to if a similar study had been conducted more recently. There are multiple factors that contribute towards evidence becoming outdated including changes to the relevant decision problem (e.g. comparators), changes to parameters (such as costs, utilities and resource use) and methodological updates (e.g. recommendations on uncertainty analysis). Researchers reviewing economic evaluations need to consider whether changes over time would influence the study design and results if the evaluation were repeated, to the extent that it is no longer helpful or informative. In this paper, we summarise these key issues and make recommendations about how and whether researchers can future proof their economic evaluations.

Five-year outcomes in trials comparing transcatheter aortic valve implantation versus surgical aortic valve replacement: a pooled meta-analysis of reconstructed time-to-event data

OBJECTIVES

The incidence of outcomes in trials comparing transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) is expected to be different in the short and long term. We planned a meta-analysis of reconstructed time-to-event data from trials comparing TAVI and SAVR to evaluate their time-varying effects on outcomes.

METHODS

We performed a systematic review of the literature from January 2007 through September 2021 on Medline, Embase, the Cochrane Central Register of Controlled Trials and specialistic websites, including randomized trials with allocation to TAVI or SAVR that reported at least 1-year follow-up and that graphed Kaplan-Meier curves of end points. The comparisons were done with grouped frailty Cox models in a landmark framework and fully parametric models.

RESULTS

Seven trials were included (7770 participants). TAVI showed a lower incidence of the composite of death or stroke in the first 6 months [risk-stratified hazard ratio (HR) 0.66, 95% confidence interval (CI) 0.56-0.77, P-value <0.001], with an HR reversal after 24 months favouring SAVR (risk-stratified HR 1.25; 95% CI 1.08-1.46; P-value 0.003). These outcomes were confirmed for all-cause death (risk-stratified HR after 24 months 1.18; 95% CI 1.03-1.35; P-value 0.01). TAVI was also associated with an increased incidence of rehospitalization after 6 months (risk-stratified HR 1.42; 95% CI 1.06-1.91; P-value 0.018) that got worse after 24 months (risk-stratified HR 1.67; 95% CI 1.24-2.24; P-value <0.001).

CONCLUSIONS

Although it could appear that there is no difference between TAVI and SAVR in the 5-year cumulative results, TAVI shows a strong protective effect in the short term that runs out after 1 year. TAVI becomes a risk factor for all-cause mortality and the composite end point after 24 months and for rehospitalization after 6 months.

A non-parametric approach for jointly combining evidence on progression free and overall survival time in network meta-analysis

Randomised controlled trials of cancer treatments typically report progression free survival (PFS) and overall survival (OS) outcomes. Existing methods to synthesise evidence on PFS and OS either rely on the proportional hazards assumption or make parametric assumptions which may not capture the diverse survival curve shapes across studies and treatments. Furthermore, PFS and OS are not independent: OS is the sum of PFS and post-progression survival (PPS). Our aim was to develop a non-parametric approach for jointly synthesising evidence from published Kaplan-Meier survival curves of PFS and OS without assuming proportional hazards. Restricted mean survival times (RMST) are estimated by the area under the survival curves (AUCs) up to a restricted follow-up time. The correlation between AUCs due to the constraint that OS>PFS is estimated using bootstrap re-sampling. Network meta-analysis models are given for RMST for PFS and PPS and ensure that OS=PFS + PPS. Both additive and multiplicative network meta-analysis models are presented to obtain relative treatment effects as either differences or ratios of RMST. The methods are illustrated with a network meta-analysis of treatments for Stage IIIA-N2 Non-Small Cell Lung Cancer. The approach has implications for health economic models of cancer treatments which require estimates of the mean time spent in the PFS and PPS health-states. The methods can be applied to a single time-to-event outcome, and so have wide applicability in any field where time-to-event outcomes are reported, the proportional hazards assumption is in doubt, and survival curve shapes differ across studies and interventions. This article is protected by copyright. All rights reserved.

Bayesian multivariate network meta-analysis model for the difference in restricted mean survival times

Network meta-analysis (NMA) is essential for clinical decision-making. NMA enables inference for all pair-wise comparisons between interventions available for the same indication, by using both direct evidence and indirect evidence. In randomized trials with time-to event outcome data, such as lung cancer data, conventional NMA methods rely on the hazard ratio and the proportional hazards assumption, and ignore the varying follow-up durations across trials. We introduce a novel multivariate NMA model for the difference in restricted mean survival times (RMST). Our model synthesizes all the available evidence from multiple time points simultaneously and borrows information across time points through within-study covariance and between-study covariance for the differences in RMST. We propose an estimator of the within-study covariance and we then assume it to be known. We estimate the model under the Bayesian framework. We evaluated our model by conducting a simulation study. Our multiple-time-point model yields lower mean squared error over the conventional single-time-point model at all time points, especially when the availability of evidence decreases. We illustrated the model on a network of randomized trials of second-line treatments of advanced non-small-cell lung cancer. Our multiple-time-point model yielded increased precision and detected evidence of benefit at earlier time points as compared to the single-time-point model. Our model has the advantage of providing clinically interpretable measures of treatment effects.

Individual Patient Data Meta-Analysis and Network Meta-Analysis

Meta-analyses are often conducted using trial-level summary data. However, when individual patient data (IPD ) is available, there is greater flexibility in the analysis and a wider range of statistical models that can be fitted. There are two approaches to fitting IPD models. The traditional two-stage approach involves analyzing each trial individually in the first stage and then combining trial estimates of treatment effectiveness in the second stage using methods developed for aggregate data meta-analysis. Growing in popularity is the one-stage approach in which trials are analyzed and synthesized within one statistical model whilst the clustering of patients within trials is accounted for. This chapter outlines both fixed effect and random effects one- and two-stage meta-analysis models for continuous, binary, and time-to-event outcomes. The meta-analysis framework is then extended to the scenario where there are more than two treatments and network meta-analysis models are described.The availability of IPD provides greater statistical power for investigating interactions between treatments and covariates. Treatment-covariate interactions contain both within- and across-trial information where the across-trial information may be subject to ecological bias. This chapter presents network meta-analysis models separating out the within- and across-trial information and finishes by considering practical solutions for dealing with missing covariate data, assessing the consistency assumption, combining IPD and aggregate data and specific considerations for time-to-event outcomes.

A Network Meta-Analysis of Cancer Immunotherapies Versus Chemotherapy for First-Line Treatment of Patients With Non-Small Cell Lung Cancer and High Programmed Death-Ligand 1 Expression

In the absence of head-to-head trials of first-line treatments for metastatic non-small cell lung cancer (NSCLC), synthesis of available evidence is needed. We conducted a systematic literature review and network meta-analysis of randomized controlled trials in patients with stage IV NSCLC and high programmed death-ligand 1 (PD-L1) expression. Patients with other-stage NSCLC or without PD-L1 expression and populations with < 80% stage IV NSCLC were excluded. Outcomes included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and treatment-related adverse events. English records from MEDLINE and Embase published through October 2020 were eligible, supplemented by hand searches of other sources. Three evidence networks were constructed based on histology (mixed, squamous, non-squamous). OS and PFS results were analyzed applying Bayesian fractional polynomial random-effects models. Hazard ratios over time with 95% credible intervals (CrIs) and expected differences in OS and PFS between each cancer immunotherapy regimen and the chemotherapy common comparator were generated. Seventeen clinical trials were included after screening 32,527 records. Heterogeneity and risk of bias were generally low across trials. In the mixed-histology network of PD-L1–high patients, expected OS was significantly longer with atezolizumab (estimated difference: 10.4 months [95% CrI: 1.9, 18.2]), pembrolizumab (7.2 [2.2, 12.3]), and cemiplimab (13.0 [4.2, 21.0]) versus chemotherapy but not with nivolumab (3.5 [−2.5, 10.6]) or nivolumab plus ipilimumab (6.7 [−0.5, 14.2]) versus chemotherapy. OS improvements were not significant compared with chemotherapy for any regimen in the squamous and non-squamous networks, except pembrolizumab plus chemotherapy in the non-squamous network. All regimens showed significantly longer expected PFS versus chemotherapy in the non-squamous network, whereas the increases were not significant in the mixed or squamous networks. ORR was significantly higher with pembrolizumab and cemiplimab versus chemotherapy in the mixed-histology network, with sintilimab in the non-squamous network, and with combination regimens, including pembrolizumab or atezolizumab, in the squamous and non-squamous networks, except with atezolizumab plus carboplatin, paclitaxel, and bevacizumab. Survival and safety versus chemotherapy were generally similar across cancer immunotherapies and histology networks. These findings may support treatment decisions for patients with high PD-L1 status receiving first-line treatment for NSCLC.

Comparative Efficacy of First-Line Treatments of Chronic Lymphocytic Leukemia: Network Meta-Analyses of Survival Curves

BACKGROUND

Multiple treatment options in first-line chronic lymphocytic leukemia (CLL) pose a challenge in identifying the best treatment. We performed novel network meta-analyses (NMA; 8 trials, 11 treatments) on the Kaplan-Meier curves to compare treatments for fludarabine-ineligible patients on progression-free survival (PFS), time-to-next-treatment (TTNT) and overall survival (OS).

METHODS

Using the Guyot method of enhanced secondary analysis of digitized survival data and applying the fixed lognormal distribution model, we extracted the survival proportions and hazard ratios (HR) over 60 months of follow-up, including PFS comparisons by unmutated/mutated IGHV and del 17p.

RESULTS

Acalabrutinib-plus-obinutuzumab was associated with higher 5-year PFS proportions than ibrutinib (HR = 0.42, 95% CrI = 0.25-0.63) but not acalabrutinib, ibrutinib-plus-obinutuzumab, ibrutinib-plus-rituximab or venetoclax-plus-obinutuzumab. In patients with un-mutated (but not with mutated) IGHV higher PFS proportions and favorable HRs were observed for acalabrutinib, acalabrutinib-plus-obinutuzumab, and ibrutinib-plus-obinutuzumab relative to ibrutinib; and targeted therapies were superior over chemoimmunotherapies in patients with del 17p. Targeted therapies containing ibrutinib or acalabrutinib regimens were associated with superior TTNT over venetoclax-plus-obinutuzumab and all chemoimmunotherapies. OS NMA generally found no difference between therapies except for some chemoimmunotherapies.

CONCLUSIONS

Overall, only acalabrutinib-plus-obinutuzumab was associated with superior 5-year PFS gains over ibrutinib, which in turn was similar or superior in PFS benefit over other targeted therapies. Acalabrutinib and ibrutinib with obinutuzumab and acalabrutinib monotherapy were associated with greater 5-year TTNT benefits. Despite marked 5-year OS for many regimens, a differential 5-year OS benefit could not be ascertained.

Comparison of Treatments for Nonmetastatic Castration-Resistant Prostate Cancer: Matching-Adjusted Indirect Comparison and Network Meta-Analysis

BACKGROUND

For nonmetastatic castration-resistant prostate cancer (nmCRPC), three drugs under patent protection-apalutamide, enzalutamide, and darolutamide-were approved based on randomized, placebo-controlled trials; one drug with generic availability-abiraterone acetate-showed efficacy in a single-arm trial and is commonly prescribed. Lacking head-to-head trials, the optimal treatment for nmCRPC is unknown, despite widely varied treatment costs. We compared the efficacy and safety of nmCRPC treatments.

METHODS

We searched bibliographic databases, regulatory documents, and trial registries for nmCRPC trials. We included published results and, when available original data. We performed matching-adjusted indirect comparison and network meta-analysis and compared treatments regarding metastasis-free survival (MFS), overall survival (OS), and serious adverse events (SAE).

RESULTS

We analyzed five trials with a total of 4,360 participants. Compared with placebo, abiraterone acetate engendered the lowest hazard of metastasis/death (hazard ratio [HR] = 0.22, 95% credible interval [CrI] = 0.12 to 0.41), followed by apalutamide (HR = 0.28, 95% CrI=0.23 to 0.34), enzalutamide (HR = 0.30, 95% CrI=0.25 to 0.36), darolutamide (HR = 0.41, 95% CrI=0.34 to 0.49); darolutamide led to the lowest hazard of death (HR = 0.69, 95% CrI= 0.53 to 0.90), followed by enzalutamide (HR = 0.73, 95% CrI=0.61 to 0.87) and apalutamide (HR = 0.75, 95% CrI=0.59 to 0.95); darolutamide resulted in the lowest odds of SAEs (odds ratio [OR] = 1.32, 95% CrI= 1.02 to 1.70), followed by enzalutamide (OR = 1.43, 95% CrI=1.08 to 1.89), apalutamide (OR = 1.58, 95% CrI=1.23 to 2.03), and abiraterone acetate (OR = 1.94, 95% CrI=1.17 to 3.22).

CONCLUSIONS

For nmCRPC, darolutamide offered optimal efficacy and safety among approved drugs, abiraterone acetate may offer comparable MFS benefit with cost-savings from generic availability. Future research is needed to more fully examine abiraterone acetate's benefit.

Assessing the Value of Cemiplimab for Adults With Advanced Cutaneous Squamous Cell Carcinoma: A Cost-Effectiveness Analysis

OBJECTIVES

To evaluate the cost-effectiveness of cemiplimab in patients with advanced cutaneous squamous cell carcinoma (CSCC) from a payer perspective in the United States.

METHODS

A partitioned survival model was developed to assess the cost-effectiveness of cemiplimab versus historical standard of care (SOC). All inputs were identified based on a systematic literature review, supplemented by expert opinion where necessary. Clinical inputs for cemiplimab were based on individual patient data from a cemiplimab phase 2 single-arm trial (NCT27060498). For SOC, analysis was based on a pooled analysis of single-arm clinical trials and retrospective studies evaluating chemotherapy and epidermal growth factor receptor inhibitors (cetuximab, erlotinib, and gefitinib) identified via a systematic literature review (6 of the 27 included studies). Overall survival and progression-free survival were extrapolated over a lifetime horizon. Costs were included for drug acquisition, drug administration, management of adverse events, subsequent therapy, disease management, and terminal care. Unit costs were based on published 2019 US list prices.

RESULTS

In the base case, cemiplimab versus SOC resulted in an incremental cost-effectiveness ratio of $99 447 per quality adjusted-life year (QALY), where incremental costs and QALYs were $372 108 and 3.74, respectively. At a willingness-to-pay threshold of $150 000/QALY, the probabilistic sensitivity analysis suggests a 90% probability that cemiplimab is cost-effective compared to SOC. Scenario analyses resulted in incremental cost-effectiveness ratios ranging from $90 590 to $148 738.

CONCLUSIONS

Compared with historical SOC, cemiplimab is a cost-effective use of US payer resources for the treatment of advanced CSCC and is expected to provide value for money.

Comparison of Systemic Treatments for Metastatic Castration-Sensitive Prostate Cancer: A Systematic Review and Network Meta-analysis

Importance

Multiple systemic treatments are available for metastatic castration-sensitive prostate cancer (mCSPC), with unclear comparative effectiveness and safety and widely varied costs.

Objective

To compare the effectiveness and safety determined in randomized clinical trials of systemic treatments for mCSPC.

Data Sources

Bibliographic databases (MEDLINE, Embase, and Cochrane Central), regulatory documents (US Food and Drug Administration and European Medicines Agency), and trial registries (ClinicalTrials.gov and European Union clinical trials register) were searched from inception through November 5, 2019.

Study Selection, Data Extraction, and Synthesis

Eligible studies were randomized clinical trials evaluating the addition of docetaxel, abiraterone acetate, apalutamide, or enzalutamide to androgen-deprivation therapy (ADT) for treatment of mCSPC. Two investigators independently performed screening. Discrepancies were resolved through consensus. A Cochrane risk-of-bias tool was used to assess trial quality. Relative effects of competing treatments were assessed by bayesian network meta-analysis and survival models. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was used.

Main Outcomes and Measures

Overall survival, radiographic progression-free survival, and serious adverse events (SAEs).

Results

Seven trials with 7287 patients comparing 6 treatments (abiraterone acetate, apalutamide, docetaxel, enzalutamide, standard nonsteroidal antiandrogen, and placebo/no treatment) were identified. Ordered from the most to the least effective determined by results of clinical trials, treatments associated with improved overall survival when added to ADT included abiraterone acetate (hazard ratio [HR], 0.61; 95% credible interval [CI], 0.54-0.70), apalutamide (HR, 0.67; 95% CI, 0.51-0.89), and docetaxel (HR, 0.79; 95% CI, 0.71-0.89); treatments associated with improved radiographic progression-free survival when added to ADT included enzalutamide (HR, 0.39; 95% CI, 0.30-0.50), apalutamide (HR, 0.48; 95% CI, 0.39-0.60), abiraterone acetate (HR, 0.51; 95% CI, 0.45-0.58), and docetaxel (HR, 0.67; 95% CI 0.60-0.74). Docetaxel was associated with substantially increased SAEs (odds ratio, 23.72; 95% CI, 13.37-45.15), abiraterone acetate with slightly increased SAEs (odds ratio, 1.42; 95% CI, 1.10-1.83), and other treatments with no significant increase in SAEs. Risk of bias was noted for 4 trials with open-label design, 3 trials with missing data, and 2 trials with potential unprespecified analyses.

Conclusions and Relevance

In this network meta-analysis, as add-on treatments to ADT, abiraterone acetate and apalutamide may provide the largest overall survival benefits with relatively low SAE risks. Although enzalutamide may improve radiographic progression-free survival to the greatest extent, longer follow-up is needed to examine the overall survival benefits associated with enzalutamide.

Comparative efficacy and safety of adjuvant nivolumab versus other treatments in adults with resected melanoma: a systematic literature review and network meta-analysis

BACKGROUND

Immune checkpoint inhibitors and targeted therapies are approved for adjuvant treatment of patients with resected melanoma; however, they have not been compared in randomized controlled trials (RCTs). We compared the efficacy and safety of adjuvant nivolumab with other approved treatments using available evidence from RCTs in a Bayesian network meta-analysis (NMA).

METHODS

A systematic literature review was conducted through May 2019 to identify relevant RCTs evaluating approved adjuvant treatments. Outcomes of interest included recurrence-free survival (RFS)/disease-free survival (DFS), distant metastasis-free survival (DMFS), all-cause grade 3/4 adverse events (AEs), discontinuations, and discontinuations due to AEs. Time-to-event outcomes (RFS/DFS and DMFS) were analyzed both assuming that hazard ratios (HRs) are constant over time and that they vary.

RESULTS

Of 26 identified RCTs, 19 were included in the NMA following a feasibility assessment. Based on HRs for RFS/DFS, the risk of recurrence with nivolumab was similar to that of pembrolizumab and lower than that of ipilimumab 3 mg/kg, ipilimumab 10 mg/kg, or interferon. Risk of recurrence with nivolumab was similar to that of dabrafenib plus trametinib at 12 months, however, was lower beyond 12 months (HR [95% credible interval] at 24 months, 0.46 [0.27-0.78]; at 36 months, 0.28 [0.14-0.59]). Based on HRs for DMFS, the risk of developing distant metastases was lower with nivolumab than with ipilimumab 10 mg/kg or interferon and was similar to dabrafenib plus trametinib.

CONCLUSION

Adjuvant therapy with nivolumab provides an effective treatment option with a promising risk-benefit profile.