Generalizability of clinical trials of advanced melanoma in the real-world, population-based setting

Emulation of ARISTOTLE and ROCKET AF trials in real-world atrial fibrillation patients results in similar efficacy and safety as original landmark trials: insights from the GARFIELD-AF registry

AIMS

This study aimed to determine the robustness, reproducibility and representativeness of the landmark Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (AF) (ARISTOTLE) and Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in AF (ROCKET AF) randomised trials through replication in an observational AF patient registry.

METHODS AND RESULTS

Patients from the Global Anticoagulant Registry in the FIELD (GARFIELD)-AF registry treated with apixaban, rivaroxaban or vitamin K antagonist (VKA) were assessed for eligibility for the ARISTOTLE and ROCKET AF trials. HRs of apixaban and rivaroxaban versus comparator for stroke/systemic embolism, major bleeding and all-cause mortality within 2 years follow-up were calculated using propensity score overlap-weighted Cox models. Among GARFIELD-AF patients on apixaban, 2570/3615 (71%) would have been eligible for ARISTOTLE. Among patients using rivaroxaban, 2005/4914 (41%) would have been eligible for ROCKET AF. Eligibility rates were steady over time, with minor differences across medical specialties. Real-world AF patients selected according to trial criteria had lower cardiovascular burden than the original trial participants, especially compared with ROCKET AF. HRs (95% CI) for apixaban versus VKA among ARISTOTLE-eligible users were 0.57 (0.34 to 0.94) for stroke/systemic embolism, 0.76 (0.48 to 1.20) for major bleeding and 0.89 (0.70 to 1.12) for all-cause mortality. Among ROCKET AF-eligible rivaroxaban users, HRs for rivaroxaban versus VKA were 0.90 (0.57 to 1.43), 0.92 (0.59 to 1.43) and 0.86 (0.69 to 1.08), respectively. All safety and efficacy estimates were similar to those in the original trials.

CONCLUSION

Real-world representativeness of the selection criteria was greater for ARISTOTLE than ROCKET AF. The pivotal randomised trials of apixaban and rivaroxaban versus warfarin can be successfully emulated in real-world AF patients by applying trial-specific selection criteria and appropriate methodology for non-randomised treatment allocation.

TRIAL REGISTRATION NUMBER

NCT01090362.

Clinical Effectiveness and Cost-Effectiveness of Multigene Panel Sequencing in Advanced Melanoma: A Population-Level Real-World Target Trial Emulation

PURPOSE

Targeted therapy and immunotherapy promise improved survival in patients with advanced melanoma, yet the effectiveness and cost-effectiveness of multigene panel sequencing compared with single-gene BRAF testing to guide therapeutic decisions is unknown.

METHODS

Our population-based quasi-experimental retrospective target trial emulation used comprehensive patient-level data for 364 British Columbia, Canada, adults with an advanced melanoma diagnosis receiving multigene panel sequencing or single-gene BRAF testing between September 1, 2016, and December 31, 2018. We 1:1 matched multigene panel patients to controls using genetic algorithm-based matching. Outcomes included 3-year overall survival (OS) and health care costs (2021 Canadian dollars [CAD]) with incremental net monetary benefit for life-years gained (LYG). Outcomes were analyzed using inverse probability of censoring weighted linear regression for the intention-to-treat (ITT) effect. The per-protocol (PP) effect estimation also included stabilized inverse probability of treatment weights. We then used Weibull regression and Kaplan-Meier survival analysis.

RESULTS

We matched 147 multigene panel patients to controls, achieving balance for all covariates. After matching, ITT incremental costs were $19,447 CAD (95% CI, -$18,516 to $76,006) and incremental LYG were 0.22 (95% CI, -0.05 to 0.49). We found uncertainty in differences on OS using Kaplan-Meier (P = .11) and Weibull regression (hazard ratio [HR], 0.73 [95% CI, 0.51 to 1.03]) in the ITT. PP incremental costs were $36,367 CAD (95% CI, -$6,653 to $120,216]) and incremental LYG were 0.56 (95% CI, 0.39 to 1.24), with corresponding differences in OS using Kaplan-Meier (P = .02) and Weibull regression (HR, 0.56 [95% CI, 0.36 to 0.87]). The probability of multigene panels being cost-effective at $100,000/LYG CAD was 55% for ITT and 65% for PP.

CONCLUSION

The cost-effectiveness of multigene panels was evenly poised at higher thresholds, even when accounting for treatment initiation. Health systems reimbursing multigene panels and expensive therapies may be confronted with a value tradeoff, in which there may be improved survival albeit with a modest change in cost-effectiveness.

Understanding Real-World Treatment Patterns and Clinical Outcomes among Metastatic Melanoma Patients in Alberta, Canada

Immunotherapy and targeted therapies have been shown to considerably improve long-term survival outcomes in metastatic melanoma patients. Real-world evidence on the uptake of novel therapies and outcomes for this patient population in Canada are limited. We conducted a population-based retrospective cohort study of all metastatic melanoma patients diagnosed in Alberta, Canada (2015-2018) using electronic medical records and administrative data. Information on BRAF testing for patients diagnosed in 2017 or 2018 was obtained through chart abstraction. In total, 434 metastatic melanoma patients were included, of which 110 (25.3%) were de novo metastatic cases. The median age at diagnosis was 66 years (IQR: 57-76) and 70.0% were men. BRAF testing was completed for the majority of patients (88.7%). Among all patients, 60.4%, 19.1%, and 6.0% initiated first-line, second-line, and third-line systemic therapy. The most common therapies were anti-PD-1 and targeted therapies. The two-year survival probability from first-line therapy, second-line therapy, and third-line therapy was 0.50 (95% CI: 0.44-0.57), 0.26 (95% CI: 0.17-0.40), and 0.14 (95% CI: 0.40-0.46), respectively. In the first-line setting, survival was highest for patients that received ipilimumab or ipilimumab plus nivolumab, while targeted therapy had the highest survival in the second-line setting. This study indicates that novel therapies improve survival in the real world but a considerable proportion of patients do not receive treatment with systemic therapy.

Efficacy and Safety of Immunotherapy-Based Combinations as First-Line Therapy for Metastatic Renal Cell Carcinoma in Patients Who Do Not Meet Trial Eligibility Criteria

BACKGROUND

Data regarding the efficacy and safety profiles of immune checkpoint inhibitors (ICIs) for metastatic renal cell carcinoma (mRCC) trial-ineligible patients in the real world remain unclear.

OBJECTIVES

The aim of this study was to clarify the impact of trial eligibility on ICI-based combination therapy for mRCC.

PATIENTS AND METHODS

We collected clinical data of mRCC patients receiving ICIs since 2016, and 222 patients were registered. Among these patients, we evaluated 93 patients treated with ICI-based combination therapy, including nivolumab plus ipilimumab, pembrolizumab plus axitinib, or avelumab plus axitinib, as first-line therapy. Patients were classified into the trial-ineligible group when they had at least one of the following factors at the time of treatment initiation: Karnofsky performance status (KPS) < 70%, hemoglobin level < 9.0 g/dL, estimated glomerular filtration rate (eGFR) < 40 mL/min/1.73 m², platelet count < 100,000/µL, neutrophil count < 1500/µL, non-clear cell histology, or brain metastasis. The remaining patients were classified into the trial-eligible group.

RESULTS

Forty-eight patients (52%) were classified into the trial-ineligible group. The frequency of patients with trial-ineligible factors was highest for low eGFR (n = 20, 45%), followed by non-clear cell histology (n = 17, 36%) and low KPS score (n = 12, 25%). There was no significant difference in progression-free survival (median: 24.0 vs. 11.0 months, p = 0.416), overall survival (1-year rate: 87.0% vs. 85.3%, p = 0.634), or objective response rate (52% vs. 42%, p = 0.308) between the trial-eligible and -ineligible patients. The incidence rate of adverse events was higher in the trial-eligible patients than in the trial-ineligible patients (91% vs. 75%, p = 0.0397); however, the rate of grade 3 or higher adverse events was comparable between the two groups (42% vs. 40%, p = 0.796).

CONCLUSIONS

There are many trial-ineligible patients in the real world. Nevertheless, the efficacy and safety of ICI-based combination therapy in trial-ineligible patients were non-inferior compared with those of trial-eligible patients.

Outcomes of patients with solid tumour malignancies treated with first-line immuno-oncology agents who do not meet eligibility criteria for clinical trials

BACKGROUND

Immuno-oncology (IO)-based therapies have been approved based on randomised clinical trials, yet a significant proportion of real-world patients are not represented in these trials. We sought to compare the outcomes of trial-ineligible vs. -eligible patients with advanced solid tumours treated with first-line (1L) IO therapy.

PATIENTS AND METHODS

Using the International Metastatic Renal Cell Carcinoma (RCC) Database Consortium and the Alberta Immunotherapy Database, patients with advanced RCC, non-small-cell lung cancer (NSCLC) or melanoma treated with 1L PD-(L)1 inhibition-based therapy were included. Trial eligibility was retrospectively determined as per commonly used exclusion criteria. The outcomes of interest were overall survival (OS), overall response rate (ORR), treatment duration (TD) and time to next treatment (TTNT).

RESULTS

A total of 395 of 1241 (32%) patients were deemed trial-ineligible. The main reasons for ineligibility based on preselected exclusion criteria were Karnofsky performance status <70%/Eastern Cooperative Oncology Group performance status >1 (40%, 158 of 395), brain metastases (32%, 126 of 395), haemoglobin < 9 g/dL (16%, 63 of 395) and estimated glomerular filtration rate <40 mL/min (15%, 61 of 395). Between the ineligible vs. eligible groups, the median OS, ORR, median TD and median TTNT were 10.2 vs. 39.7 months (p < 0.01), 36% vs. 47% (p < 0.01), 2.7 vs. 6.9 months (p < 0.01) and 6.0 vs. 16.8 months (p < 0.01), respectively. Subgroup analyses showed statistically significant inferior OS, TD and TTNT for trial-ineligible vs. -eligible patients across all tumour types. Adjusted hazard ratios for death in RCC, NSCLC and melanoma were 1.84 (95% confidence interval [CI] 1.22-2.77), 2.21 (95% CI 1.58-3.11) and 1.82 (95% CI 1.21-2.74), respectively..

CONCLUSIONS

Thirty-two percent of real-world patients treated with contemporary 1L IO-based therapies were ineligible for clinical trials. Although one-third of the trial-ineligible patients responded to treatment, the overall trial-ineligible population had inferior outcomes than trial-eligible patients. These data may guide patient counselling and temper expectations of benefit.

Clinical Trial Generalizability Assessment in the Big Data Era: A Review

Clinical studies, especially randomized, controlled trials, are essential for generating evidence for clinical practice. However, generalizability is a long‐standing concern when applying trial results to real‐world patients. Generalizability assessment is thus important, nevertheless, not consistently practiced. We performed a systematic review to understand the practice of generalizability assessment. We identified 187 relevant articles and systematically organized these studies in a taxonomy with three dimensions: (i) data availability (i.e., before or after trial (a priori vs. a posteriori generalizability)); (ii) result outputs (i.e., score vs. nonscore); and (iii) populations of interest. We further reported disease areas, underrepresented subgroups, and types of data used to profile target populations. We observed an increasing trend of generalizability assessments, but < 30% of studies reported positive generalizability results. As a priori generalizability can be assessed using only study design information (primarily eligibility criteria), it gives investigators a golden opportunity to adjust the study design before the trial starts. Nevertheless, < 40% of the studies in our review assessed a priori generalizability. With the wide adoption of electronic health records systems, rich real‐world patient databases are increasingly available for generalizability assessment; however, informatics tools are lacking to support the adoption of generalizability assessment practice.

Economic Evaluation of Systemic Treatments for Advanced Melanoma: A Systematic Review

BACKGROUND

Many high cost treatments for advanced melanoma have become available in recent years. National health technology assessment agencies have raised concerns regarding uncertainty in their clinical and cost-effectiveness.

OBJECTIVE

The aim of this systematic review is to identify economic evaluations of treatments for advanced melanoma and review model assumptions, outcomes, and quality as preparation for a health technology assessment.

METHODS

A search of Embase, MEDLINE, EconLit, and the Cochrane Database was conducted. Only studies using decision-analytic models were included. Two authors independently completed full-text review and data extraction.

RESULTS

Fifteen studies were identified. There were major differences in the structural assumptions underpinning the models. There was general agreement in study conclusions, although the predicted costs and quality-adjusted life years for each treatment varied. BRAF monotherapy (vemurafenib, dabrafenib) or BRAF/MEK combination therapy (BRAF monotherapy with cobimetinib or trametinib) has not been shown to be cost-effective in any jurisdiction. PD-1 inhibitors (pembrolizumab, nivolumab) are consistently found to be cost-effective compared with ipilimumab, although their cost-effectiveness compared with chemotherapy is not established. Combination therapy with nivolumab and ipilimumab is unlikely to be cost-effective in any setting. One study including all agents found that none of the new treatments were cost-effective relative to chemotherapy. Publication of the study in a health economics journal is associated with better reporting of and higher-quality assessment than those published in clinical journals.

CONCLUSION

Despite differences in model structures and assumptions, the conclusions of most included studies were consistent. Health technology assessment has a key role in maximizing value from high-cost innovative treatments. Consideration should be given to divestment from BRAF/MEK inhibitors and ipilimumab in favor of reimbursement of PD-1 inhibitors.

Systemic Therapies for Advanced Melanoma

The incidence of metastatic melanoma continues to increase each decade. Although surgical treatment is often curative for localized stage I and stage II disease, the median survival for patients with distant metastases is less than 1 year. The last 2 decades have witnessed a breakthrough in therapeutic options with the development of immune checkpoint inhibitors, small molecule targeted therapy, and oncolytic viral therapy. This article provides an overview of the treatment options available for advanced melanoma, including chemotherapy, targeted therapy, immunotherapy, interleukin-2, and oncolytic viral agents.