Bayesian survival extrapolation for cost-effectiveness analysis: a case study of RELAY for ramucirumab in combination with erlotinib in the treatment of non-small-cell lung cancer.

AIM: Increasing trend for progression-free survival (PFS)-based primary endpoint in oncology has led to lack of mature overall survival (OS) data at the time of approval. To address this evidence gap in economic evaluations, we used a joint Bayesian approach to predict survival outcomes using immature OS data from the RELAY trial. METHODS: Patient data from RELAY and systematic literature review (SLR) of phase 3 randomized clinical trials with hazard ratio (HR) estimates of mature PFS and immature OS were considered. OS and PFS were analyzed individually using a univariate model; bivariate analysis was performed using a joint model based on modified Bayesian normal induced copula estimation model. First, a Bayesian univariate model incorporated informative priors based on predicted HR and acceleration factor for OS and PFS. Second, a Bayesian-based joint model of RELAY PFS and OS data was based on the correlation between PFS and OS established in trials of similar populations. Marginal distribution of PFS was used to estimate the same for OS. RESULTS: Publications (N = 122) of first-line treatments in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer were identified in the SLR, of which 36 trials were linked to RELAY. Twenty-six trials with HR data were used. The univariate model could predict OS with reduced uncertainty compared with the frequentist approach. In the joint model, the marginal OS distribution borrowed strength from the marginal PFS distribution through the established correlation coefficient. LIMITATIONS: Bayesian approach was successfully used in RELAY analysis but may not be universally applied to oncology trials due to the different associations of OS and PFS and different trial patient populations. CONCLUSIONS: We demonstrated that both the univariate and joint Bayesian models reduced uncertainty in predicting OS compared to frequentist method. The methodology introduced here will have potential applications in clinical decision-making for other oncology trials.

Patient Characteristics, Testing and Treatment Patterns, and Outcomes in EGFR-Mutated Advanced Non-Small Cell Lung Cancer: A Multinational, Real-World Study.

INTRODUCTION: Treatment landscape for advanced/metastatic NSCLC (aNSCLC) has evolved considerably over the past few decades with the advent of targeted therapies for epidermal growth factor receptor-mutated (EGFRm+) aNSCLC treatment. This study described real-world patient and disease characteristics, treatment and practice patterns, and clinical, economic, and patient-reported outcomes (PROs) in patients with EGFRm+ aNSCLC. METHODS: Data were derived from the Adelphi NSCLC Disease Specific Programme™ (DSP™), a point-in-time survey conducted between July and December 2020. The survey included oncologists and pulmonologists, and their consulting patients (with physician-confirmed EGFRm+ aNSCLC) from nine countries: the US, Brazil, the UK, Italy, France, Spain, Germany, Japan, and Taiwan. All analyses were descriptive. RESULTS: Overall, 542 physicians reported data for 2857 patients (mean age 65.6 years), and most patients were female (56.0%), white (61.0%), and had stage IV disease at initial diagnosis (76.0%), and adenocarcinoma histology (89.0%). Most patients received EGFR-tyrosine kinase inhibitors (TKI) therapy in first- (91.0%), second- (74.0%), and third-line (67.0%). The most common tumor samples and methods for EGFR detection were EGFR-specific mutation detection tests (44.0%) and core needle biopsy (56.0%). Median time to next treatment was 14.0 (IQR 8.0-22.0) months and disease progression was the main physician-reported reason for early discontinuation. The most common physician-reported disease symptoms were cough (51.0%), fatigue (37.0%), and dyspnea (33.0%). In patients assessed for PROs, mean EQ-5D-5L index and FACT-L health utility scores were 0.71 and 83.5, respectively. On average, patients lost 10.6 h of work/week for approximately 29.2 weeks due to EGFRm+ aNSCLC. CONCLUSION: This real-world multinational data set showed that most patients with EGFRm+ aNSCLC were treated per the country relevant clinical guidelines, with progression as the main reason for early treatment discontinuation. For the included countries, these findings may offer a useful benchmark for decision makers to determine future allocation of healthcare resources for patients with EGFRm+ aNSCLC.

Treatment Patterns, Clinical Outcomes and Health Care Resource Utilisation in Patients with EGFR-mutated Metastatic Non-Small Cell Lung Cancer: A Real-World Study in South Korea.

BACKGROUND: Despite the dynamic treatment landscape for EGFR mutant-positive metastatic non-small cell lung cancer (EGFRm+ mNSCLC), most of the earlier studies have focused on US or Western populations. OBJECTIVE: The objective of this study was to explore real-world treatment patterns and outcomes of South Korean patients with EGFRm+ mNSCLC. METHODS: Retrospective chart review of adult patients with EGFRm+ mNSCLC who received systemic treatment between January-2019 and June-2019. RESULTS: A total of 162 patients were included from 21 hospitals, with a median follow-up of 15.6 months. Median age was 65.0 years, 22% had central nervous system metastasis, and 57% and 38% had exon 19 deletion and exon 21 L858R, respectively. Among 144 patients (89%) who received first-line EGFR-tyrosine kinase inhibitor, afatinib was most the common (44%), followed by gefitinib (28%) and erlotinib (13%). First-line chemotherapy was more common when an EGFR-mutation was detected after versus before first-line treatment initiation (31% vs 5%). Discontinuation of first-line treatment was mostly due to disease-progression (81%) and toxicity (7%). Among 58 (78%) patients who received second-line treatment, osimertinib was the most common (40%). Most (60%) patients reported ≥1 Grade ≥3 adverse event during first-line treatment. Following initiation of first-line treatment, physician visits and chest X-rays were the most frequent healthcare utilisation events. Rates of emergency-room visits and hospitalization were 12% and 16%, respectively, with a mean length-of-stay of 10.4 days. At 12 months, overall survival rate was 95%, and numerically worse for patients with exon 21 versus 19 mutations. CONCLUSIONS: Characteristics and clinical outcomes of Korean patients with EGFRm+ mNSCLC in real-world practice were comparable to those observed in clinical trials. As osimertinib was not reimbursed for first-line treatment before study completion, further investigation is warranted to explore evolving treatment practice.

Health state utility values associated with advanced gastric, oesophageal, or gastro-oesophageal junction adenocarcinoma: a systematic review.

OBJECTIVES: To systematically identify utility values associated with advanced gastric cancer (GC), oesophageal cancer (OC), or gastro-oesophageal junction (GEJ) cancer. Utility values relating to health states are an essential component for cost-utility analysis (CUA). METHODS: MEDLINE, Embase, Cochrane Library, and EconLit databases were reviewed for relevant studies using a pre-defined search strategy. Studies eligible for inclusion reported health state utility values (HSUVs) using direct (standard gamble [SG] and time-trade-off [TTO]) and indirect (such as EuroQol 5D [EQ-5D], short-form 6D [SF-6D], and the 15-dimensional instrument [15D]) methods for patients with advanced GC, OC, or GEJ cancer. RESULTS: A total of 539 unique publications were identified, of which eight met the inclusion criteria (GC, n = 2; mixed population [gastrointestinal cancers], n = 4; OC, n = ). The most commonly used instrument to estimate HSUVs was the EQ-5D (n = 7). Utilities were also estimated using the SF-6D and the 15D in the same study (n = 1). Direct elicitation methods included the TTO (n = 2) and SG (n = 1). Across the eight identified publications, health states and study populations were heterogeneous and sample sizes were limited. LIMITATIONS: This review, as with all summaries of this nature, is only as robust as the data derived from the identified studies. The systematic review process does not resolve any design issues or biases associated with the original studies. CONCLUSIONS: Limited data estimate HSUVs in patients with advanced GC, OC, or GEJ cancer. Utilities for advanced GC alone and advanced OC alone were reported in only two publications for each cancer type. No publications considered advanced GEJ utilities alone, and four publications considered utilities for a mixed population of gastrointestinal cancer types. Comparisons are confounded by heterogeneity across the identified publications. Further research into HSUVs associated with advanced GC and OC is required to improve the evidence available for use in CUAs.