Transportability of Overall Survival Estimates From the United States to Germany in eGFR+ Advanced NSCLC Patients Post-Tyrosine Kinase Inhibitor (TKI) Treatment
Author(s)
Alexandra Starry1, Vartika Savarna, MPP1, Alessandria Strübing, MPH2, Marian Eberl, MSc2, Summera Qiheng Zhou, BEc, BS, MS3, Bernhard Mörtl, PhD4, Philani Mpofu, PhD5, Alind Gupta, PhD6.
1Cytel, Berlin, Germany, 2Daiichi Sankyo Europe, Munich, Germany, 3Daiichi Sankyo, Edina, MN, USA, 4Daiichi Sankyo Deutschland GmbH, München, Germany, 5Flatiron Health, New York, NY, USA, 6Dalla Lana School of Public Health,University of Toronto, Mississauga, ON, Canada.
1Cytel, Berlin, Germany, 2Daiichi Sankyo Europe, Munich, Germany, 3Daiichi Sankyo, Edina, MN, USA, 4Daiichi Sankyo Deutschland GmbH, München, Germany, 5Flatiron Health, New York, NY, USA, 6Dalla Lana School of Public Health,University of Toronto, Mississauga, ON, Canada.
OBJECTIVES: Assessing the transportability of real-world data (RWD) across countries is increasingly important for health technology assessments. This study evaluated the transportability of real-world overall survival (rwOS) estimates in EGFR+ advanced non-small cell lung cancer (aNSCLC) patients treated with EGFR TKIs using US Electronic Medical Records (Flatiron Health) and German claims data (AOK PLUS).
METHODS: Adult patients diagnosed with EGFR+ aNSCLC between 2016 and 2023, who received first- or second line (LOTs) EGFR TKI therapy followed by a subsequent treatment were eligible. The start date of the subsequent LOT was defined as index. rwOS was measured from index until death. G-computation was used to adjust for baseline differences (age, sex, metastasis sites, index treatment, number of prior LOTs, time since diagnosis and index year) between US and German cohorts. Model parameters were estimated from US data and used to generate a survival curve standardized to the German cohort’s baseline covariates. This standardized rwOS was compared to the observed rwOS in Germany to assess comparability.
RESULTS: US (n=1,407) and German (n=84) cohorts had median ages of 68.0 and 66.9 years; 31% vs. 33% male, respectively. Most patients were indexed at 2LOT (US: 85%, Germany: 76%). The observed median rwOS was 16.3 months (95% confidence interval [CI]: 15-17.6) in the US and 10.1 months (95% CI: 6.9-14.7) in Germany - a 6.2-month difference. After adjusting for baseline differences, the standardized median rwOS for the German cohort was 13.4 months (95% CI: 11.5-15.7), reducing the difference to 3.3 months.
CONCLUSIONS: This transportability study showed US RWD requires cohort adjustments to estimate survival of German asNSCLC patients. The standardized median rwOS fell within observed German rwOS CI. Due to small sample size and limited clinical data in German claims, additional analysis is planned using German registry data to evaluate if it further improves transportability.
METHODS: Adult patients diagnosed with EGFR+ aNSCLC between 2016 and 2023, who received first- or second line (LOTs) EGFR TKI therapy followed by a subsequent treatment were eligible. The start date of the subsequent LOT was defined as index. rwOS was measured from index until death. G-computation was used to adjust for baseline differences (age, sex, metastasis sites, index treatment, number of prior LOTs, time since diagnosis and index year) between US and German cohorts. Model parameters were estimated from US data and used to generate a survival curve standardized to the German cohort’s baseline covariates. This standardized rwOS was compared to the observed rwOS in Germany to assess comparability.
RESULTS: US (n=1,407) and German (n=84) cohorts had median ages of 68.0 and 66.9 years; 31% vs. 33% male, respectively. Most patients were indexed at 2LOT (US: 85%, Germany: 76%). The observed median rwOS was 16.3 months (95% confidence interval [CI]: 15-17.6) in the US and 10.1 months (95% CI: 6.9-14.7) in Germany - a 6.2-month difference. After adjusting for baseline differences, the standardized median rwOS for the German cohort was 13.4 months (95% CI: 11.5-15.7), reducing the difference to 3.3 months.
CONCLUSIONS: This transportability study showed US RWD requires cohort adjustments to estimate survival of German asNSCLC patients. The standardized median rwOS fell within observed German rwOS CI. Due to small sample size and limited clinical data in German claims, additional analysis is planned using German registry data to evaluate if it further improves transportability.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
MSR205
Topic
Health Policy & Regulatory, Methodological & Statistical Research, Study Approaches
Topic Subcategory
Artificial Intelligence, Machine Learning, Predictive Analytics
Disease
Oncology