Treatment (tx) patterns in patients (pts) with lung cancer starting 1st or 2nd generation (1G/2G) EGFR-TKI: A US insurance claims database analysis

Abstract

Background: Approximately 50% of pts with EGFR mutated (EGFRm) NSCLC who progress on first-line (1L) Tx with 1G/2G EGFR-TKIs harbor the EGFR T790M mutation and are eligible for osimertinib, a 3G EGFR-TKI (first US approval in 2015). Pts with undetectable T790M typically receive chemotherapy. Presently, the Tx pattern following disease progression on 1L EGFR-TKI is poorly characterized. Using a US claims database, we describe 2L Tx in pts following 1L 1G/2G EGFR-TKIs, stratified by starting year of 1L Tx. Method(s): This is a retrospective observational study from the US Truven MarketScan Databases. Data included inpatient and outpatient insurance claims for diagnoses, Txs, and procedures. We studied a cohort of pts first diagnosed with lung cancer 2013-2017: >=18 yrs, received 1L erlotinib, gefitinib or afatinib, >=6 mths baseline data, no systemic therapies or lung surgeries for curative intent prior to TKI. Patients were followed from diagnosis and censored at end of enrolment or Sep 30, 2017. Result(s): We identified 1104 pts: median age 65 yrs (range 25-94); 64% female; uniform US distribution; 21% high Charlson Comorbidity Index (>=5); 78% metastatic disease; 31% brain metastases. Prior to 1L EGFR-TKI Tx, 62% had a biopsy and 37% had an EGFR testing claim (72% either biopsy or EGFR test). 1L Tx included erlotinib (86%), afatinib (13%) and gefitinib (1%). At time of analysis, 649/1104 (59%) pts were deemed still on 1L EGFR-TKI. 455/1104 (41%) pts were deemed off 1L EGFR-TKI: 281/455 (62%) with a 2L Tx claim (Table); 174/455 (38%) no 2L Tx claim and no 1L prescription >90 days of censor date. Conclusion(s): With 62% of pts receiving 2L Tx after 1L EGFR-TKI, the study is consistent with emerging evidence indicating that not all patients are able to receive 2L Tx during follow-up after 1L 1G/2G EGFR-TKI. This study thus supports the importance of using the most effective EGFR-TKI as initial therapy, rather than reserving it as a 2L option, when it may reach fewer patients. (Table Presented) .