Real-world (rw) study to identify disparities in outcomes for patients (pts) with early-stage resected NSCLC who received biomarker-targeted adjuvant treatment (BTRx).

8071 Background: BTRx improves survival of pts with resected early-stage NSCLC, making thorough biomarker testing critical in this setting. Disparities in testing and receipt of guideline-supported BTRx may adversely impact outcomes. We evaluated rw biomarker testing patterns, outcomes, and receipt of BTRx in pts with resected NSCLC. Methods: This was a retrospective US cohort study of Flatiron Health data from pts with stage IB–IIIB (T3N2) NSCLC diagnosed during 2021–2023, who had surgical resection. Biomarker testing, BTRx rates, and clinical outcomes (rw recurrence-free survival [rwRFS]; overall survival [OS]) were evaluated and compared across clinical and sociodemographic groups. BTRx was defined as 1) osimertinib for EGFR+ (Ex19del/L858R) NSCLC; 2) atezolizumab or pembrolizumab (per PD-L1 status) for EGFR- and ALK-negative (-) NSCLC. Results: In this cohort (N=885), biomarker testing rates were lower among stage I (75%) vs III (93%), older (83%) vs younger (87%), non-Hispanic Black (74%) vs White (84%), and pts with smoking (83%) vs no smoking history (89%) (Table). 539 (61%) pts received adjuvant therapy; 231 (43%) had actionable biomarkers, of whom 137 (59%) received BTRx, with rates highest for pts with EGFR+ disease (85%) and lowest for pts with EGFR-/ALK- disease (49%). BTRx was received more often by pts who never smoked (76% vs 55% of pts who smoked) and pts of Asian ethnicity (100% vs 56% White) (all p<0.05). At 24 months, 90% of pts who had BTRx were alive vs 77% who did not (p<0.05). Median rwRFS was 35 months for BTRx vs 28 months for non-BTRx cohort (p<0.05). In multivariable analysis among pts who had BTRx, younger age was significantly associated with OS. Conclusions: In this large rw analysis, BTRx was significantly associated with OS in early-stage NSCLC, irrespective of age, stage and sex. Ensuring biomarker testing and BTRx for all pts may reduce outcomes disparities in NSCLC. Table Overall Stage IB Stage IIIB <65 yrs ≥65 yrs Male Female Non-Hispanic White Non-Hispanic Black Smoked Never smoked SES Quintile 1 SES Quintile 5 ≥1 Biomarker test after diagnosis, % 84 75 93* 87 83 85 83 84 74 83 89 80 86 Received adjuvant Rx (n=539), % 61 31 90* 74 56* 59 63 62 60 60 64 63 65 BTRx rate in pts with actionable bioms (n=231), % 59 64 73 57 60 63 57 56 61 55 76* 51 68 24-mo OS, % (95% CI) (all pts) 84 (81–87) 87 (80–92) 72(46–87)** † 92 (86–96) 81 (77–85)** † 81 (75–85) 87 (82–90)** † 86 (82–89) 88 (70–96) 83 (80–87) 89 (79–94) 85 (74–92) 88(80–93) 24-mo OS, % (95% CI) (pts with BTRx) 90 (80–95) 91 (51–99) NR 100 (100–100) 86 (71–93)** 83 (58–94) 94 (82–98) 88 (73–95) 100 (100–100) 89 (76–95) 95 (68–99) 80 (41–95) 86* (53–96) *χ2-test p<0.05. **Log-r