Guideline concordant osimertinib and durvalumab in two US non-small cell lung cancer cohorts.

37 Background: Adjuvant osimertinib (osi) and consolidative durvalumab (durva) in non-small cell lung cancer (NSCLC) improve patient (pt) survival; therefore, adherence to oncology guidelines for their use is of great interest. We sought to understand the rates and clinical factors associated with receipt of guideline-concordant care (GCC) across two clinical scenarios among pts with non-metastatic NSCLC. Methods: This study examined two cohorts from the US-based, EHR-derived, de-identified Flatiron Health Research Database. Included pts were age 18+, treated in a community oncology practice with or without access to the clinical decision support tool Flatiron Assist (FA), and had either surgically resected stage II–IIIA EGFR-mutant NSCLC diagnosed December 2020–April 2024 (Cohort A) or definitive chemoradiotherapy for unresectable stage III NSCLC diagnosed February 2018–April 2024 (Cohort B). We calculated the percentage of pts receiving osi (Cohort A) or durva (Cohort B) overall and by pt characteristics. Multivariable logistic regression was used to estimate the association between pt characteristics and receipt of GCC with adjusted odds ratios (aOR). Results: In Cohort A, 265/378 pts (70%) received adjuvant osi. In Cohort B, 6295/9307 pts (68%) received consolidative durva. After adjusting for pt factors, pts in Cohort A who received GCC were more likely to be Latinx vs. non-Latinx White, never- vs. ever-smokers, or diagnosed before 2022 vs. 2024 (Table). In Cohort B, pts who received GCC were more likely to be younger, female, non-Latinx White, ECOG 0, or diagnosed in 2024 vs. 2018. There was no significant difference in GCC by FA access in either cohort. Conclusions: Across two straightforward clinical scenarios in non-metastatic NSCLC, the pts most likely to receive GCC had vastly different characteristics highlighting the complex nuances affecting guideline adherence. Overall, 30% of pts did not receive GCC despite clear indications for osi and durva. Unmeasured comorbidities may explain some, but not all practice variation. Further research is needed to elucidate reasons for guideline non-concordance and inform strategies to aid clinicians in prescribing life-saving therapies. aOR of receiving concordant osi, (95% CI) aOR of receiving concordant durva, (95% CI) Age at diagnosis ≥80 vs. <50 2.72 (0.27, 21.5) 0.62 (0.41, 0.93) Male vs. female 0.74 (0.44, 1.26) 0.91 (0.83, 0.99) Latinx ethnicity vs. non-Latinx White 5.72 (1.18, 50.9) 0.85 (0.66, 1.12) Never-smoker vs. ever-smoker 2.69 (1.55, 4.8) 0.87 (0.70, 1.08) South vs. Northeast census region 0.65 (0.27, 1.48) 0.97 (0.84, 1.13) Highest area-level socioeconomic status vs. lowest 0.98 (0.39, 2.44) 1.16 (0.97, 1.41) Medicare vs. Commercial insurance 0.54 (0.24, 1.17) 1.04 (0.90, 1.21) No FA vs. FA access at site 0.82 (0.43, 1.52) 1.00 (0.87, 1.14) Diagnosis year 2024 vs. 2021/prior (osi) or 2018 (durva) 0.39 (0.16, 0.91) 1.39 (1.12, 1.72)