37P ReAlec interim analysis: An observational study to evaluate the real-world clinical management and outcomes of patients (pts) with advanced ALK+ NSCLC treated with alectinib

Alectinib is a preferred first-line treatment for pts with advanced ALK+ NSCLC and the sequence of post-alectinib treatments used in the real-world is not well characterised. ReAlec (NCT04764188) is a real-world, observational, multicentre, cohort study of the clinical management and outcomes of pts treated with alectinib. We report results from the primary interim analysis of cohort 1 (pts treated with first-line alectinib). Eligible pts were ≥18 years old with advanced ALK+ NSCLC and initiated on-label, first-line alectinib after (arm A) or before (arm B) enrolment. Pts will be followed for up to 6 years. Retrospective medical history was collected at enrolment and additional data were recorded during routine visits. Co-primary objectives were progression-free survival and next line of therapy post-alectinib. Key secondary objectives were demographics, disease characteristics and safety. In total 745 pts were enrolled; demographics and disease characteristics are reported in the table. At data cutoff (10 May 2023), median treatment duration on the study was 8.3 months (arm A) and 13.8 months (arm B). Rates of alectinib discontinuation were 21.9% (arm A) and 15.3% (arm B); 73.2% (arm A) and 86.7% (arm B) of these pts discontinued alectinib due to progressive disease. The most common next line of therapy was lorlatinib (arm A: 60.5%; arm B: 67.7%). Treatment-related adverse events (TRAE) occurred in 26.3% of pts and were mostly Grade 1–2 and non-serious. TRAEs leading to dose modification/interruptions and treatment discontinuation occurred in 6.4% and 0.9% of pts, respectively. Grade 5 events unrelated to treatment occurred in 20 (2.7%) pts. Table: 37PArm A (n=256)Arm B (n=489)Median age, years (range)58 (22–86)58 (24–91)Male, %46.543.4Race, %AsianWhiteOther26.662.910.514.576.39.2ECOG PS, %0123n=21737.852.59.20.5n=42160.836.12.90.2Stage at initial diagnosis, %IIIIIIIVMissing2.02.016.479.703.52.710.682.60.6Metastatic disease at baseline, %90.693.7Prior therapy at any stage, %Cancer therapyRadiotherapySurgery16.416.422.716.621.526.8Median time from metastatic diagnosis to alectinib, days (95% CI)28.0 (24.0–32.0)28.0 (26.0–31.0)Median time from ALK test (at initial diagnosis) to alectinib, days (95% CI)10.5 (9.0–14.0)14.0 (12.0–16.0) Open table in a new tab Real-world demographics and disease characteristics of pts with advanced ALK+ NSCLC, and the safety profile of alectinib, were in line with clinical experience. Post-alectinib treatments and their effectiveness will continue to be evaluated.