Outcomes of first, second, and third-generation anaplastic lymphoma kinase (ALK) inhibitors in non-small cell lung cancer brain metastases (NSCLCBM).

2034 Background: Non-small cell lung cancer (NSCLC) is the most common cause of brain metastases. ALK, which codes for tyrosine kinase receptors, is rearranged in 4-7% of NSCLC. First-generation ALK inhibitors have restricted efficacy due to poor blood-brain barrier (BBB) penetration and ALK-resistant tumor mutations. Second-generation ALK inhibitors have shown better BBB penetration, while third-generation ALK inhibitors were efficacious even against ALK-resistant mutations. In this retrospective study, we investigated the overall survival (OS) and progression-free survival (PFS) in NSCLCBM patients treated with first, second, and third-generation ALK inhibitors. Methods: NSCLCBM patients between 2010 and 2019 were evaluated. We analyzed data regarding molecular marker status, systemic therapies, and date of progression. OS was defined as the start date of systemic therapy to the date of last follow-up or death. The Cox proportional model was used to estimate OS and PFS. Results: A total of 90 patients had ALK gene rearrangement. 16 ALK positive patients received first-generation ALK inhibitor (crizotinib), with a median age of 59.2 years, 50% of the cohort being female and 83.3% being white. Another 17 patients received second-generation (alectinib, ceritinib, brigatinib) and third-generation ALK inhibitors (lorlatinib), with a combined median age of 52.2 years and a cohort of 52.6% females and 72.2% white patients. The 5-year OS rate was 49% (95% confidence interval (CI) = 24%, 71%) for first-generation ALK inhibitors and 76% (95% CI = 40%, 92%) for second and third-generation ALK inhibitors (p-value (p) = 0.019). The median PFS (mPFS) for patients who received first-generation ALK inhibitors was 45.3 months and for those who received second or third-generation ALK inhibitors was 180.1 months. The respective 5-year PFS rate was 43% (95% CI = 19%, 65%) and 72% (95% CI = 42%, 89%). Conclusions: Newer generations of targeted therapies in NSCLCBM have improved BBB penetration and effectiveness against resistant mutations. We determined that there was a significant 5-year OS benefit in patients who received second and third-generation ALK inhibitors compared to first-generation ALK inhibitors, and a respective trend towards significant PFS benefit in newer-generation ALK inhibitors when compared to first-generation. These results are encouraging, but the effect on intracranial lesion size and response rates should be examined in the future.[Table: see text]