Management of patients with ALK-positive advanced non-small cell lung cancer who received brain radiotherapy on study in the phase 3 CROWN trial.

9063 Background: Approximately 30% of patients with ALK-positive non-small cell lung cancer (NSCLC) present with brain metastases at diagnosis. Lorlatinib is a potent brain-penetrant ALK tyrosine kinase inhibitor (TKI) that showed improved time to intracranial (IC) progression compared with crizotinib in patients with and without brain metastases at baseline. This post hoc analysis from the phase 3 CROWN study summarizes the management of patients who received brain radiotherapy (RT) during the study. Methods: In the CROWN study, 296 patients with previously untreated ALK-positive advanced NSCLC were randomized 1:1 to receive oral lorlatinib 100 mg once daily (n = 149) or crizotinib 250 mg twice daily (n = 147). Patients who received brain RT while on study treatment or after the initiation of subsequent systemic anticancer therapy were included in this post hoc analysis. Results: As of September 20, 2021, at approximately 3 years of follow-up, median time to IC progression was not reached (NR; 95% CI, NR-NR) in the lorlatinib arm and was 16.6 (95% CI, 11.1-NR) months in the crizotinib arm. At the time of this analysis, 4 of 149 patients (2.7%) in the lorlatinib arm and 20 of 147 patients (13.6%) in the crizotinib arm received brain RT; study treatment was ongoing in 2 of 4 patients (50.0%) in the lorlatinib arm and discontinued in all 20 patients in the crizotinib arm. Median time from randomization to first brain RT was 18.2 (range, 6.4-31.3) months in the lorlatinib arm and 11.1 (range, 2.5-37.5) months in the crizotinib arm. In patients who had brain RT, median duration of treatment was 20.0 (IQR, 6.3-37.1) months with lorlatinib and 7.8 (IQR, 4.0-11.1) months with crizotinib. In the lorlatinib arm, 2 of 4 patients (50.0%) received concomitant brain RT and continued lorlatinib beyond progression. In the crizotinib arm, patients received brain RT while on study treatment or on subsequent systemic anticancer therapies with ALK TKIs or chemotherapy. Follow-up analysis is ongoing. Conclusions: At approximately 3 years of follow-up in the CROWN study, fewer patients in the lorlatinib arm received brain RT than those in the crizotinib arm. At the time of this analysis, study treatment was ongoing in 2 of 4 patients (50.0%) in the lorlatinib arm but was discontinued in all patients in the crizotinib arm. Patients were mostly managed with other ALK TKIs and/or chemotherapy following brain RT in the crizotinib arm. ClinicalTrials.gov: NCT03052608. Clinical trial information: NCT03052608 .