Background: Lorlatinib, a brain-penetrant, third generation ALK tyrosine kinase inhibitor (TKI), demonstrated statistically significant and clinically meaningful improvement in progression-free survival (PFS) vs crizotinib in a phase 3 study in pts with previously untreated ALK+ advanced NSCLC (CROWN; NCT03052608). This study investigated the efficacy of treatments following progression on lorlatinib or crizotinib from the CROWN trial. Methods: Pts were randomized 1:1 to receive oral lorlatinib 100 mg daily or crizotinib 250 mg twice daily. The primary endpoint was PFS assessed per blinded independent central review, and secondary endpoints included time from randomization to the date of progression of disease on first subsequent systemic anticancer therapy or death (PFS2). Results: As of September 20, 2021, 91 of 149 patients (61.1%) vs 12 of 147 patients (8.2%) were still receiving lorlatinib vs crizotinib, respectively. In the lorlatinib arm, 33 of 149 patients (22.1%) received ≥1 subsequent systemic anticancer therapy vs 103 of 147 patients (70.1%) in the crizotinib arm. Among the patients who received subsequent systemic anticancer therapy, most patients in both treatment arms received ALK TKIs as first subsequent treatment: 63.6% and 93.2% in the lorlatinib and crizotinib arms. Chemotherapy was administered as first subsequent therapy to 36.3% and 2.9% of the patients, respectively. Median duration of treatment on first subsequent anticancer therapy was 9.6 months (IQR, 2.9-18.1 months) for lorlatinib arm and 13.3 months (IQR, 4.8-21.2 months) for crizotinib arm. Median PFS2 was not reached (NR; 95% CI, NR-NR) in the lorlatinib arm and was 39.6 months (95% CI, 27.4-NR) in the crizotinib arm, with a hazard ratio for lorlatinib vs crizotinib of 0.45 (95% CI, 0.30-0.67). Conclusions: While subsequent anticancer therapies offered clinical benefit in both treatment arms, PFS2 results indicated that clinical benefit was prolonged with lorlatinib vs crizotinib. Clinical trial information: NCT03052608.