Background: Approximately 3–5% of NSCLC harbors ALK gene rearrangements. Crizotinib is a first-in-class, oral, small-molecule competitive ALK inhibitor with anti-MET activity. Methods: PROFILE 1005 is an ongoing global, multicenter, open-label, single-arm, phase II study evaluating the safety and efficacy of crizotinib (250 mg BID in 3-week cycles) in patients with advanced ALK-positive NSCLC who progressed after ≥1 chemotherapy for recurrent/advanced/metastatic disease. Tumor response was evaluated by RECIST 1.1 every 6 weeks. Patient-reported symptoms and global quality of life (QOL) were assessed using the EORTC QLQ-C30 and LC-13 at baseline, day 1 each cycle and at end of treatment. Results: As of June 2011, 439 patients were evaluable for safety and 255 patients for tumor response. Median age was 53 years. The majority of patients were female (53%), never smokers (65%), and had adenocarcinoma (92%), ECOG PS 0–1 (83%) and ≥2 prior chemotherapy regimens (85%). Among patients evaluable for efficacy, median treatment duration was 25 weeks (77% of patients still ongoing). ORR was 53% (95% CI: 47–60), disease control rate at 12 weeks was 85% (95% CI: 80–89), median duration of response was 43 weeks (96% CI 36–50) and median PFS was 8.5 months (95% CI: 6.2–9.9). The most frequent treatment-related AEs were visual effects (50%), nausea (46%), vomiting (39%), and diarrhea (35%), mostly grade 1–2. 29 patients (6.6%) had treatment-related SAEs, including dyspnea and pneumonitis (4 patients each; 0.9%), and febrile neutropenia and renal cyst (2 patients each; 0.5%). A statistically significant (p<0.05) and clinically meaningful (≥ 10 points) improvement from baseline was observed for patient-reported overall pain, pain in chest, cough, dyspnea, insomnia, fatigue and global QOL. Conclusions: Crizotinib demonstrated a high response rate and PFS, favorable tolerability profile and improvement in patient-reported symptoms. These results provide strong evidence for crizotinib as a standard of care for advanced ALK-positive NSCLC.