Is there a progression‐free survival benefit of first‐line crizotinib versus standard chemotherapy and second‐line crizotinib in ALK‐positive advanced lung adenocarcinoma? A retrospective study of Chinese patients

Although crizotinib has demonstrated promising efficacy and acceptable toxicity in patients with advanced non‐small cell lung cancer (NSCLC), the available evidence in Chinese populations is currently limited. This study compared the progression‐free survival (PFS) of Chinese patients with anaplastic lymphoma kinase (ALK)‐positive, advanced lung adenocarcinoma who received first‐line crizotinib therapy with that of patients who received first‐line standard chemotherapy, and also the PFS benefit of first‐line versus second‐line crizotinib treatment. Data on 80 patients with ALK‐positive, advanced lung adenocarcinoma who received crizotinib or standard chemotherapy as first‐line treatments between June 2013 and December 2014 were retrospectively collected; 26 of the patients received crizotinib as second‐line therapy after progressive disease (PD) occurred on first‐line chemotherapy. Tumor responses were assessed using Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1. The median PFS was 13.3 months (95% CI: 6.5–20.0 months) in patients who received first‐line crizotinib as compared with 5.4 months (95% CI: 4.4–6.5 months) in patients who received first‐line standard chemotherapy (adjusted hazard ratio for progression or death with crizotinib, 0.20; 95% CI: 0.11–0.36; P < 0.001). In patients who received second‐line crizotinib therapy, the median PFS was 9.9 months (95% CI: 6.4–13.4 months). The difference between first‐line and second‐line crizotinib treatment was not statistically significant (adjusted hazard ratio for progression, 0.56; 95% CI: 0.29–1.11; P = 0.092). Thus, there was a significant PFS benefit of first‐line crizotinib versus first‐line standard chemotherapy in Chinese patients with ALK‐positive lung adenocarcinoma. Additionally, crizotinib showed promising efficacy in patients who received it as second‐line therapy after PD had occurred on first‐line chemotherapy.