Final OS analysis from the phase III j-alex study of alectinib (ALC) versus crizotinib (CRZ) in Japanese ALK-inhibitor naïve ALK-positive non-small cell lung cancer (ALK+ NSCLC).

Abstract

9022 Background: The primary analysis of the J-ALEX (JapicCTI-132316) study for the ALK-inhibitor naïve ALK+ NSCLC demonstrated superior progression-free survival (PFS) in Japanese patients randomized to the ALC, compared with those assigned in the CRZ (HR 0.34, 99.7% CI 0.17–0.71, stratified log-rank p<0·0001) by the Independent Review Facility (IRF) (Hida et al., Lancet 2017). The final PFS and 2nd overall survival (OS) interim analysis (IA) data were subsequently reported (Nakagawa et al., Lung cancer 2020). Here, we report the final OS data. Methods: ALK+ NSCLC (by IHC and FISH or RT-PCR) patients were randomized 1:1 either to receive ALC (Japanese approved dose 300 mg BID, n = 103) or CRZ (250 mg BID, n = 104). Stratification factors included ECOG PS, treatment line, and clinical stage. The primary endpoint was PFS according to the blinded IRF. Secondary endpoints included OS, objective response rate, and safety. Results: After a median follow-up of 68.6 months in the ALC arm and 68.0 months in the CRZ arm, death events occurred in 40.8% and 39.4% in the ALC and the CRZ arms, respectively. Five-year survival rates for patients in the ALC and CRZ arm were 60.85% and 64.11%, respectively. The final OS HR was 1.03 (95%CI 0.67-1.58), however, median OS was not reached in either arm. Of note, patients in the CRZ arm tended to have their treatment switched earlier than those in the ALC arm (median time to treatment-switch: 12.3 months vs. NE). Most of the patients (78.8%) in the CRZ arm received ALC as a 1st subsequent therapy, whereas only 10.7% of patients in the ALC arm received CRZ. Conclusions: In this final J-ALEX OS analysis, prolongation of OS in the ALC arm was not observed compared to the CRZ arm. However, OS result may be substantially confounded since 78.8% of the patients in the CRZ arm received ALC as initial, subsequent therapy. Clinical trial information: 132316.