The overall survival benefit in Chinese ALK⁺ NSCLC patients received targeted therapies

Anaplastic lymphoma kinase (ALK) gene rearrangement is a series of mutations of non-small cell lung cancer (NSCLC) patients. Since 2011, multiple ALK inhibitors (ALKis) have been developed and launched for targeted therapy. In this study, we sought to investigate different strategies of sequential applying the ALKis and their clinical benefits to the overall survival (OS).

A total of 176 patients with advanced NSCLC (stage IIIB-IV) harboring the ALK rearrangement were included in this cohort study. They were diagnosed between February 1, 2012 and November 19, 2019 at Peking University Cancer Hospital. Clinical characters were reviewed from patients' records. Strategies of drugs, progression-free survival (PFS) and OS were collected during the follow-ups. The Kaplan-Meier method and multivariate Cox proportional-hazard analysis were used to conduct the analyses survival and to examine the relationship between the variables and OS.

A significantly longer OS was observed either in patients treated with crizotinib [N=106, median OS (mOS): 32.9 months] or in patients treated with a next-generation ALKi [N=34, mOS: not reached (NR)] as the initial ALKi, compared with patients treated with conventional chemotherapy but no ALKi (N=36, mOS: 10.3 months, P<0.001). After disease progression with initial crizotinib, patients who received no ALKi had shorter OS than those who received only crizotinib beyond progressive disease (CBPD) (mOS: 9.7 vs. 20.3 months; P=0.015), only subsequent next-generation ALKis (mOS: 9.7 vs. 41.1 months; P<0.001), and CBPD followed with subsequent next-generation ALKis (mOS: 9.7 months vs. NR; P<0.001). Patients treated with 2 types of ALKi had better survival than those treated with 1 ALKi (mOS: 45.8 vs. 21.3 months, P=0.003), but no such survival benefit was observed in patients treated with ≥3 ALKis (P=0.366).

ALKis have been shown to be clinically effective in treating NSCLC patients with ALK rearrangements. In the case of disease progression with crizotinib, either of CBPD or sequential other ALKis can extend patients' OS. The sequential application of multiple ALKis was found to be better than it of single ALKi in prolonging OS. However, the question of which inhibitor to select as the initial inhibitor needs to be examined further in future studies.