The impact of sequential therapy of crizotinib followed by alectinib: Real-world data analysis of 840 ALK-inhibitor naïve patients with NSCLC harboring ALK-rearrangement (WJOG9516L).

Abstract

9038 Background: Previous clinical trials demonstrated that alectinib (ALEC) had a longer time-to-progression than crizotinib (CRZ) in 1st-line settings. Information on long-term overall survival (OS), however, is still limited with a few studies having reported that the sequential strategy of “CRZ followed by other ALK-inhibitor” can provide extended OS. In Japan, ALEC was approved for a 1st-line setting earlier than in other countries. Methods: We reviewed the clinical data of ALK-rearranged NSCLC patients who received CRZ or ALEC between May 2012 and Dec 2016. Patients were divided into two groups according to the first-administered ALK inhibitor, the CRZ or ALEC group. In order to evaluate the efficacy of the sequential strategy of “CRZ followed by ALEC”, the combined time to treatment failure (TTF) was calculated in the CRZ group as defined by the sum of the “TTF of CRZ” plus the “TTF of ALEC” if patients were treated with ALEC followed by CRZ. In the ALEC group, the “TTF of ALEC” was calculated. The primary endpoint is the comparison between the combined TTF in the CRZ group with the TTF in the ALEC group. Results: Of 864 patients enrolled from 61 institutions, 840 patients were analyzed. Median age was 61 (range, 20-94); 56% were female; and 95% had adenocarcinoma. There were 535/305 patients in the CRZ/ALEC group. In the CRZ group, 282 patients received ALEC after CRZ failure. The combined TTF in the CRZ group was significantly longer than TTF in the ALEC group; median, 34.4 vs 27.2 months (mo); hazard ratio (HR), 0.709 [95%CI;0.559- 0.899]; P= 0.0044. However, there was no significant difference in OS between the patients who received ALEC after CRZ in the CRZ group and the patients in the ALEC group; median, 88.4 months vs. not reached; HR 1.048 [95%CI;0.758-1.451]; P= 0.7770. In the whole population, the CRZ group had a significantly shorter OS than the ALEC group; median, 53.6 mo vs not reached HR, 1.821 [95%CI;1.372-2.415]; P< 0.0001. Conclusions: The combined TTF in the CRZ group was significantly longer than TTF in the ALEC group, however, OS benefit of sequential therapy of CRZ followed by ALEC was not shown. Clinical trial information: UMIN000028605.