Data from Co-Clinical Trials Demonstrate Superiority of Crizotinib to Chemotherapy in <i>ALK</i>-Rearranged Non–Small Cell Lung Cancer and Predict Strategies to Overcome Resistance

Purpose: To extend the results of a phase III trial in patients with non–small cell lung cancer with adenocarcinomas harboring EML4-ALK fusion.

Experimental Design: We conducted a co-clinical trial in a mouse model comparing the ALK inhibitor crizotinib to the standard-of-care cytotoxic agents docetaxel or pemetrexed.

Results: Concordant with the clinical outcome in humans, crizotinib produced a substantially higher response rate compared with chemotherapy, associated with significantly longer progression-free survival. Overall survival was also prolonged in crizotinib- compared with chemotherapy-treated mice. Pemetrexed produced superior overall survival compared with docetaxel, suggesting that this agent may be the preferred chemotherapy in the ALK population. In addition, in the EML4-ALK–driven mouse lung adenocarcinoma model, HSP90 inhibition can overcome both primary and acquired crizotinib resistance. Furthermore, HSP90 inhibition, as well as the second-generation ALK inhibitor TAE684, demonstrated activity in newly developed lung adenocarcinoma models driven by crizotinib-insensitive EML4-ALK L1196M or F1174L.

Conclusions: Our findings suggest that crizotinib is superior to standard chemotherapy in ALK inhibitor–naïve disease and support further clinical investigation of HSP90 inhibitors and second-generation ALK inhibitors in tumors with primary or acquired crizotinib resistance. Clin Cancer Res; 20(5); 1204–11. ©2013 AACR.