Differential protein stability and clinical responses of EML4-ALK fusion variants to various ALK inhibitors in advanced ALK-rearranged non-small cell lung cancer.

Anaplastic lymphoma kinase (ALK) inhibition using crizotinib has become the standard of care in advanced ALK-rearranged non-small cell lung cancer (NSCLC), but the treatment outcomes and duration of response vary widely. Echinoderm microtubule-associated protein-like 4 (EML4)-ALK is the most common translocation, and the fusion variants show different sensitivity to crizotinib in vitro. However, there are only limited data on the specific EML4-ALK variants and clinical responses of patients to various ALK inhibitors. By multiplex reverse-transcriptase PCR, which detects 12 variants of known EML4-ALK rearrangements, we retrospectively determined ALK fusion variants in 54 advanced ALK rearrangement-positive NSCLCs. We subdivided the patients into two groups (variants 1/2/others and variants 3a/b) by protein stability and evaluated correlations of the variant status with clinical responses to crizotinib, alectinib, or ceritinib. Moreover, we established the EML4-ALK variant-expressing system and analyzed patterns of sensitivity of the variants to ALK inhibitors. Of the 54 tumors analyzed, EML4-ALK variants 3a/b (44.4%) was the most common type, followed by variants 1 (33.3%) and 2 (11.1%). The 2-year progression-free survival (PFS) rate was 76.0% [95% confidence interval (CI) 56.8-100] in group EML4-ALK variants 1/2/others versus 26.4% (95% CI 10.5-66.6) in group variants 3a/b (P = 0.034) among crizotinib-treated patients. Meanwhile, the 2-year PFS rate was 69.0% (95% CI 49.9-95.4) in group variants 1/2/others versus 32.7% (95% CI 15.6-68.4) in group variants 3a/b (P = 0.108) among all crizotinib-, alectinib-, and ceritinib-treated patients. Variant 3a- or 5a-harboring cells were resistant to ALK inhibitors with >10-fold higher half maximal inhibitory concentration in vitro. Our findings show that group EML4-ALK variants 3a/b may be a major source of ALK inhibitor resistance in the clinic. The variant-specific genotype of the EML4-ALK fusion allows for more precise stratification of patients with advanced NSCLC.

Woo CG ，Seo S ，Kim SW ，Jang SJ ，Park KS ，Song JY ，Lee B ，Richards MW ，Bayliss R ，Lee DH ，Choi J ... -  《-》

Clinical outcomes in ALK-rearranged lung adenocarcinomas according to ALK fusion variants.

Cha YJ ，Kim HR ，Shim HS 《Journal of Translational Medicine》

Updated Efficacy and Safety Data and Impact of the EML4-ALK Fusion Variant on the Efficacy of Alectinib in Untreated ALK-Positive Advanced Non-Small Cell Lung Cancer in the Global Phase III ALEX Study.

At the prior data cutoff (February 9, 2017) the ALEX trial showed superior investigator-assessed progression-free survival (PFS) for alectinib versus crizotinib in untreated, anaplastic lymphoma kinase (ALK)-positive, advanced NSCLC (hazard ratio = 0.47, 95% confidence interval: 0.34-0.65, p < 0.001). The median PFS in the alectinib arm was not reached versus 11.1 months with crizotinib. Retrospective analyses suggest that the echinoderm microtubule-associated protein-like 4 gene-ALK variant (EML4-ALK) may influence ALK-inhibitor treatment benefit. We present updated analyses, including exploratory subgroup analysis by EML4-ALK variant, after an additional 10 months' follow-up (cutoff December 1, 2017). Patients were randomized to receive twice-daily alectinib, 600 mg, or crizotinib, 250 mg, until disease progression, toxicity, death, or withdrawal. PFS was determined by the investigators. Baseline plasma and tissue biomarker samples were analyzed by using hybrid-capture, next-generation sequencing to determine EML4-ALK variant. Baseline characteristics were balanced. Investigator-assessed PFS was prolonged with alectinib (stratified hazard ratio = 0.43, 95% confidence interval: 0.32-0.58). The median PFS times were 34.8 months with alectinib and 10.9 months with crizotinib. EML4-ALK fusions were detectable in 129 patient plasma samples and 124 tissue samples; variants 1, 2, and 3/ab did not affect PFS, objective response rate, or duration of response. Investigator-assessed PFS was longer for alectinib than for crizotinib across EML4-ALK variants 1, 2, and 3a/b in plasma and tissue. Despite longer treatment duration (27.0 months in the case of alectinib versus 10.8 months in the case of crizotinib), the safety of alectinib compared favorably with that of crizotinib. Alectinib continues to demonstrate superior investigator-assessed PFS versus crizotinib in untreated ALK-positive NSCLC, irrespective of EML4-ALK variant.

Camidge DR ，Dziadziuszko R ，Peters S ，Mok T ，Noe J ，Nowicka M ，Gadgeel SM ，Cheema P ，Pavlakis N ，de Marinis F ，Cho BC ，Zhang L ，Moro-Sibilot D ，Liu T ，Bordogna W ，Balas B ，Müller B ，Shaw AT ... -  《-》

Inflammation-related molecular signatures involved in the anticancer activities of brigatinib as well as the prognosis of EML4-ALK lung adenocarcinoma patient.

Although ALK tyrosine kinase inhibitors (ALK-TKIs) have shown remarkable benefits in EML4-ALK positive NSCLC patients compared to conventional chemotherapy, the optimal sequence of ALK-TKIs treatment remains unclear due to the emergence of primary and acquired resistance and the lack of potential prognostic biomarkers. In this study, we systematically explored the validity of sequential ALK inhibitors (alectinib, lorlatinib, crizotinib, ceritinib and brigatinib) for a heavy-treated patient with EML4-ALK fusion via developing an in vitro and in vivo drug testing system based on patient-derived models. Based on the patient-derived models and clinical responses of the patient, we found that crizotinib might inhibit proliferation of EML4-ALK positive tumors resistant to alectinib and lorlatinib. In addition, NSCLC patients harboring the G1269A mutation, which was identified in alectinib, lorlatinib and crizotinib-resistant NSCLC, showed responsiveness to brigatinib and ceritinib. Transcriptomic analysis revealed that brigatinib suppressed the activation of multiple inflammatory signaling pathways, potentially contributing to its anti-tumor activity. Moreover, we constructed a prognostic model based on the expression of IL6, CXCL1, and CXCL5, providing novel perspectives for predicting prognosis in EML4-ALK positive NSCLC patients. In summary, our results delineate clinical responses of sequential ALK-TKIs treatments and provide insights into the mechanisms underlying the superior effects of brigatinib in patients harboring ALKG1269A mutation and resistant towards alectinib, lorlatinib and crizotinib. The molecular signatures model based on the combination of IL6, CXCL1 and CXCL5 has the potential to predict prognosis of EML4-ALK positive NSCLC patients.

Ge FJ ，Dai XY ，Qiu Y ，Liu XN ，Zeng CM ，Xu XY ，Chen YD ，Zhu H ，He QJ ，Gai RH ，Ma SL ，Chen XQ ，Yang B ... -  《-》

Protocol Design for the Bench to Bed Trial in Alectinib-Refractory Non-Small-Cell Lung Cancer Patients Harboring the EML4-ALK Fusion Gene (ALRIGHT/OLCSG1405).

Based on our preclinical study results, which showed that the activation of the hepatocyte growth factor/MET pathway is a potential mechanism of acquired resistance to alectinib, we launched the ALRIGHT (OLCSG1405 [alectinib-refractory non-small-cell lung cancer patients harboring the EML4-ALK fusion gene]), a phase II trial of the anaplastic lymphoma kinase (ALK)/MET inhibitor crizotinib in patients with non-small-cell lung cancer refractory to alectinib and harboring the echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion gene. Patients with ALK-rearranged tumors who have developed disease progression during alectinib treatment will receive crizotinib monotherapy until disease progression or the occurrence of unacceptable toxicity. The primary endpoint is set as the objective response rate, assuming that a response in 50% of eligible patients will indicate potential usefulness and that 15% would be the lower limit of interest (1-sided α of 0.05, β of 0.20). The estimated accrual number of patients is 9. The secondary endpoints include progression-free survival, overall survival, adverse events, and patient-reported outcomes. We will also take tissue samples before crizotinib monotherapy to conduct an exploratory analysis of ALK and hepatocyte growth factor/MET expression levels and gene alterations (eg, mutations, amplifications, and translocations). We will obtain information regarding whether crizotinib, which targets not only ALK, but also MET, can truly produce efficacy with acceptable safety profiles in ALK+ non-small-cell lung cancer even in the alectinib-refractory setting.

Isozaki H ，Hotta K ，Ichihara E ，Takigawa N ，Ohashi K ，Kubo T ，Ninomiya T ，Ninomiya K ，Oda N ，Yoshioka H ，Ichikawa H ，Inoue M ，Takata I ，Shibayama T ，Kuyama S ，Sugimoto K ，Harada D ，Harita S ，Sendo T ，Tanimoto M ，Kiura K ... -  《-》