Activity of Lorlatinib Based on ALK Resistance Mutations Detected on Blood in ALK Positive NSCLC Patients

3055 Background: Acquired ALK resistance mutations (mut.) are the main mechanism of tyrosine kinase inhibitor (TKI) resistance (30-50%). While next-generation TKIs are more active on mut. than earlier TKIs, compound ALK resistance are associated with failure to next-generation TKIs. We evaluated the clinical utility of detecting ALK resistance mutations in blood to predict TKI efficacy. Methods: ALK positive advanced NSCLC pts were prospectively enrolled between Oct. 2015 and Aug. 2018 in 8 French institutions. Prospective samples were collected; ctDNA was analyzed by amplicon-based Inivata InVisionFirst-Lung. Results: A total of 101 pts with advanced ALK positive NSCLC were enrolled and 328 samples collected. In samples collected at TKI failure (N=74), we detected 9 single and 7 complex (≥2) ALK resistance mut. (22%), associated with EML4-ALK variant 3 (38%) vs. variant 2 (13%) vs. variant 1 (none); 30% had other somatic mut. (mainly TP53 and KRAS, PI3KCA, MET, etc.). No mutations were detected in 48% of samples (ctDNA neg). ALK mut. were more frequent after 2nd/3rd generation TKI (43% post-lorlatinib (7), 29% post-2nd gen. (31), 11% post-crizotinib (36)). ALKG1202R was the most common, as single (n=3) or complex mut. (n=4). The median overall survival (mOS) was 100.4 mo. (95% CI 41.9-158.9) and the median progression free-survival (mPFS) to subsequent line was 2.8 mo. (0.7-4.9). Patients with ctDNA neg had mOS of 105 mo. (39.3-172.1) vs. 58.5 mo. (33.1-84.0) if ≥1 ALK mut. vs. 44.1 mo. (20.0-68.2) if others ( P=0.001). Pts with the complex ALK mut. had worse OS compared to singles ALK mut. (mOS 26.9 mo. vs. 58.5 mo., P=0.001); ALK complex mut. were associated with poor efficacy to subsequent therapy (PFS <3 mo. in 57%; no cases with PFS >6 mo.) vs. single mut., with longer PFS (PFS >6 mo. in 56%). Detectable ALKG1202R mut. were associated with shorter median OS (58.3 mo.; 7.9-109.1) vs. overall population; 86% of cases developed rapid PD (PFS <3mo.) to subsequent therapy with only one durable response to lorlatinib (PFS >6mo.). Conclusions: The absence of ctDNA mutations at TKI failure was associated with prolonged OS, whereas complex ALK mutations at TKI failure may predict resistance to subsequent therapy. Larger and specifically designed studies should be performed to validate these findings.

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Identification of Mechanisms of Resistance to ALK Inhibitors. Next-generation sequencing-based liquid biopsy profiling: A step towards personalized treatment.

10.21203/rs.3.rs-86055/v1 ◽

2020 ◽

Author(s):

Estela Sánchez-Herrero ◽

Roberto Serna-Blasco ◽

Vadym Ivanchuk ◽

Rosario García-Campelo ◽

Manuel Dómine ◽

...

Keyword(s):

Next Generation Sequencing ◽

Disease Progression ◽

Line Treatment ◽

Next Generation ◽

Resistance Mutations ◽

Primary Resistance ◽

Alk Inhibitors ◽

Alk Positive ◽

Nsclc Patients ◽

Generation Sequencing

Abstract Background: Despite impressive and durable responses, patients treated with ALK inhibitors (ALK-Is) ultimately progress. We investigated potential resistance mechanisms in a series of ALK-positive non-small cell lung cancer (NSCLC) patients progressing on different types of ALK-Is.Methods: 26 plasma and 2 cerebrospinal fluid samples collected upon disease progression to an ALK-I, from 24 advanced ALK-positive NSCLC patients, were analyzed by next-generation sequencing (NGS). A tool to retrieve variants at the ALK locus was developed. Results: 61 somatic mutations were detected in 14 genes: TP53, ALK, PIK3CA, SMAD4, MAP2K1 (MEK1) FGFR2, FGFR3, BRAF, EGFR, IDH2, MYC, MET, CCND3 and CCND1. Overall, We identified at least one mutation in ALK locus in 10 (38.5%) plasma samples, being the G1269A and G1202R mutations the most prevalent among patients progressing to first- and second-generation ALK-I treatment, respectively. An exon 19 deletion in EGFR was identified in a patient showing primary resistance to ALK-I. Likewise, the G466V mutation in BRAF and the F129L mutation in MAP2K1 (MEK1) were identified as the underlying mechanism of resistance in three patients who gained no or little benefit from second-line treatment with an ALK-I. Putative ALK-I resistance mutations were also found in PIK3CA and IDH2. Finally, a c-MYC gain, along with a loss of CCND1 and a FGFR3, were detected in a patient progressing on a first-line treatment with crizotinib. Conclusions: NGS analysis of liquid biopsies upon disease progression identified putative ALK-I resistance mutations in most cases, being a valuable approach to devise therapeutic strategies upon ALK-I failure.

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