ALK G1269A

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. 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.

Our findings suggest that real-time quantitative monitoring of ALK resistance mutations during the response period could provide a time course of changes while acquiring resistance mutations. This information would be beneficial for designing an appropriate treatment strategy.

The model is a non-small cell lung cancer harboring EML4-ALK fusion and ALK C1156Y/G1269A mutation, sensitive to the 3rd generation ALK TKI lorlatinib... We demonstrated potential targetable features of DTP cells. A combination of targeted therapies with DTP drug candidates could represent a therapeutic opportunity to improve the depth of response and delay the emergence of resistance in patients.

This study demonstrated that the combination of p53 protein agonist and lorlatinib may provide a new therapeutic strategy for NSCLC patients with lorlatinib resistance and TP53 mutation. Furthermore, the results also provide guidance for selecting optimal chemo-regimens for NSCLC patients after ALK-TKIs failure.

This study is the first analysis of CNS specific outcomes with detailed genomic annotation for ALK+ NSCLC patients who received definitive alectinib for BM. Further investigation into the role of CNS-penetrant TKIs and the genomic alterations predictive of CNS failure are needed.

This study is the first analysis of CNS specific outcomes with detailed genomic annotation for ALK+ NSCLC patients who received definitive alectinib for BM. Further investigation into the role of CNS-penetrant TKIs and the genomic alterations predictive of CNS failure are needed.

Of these, 52 received first-line alectinib treatment (1L) and 56 received alectinib after crizotinib resistance (2L). Also, NF2-mutant patients only had a median PFS of 4 months, significantly poorer than those without (HR 11.1, 95CI 2.17-50; p<0.001). Conclusions By analyzing different mutational profiles of ALK-rearranged patients after alectinib treatment, we proposed MET and NF2 as putative mechanisms that conferred resistance to early resistance of first-line alectinib, which shone light on future tailored treatment for ALK-positive NSCLCs.

Crizotinib, ceritinib, alectinib, brigatinib, and lorlatinib are approved tyrosine kinase inhibitors (TKIs) for ALK-positive NSCLC, but durability of response is partly limited by ALK resistance mutations...Ascites mononuclear cells were isolated by Ficoll centrifugation and cultured in media (DMEM F12 Glutamax, 10% antibiotics/antimycotics, 10% FBS, hydrocortisone, adenine, RockInhibitor, and 1/10 cholera toxin)... NVL-655 has demonstrated activity in many preclinical models bearing ALK compound mutations, including the MR448re (EML4-ALK v3 G1202R/T1151M) model. The potent preclinical activity of NVL-655 suggests potential clinical utility for ALK-positive patients, including those with resistant compound mutations. The MR448re PDC and xenograft are valuable additions to the ALK therapeutic research landscape where there is limited availability of patient-derived models with lorlatinib-resistant ALK compound mutations.

In 20 eligible patients (median [m]age 63 years [range, 40-89], females 75%, adenocarcinoma 100%, failure of alectinib 90%, FoundationOne Liquid CDx 80%), CGP has altered NLST recommendation in 30% of cases (Figure 2)... CGP has a significant impact on the decision-making process in ALK-rearranged aNSCLC following progression on 2nd/3rd-generation ALK TKIs.

In 20 eligible patients (median [m]age 63 years [range, 40-89], females 75%, adenocarcinoma 100%, failure of alectinib 90%, FoundationOne Liquid CDx 80%), CGP has altered NLST recommendation in 30% of cases...mOS was 13.2 months (95% CI, 2.9-NR) and 13.0 months (95% CI, 6.0-NR) in groups 1 and 2, respectively (p-0.86). CGP has a significant impact on the decision-making process in ALK-rearranged aNSCLC following progression on 2/3-generation ALK TKIs.

Another pt with the G1202R mutation following alectinib treatment had tumor shrinkage of 27.9%. APG-2449 has a favorable safety and PK profile and was well tolerated in 84 subjects. Preliminary efficacy was observed in pts whose disease was resistant to second-generation TKIs, especially among those with brain metastases, and in TKI-naïve pts. Biomarker data indicated potential target engagement on FAK and immunomodulatory effects of APG-2449.

cfDNA-NGS facilitates detection of ALK fusions and resistance mutations, assessment of prognosis, and monitoring dynamic changes of genomic alterations in ALK+ NSCLC treated with ALK-TKI.

ALK rearrangements are detected in approximately 4% of patients with advanced non-small cell lung cancer (NSCLC), and the tyrosine kinase inhibitors (TKIs) crizotinib, alectinib, brigatinib, ceritinib, and lorlatinib have been approved by the FDA for the treatment of ALK-positive NSCLC. The dPCR method was highly sensitive in detecting gene mutations with low allele frequency. It was also found to be able to monitor variable resistance mutations over time during ALK-TKI treatment. In addition, we found that the appearance of G1202R did not always indicate clinical acquisition of resistance that required drug modification.

Here, we report, for the first time, a novel, sequentially-evolved EML4-ALK variant 3 G1202R/S1206Y double mutation in cis detected in a patient with ALK-positive NSCLC after disease progression on sequential crizotinib, alectinib, and then lorlatinib. Three-dimensional computer modeling of this double mutation and other G1202R-based double mutations with lorlatinib (ALK G1202R/L1196M, ALK G1202R/F1174C, ALK G1202R/l1198F, ALK G1202R/G1269A) were provided to reveal how these double mutations may confer resistance to lorlatinib through diverse steric hindrances in the ALK kinase domain. In addition, we performed a comprehensive literature review on published acquired double or triple ALK mutations that are resistant to lorlatinib from both patient samples and in vitro mutagenesis experiments.

The mechanisms of ALK TKI resistance were heterogeneous; ALK mutations were found in less than one-third of patients. Compound ALK mutations, which may confer lorlatinib resistance, may occur in crizotinib, ceritinib, and alectinib-resistant lung cancers.

In samples from EGFRm ex19/21 pts treated with 1st/2nd generation (gen.) TKI (n=51), the T790M mutation was detected in 27%; in those from pts treated with osimertinib (n=15), the C797S rate was 13%. In ALKr pts treated with crizotinib (n=17), ≥1 ALK resistance mutations were found in 12% (1 G1269A+F1174L, 1 G1202R), after 2nd gen. (n=16) in 31% (3 G1202R, 1 D1203N+F1174C, 1 T1151R) and after lorlatinib (n=16) in 13% (2 G1202R)... ctDNA is feasible in pts with NSCLC harbouring EGFRm, ALKr, BRAFV600Em for detecting driver and resistance GAs at PD, providing clinical informative for treatment selection at TKI failure in 22% of cases. Outcomes of the following therapies based on ctDNA will be presented at the congress.

Finally, a c-MYC gain, along with a loss of CCND1 and FGFR3, were detected in a patient progressing on a first-line treatment with crizotinib. We conclude that NGS analysis of liquid biopsies upon disease progression identified different putative ALK-I-resistance mutations in most cases, and could be a valuable approach for therapy decision making.

Our study highlighted the advantage of ctDNA analysis for monitoring tumor evolution. TP53 mutations promoted genetic evolution and accelerated occurrence of resistance. We also unveiled ALK-dependent resistance mechanisms, mainly by G1269A, G1202R and E1210K mutations, and ALK-independent resistance mechanisms to ensartinib.

Liquid biopsy was collected immediately before starting brigatinib or lorlatinib. Poor outcomes were observed for brigatinib in 3 heavily-pretreated patients with ctDNA ALKm. The recent use of 2nd-gen TKI upfront calls for similar studies to confirm if ctDNA may be a biomarker for guiding the sequential therapy.

The combination of a genetic analysis and computational simulation model may make a prediction of resistance mechanisms for overcoming ALK-TKI resistance, and the construction of a genomic and simulation fused database is important for the development of personalized medicine in this field.

This study shows that mechanisms of resistance to lorlatinib are diverse and complex, requiring new therapeutic strategies to tailor treatment upon disease progression.

Consistent with previous reports, ensartinib showed high clinical efficacy. Longitudinal ctDNA analysis could be a powerful tool in predicting treatment outcomes and revealing resistant mechanisms of ensartinib. We observed G1269A, G1202R and E1210K as the major resistant mutations to ensartinib.

" From April 2015 to July 2019, 92 patients enrolled; 81 (88.0%) received ALK TKI as first-line (crizotinib, n = 59; alectinib, n = 22), 10 (10.9%) received TKI as second-line (alectinib, n = 6; crizotinib, n = 2; ceritinib, n = 1; brigatinib, n = 1), and 1 (1.1%) was treated in third-line (lorlatinib). NGS of cell-free plasma DNA is useful not only for the detection of ALK fusions and resistance mutations but also for assessing prognosis and monitoring the dynamic changes of genomic alterations in ALK+ NSCLC treated with ALK TKI. Research Funding: Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Korean government (MSIT) (No.NRF-2017M3A9G5060259)Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Kor"

After alectinib failure, G1202R and I1171N mutations were detected in 7 of 15 specimens. G1202R, F1174V and G1202R, and P-gp overexpression were observed in 3 of 7 samples after ceritinib treatment. L1196M + G1202R, a compound mutation, was detected in 1 specimen after lorlatinib treatment...In conclusion, resistance to ALK-TKIs based on secondary mutation in this study was similar to that in previous reports, except for crizotinib resistance. The appropriate treatment matching resistance mechanisms contributes to the efficacy of multiple ALK-TKI treatment strategies.

And mutations (L1196M, G1269A, F1174L, and R1275Q) induce diverse conformational changes of brigatinib and the obvious energy variation of residues Glu1167, Arg1209, Asp1270, and Asp1203. Together, the detailed explanation of mechanisms of those mutations with brigatinib further provide several guidelines for the development of more effective ALK inhibitors.