ALK I1171

Several anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) have been developed for the treatment of echinoderm microtubule-associated protein-like 4 (EML4)-ALK-rearranged non-small cell lung cancer (NSCLC), with the newer generation agents brigatinib, alectinib and lorlatinib showing prolonged responses. The second ALK resistance mutation detected after a chemotherapy interval, the G1202R, is the most common resistance mutation after second generation ALK TKIs and has been associated with sensitivity to third generation TKIs, such as lorlatinib. This case of a patient with EML4-ALK-rearranged NSCLC shows that sequential treatment with next-generation ALK TKIs, including rechallenge, can induce profound remissions, even in heavily pretreated patients, and that ALK-targeted strategies may be personalized by considering the presence of distinct ALK resistance mutations.

V3 status is also associated with specific patterns of clinically important ALK resistance mutations. These tumor-intrinsic features may inform rational selection and optimization of first-line and consolidative therapy.

Furthermore, the US simulation results elucidate that the pathways through which lorlatinib dissociates vary across mutant systems, and the distinct environments during the dissociation process culminate in diverse resistance mechanisms. Collectively, these insights provide important clues for the design of novel inhibitors to combat resistance.

ALK inhibitors first-line crizotinib, second-line ceritinib, and alectinib are effective against NSCLC patients with these rearrangements. Based on the Y1278-C1097 H-bond and E1167-K1150 salt bridge interaction, I1171N strongly promotes the constitutively active kinase independent of ATP. This structural mechanism study will aid in understanding the oncogenic activity of ALK and the basis for improving the ALK inhibitors.

We found that F1174 and R1275Q-related anaplastic lymphoma kinase mutations are the most common pathogenic mutations in neuroblastoma. Anaplastic lymphoma kinase mutation status did not show any heterogeneity, and the mutations were correlated with intermediate- or high-risk groups.

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.

Its role in populations who have shown resistance to Alectinib and Crizotinib after initial response has not been evidenced by a large randomized controlled trial. Brigatinib therapy resulted in rapid improvement for our patient with previously treated ALK mutation NSCLC and severe acute respiratory therapy due to aggressive lymphangitic spread. The long-term response for this patient remains unknown and the broader applicability of these results will have to await further reporting and randomized trials.

Legal entity responsible for the study Fondazione Policlinico Universitario A Gemelli – IRCCS. In post-lorlatinib NGS-assay, 2 pts had ALK-compound mutations, while 4 pts had newly off-target alterations (CDKN2A/B CDKN2B loss, NF1 deletion, DNMT3A/ARID1A/CHECK2 M+). Conclusions Implementation of longitudinal genomic assessment is required in order to provide an extensive overview of resistance mechanisms and clinical outcomes according to current ALK-inhibitors treatment sequences.

In Cohort 1 (n=21), 15 (71%) pts had progressed on alectinib, 5 (24%) on ceritinib and 1 (5%) on ensartinib. In Cohort 2 (n=18), pts had progressed on crizotinib followed by alectinib (n=9, 50%), ceritinib (n=4, 22%) or brigatinib (n=3, 17%); 2 (11%) pts progressed on crizotinib, then ceritinib followed by alectinib...Of 5 pts with ALK resistance mutations (I1171N, V1180L, L1196M, G1202R, and E1210K) who subsequently received lorlatinib, repeat ctDNA NGS after 2 months demonstrated clearance of ALK resistance mutation(s) in 4/5 (80%) pts (i.e. undetectable on repeat testing)... Resistance mechanisms to ALK inhibitors are heterogenous, including both ALK dependent and independent pathways. DDR and cell cycle gene alterations were commonly detected and may represent previously unreported acquired resistance alterations. Comprehensive ctDNA NGS analysis at progression may help detect novel resistance alterations in patients on ALK inhibitors.

He achieved complete remission after 2 cycles with multi-agent chemotherapy (dexamethasone, ifosfamide, methotrexate, cytarabine, etoposide, cyclophosphamide, doxorubicin and brentuximab)...He had progressive disease after 3 weeks and was changed to combination chemotherapy with brentuximab and nivolumab with the addition of alectinib, a second generation ALK inhibitor. He again had progressive disease within 3 weeks and received therapy with ifosfamide, carboplatin and etoposide with a mixed response...Based on preclinical studies and limited clinical studies demonstrating that ALKI1171T mutations are resistant to crizotinib and alectinib but may maintain sensitivity to ceritinib, the patient started ceritinib in combination with brentuximab... Testing for the presence of ALK rearrangements via IHC is standard in pediatric ALCL but cannot solely predict sensitivity to specific inhibitors. Consideration should be made for upfront ALK gene sequencing as this may drive therapeutic decisions regarding which inhibitor is most likely to result in a clinical response.

This treatment may provide a new therapeutic strategy for ALK TKIs resistant patients, especially in position 1171 of ALK exon20.

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.

Results Of the 133 pts who progressed on alectinib, with or without prior crizotinib or chemotherapy, 131 had evaluable baseline plasma data. The presence of secondary ALK mutations at baseline was associated with a similar ORR (34.5%) and median DoR (5.6 months) and shorter median PFS (3.7 months), with response/clinical benefit observed in pts with G1202R, L1196M, and I1171N ALK secondary mutations. Table: 1009P Brigatinib efficacy parameters a according to baseline ALK mutation status conclusions Brigatinib showed clinically meaningful activity in pts with alectinib-resistant ALK+ NSCLC with or without a detectable ALK fusion and/or secondary mutations.

Structural analysis revealed increased potency against compound mutations through improved inhibition of either G1202R or I1171N/S/T mutant kinases. Overall, we propose a classification of heterogenous ALK compound mutations enabling the development of distinct therapeutic strategies for precision targeting following sequential tyrosine kinase inhibitors.

In contrast to wild conformation, the mutant conformations exhibited a reduced node degree in their residue interaction networks. Collectively, our findings provide deeper insights into the deleterious effects of I1171N + F1174I and I1171N + L1198H ALK compound mutations, which may contribute to NSCLC pathogenesis.Communicated by Ramaswamy H. Sarma.

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.

She was treated with alectinib and acquired ALK p.I1171N and p.V1180L mutations...After sequential lines of ceritinib and chemotherapy, lorlatinib was chosen as the fourth-line therapy and maintained control for 6 months...To the best of our knowledge, this case is the first to provide clinical evidence of antitumor activity of olaparib plus ALK TKI in ALK-positive, gBRCA-mutated metastatic NSCLC. Together with previous reports in EGFR-positive or driver-negative patients, our finding warrants further studies on PARP inhibition in BRCA1/2-mutated NSCLC.

TRKB inhibition in the central nervous system has been implicated in adverse events observed with FDA-approved ALK inhibitor lorlatinib. In cell-based assays, NVL-655 was observed to inhibit proliferation of a human anaplastic large cell lymphoma cell line harboring NPM1-ALK fusion and human neuroblastoma cell lines harboring ALK activating mutations or amplification. In conclusion, the preclinical profile of NVL-655 supports its potential to address a medical need for patients with ALK-driven disease in both NSCLC and other cancers such as anaplastic large cell lymphoma and neuroblastoma.

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.

These discrepancies created the capacity of the double mutant ALK I1171N/F1174I to confer drug resistance to lorlatinib. Our result anticipates to provide a mechanistic insight into the mechanism of drug resistance induced by ALK I1171N/F1174I that are resistant to lorlatinib treatment in NSCLC.

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.

One patient was deemed as sensitive to carboplatin but tumor showed to be resistant...The patient started alectinib but showed progression after 12 months...Treatment was switched to brigatinib with no response...The In vitro results demonstrated no activity of lorlatinib but a strong response to crizotinib... We present clinical evidence that PDOs are an alternative tool in oncogenic addicted tumors helping to guide treatment decisions and increasing a more personalized sequential treatment approach.

The majority, 81% (n = 22) had EGFR mutated NSCLC, and had progressed on EGFR TKIs (15 with previously identified T790M had progressed on osimertinib), and 19% (n = 5) had ALK fusions... Molecular profiling upon development of resistance to targeted therapy in our cohort revealed actionable resistance mechanisms for over a third of patients and clinical trial options for 67% . These incremental benefits for patients highlight the importance of routine molecular profiling in the setting of acquired TKI resistance in lung cancer.

Clinical sequencing using NGS-based multiplex gene assays between collaborating domestic medical institutions was feasible, with a success rate of > 97%. Overall, clinical sequencing benefits therapeutic decision-making in patients with advanced cancer.

We present a case of ALK-rearranged lung adenocarcinoma with acquired resistance to ALK inhibition, in which the BRAF V600E mutation is a novel resistance mechanism. This provides evidence that BRAF V600E mutation is one mechanism of ALK-TKI resistance.

Surprisingly, EML4-ALK I1171N + F1174I compound mutant-expressing tumors were not completely shrunk but regrew within a short period of time after alectinib or lorlatinib treatment. However, the relapsed tumor was markedly shrunk after switching to the gilteritinib in vivo model. In addition, gilteritinib was effective against NTRK-rearranged cancers including entrectinib-resistant NTRK1 G667C-mutant and ROS1 fusion-positive cancer.

Brigatinib showed clinically meaningful efficacy in Japanese patients with ALK+ NSCLC refractory to alectinib (with or without prior crizotinib).

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.

No distinct mutation spectrum in relation to neuroblastoma tumours genomic subtypes could be detected although there was a paucity of ALK mutations among 11q-deleted tumors. As ALK mutations status opens up an excellent opportunity for application of small molecule inhibitors targeting ALK, early and sensitive detection of ALK alterations is clinically important considering its potential role in tumour progression.

EML4-ALK rearranged malignant pleural mesothelioma (MPM) is rare and its responses to anaplastic lymphoma kinase (ALK) inhibitors, including alectinib and lorlatinib, remain unexplored. Moreover, our case also revealed acquired mechanisms of lorlatinib resistance mediated by multiple mutations ALK I1171N, L1196M, and G1202R, contributing an incremental step to our understanding of the complexity of acquired resistance mechanisms in sequential ALK inhibitor therapy. The reviews of this paper are available via the supplemental material section.

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.

Brigatinib showed clinically meaningful efficacy in Japanese patients refractory to prior alectinib (first line or post crizotinib), regardless of prior chemotherapy. The safety profile of brigatinib was consistent with prior studies and no new safety findings were identified. Research Funding: Takeda Pharmaceutical Company Ltd