EML4-ALK L1196M

Collectively, resistance of ALK-positive NSCLC cells to crizotinib is induced by G1202R and L1196M mutations through activation of the MDM2/MEK/ERK signalling axis, promoting EMT process and metastasis. These findings suggest that the combination of MDM2 inhibitors and crizotinib could be a potential therapeutic strategy.

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.

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.

19 novel imidazo[1,2-b]pyridazine macrocyclic derivatives were designed, synthesized, and tested for their biological activities in an effort to develop ALK inhibitors that would overcome second-generation ALK-TKIs, particularly the G1202R mutation and the lorlatinib-resistant L1196M/G1202R double mutations...This was equally effective to the reference drug Repotrectinib (IC = 40, 164, and 208 nM). The kinase selectivity profile, liver microsome stability test and in vivo pharmacokinetic properties in SD rats of compound O-10 were further evaluated. O-10 was regarded as an effective ALK inhibitor for the treatment of mutations overall.

Second- (ceritinib, alectinib, brigatinib, and ensartinib) and third-generation (lorlatinib) ALK TKIs have higher intracranial responses than crizotinib but are still limited by emergence of resistance mutations, most commonly G1202R-containing single and compound mutations. Patient-derived models are widely viewed as among the most disease-relevant models for evaluating new therapies and drug resistance. Using a xenograft model derived from an alectinib-relapsed patient, we showed that NVL-655 had high intracranial activity against brain tumors bearing the ALK G1202R mutation that confers resistance to multiple ALK TKIs. NVL-655 is being evaluated in a Phase 1/2 clinical trial for patients with advanced NSCLC and other solid tumors harboring ALK rearrangement or activating ALK mutation (ALKOVE-1): NCT05384626.

Despite early progression within 3 mo under crizotinib, a durable response was achieved with alectinib...Another rebiopsy revealed ALK:p.L1196M, but the tumor did not respond to brigatinib or carboplatin/pemetrexed, before stabilization under lorlatinib...Lorlatinib retained efficacy in the heavily pretreated setting, while its upfront use could possibly have prevented the stepwise emergence of compound ALK mutations. Furthermore, the disease course was more aggressive and OS shorter compared to the V2/TP53wt ALK+ lung adenocarcinoma, while crizotinib, ceritinib and brigatinib did not confer the benefit expected according to NGS results, which also underline the need for more potent drugs against ALK in the high-risk setting of neuroendocrine histology.

Five tyrosine kinase inhibitors (TKIs) have been approved for treatment of ALK-positive non-small cell lung cancer (NSCLC), including first- (crizotinib), second- (ceritinib, alectinib, and brigatinib), and third- (lorlatinib) generation therapies. NVL-655 showed activity in diverse patient-derived models of ALK-positive cancers, including ones that exhibited clinical resistance to prior-generation ALK TKIs. The broad preclinical activity of NVL-655 suggests potential utility as a best-in-class therapy for ALK-positive cancer patients.

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.

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.

Sequential postprogression plasma profiling revealed that increased lines of ALK inhibitors can accelerate the accumulation of ALK resistance mutations and may lead to treatment-refractory compound ALK mutations. The selection for optimal first-line TKI is very important to achieve a more efficacious long-term strategy and prevent the emergence of on-target resistance, which may provide guidance for clinical decision making.

Herein, we present an acquired TPM3-NTRK1 fusion resistant to larotrectinib in lung adenocarcinoma with EML4-ALK fusion progressed on lorlatinib.Case Presentation: A 48-year-old male with stage IV adenocarcinoma of lung with metastatic disease of bone was initially treated with carboplatin, pemetrexed, and pembrolizumab...Upon progression of disease (PD), systemic therapy regimen was switched to combination of carboplatin, paclitaxel, and bevacizumab...Subsequently, he was started on alectinib 600 mg twice a day given EML 4-ALK fusion mutation [4.8% of variant allele frequency (VAF)] in circulating tumor DNA (ctDNA) NGS assay...We report the case of acquired TPM3-NTRK1 fusion resistant to larotrectinib and acquired ALK L1196M in lung adenocarcinoma with EML4-ALK fusion progressed on lorlatinib. Further investigations are warranted to explore the mechanism of resistance to ALK TKIs.