Anaplastic Lymphoma Kinase Resistance Mutations Research Articles

Response to lorlatinib rechallenge in a case of ALK-rearranged metastatic NSCLC with a resistance mutation to second generation TKIs.

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. With the increasing number of target therapies available, the optimal sequence is yet to be defined, as resistance profiles may evolve over time and in response to sequential ALK inhibitors. Therefore, ALK-targeted strategies may be personalized based upon the presence of specific ALK resistance mutations. Here, we report on the case of a patient who has been treated with a sequence of three ALK TKIs after receiving diagnosis of ALK-rearranged metastatic NSCLC in 2015 and gained further benefit upon lorlatinib rechallenge after the acquisition of the G1202R resistance mutation to second generation TKIs. In this case, the first ALK resistance mutation detected after progression on first line TKI, the I1171N, is a common resistance mutation after alectinib and confers sensitivity to brigatinib, that the patient received afterwards with a long-term disease stability. 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.

Detection of resistance mutations in patients with anaplastic lymphoma kinase-rearranged lung cancer through liquid biopsy.

Tyrosine kinase inhibitors (TKIs) significantly improve clinical outcomes in patients with non-small cell lung cancer due to anaplastic lymphoma kinase (ALK) gene rearrangement. However, the rate of relapse with TKIs is high owing to the development of resistance mutations during treatment. Repeated biopsies during disease progression are crucial for elucidating the molecular mechanisms underlying the development of resistance to ALK inhibitors. Analysis of cell-free DNA (cfDNA) obtained from plasma is a novel approach for tumor genotyping. In this mixed prospective and retrospective observational cohort study, we investigated the clinical feasibility of continuous quantitative monitoring of ALK-acquired mutations in plasma obtained from patients with ALK+ non-small cell lung cancer by using a highly sensitive and specific droplet digital polymerase chain reaction (ddPCR) assay. We enrolled nine patients, including three treatment-naïve patients recently diagnosed with ALK+ non-small cell lung cancer via tissue biopsy and expected to receive ALK TKIs and six patients already receiving ALK TKIs. Plasma samples were collected from these patients every 3 months. cfDNA was extracted from 66 samples during the study period, and 10 ALK mutations were simultaneously evaluated. The numbers of samples showing the G1202R, C1156Y, G1269A, F1174L, T1151ins, and I1171T mutations were 32, 16, 5, 4, 1, and 1, respectively. The L1196M, L1152R, V1180L, and S1206Y mutations were not detected. Correlation analyses between progression-free survival and the time from treatment initiation (or treatment modification) to the detection of resistance mutations revealed that although resistance mutations may occur before a drug change becomes necessary, there is a duration during which the disease does not progress. 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.

An update on lorlatinib: a novel first line treatment for ALK-positive advanced lung cancer

ABSTRACT Introduction Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) have significantly improved the prognosis of ALK-rearranged non-small cell lung cancer (NSCLC), but these patients will eventually develop resistance and progression of disease after 10 months of first-generation and more than 30 months after second-generation TKIs. Lorlatinib is a third-generation highly selective ALK-TKI capable of inducing significant and durable CNS responses and overcoming known ALK resistance mutations. Areas covered This review summarizes the mechanism of action, efficacy, and safety of lorlatinib in ALK-positive NSCLC. The authors provide their expert opinions on the use of this drug, including its future prospects. Expert opinion Lorlatinib has shown good efficacy and safety in ALK-positive NSCLC patients progressing to first- and second-generation ALK-TKIs. The phase III trial CROWN evaluating lorlatinib as first-line therapy has provided promising results; however, the comparing arm was crizotinib, supplanted now by second-generation agents. Whether lorlatinib can replace them as upfront strategy is a relevant question that still remains open. In our opinion, longer follow-up and face-to-face studies are required to determine which is the best treatment sequence strategy. The advent of liquid biopsy will contribute to treatment tailoring according to the genomic profile at progression.

Abstract 4120: Acquired TPM3-NTRK1 fusion resistant to larotrectinib in a non-small cell lung cancer with EML4-ALK fusion progressed on lorlatinib

Abstract Background: As oncogenic driver genes have been detected, targeted therapy plays a crucial role in non-small cell lung cancer (NSCLC) with targeted mutation. Lorlatinib, a selective third-generation inhibitor of anaplastic lymphoma kinase (ALK), is a treatment option for ALK-positive NSCLC patients who previously failed on ALK tyrosine kinase inhibitors (TKIs). Larotrectinib, a highly selective tropomyosin receptor kinase (TRK) inhibitor, is a treatment option for NSCLC with neurotrophic tyrosine receptor kinase (NTRK) mutation. 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. Follow up CT in 4 months showed numerous hepatic lesions and liver biopsy demonstrated large cell neuroendocrine carcinoma. Upon progression of disease (PD), systemic therapy regimen was switched to combination of carboplatin, paclitaxel, and bevacizumab. After two months since starting the new regimen, a second PD was observed. Follow-up MRI brain demonstrated multiple small metastatic lesions. 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. Follow-up CT chest in 5 months showed 5 mm left lower lobe nodule which remained unchanged in size. He maintained SD for 9 months before repeat MRI brain demonstrated PD with new leptomeningeal carcinomatosis. Subsequently, he received whole brain radiotherapy and the treatment regimen was switched to lorlatinib 100 mg daily. In 7-week follow-up CT, the 5 mm nodule in the left lower lobe was stable. Follow-up MRI brain in 16 weeks showed decrease in size and number of numerous enhancing parenchymal and leptomeningeal lesions. Overall SD was maintained for 8 months before follow-up MRI brain showed new punctate lesions. Repeat ctDNA NGS assay revealed new TPM3-NTRK1 fusion (VAF 0.2%) and ALK L1196M (VAF 2.8%), and a decision was made to add larotrectinib 100 mg daily. The 6-week follow-up MRI brain showed new parenchymal brain metastases. Discussion: It has been reported that the development of ALK resistance mutations may be associated with specific EML4-ALK variants. However, the influence of the specific EML4-ALK variants in NSCLC was not fully investigated. 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. Citation Format: Horyun Choi, Jinah Kim, Yeun Ho Lee, Leeseul Kim, Na Hyun Kim, Young Kwang Chae. Acquired TPM3-NTRK1 fusion resistant to larotrectinib in a non-small cell lung cancer with EML4-ALK fusion progressed on lorlatinib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4120.

Efficacy and safety of lorlatinib in Asian and non-Asian patients with ALK-positive advanced non-small cell lung cancer: Subgroup analysis of a global phase 2 trial

ObjectivesTo analyze the efficacy and safety of lorlatinib in Asian and non-Asian patients with pretreated anaplastic lymphoma kinase (ALK)-positive, advanced non-small cell lung cancer (NSCLC) from a phase 1/2 study. Materials and methodsIn this ongoing phase 2 part of the trial, patients with ALK- or ROS1-positive, advanced NSCLC enrolled into six expansion cohorts (EXP1–6), based on ALK and ROS1 status and previous therapy, and received lorlatinib 100 mg once daily. The primary endpoint was objective tumor response and intracranial response. Post hoc analyses of activity were conducted in Asian and non-Asian (based on race) ALK-positive patients who received either previous crizotinib with or without chemotherapy (EXP2–3A) or at least one second-generation ALK tyrosine kinase inhibitor with any number of chemotherapy regimens (EXP3B–5). Analysis of safety (adverse events [AEs]) was in the phase 1 and 2 study population who started lorlatinib 100 mg once daily. Results17 Asian patients were enrolled in EXP2–3A and 53 in EXP3B–5; 33 non-Asian patients were enrolled in EXP2–3A and 73 in EXP3B–5. Objective response rates in the Asian and non-Asian subgroups were 82.4% (95% confidence interval [CI]: 56.6–96.2) and 63.6% (95% CI: 45.1–79.6) in EXP2–3A, and 47.2% (95% CI: 33.3–61.4) and 30.1% (95% CI: 19.9–42.0) in EXP3B–5, and median progression-free survival was 13.6 and 12.5 months (EXP2–3A) and 6.9 and 5.5 months (EXP3B–5). Lorlatinib exhibited antitumor activity across ALK resistance mutations, while no differences according to the EML4-ALK variant could be detected. The most common treatment-related AEs were hypercholesterolemia, hypertriglyceridemia, edema, and peripheral neuropathy in both Asian and non-Asian subgroups. ConclusionLorlatinib showed substantial overall and intracranial activity in pretreated patients with ALK-positive NSCLC in both Asian and non-Asian patients. AE profiles were similar between Asian and non-Asian patients. ClinicalTrials.gov NCT01970865.

Real-world circulating tumor DNA analysis depicts resistance mechanism and clonal evolution in ALK inhibitor-treated lung adenocarcinoma patients

BackgroundSequential treatment with different generations of anaplastic lymphoma kinase (ALK) inhibitors have been widely applied to ALK-positive lung cancer; however, resistance mutations inevitably developed. Further characterization of ALK resistance mutations may provide key guidance to subsequent therapies. Here we explored the emergence of secondary ALK mutations during sequential ALK tyrosine kinase inhibitor (TKI) treatment in a real-world study of Chinese lung adenocarcinoma (ADC) patients.MethodsA clinical-genomic database was queried for lung ADC patients with at least one ALK inhibitor treatment and at least one plasma sample collected following ALK inhibitor treatment. Targeted genome profiling was performed with a 139-gene panel in baseline tumor tissue and serial plasma samples of patients.ResultsA total of 116 patients met inclusion criteria. ALK G1202R was more common in patients with echinoderm microtubule-associated protein-like 4 (EML4)-ALK v3 fusion, whereas ALK L1196M was more common in v1. TP53 mutant patients were significantly associated with harboring multiple ALK resistance mutations (P = 0.03) and v3+/TP53 mutant patients had the highest rate of multiple ALK resistance mutations. The sequential use of ALK TKI led to an increased incidence of concurrent ALK mutations along the lines of therapies. Alectinib had a lower rate (9%) harboring ALK resistance mutation as first-line ALK TKI compared with crizotinib (36%). ALK compound mutations identified included ALK D1203N/L1196M, ALK G1202R/L1196M, and ALK G1202R/F1174C, which may be lorlatinib resistant. Using paired pretreatment and post-treatment samples, we identified several ALK-independent resistance-related genetic alterations, including PTPRD and CNKN2A/B loss, MYC, MYCN and KRAS amplification, and EGFR19del.ConclusionsSequential 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.

Update on Lorlatinib: Role in Reducing the Risk of Disease Progression in ALK-Positive NSCLC.

Lorlatinib is an oral third-generation inhibitor of anaplastic lymphoma kinase (ALK) with activity in advanced ALK-positive non-small cell lung cancer (NSCLC) in both the first and subsequent line setting. Superior systemic and intracranial efficacy of lorlatinib over crizotinib, a first-generation ALK tyrosine kinase inhibitor (TKI), in treatment-naïve patients with advanced ALK-positive NSCLC was demonstrated by the phase 3 CROWN trial. Lorlatinib retains anti-tumor effect against single and some compound ALK resistance mutations after disease progression on first- and second-generation ALK TKIs. Currently, alectinib, brigatinib, ceritinib, crizotinib and lorlatinib are approved for treatment of advanced ALK-positive NSCLC. However, no head-to-head studies have directly compared lorlatinib to second-generation ALK inhibitors. Herein, we aim to provide an overview of the efficacy and safety of lorlatinib and discuss where lorlatinib stands in the therapeutic approach to advanced ALK-positive NSCLC.

Fatal Tumour Lysis Syndrome Induced by Brigatinib in a Lung Adenocarcinoma Patient Treated With Sequential ALK Inhibitors: A Case Report

Tumour lysis syndrome (TLS) represents a group of fatal metabolic derangements resulting from the rapid breakdown of tumour cells. TLS typically occurs soon after the administration of chemotherapy in haematologic malignancies but is rarely observed in solid tumours. Here, we report a case of brigatinib-induced TLS after treatment with sequential anaplastic lymphoma kinase (ALK) inhibitors in a patient with advanced ALK-rearranged lung adenocarcinoma. The patient was treated sequentially with crizotinib, alectinib, and ensartinib. High-throughput molecular profiling after disease progression indicated that brigatinib may overcome ALK resistance mutations, so the patient was administered brigatinib as the fourth-line treatment. After 22 days of therapy, he developed oliguria, fever, and progressive dyspnoea. Clinical manifestations and laboratory findings met the diagnostic criteria for TLS. The significant decrease in the abundance of ALK mutations in plasma indicated a therapeutic response at the molecular level. Consequently, the diagnosis of brigatinib-induced TLS was established. To the best of our knowledge, this is the first case of TLS induced by sequential targeted therapy in non-small cell lung cancer. With the extensive application of sequential therapy with more potent next-generation targeted therapeutic drugs, special attention should be given to this rare but severe complication.

Genetic landscape of patients with ALK-rearranged non–small-cell lung cancer (NSCLC) and response to ceritinib in ASCEND-1 study

ObjectivesTo better understand genetic determinants of response to ceritinib, an exploratory analysis was conducted using tumor biopsies from anaplastic lymphoma kinase (ALK)-rearranged (ALK+) non–small-cell lung cancer (NSCLC) patients treated with ceritinib at doses of ≥ 300 mg in the ASCEND-1 study. MethodsASCEND-1 was an open-label, multicentre, phase 1, dose–escalation and expansion study of ceritinib (fasted) in ALK inhibitor (ALKi)-naïve or ALKi-pretreated patients with locally advanced or metastatic ALK + NSCLC. Biopsies were assayed by next-generation sequencing (NGS) using a Foundation Medicine panel targeting 295 genes. Somatic alterations were correlated with clinical outcome (cut-off 14-Apr-2014). A total of 285 ALK + NSCLC patients were treated with ceritinib at doses ≥ 300 mg. ResultsNGS data were generated for 85 pts (ALKi-pretreated [n = 54]; ALKi-naïve [n = 31]), 57 were collected from patients before exposure to any ALKi. NGS did not detect ALK rearrangement in 14 of 85 patients; several of these ALK NGS negative cases harbored alternative drivers, e.g. EGFR mutation. Of the 71 biopsies with NGS confirmed ALK rearrangement, the most frequently detected rearrangements were EML4-ALK variant 1 (V1) and EML4-ALK V3 (36.6% [26/71] and 32.4% [23/71] respectively). Eight (six crizotinib-pretreated and two pretreated with crizotinib followed by alectinib) of the 21 ALKi-pretreated patients carried a point mutation of the ALK TKD, and had the biopsy collected between 1 and 14 days before ceritinib; with the exception of one patient with a G1202R point mutation, all patients derived clinical benefit from ceritinib treatment.Of the 14 ALKi-naïve patients, ceritinib was effective in almost all patients, including a patient carrying a concomitant ERBB4 and HGF amplification. ConclusionsThis exploratory analysis highlights the potential role of NGS in improving our understanding of response and resistance to ceritinib. It also illustrates that ceritinib is active against almost all ALK resistance mutations found in ALKi-pretreated patients.Trial registration: ClinicalTrials.gov, NCT01283516. Registered January 26, 2011, https://clinicaltrials.gov/ct2/show/NCT01283516

Actionability of on-target ALK Resistance Mutations in Patients With Non-Small Cell Lung Cancer: Local Experience and Review of the Literature

IntroductionNon-small cell lung cancer (NSCLC) patients with Anaplastic Lymphoma Kinase (ALK) gene fusions respond well to ALK inhibitors but commonly develop on-target resistance mutations. The objective of this study is to collect clinical evidence for subsequent treatment with ALK inhibitors. Patients and MethodsLocal experience with on-target ALK resistance mutations and review of the literature identified 387 patients with ALK inhibitor resistance mutations. Clinical benefit of mutation-inhibitor combinations was assessed based on reported response, progression-free survival and duration of treatment. Furthermore, this clinical evidence was compared to previously reported in vitro sensitivity of mutations to the inhibitors. ResultsOf the pooled population of 387 patients in this analysis, 239 (62%) received at least 1 additional line of ALK inhibition after developing on-target resistance to ALK inhibitor therapy. Clinical benefit was reported for 177 (68%) patients, but differed for each mutation-inhibitor combination. Agreement between in vitro predicted sensitivity of 6 published models and observed clinical benefit ranged from 69% to 89%. The observed clinical evidence for highest probability of response in the context of specific on-target ALK inhibitor resistance mutations is presented. ConclusionMolecular diagnostics performed on tissue samples that are refractive to ALK inhibitor therapy can reveal new options for targeted therapy for NSCLC patients. Our comprehensive overview of clinical evidence of drug actionability of ALK on-target resistance mechanisms may serve as a practical guide to select the most optimal drug for individual patients.

TPX-0131, a Potent CNS-penetrant, Next-generation Inhibitor of Wild-type ALK and ALK-resistant Mutations.

Since 2011, with the approval of crizotinib and subsequent approval of four additional targeted therapies, anaplastic lymphoma kinase (ALK) inhibitors have become important treatments for a subset of patients with lung cancer. Each generation of ALK inhibitor showed improvements in terms of central nervous system (CNS) penetration and potency against wild-type (WT) ALK, yet a key continued limitation is their susceptibility to resistance from ALK active-site mutations. The solvent front mutation (G1202R) and gatekeeper mutation (L1196M) are major resistance mechanisms to the first two generations of inhibitors while patients treated with the third-generation ALK inhibitor lorlatinib often experience progressive disease with multiple mutations on the same allele (mutations in cis, compound mutations). TPX-0131 is a compact macrocyclic molecule designed to fit within the ATP-binding boundary to inhibit ALK fusion proteins. In cellular assays, TPX-0131 was more potent than all five approved ALK inhibitors against WT ALK and many types of ALK resistance mutations, e.g., G1202R, L1196M, and compound mutations. In biochemical assays, TPX-0131 potently inhibited (IC50 <10 nmol/L) WT ALK and 26 ALK mutants (single and compound mutations). TPX-0131, but not lorlatinib, caused complete tumor regression in ALK (G1202R) and ALK compound mutation-dependent xenograft models. Following repeat oral administration of TPX-0131 to rats, brain levels of TPX-0131 were approximately 66% of those observed in plasma. Taken together, preclinical studies show that TPX-0131 is a CNS-penetrant, next-generation ALK inhibitor that has potency against WT ALK and a spectrum of acquired resistance mutations, especially the G1202R solvent front mutation and compound mutations, for which there are currently no effective therapies.

How to select the best upfront therapy for metastatic disease? Focus on ALK-rearranged non-small cell lung cancer (NSCLC).

Anaplastic lymphoma kinase (ALK) inhibitors have demonstrated robust clinical activity in patients with ALK-rearranged lung cancers. The echinoderm microtubule-associated protein-like (EML)-ALK translocation was first discovered in 2007 and 4 years later, crizotinib, a first-generation ALK inhibitor was approved. Since then, subsequent generations of ALK inhibitors have demonstrated superior efficacy and better CNS activity compared to crizotinib. Alectinib and brigatinib, both second-generation ALK inhibitors have been compared directly to crizotinib in the first-line setting and has demonstrated improved progression free survival (PFS) and intracranial response. Ceritinib, another second-generation ALK inhibitor has been shown to be superior to chemotherapy in ALK-rearranged disease with good CNS activity. Initial responses to ALK inhibitors are not always durable and resistance can occur as on-target or off-target alterations. Lorlatinib, a third-generation ALK inhibitor, has demonstrated activity in the treatment naïve setting and in resistance to crizotinib and second-generation ALK inhibitors. Lorlatinib has also shown improved PFS in patients harboring EML4-ALK variant 3, which is associated with the development of ALK resistance mutations, specifically G1202R. Another new ALK inhibitor, ensartinib, has demonstrated efficacy in the first-line setting and in alectinib refractory disease. Additional studies are underway examining mechanisms of resistance and best treatment options post resistance.

Later-Line Treatment with Lorlatinib in ALK- and ROS1-Rearrangement-Positive NSCLC: A Retrospective, Multicenter Analysis.

In clinical practice, patients with anaplastic lymphoma kinase (ALK)-rearrangement–positive non–small-cell lung cancer commonly receive sequential treatment with ALK tyrosine kinase inhibitors. The third-generation agent lorlatinib has been shown to inhibit a wide range of ALK resistance mutations and thus offers potential benefit in later lines, although real-world data are lacking. This multicenter study retrospectively investigated later-line, real-world use of lorlatinib in patients with advanced ALK- or ROS1-positive lung cancer. Fifty-one patients registered in a compassionate use program in Austria, who received second- or later-line lorlatinib between January 2016 and May 2020, were included in this retrospective real-world data analysis. Median follow-up was 25.3 months. Median time of lorlatinib treatment was 4.4 months for ALK-positive and 12.2 months for ROS-positive patients. ALK-positive patients showed a response rate of 43.2%, while 85.7% percent of the ROS1-positive patients were considered responders. Median overall survival from lorlatinib initiation was 10.2 and 20.0 months for the ALK- and ROS1-positive groups, respectively. In the ALK-positive group, lorlatinib proved efficacy after both brigatinib and alectinib. Lorlatinib treatment was well tolerated. Later-line lorlatinib treatment can induce sustained responses in patients with advanced ALK- and ROS1-positive lung cancer.

Ensartinib as Treatment for ALK-Rearranged NSCLC

Ensartinib as Treatment for ALK-Rearranged NSCLC

Pharmacological and clinical properties of lorlatinib in the treatment of ALK-rearranged advanced non-small cell lung cancer

ABSTRACT Introduction Approximately 3–7% of advanced non-small cell lung cancers (NSCLC) are driven by an anaplastic lymphoma kinase (ALK) rearrangement. Crizotinib, ceritinib, alectinib, and brigatinib are active ALK inhibitors (ALKi) used to treat this oncogene-driven subset of NSCLC. Resistance occurs with time to ALKi and new therapeutics are being developed. Lorlatinib is an efficacious third-generation ALKi with an ability to overcome resistance mutations that develop with first- or second-generation ALKi. Areas covered Herein, the authors review the mechanism of action, pharmacokinetics, pharmacodynamics, clinical efficacy, and safety of lorlatinib and provide their future perspectives on this drug. Expert commentary Lorlatinib is a potent ALK and ROS-1 inhibitor that also has activity against many acquired ALK resistance mutations. Clinical trials show the robust systemic and intracranial anti-tumor activity of lorlatinib in ALK rearranged advanced NSCLC. Adverse events of lorlatinib are unique and manageable. These include hypocholesteremia, hypertriglyceridemia, edema, cognitive effects, weight gain, and diarrhea. Loratinib will play an increasing role in the management of ALK-rearranged NSCLC with the optimal sequencing of ALKi undergoing further research.

Lorlatinib for the treatment of ALK-positive metastatic non-small cell lung cancer

ABSTRACTIntroduction: The treatment of lung cancer has changed dramatically with the development of tyrosine kinase inhibitors (TKIs) that target sensitizing somatic (gene) activations including anaplastic lymphoma kinase (ALK)-rearrangements. Despite remarkable initial responses, patients develop progressive disease via various resistance mechanisms, some of which are ALK dependent. Various next-generation ALK TKIs have been developed to improve on central nervous system (CNS) activity and also target the multitude of acquired resistance mechanisms. Of these, lorlatinib has the greatest spectrum of clinical activity against multiple ALK resistance mutations and has also demonstrated promising efficacy in patients with known brain metastases.Areas covered: We discuss the structure, pharmacology and efficacy of lorlatinib and also provide future perspectives in the management of patients with ALK-rearranged non-small cell lung cancer (NSCLC).Expert opinion: Patients invariably develop resistance during treatment with lorlatinib. Unique combinations of ALK resistance mutations may confer sensitivity to alternate ALK TKIs. There is a move toward individualized biomarker-driven treatment strategies to identify the select group of candidates that can benefit from existing therapies.

Preliminary results of single arm phase 2 trial of brigatinib in patients (pts) with progression disease (PD) after next-generation (NG) anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) in ALK + non-small cell lung cancer (NSCLC).

9027 Background: NG ALK TKIs are the standard first-line therapy for patients with advanced ALK + NSCLC. Brigatinib has activity against ALK resistance mutations and has CNS activity. The efficacy of brigatinib after NG ALK TKI is undetermined. Methods: Pts with stage IIIB/IV ALK + NSCLC, and PD after NG ALK TKI’s were eligible. Pts were required to have measurable disease, performance status 0-2, and adequate organ function. Pts were required to undergo tumor biopsy ≤ 60 days of enrollment; ctDNA was collected at baseline, at time of imaging, and PD. Brigatinib treatment was 90 mg daily for 7 days and then 180 mg daily (1 cycle = 28 days). Primary objective was objective response rate (ORR), and ORR of 20% was determined to be worthy of further investigation. Response was assessed every 2 cycles. A 2-stage design was used; if &gt; 2 responses in 20 pts in the 1st stage, study proceeded to 2nd stage; if ≥ 5 responses in 40 pts therapy considered active. Results: Between 3/2017 and 11/2018, 20 pts were enrolled in the 1st stage. Pt characteristics were: median age 55 years (range 32 to 71), median number of prior therapies 3 (range 1 to 6), 12 had CNS disease at the baseline (8 pts had CNS PD). ALK resistance mutation detected in 3 of 8 pts on standard of care molecular testing. ORR results were confirmed partial response (n = 8), stable disease (n = 7), PD (n = 3), unconfirmed response (n = 1), and non-evaluable due adverse events (AE’s) (n = 1). The grade 3 or 4 AE’s were: pneumonitis (n = 2); 1 of each: acute renal failure, respiratory failure, sepsis, hypertension, CPK elevation, and headache. With median follow-up of 6.7 months (11 PFS events), the median PFS was 6.4 months (95% CI: 4.6 to NE). Overall survival data is immature. 3 of 3 pts with a known ALK mutation (F1174C in 2 pts, I1171T in 1 pt) responded, 2 of 5 pts without ALK mutation responded. Additional study related tumor analysis and ctDNA analyses are ongoing. Conclusions: Brigatinib has activity after progression on next generation ALK TKI. The study is enrolling additional patients in the second stage. Detailed molecular and site of disease (CNS versus extra-CNS) activity analyses are underway Clinical trial information: NCT02706626.

Defining molecular risk in ALK+ NSCLC.

Anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancers (NSCLC) have the best prognosis among metastatic pulmonary malignancies, with a median patient survival currently exceeding 5 years. While this is definitely a major therapeutic success for thoracic oncology, it may not be entirely attributable to rapid drug development and the strenuous clinical efforts. At the genetic level, ALK+ disease is also unique, distinguished by the lowest tumor mutational burden (mean below 3 mutations/Mbp), the lowest frequency of TP53 mutations (20–25%) and very few other co-mutations compared to other NSCLC. The relative simplicity and stability of the genetic landscape not only contribute to the relatively favourable clinical course, but also make study of the effects from individual molecular features easier. EML4-ALK fusion variant 3 (E6;A20) and TP53 mutations were recently identified as main molecular determinants of adverse outcome: they occur in about 30–40% and 20–25% of newly-diagnosed cases, respectively, have possibly synergistic effects and are independently associated with more aggressive disease, shorter progression-free survival under treatment with ALK inhibitors and worse overall survival. Secondary detection of TP53 mutations at disease progression in previously negative patients defines another subset (about 20%) with similarly poor outcome, while detection of ALK resistance mutations guides next-line therapy. As our biological understanding deepens, additional molecular risk factors will be identified and refine our concepts further. The translation of clinical risk at the molecular level and the ability to predict early events are of key importance for individualized patient management and preclinical modeling in order to advance therapeutic options.

Highly sensitive detection of ALK resistance mutations in plasma using droplet digital PCR

BackgroundOn-target resistance mechanisms found in one-third of patients receiving anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) are secondary ALK mutations in ALK-rearranged non-small cell lung cancer (NSCLC). There are large variations in the resistant mutations, unlike the epithelial growth factor receptor (EGFR) T790 M seen with the use of EGFR-TKIs. Liquid biopsy approaches using cell-free DNA (cfDNA) are used for screening and monitoring of mutations in NSCLC. However, feasible protocol for the simultaneous detection of multiple secondary ALK mutations using droplet digital PCR (ddPCR) has not been developed. An efficient strategy using cfDNA in cancer diagnostics, the development of more accurate and cost-effective tools to identify informative multiple secondary ALK mutations is clinically required.MethodsTo establish a feasible assay to monitor ALK-TKI resistance mutations, we first evaluated the feasibility of ddPCR-based screening for cfDNA mutation detection of 10 distinct secondary ALK mutations. Positive samples were then re-analyzed using mutation-specific probes to track the growth of mutation clones with a high sensitivity.ResultsBlood samples from seven ALK-positive patients were analyzed using the ddPCR protocol. Secondary G1202R ALK mutations were identified in 2 of 7 patients by the screening assay. Using the mutation-specific probes, monitoring the resistant clone during the clinical course of the disease was well demonstrated in each of the patients.ConclusionThe protocol for ddPCR-based liquid biopsy has a feasibility for the screening of secondary ALK-TKI resistance mutations and offers a tool for a cost-effective monitoring of progression in NSCLC.

Clinical Utility of Cell-Free DNA for the Detection of ALK Fusions and Genomic Mechanisms of ALK Inhibitor Resistance in Non-Small Cell Lung Cancer.

Purpose: Patients with advanced non-small cell lung cancer (NSCLC) whose tumors harbor anaplastic lymphoma kinase (ALK) gene fusions benefit from treatment with ALK inhibitors (ALKi). Analysis of cell-free circulating tumor DNA (cfDNA) may provide a noninvasive way to identify ALK fusions and actionable resistance mechanisms without an invasive biopsy.Patients and Methods: The Guardant360 (G360; Guardant Health) deidentified database of NSCLC cases was queried to identify 88 consecutive patients with 96 plasma-detected ALK fusions. G360 is a clinical cfDNA next-generation sequencing (NGS) test that detects point mutations, select copy number gains, fusions, insertions, and deletions in plasma.Results: Identified fusion partners included EML4 (85.4%), STRN (6%), and KCNQ, KLC1, KIF5B, PPM1B, and TGF (totaling 8.3%). Forty-two ALK-positive patients had no history of targeted therapy (cohort 1), with tissue ALK molecular testing attempted in 21 (5 negative, 5 positive, and 11 tissue insufficient). Follow-up of 3 of the 5 tissue-negative patients showed responses to ALKi. Thirty-one patients were tested at known or presumed ALKi progression (cohort 2); 16 samples (53%) contained 1 to 3 ALK resistance mutations. In 13 patients, clinical status was unknown (cohort 3), and no resistance mutations or bypass pathways were identified. In 6 patients with known EGFR-activating mutations, an ALK fusion was identified on progression (cohort 4; 4 STRN, 1 EML4; one both STRN and EML4); five harbored EGFR T790M.Conclusions: In this cohort of cfDNA-detected ALK fusions, we demonstrate that comprehensive cfDNA NGS provides a noninvasive means of detecting targetable alterations and characterizing resistance mechanisms on progression. Clin Cancer Res; 24(12); 2758-70. ©2018 AACR.