STRN-ALK Fusion in Advanced Salivary Gland Carcinoma With Response to Anaplastic Lymphoma Kinase Inhibition: Case Report and Literature Review.

Salivary gland carcinomas are a heterogeneous group of rare tumors. There is no established standard of care therapy for metastatic disease. We describe the case of a patient with metastatic salivary gland adenocarcinoma harboring STRN-ALK translocation, with tumor response and clinical benefit from anaplastic lymphoma kinase (ALK) inhibition. Our patient experienced clinical benefit from first and second generation ALK inhibition in a chemotherapy refractory tumor. Tumor mutation profiling can identify mutations that may render tumors sensitive to targeted therapy with tyrosine kinase inhibitors.

Real-world treatment sequencing and effectiveness of second- and third-generation ALK tyrosine kinase inhibitors for ALK-positive advanced non-small cell lung cancer.

INTRODUCTION: With multiple targeted therapies approved for anaplastic lymphoma kinase (ALK)-positive metastatic non-small cell lung cancer (NSCLC), it is increasingly important to understand outcomes with various sequences of next-generation ALK tyrosine kinase inhibitors (TKIs). We describe contemporary sequencing patterns and treatment effectiveness of first-line (1L) and second-line (2L) treatments in patients who received second-generation ALK TKIs in the 1L treatment of ALK-positive NSCLC in the United States. METHODS: A cohort of adults with ALK-positive advanced NSCLC who initiated treatment with 1L alectinib or brigatinib between June 2017 and April 2021 in the Flatiron Health electronic health record-derived de-identified database were followed through April 2023. Time to treatment discontinuation (TTD) in 1L and 2L, TTD on 1L plus 2L sequential therapy (TTD2), and total time on sequential ALK TKI therapy (including beyond 2L) were evaluated. RESULTS: Patients (N=273) were followed up for a median duration of 28.9 months. Among patients who discontinued 1L therapy, 22% died after 1L discontinuation (median time from discontinuation to death, 4.0 months) without receiving 2L therapy. Median (95% confidence interval [CI]) TTD was 21.9 (15.2-25.8) and 7.3 (5.3-10.2) months in 1L and 2L, respectively. Median (95% CI) TTD2 was 29.4 (25.1-36.1) months and total time on sequential ALK TKI treatment was 28.0 (23.6-32.9) months. CONCLUSIONS: In this large real-world study, TTD2 and the total time on sequential ALK TKIs was approximately 2.5 years. The high attrition rate from 1L to 2L and the longest clinical benefit observed with 1L therapy support using the drug with the longest 1L effectiveness up front in patients with ALK-positive advanced NSCLC.

Targeting ALK receptors in non-small cell lung cancer: what is the road ahead?

INTRODUCTION: Anaplastic lymphoma kinase (ALK) gene-rearrangements are identified in about 3-5% of non-small cell lung cancers (NSCLC), and ALK-rearranged NSCLC is to be considered an oncogene-addicted cancer with peculiar clinical characteristics. AREAS COVERED: Several ALK inhibitors have been studied and approved for use in the treatment of advanced ALK-rearranged NSCLC with reported superiority in terms of efficacy and safety profile compared with chemotherapy. Second- and third-generation ALK inhibitors (alectinib, brigatinib, and lorlatinib) offer to NSCLC patients a clinically meaningful prolongment of survival with a very good quality of life profile. However, resistances to these agents always occur, with less satisfying options for second-line treatments. Direct comparisons among these agents are not available, and the choice among brigatinib, alectinib, and lorlatinib as first-line treatment remains challenging. Very recently, alectinib has been demonstrated to improve efficacy outcomes compared with chemotherapy also in resected stage IB-IIIA ALK-rearranged NSCLC, extending the clinical benefit offered by ALK inhibitors also to the adjuvant setting. EXPERT OPINION: Future development of ALK inhibitors in NSCLC treatment includes the search for optimal management of acquired resistance to first-line treatments and the extension of use of ALK inhibitors also to neoadjuvant and preferably to perioperative setting.

Metastatic Non-Myofibroblastic Sarcoma Harbouring EML4-ALK Fusion-Dramatic Response to ALK Tyrosine Kinase Inhibitors and Development of Resistance Mutations.

BACKGROUND: Anaplastic lymphoma kinase (ALK) rearrangements are rare in non-myofibroblastic sarcoma and there is limited data on the efficacy of ALK tyrosine kinase inhibitors (TKIs) and mechanisms of resistance in these patients. CASE: A 58 year-old man with metastatic non-myofibroblastic sarcoma was found to have an EML4-ALK fusion on molecular sequencing. After progression on first line systemic therapy with doxorubicin, the patient received alectinib, a second generation ALK inhibitor, and had a marked clinical and radiological response. He progressed after 5 months of treatment. Repeat lung biopsy identified the emergence of an ALK I1171N resistance mutation. He was then treated with lorlatinib, again with rapid clinical improvement and significant partial radiological response. He progressed after 4 months, at which time a repeat lung biopsy identified a new ALK kinase domain mutation G1202R. The patient was subsequently treated with chemotherapy, though unfortunately died shortly after due to rapidly progressive disease. CONCLUSION: This case report adds to a body of evidence demonstrating the potential transformative response to targeted therapy in non-lung solid organ tumours harbouring ALK fusions. This is the first description tracking the development of resistance mutations in a patient with non-myofibroblastic sarcoma and questions the utility of the presence of G1202R mutation as a marker of lorlatinib sensitivity in non-lung ALK rearranged tumours, contrary to experience in lung cancer.

Complete and durable regression of leptomeningeal involvement during lorlatinib treatment in a patient with lung cancer.

Metastatic spread to the central nervous system (CNS) is frequent in anaplastic lymphoma kinase ( ALK )-rearranged non-small cell lung cancer (NSCLC) and has an important impact on patient prognosis and quality of life. Leptomeningeal involvement may occur in up to 10% of cases of ALK-positive NSCLC. Lorlatinib is a third-generation ALK inhibitor that has excellent CNS penetrability and demonstrated its efficacy both in pretreated and treatment-naive patients. Herein, we present the case of a 34-year-old patient diagnosed with stage IV ALK-rearranged NSCLC who received two lines of ALK inhibitors (crizotinib followed by alectinib) and several courses of brain stereotactic ablative radiotherapy until leptomeningeal involvement was detected. Third-line lorlatinib was then administered, and 2 months later encephalic MRI documented complete regression of the leptomeningeal involvement that is still maintained after 36 months while treatment with lorlatinib is still ongoing with good tolerability. To the best of our knowledge, this is the longer intracranial response reported in the literature, underlining the importance of the most appropriate choice of systemic treatments and their integration with loco-regional approaches to improve outcomes.

Top advances of the year: Targeted therapy for lung cancer.

The past year has offered significant advancements in the field of non-small cell lung cancer (NSCLC), both in the early and advanced disease settings. The identification of guideline-recommended actionable targets has provided the foundation for developing multiple new therapeutic agents. There has been a focus on developing drugs designed to overcome acquired resistance, a limitation of tyrosine kinase inhibitor-based therapy in lung cancer. In addition, there is an emerging trend toward combination therapies for patients in the first-line setting with the goal of preventing or delaying resistance. Another promising area of development has been the use of antibody-drug conjugates, where there are the initial reports of central nervous system efficacy and activity in patients with genomic alterations. Over the past year, numerous publications and presentations have highlighted multiple therapeutic advances, offering new treatment options for patients with NSCLC. The focus of this review is to summarize the most impactful findings, emphasizing their significance in the evolving treatment landscape for NSCLC. Several landmark trials in lung cancer with practice-changing clinical implications have been presented and published in 2023. This article reviews a selection of these trials as they relate to early and advanced-stage oncogene-driven lung cancer. The ADAURA and ALINA trials, in which targeted therapy given in the adjuvant setting has demonstrated improved clinical outcomes, are reviewed. In the advanced-stage setting, recent trials in the context of specific oncogene drivers are reviewed, including EGFR, ALK, ROS1, RET, ERBB2 (HER2), BRAF, MET exon 14 skipping (METex14), and KRAS alterations. Also discussed are the results of several trials that have evaluated the use of combination therapies and resistance-mechanism agnostic treatment strategies. PLAIN LANGUAGE SUMMARY: Targeted therapy plays an important role for patients with early and advanced-stage non-small cell lung cancer carrying specific genetic alterations. New strategies that combine multiple therapies are now being studied in randomized clinical trials, with the goal of enhancing the effectiveness of targeted therapy for patients with advanced lung cancer.

Expert Consensus on the Management of Adverse Events of Lorlatinib in the Treatment of ALK+ Advanced Non-small Cell Lung Cancer.

The use of anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs), such as lorlatinib, for the treatment of patients with ALK gene rearrangement (or ALK-positive) non-small cell lung cancer (NSCLC) has been shown to improve the overall survival and quality of life of these patients. However, lorlatinib is not exempt from potential adverse events. Adequate monitoring and management of these adverse events are critical for increasing patient adherence to lorlatinib, thereby maximizing the benefits of treatment and minimizing the risks associated with treatment discontinuation. Considering that the adverse events of lorlatinib can affect different organs and systems, the participation of a multidisciplinary team, including cardiologists, neurologists, internal medicine specialists, and oncology pharmacists, is needed. This article presents specific and pragmatic strategies for identifying and treating the most relevant adverse events associated with lorlatinib in patients with advanced ALK-positive NSCLC based on the clinical experience of a multidisciplinary panel of experts.

Real-world evidence of brigatinib as second-line treatment after crizotinib for ALK+ non-small cell lung cancer using South Korean claims data (K-AREAL).

PURPOSE: There is a lack of real-world data in Asian populations for brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor for patients with non-small cell lung cancer (NSCLC). This study analysed real-world outcomes and dosing patterns for brigatinib in patients with crizotinib-refractory ALK+ NSCLC in South Korea. METHODS: This retrospective, non-interventional, cohort study used South Korean Health Insurance and Review Assessment claims data for adults with ALK+ NSCLC who initiated brigatinib between 19 April 2019 and 31 March 2021 after receiving prior crizotinib. Patients' characteristics, time to discontinuation (TTD), time to dose reduction, overall survival (OS) and treatment adherence were assessed. RESULTS: The study included 174 patients (56.9% male; 27.0% with a history of brain metastases). Median duration of prior crizotinib was 17 (range 0.3-48) months. Median follow-up after brigatinib initiation was 18 (range 0-34) months. Overall, 88.5% of patients received full-dose brigatinib (180 mg/day) and 93.1% of patients were adherent (proportion of days covered ≥0.8). The median TTD was 24.9 months (95% CI 15.2-not reached). The probability of continuing treatment was 63.2% at 1 year and 51.5% at 2 years. The probability of continuing at full or peak dose was 79.7% at 1 year and 75.6% at 2 years. Median OS was not reached. The 2-year OS rate was 68.7%. CONCLUSIONS: In this first nationwide retrospective study using national insurance claim data, brigatinib demonstrated real-world clinical benefit as second-line treatment after prior crizotinib in ALK+ NSCLC patients in South Korea.

IC Regimen: Delaying Resistance to Lorlatinib in ALK Driven Cancers by Adding Repurposed Itraconazole and Cilostazol.

Lorlatinib is a pharmaceutical ALK kinase inhibitor used to treat ALK driven non-small cell lung cancers. This paper analyses the intersection of past published data on the physiological consequences of two unrelated drugs from general medical practice-itraconazole and cilostazol-with the pathophysiology of ALK positive non-small cell lung cancer. A conclusion from that data analysis is that adding itraconazole and cilostazol may make lorlatinib more effective. Itraconazole, although marketed worldwide as a generic antifungal drug, also inhibits Hedgehog signaling, Wnt signaling, hepatic CYP3A4, and the p-gp efflux pump. Cilostazol, marketed worldwide as a generic thrombosis preventative drug, acts by inhibiting phosphodiesterase 3, and, by so doing, lowers platelets' adhesion, thereby partially depriving malignant cells of the many tumor trophic growth factors supplied by platelets. Itraconazole may enhance lorlatinib effectiveness by (i) reducing or stopping a Hedgehog-ALK amplifying feedback loop, by (ii) increasing lorlatinib's brain levels by p-gp inhibition, and by (iii) inhibiting growth drive from Wnt signaling. Cilostazol, surprisingly, carries minimal bleeding risk, lower than that of aspirin. Risk/benefit assessment of the combination of metastatic ALK positive lung cancer being a low-survival disease with the predicted safety of itraconazole-cilostazol augmentation of lorlatinib favors a trial of this drug trio in ALK positive lung cancer.

Ultra-fast UPLC-MS/MS approach for estimating X-376 in human liver microsomes: Evaluation of metabolic stability via in silico software and in vitro analysis.

X-376 is a novel anaplastic lymphoma kinase (ALK) inhibitor that is capable of penetrating the blood brain barrier. This makes it suitable for use in patients with ALK-positive non-small cell lung cancer (NSCLC) who have metastases in the central nervous system. This study developed a highly sensitive, fast, eco-friendly, and reliable UPLC-MS/MS approach to quantify X-376 in human liver microsomes (HLMs). This approach was used to evaluate X-376's metabolic stability in HLMs in vitro. The UPLC-MS/MS analytical technique validation followed US-FDA bio-analytical method validation guidelines. StarDrop software, containing P450 metabolic and DEREK modules, was utilized to scan X-376's chemical structure for metabolic lability and hazardous warnings. X-376 and Encorafenib (ENF as internal standard) were resoluted on the Eclipse Plus C18 column utilizing an isocratic mobile phase method. The X-376 calibration curve was linear from 1 to 3000 ng/mL. The precision and accuracy of this study's UPLC-MS/MS approach were tested for intra- and inter-day measurements. Inter-day accuracy was -1.32% to 9.36% while intra-day accuracy was -1.5% to 10.00%. The intrinsic clearance (Clint) and in vitro half-life (t1/2) of X-376 were 59.77 mL/min/kg and 13.56 min. The high extraction ratio of X-376 supports the 50 mg twice-daily dose for ALK-positive NSCLC and CNS metastases patients. In silico software suggests that simple structural changes to the piperazine ring or group substitution in drug design may improve metabolic stability and safety compared to X-376.

Nephrotoxicity of targeted therapy used to treat lung cancer.

Lung cancer is the leading cause of cancer-related death worldwide, especially non-small cell lung cancer. Early diagnosis and better treatment choices have already provided a more promising prognosis for cancer patients. In targeted therapy, antagonists target specific genes supporting cancer growth, proliferation and metastasis. With the incorporation of targeted therapies in routine cancer therapy, it is imperative that the array of toxicities associated with these agents must be well-recognized and managed, especially since these toxicities are distinct from those seen with conventional cytotoxic agents. Drug-related nephrotoxicity has attracted attention when initiating cancer therapy. Our review aims to summarize the adverse renal effects caused by targeted therapy during lung cancer treatment, mainly focusing on EGFR and ALK tyrosine kinase inhibitors. Also, we discuss the possible mechanism of the side effect and provide managements to help improve the renal function in clinical practice.

Population modeling analyses of crizotinib in pediatric patients with ALK-positive advanced cancers.

BACKGROUND: Alterations in the ALK (anaplastic lymphoma kinase) gene play a critical role in pathogenesis of anaplastic large cell lymphoma (ALCL). Crizotinib is a small molecule competitive inhibitor of ALK, ROS1, and MET kinases and was approved for pediatric patients with ALK-positive relapsed or refractory, systemic ALCL, and ALK-positive unresectable, recurrent, or refractory inflammatory myofibroblastic tumors (IMT). PROCEDURE: Crizotinib data from pediatric patients with relapsed or refractory solid tumors, IMT, or ALCL were included in the analyses. All patients received crizotinib orally at doses ranging from 100 to 365 mg/m2 twice daily (BID). PopPK analyses were conducted to characterize crizotinib disposition in pediatric patients. Exposure-response (ER) safety and antitumor analyses were conducted to characterize relationships between crizotinib dose or exposure with safety and antitumor activity endpoints of interest. RESULTS: The population pharmacokinetic (popPK), ER safety, and ER antitumor analysis included 98, 110, and 36 pediatric patients, respectively. A one-compartment pharmacokinetic model with allometric scaling, first-order elimination, and first-order absorption with lag time adequately described the data. Natural log-transformed model-predicted crizotinib AUCss (steady-state area under the concentration-time curve) demonstrated a significant, positive relationship with Grade ≥3 NEUTROPENIA and Any Grade VISION DISORDER. Crizotinib dose demonstrated a positive relationship with objective response rate. CONCLUSIONS: No significant differences in PK were identified across a wide range of ages or across tumor types, suggesting body surface area (BSA)-based dosing adequately adjusted for differences in patient size to achieve similar systemic crizotinib exposures across young children and adolescent pediatric patients. None of the myelosuppressive events except Grade ≥3 NEUTROPENIA had significant relationships identified with crizotinib dose or exposure, suggesting crizotinib is a tolerable treatment with less hematological toxicity than traditional chemotherapy regimens for pediatric patients with ALK-mutated cancers. Results from the presented analyses support the pediatric dosing recommendations in the product label.

ALK Inhibitor and Chemotherapy Combinations in Models of ALK-Translocated NSCLC.

BACKGROUND/AIM: Randomized trials have shown the benefit of combining tyrosine kinase inhibitors (TKI) and chemotherapy in the treatment of epidermal growth factor receptor-mutant non-small-cell lung cancer (NSCLC). For anaplastic lymphoma kinase-rearranged (ALK+) NSCLC, prospective trial results of the combination are not available and have not even been thoroughly investigated in vitro. In this study, we investigated combinations of TKI and chemotherapy using in vitro models of ALK+ NSCLC. MATERIALS AND METHODS: ALK+ cell line models H3122, H2228, and DFCI032 with differing primary resistance to ALK receptor TKIs were used. We investigated short-(viability assay) and long-term (colony-formation assay) cytotoxicity, apoptosis, and cell signaling in response to the combinations of agents. We selected the most commonly used agents, alectinib, cisplatin, and pemetrexed, to investigate the combination effects. RESULTS: In the combination experiments with short-term exposure, synergism between TKI and pemetrexed was observed, while cisplatin had antagonistic effects. In the long-term experiments, the combination of cisplatin and TKI was synergistic in all lines, while no synergism was observed with pemetrexed. Among the chemotherapy and TKI sequences, cisplatin followed by TKI was more cytotoxic than the opposite in two out of the three models. In the TKI-sensitive H3122 cell line, the combination of chemotherapy and TKI combination increased apoptosis. Interestingly, pemetrexed treatment resulted in the activation of ALK, which was abolished with TKI. CONCLUSION: Combining TKI and chemotherapy in ALK+ models has some synergistic effects that overcome primary TKI resistance. However, the synergy varies depending on the chemotherapeutic agent, cytotoxic assay, and the cell line used. Prospective clinical trials are warranted to fully characterize the potential of combination chemotherapy with TKIs in ALK+ NSCLC.

Antineoplastic Effect of ALK Inhibitor Crizotinib in Primary Human Anaplastic Thyroid Cancer Cells with STRN-ALK Fusion In Vitro.

Anaplastic thyroid cancer (ATC) is one of the deadliest human cancers and represents <2% of thyroid carcinomas. A therapeutic target for ATC is represented by anaplastic lymphoma kinase (ALK) rearrangements, involved in tumor growth. Crizotinib is an oral small-molecule tyrosine kinase inhibitor of the ALK, MET, and ROS1 kinases, approved in ALK-positive non-small cell lung cancer. Until now, the effect of crizotinib in "primary human ATC cells" (pATCs) with transforming striatin (STRN)-ALK fusion has not been reported in the literature. In this study, we aimed to obtain pATCs with STRN-ALK in vitro and evaluate the in vitro antineoplastic action of crizotinib. Thyroid surgical samples were obtained from 12 ATC patients and 6 controls (who had undergone parathyroidectomy). A total of 10/12 pATC cultures were obtained, 2 of which with transforming STRN-ALK fusion (17%). Crizotinib inhibited proliferation, migration, and invasion and increased apoptosis in 3/10 pATC cultures (2 of which with/1 without STRN-ALK), particularly in those with STRN-ALK. Moreover, crizotinib significantly inhibited the proliferation of AF cells (a continuous cell line obtained from primary ATC cells). In conclusion, the antineoplastic activity of crizotinib has been shown in human pATCs (with STRN-ALK) in preclinical studies in vitro, opening the way to future clinical evaluation in these patients.

Lysophosphatidic Acid Stimulates Mitogenic Activity and Signaling in Human Neuroblastoma Cells through a Crosstalk with Anaplastic Lymphoma Kinase.

Lysophosphatidic acid (LPA) is a well-documented pro-oncogenic factor in different cancers, but relatively little is known on its biological activity in neuroblastoma. The LPA effects and the participation of the tyrosine kinase receptor anaplastic lymphoma kinase (ALK) in LPA mitogenic signaling were studied in human neuroblastoma cell lines. We used light microscopy and [3H]-thymidine incorporation to determine cell proliferation, Western blot to study intracellular signaling, and pharmacological and molecular tools to examine the role of ALK. We found that LPA stimulated the growth of human neuroblastoma cells, as indicated by the enhanced cell number, clonogenic activity, and DNA synthesis. These effects were curtailed by the selective ALK inhibitors NPV-TAE684 and alectinib. In a panel of human neuroblastoma cell lines harboring different ALK genomic status, the ALK inhibitors suppressed LPA-induced phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2), which are major regulators of cell proliferation. ALK depletion by siRNA treatment attenuated LPA-induced ERK1/2 activation. LPA enhanced ALK phosphorylation and potentiated ALK activation by the ALK ligand FAM150B. LPA enhanced the inhibitory phosphorylation of the tumor suppressor FoxO3a, and this response was impaired by the ALK inhibitors. These results indicate that LPA stimulates mitogenesis of human neuroblastoma cells through a crosstalk with ALK.

Novel Amphiphilic PROTAC with Enhanced Pharmacokinetic Properties for ALK Protein Degradation.

Advancements in anticancer strategies spotlight proteolysis targeting chimera (PROTAC) technology, yet it is hindered by poor water solubility and bioavailability. This study introduces a novel amphiphilic PROTAC, B1-PEG, synthesized through PEGylation of an optimized PROTAC molecule, B1, to enhance its properties. B1-PEG is engineered to self-organize into micelles in water and releases its active form in response to the tumor-specific high GSH environment. Comparative pharmacokinetic analysis revealed B1-PEG's superior bioavailability at 84.8%, outperforming the unmodified PROTAC molecule B1. When tested in a H3122 xenograft mouse model, B1-PEG significantly regressed tumors, underscoring its potential as a formidable candidate in targeted cancer therapy. Our findings offer a promising direction for overcoming bioavailability limitations in PROTAC drug design.

Real-World Treatment Patterns and Outcomes Across Three Lines of Therapy in Patients with ALK+ NSCLC.

INTRODUCTION: Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) are standard first- and second-line treatment for advanced ALK+ non-small cell lung cancer (NSCLC). We evaluated outcomes in patients with ALK+ NSCLC receiving third-line ALK TKI versus non-ALK-directed therapy. METHODS: Flatiron Health OncoEMR data were extracted for patients with ALK+ NSCLC initiating first-line ALK TKI between January 2015 and March 2022 followed by second-line ALK TKI and third-line ALK TKI (group A) or non-TKI therapy (group B). Time-to-treatment discontinuation (TTD) and overall survival (OS) were analyzed using multivariate modelling. RESULTS: Among patients receiving third-line ALK TKI (A, n = 85) or non-TKI therapy (B, n = 43), most received first-line crizotinib (A/B: 64%/60%) and second-line alectinib (36%/30%), ceritinib (24%/19%), or lorlatinib (15%/30%). Common third-line treatments were lorlatinib/alectinib (41%/33%) in A and immunotherapy, chemotherapy, or chemotherapy + immunotherapy (30%/28%/21%) in B. Group A versus B had longer TTD of first-line treatment (hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.41-0.93; p = 0.020) and second-line treatment (HR 0.50, 95% CI 0.33-0.75; p < 0.001) and longer OS from start of first-line treatment (HR 0.32, 95% CI 0.19-0.54; p < 0.001) and second-line treatment (HR 0.40, 95% CI 0.24-0.66; p < 0.001). For third-line treatment, median TTD (A/B) was 6.2/2.4 months (HR 0.61, 95% CI 0.37-1.00; p = 0.049) and OS was 17.6/6.5 months (HR 0.57, 95% CI 0.33-0.98; p = 0.042). CONCLUSIONS: Patients receiving third-line non-ALK-directed therapy had suboptimal outcomes on prior TKIs. Patients with longer duration of prior ALK TKI treatment appeared to benefit from third-line ALK TKIs.

Anaplastic Lymphoma Kinase signaling stabilizes SLC3A2 expression via MARCH11 to promote neuroblastoma cell growth.

Solute Carrier Family 3, Member 2 (SLC3A2 or 4F2hc) is a multifunctional glycoprotein that mediates integrin-dependent signaling, acts as a trafficking chaperone for amino acid transporters, and is involved in polyamine transportation. We identified SLC3A2 as a potential Anaplastic Lymphoma Kinase (ALK) interacting partner in a BioID-proximity labeling screen in neuroblastoma (NB) cells. In this work we show that endogenous SLC3A2 and ALK interact in NB cells and that this SLC3A2:ALK interaction was abrogated upon treatment with the ALK inhibitor lorlatinib. We show here that loss of ALK activity leads to decreased SLC3A2 expression and reduced SLC3A2 protein stability in a panel of NB cell lines, while stimulation of ALK with ALKAL2 ligand resulted in increased SLC3A2 protein levels. We further identified MARCH11, an E3 ligase, as a regulator of SLC3A2 ubiquitination downstream of ALK. Further, knockdown of SLC3A2 resulted in inhibition of NB cell growth. To investigate the therapeutic potential of SLC3A2 targeting, we performed monotreatment of NB cells with AMXT-1501 (a polyamine transport inhibitor), which showed only moderate effects in NB cells. In contrast, a combination lorlatinib/AMXT-1501 treatment resulted in synergistic inhibition of cell growth in ALK-driven NB cell lines. Taken together, our results identify a novel role for the ALK receptor tyrosine kinase (RTK), working in concert with the MARCH11 E3 ligase, in regulating SLC3A2 protein stability and function in NB cells. The synergistic effect of combined ALK and polyamine transport inhibition shows that ALK/MARCH11/SLC3A2 regulation of amino acid transport is important for oncogenic growth and survival in NB cells.

Structure-guided conversion from an anaplastic lymphoma kinase inhibitor into Plasmodium lysyl-tRNA synthetase selective inhibitors.

Aminoacyl-tRNA synthetases (aaRSs) play a central role in the translation of genetic code, serving as attractive drug targets. Within this family, the lysyl-tRNA synthetase (LysRS) constitutes a promising antimalarial target. ASP3026, an anaplastic lymphoma kinase (ALK) inhibitor was recently identified as a novel Plasmodium falciparum LysRS (PfLysRS) inhibitor. Here, based on cocrystal structures and biochemical experiments, we developed a series of ASP3026 analogues to improve the selectivity and potency of LysRS inhibition. The leading compound 36 showed a dissociation constant of 15.9 nM with PfLysRS. The inhibitory efficacy on PfLysRS and parasites has been enhanced. Covalent attachment of L-lysine to compound 36 resulted in compound 36K3, which exhibited further increased inhibitory activity against PfLysRS but significantly decreased activity against ALK. However, its inhibitory activity against parasites did not improve, suggesting potential future optimization directions. This study presents a new example of derivatization of kinase inhibitors repurposed to inhibit aaRS.