Vitrakvi (larotrectinib)

Recent approval of the TRK inhibitor larotrectinib by the Food and Drug Administration (FDA) has brought interest in the study and recognition of NTRK fusions in multiple types of tumors. Trials that assess the response to this drug in cancers carrying NTRK fusions have yielded favorable results. We discuss a rare presentation of an adult-type GBM with epithelioid morphology and a BCR::NTRK2 gene fusion.

We detected (de novo/somatic) missense mutation variants in cis position of the NTRK1 gene in a subset of DDLPS indicating modifying mutations that may contribute to tumorigenesis in a subset of DDLPS. These variants beget resistance to TRK inhibitors indicating an interesting biomarker for other studies with TRK inhibitors.

One patient was succumbed to the disease at 12 months despite adjunctive treatment with TRK inhibitor larotrectinib after surgery...The final diagnosis relies on molecular assays. Patients with advanced disease may benefit from TRK inhibitor treatment.

Hence, we now have multiple genomic biomarker-based, tissue-agnostic Food and Drug Administration approvals for both gene- and immune-targeted therapies (larotrectinib/entrectinib, for NTRK fusions; selpercatinib, RET fusions; dabrafenib plus trametinib, BRAFV600E mutations; pembrolizumab/dostarlimab, microsatellite instability; and pembrolizumab for high tumor mutational burden; pemigatinib is also approved for FGFR1-rearranged myeloid/lymphoid neoplasms). Resistance to biomarker-driven therapeutics is often due to secondary mutations or co-driver gene defects; studies are now addressing the need for customized drug combinations matched to the complex molecular alteration portfolio in each tumor. Future investigation should expand tissue-agnostic therapeutics to encompass both hematologic and solid malignancies and include biomarkers beyond those that are DNA-based.

P2, N=70, Active, not recruiting, Children's Oncology Group | Trial completion date: Mar 2024 --> Sep 2024 | Trial primary completion date: Mar 2024 --> Sep 2024

Patients treated with RET protein tyrosine kinase inhibitors (TKIs) selpercatinib or pralsetinib develop RET TKI resistance by secondary RET mutations or alterative oncogenes, of which alterative oncogenes pose a greater challenge for disease management because of multiple potential mechanisms and the unclear tolerability of drug combinations. Preclinical experiments validated selpercatinib plus larotrectinib or entrectinib inhibited RET/NTRK3 dependent cells, whereas selpercatinib plus entrectinib was necessary to inhibit cells with RET/NTRK3/ALK triple alterations or a mixture of cell population carrying these genetic alterations. Thus, RET-altered MTC adapted to selpercatinib and larotrectinib with acquisition of ETV6::NTRK3 and EML4::ALK oncogenes can be managed by combination of selpercatinib and entrectinib providing proof-of-concept of urgency of incorporating molecular profiling in real-time and personalized N-of-1 care transcending one-size-fits-all approach.

This is the first report of an MYO5A::NTRK3 fusion in a pediatric GNT. GNT kinase-fused is a provisional methylation class not currently included in the WHO classification of CNS tumors. This case highlights the impact of thorough molecular characterization of CNS tumors, especially with the increasing availability of novel gene targeting therapies.

Despite the rare occurrence, these alterations have gained importance owing to approval of drugs like entrectinib and larotrectinib targeting the kinase domain of the gene. Detection of these rests on the use of conventional modalities like Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH); however, accurate characterization requires direct sequencing methods. We report an interesting case of an NTRK fusion-positive NSCLC, exhibiting good response to entrectinib.

P2, N=13, Recruiting, Children's Hospital of Philadelphia | Not yet recruiting --> Recruiting

Our analysis provides a broad molecular view of the NTRK family. The real-world adverse drug event analysis of entrectinib and larotrectinib contributes to more refined medication management.

© 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland

The representative second-generation inhibitors selitrectinib and repotrectinib were designed to overcome clinic acquired resistance of the first-generation inhibitors larotrectinib or entrectinib resulted from solvent-front and gatekeeper on-target mutations. In this review, we summarize the acquired resistance mechanism of the first- and second-generation TRK inhibitors, and firstly put forward the emerging selective type II TRK inhibitors to overcome xDFG mutations mediated resistance. Additionally, we concluded our perspectives on new challenges and future directions in this field.

Conclusions Laro demonstrated durable responses, extended survival benefit and a favourable safety profile in pts with advanced lung cancer harbouring NTRK gene fusions. These results support the adoption of ctDNA next-generation sequencing panels that include NTRK gene fusions in clinical practice.

Tropomyosin receptor kinases (TRKs), the superfamily of transmembrane receptor tyrosine kinases, have recently become an attractive method for precision anticancer therapies since the approval of Larotrectinib and Entrectinib by FDA. Finally, the binding mode of compound 30f predicted by molecular docking well explained the good enzyme inhibitory activity of indazolylaminoquinazoline compounds as TRK inhibitor. Thus, compound 30f can be used as a promising lead molecule for further structural optimization.

An ETV6:NTRK fusion detected in tumor tissue, was treated with larotrectinib; at progression, sequencing of cfDNA identified an NTRK3 G623R alteration as the acquired mechanism of resistance; the patient enrolled in a clinical trial of a second generation TRK inhibitor with clinical benefit. In metastatic PanNENs, cfDNA-based NGS identified tumor-associated mutations in 66% of plasma samples with a high level of plasma-tissue agreement in PanNEN associated genes. Clonal evolution, actionable alterations, and resistance mechanisms were detected through circulating cfDNA genotyping.

P2, N=215, Active, not recruiting, Bayer | Recruiting --> Active, not recruiting

P2, N=32, Active, not recruiting, The University of Sydney | Recruiting --> Active, not recruiting

These results identify the NGF-TrkA axis as an important suppressor of anti-tumor immunity and suggest larotrectinib might be repurposed for immune sensitization. Moreover, by enlisting low-affinity T cells, anti-NGF reduces acquired resistance to immune checkpoint blockade and prevents melanoma recurrence.

P4, N=200, Recruiting, Fudan University

P2, N=49, Active, not recruiting, National Cancer Institute (NCI) | Recruiting --> Active, not recruiting

In 2017, first-generation TRK inhibitor (TRKi) larotrectinib was granted accelerated approval from the FDA, having demonstrated histologic-agnostic activity against NTRKs fusions tumors. Since this new era has begun, resistance to first-generation TRKi has been described and has opened the development of second-generation molecules, such as selitrectinib and repotrectinib. In this review, we provide a brief overview of the studies on NTRK alterations found in pediatric central nervous system tumors and first and second-generation TRKi useful in clinical practice.

This case suggests that multimodal therapy dominated by liver transplantation, including preoperative TACE, postoperative adjuvant chemotherapy, and TRK inhibitors, is an effective treatment modality for unresectable primary hepatic YST.

Presently, larotrectinib and entrectinib are the only FDA-approved therapies for NTRK-mutated cancers...The treatment landscape for NTRK cancers is still being explored, with numerous new tyrosine kinase inhibitors currently in development or undergoing phase 1 and 2 clinical trials. In this review, we delve into both established and novel therapies targeting NTRK-mutated NSCLC.

P2, N=13, Not yet recruiting, Children's Hospital of Philadelphia | Initiation date: Nov 2023 --> Feb 2024

In the treatment of NTRK fusion-positive tumors, there are cases in which 2 approved first-generation TRK inhibitors can be used sequentially.

The solvent front and xDFG mutations induced by larotrectinib and entrectinib result in acquired resistance in advanced-stage patients...In biochemical and cellular assays, 40l showed better inhibitory activity against TRKA than that by the positive control, selitrectinib...In vitro assays indicated that 40l possessed outstanding plasma stability and moderate liver microsomal stability. Based on the above results, compound 40l could be further optimized to overcome the solvent front and xDFG TRK mutations.

The tropomyosin receptor kinase inhibitors (TRKi) larotrectinib and entrectinib are among the first agents with tissue agnostic FDA approvals for cancer treatment, and additional TRKi are undergoing development...There are numerous ongoing studies investigating TRKi as frontline, adjuvant, and salvage therapy. It will be critical to continue to gather long term safety data on the use of these agents, particularly in children.

DNA- and RNA-based screening systems may be useful for detecting tyrosine kinase fusion genes in specific fusion-negative sarcomas and identifying key therapeutic targets, leading to possible breakthroughs in the treatment of bone and soft tissue sarcomas. Given that current DNA sequencing misses fusion genes, RNA-based screening systems should be widely considered as a worldwide test for sarcoma. If standard treatments such as chemotherapy are not effective, or even if the sarcoma is of bone, RNA sequencing should be considered to identify as many therapeutic targets as possible.

No abstract available

Novel systemic therapies with intracranial utility include new anaplastic lymphoma kinase inhibitors like brigatinib and ensartinib; selective "rearranged during transfection" inhibitors like selpercatinib and pralsetinib; B-raf proto-oncogene inhibitors like encorafenib and vemurafenib; Kirsten rat sarcoma viral oncogene inhibitors like sotorasib and adagrasib; ROS1 gene rearrangement (ROS1) inhibitors, anti-neurotrophic tyrosine receptor kinase agents like larotrectinib and entrectinib; anti-human epidermal growth factor receptor 2/epidermal growth factor receptor exon 20 agent like poziotinib; and antibody-drug conjugates like trastuzumab-emtansine and trastuzumab-deruxtecan. This review highlights the modern multidisciplinary management of BM, emphasizing the integration of systemic and local therapies.

Importantly, compared with the combination of Larotrectinib and Tepotinib, 1D228 monotherapy in MKN45 xenograft tumor models showed stronger antitumor activity and lower toxicity. 1D228 suppressed the migration and tube formation of endothelial cells, which are the key functions of tumor angiogenesis. Taken together, compound 1D228 may be a promising candidate for the next generation of c-Met and TRK inhibitors for cancer treatment, and offers a novel potential treatment strategy for cancer patients with abnormal expressions of c-Met or NTRK, or simultaneous of them.

P=N/A, N=368, Completed, Bayer | Active, not recruiting --> Completed | Trial completion date: Nov 2023 --> Aug 2023 | Trial primary completion date: Nov 2023 --> Aug 2023

Our patient is now 1 year from resection without disease progression on larotrectinib. This case highlights the importance of expanded NGS testing, particularly in rare tumors.

Three patients recurred after first-line therapy: 1 with BRAF mutated GBM, 1 with GBM harboring FGFR3-TACC3 fusion, and 1 with NTRK1 fusion positive glioneuronal tumor received specific BRAF/MEK inhibitor (dabrafenib/trametinib), FGFR inhibitor (pemigatinib), and NTRK inhibitor (larotrectinib), respectively. The incidence of actionable molecular alterations in IDH wt gliomas and glioneuronal/neuronal tumors was low. However, the use of targeted therapies may lead to significant impact on the outcome.

Pediatric and adult patients will be followed for ≥ 5 years and ≥ 2 years, respectively, unless lost to follow-up, withdrawal, or death. Enrollment is ongoing worldwide; 24 patients with primary CNS cancer have been enrolled to date.

We report a large cohort of patients with TRK fusion-driven primary CNS tumors. Children with LGG glioma had a favorable outcome compared to adult and HGG. Larotrectinib appears to be associated with a better response rate and longer duration of response compared to non-targeted therapy.

Larotrectinib demonstrated rapid, durable responses and a manageable safety profile in patients with TRK fusion primary CNS tumors. This supports the wider adoption of next-generation sequencing panels that include NTRK gene fusions when testing patients with CNS tumors.

In silico investigation revealed that larotrectinib, entrectinib, and infigratinib can target the key residues of the studied proteins. Therefore, these approved kinase inhibitors could be considered potential therapies for MDR cancers by targeting these transporters.Communicated by Ramaswamy H. Sarma.

Challenges remain in accurately diagnosing NTRK gene alterations and integrating screening into routine clinical practice. Trk inhibitors have surpassed their conventional role of inhibition and are now seeing new applications in radiopharmaceutical development and as molecular targeting agents.

Two of the patients had extensive disease and underwent chemotherapy. Larotrectinib was approved for one patient who demonstrated a striking reduction in tumor volume upon initiation of this treatment.

Tropomyosin receptor kinase (TRK) fusion proteins result from translocations involving the NTRK gene and cause cancer in a range of tumor types. Larotrectinib is an agent that specifically targets TRK fusion proteins and is approved for the treatment of patients with TRK fusion cancer. This study looked at how well larotrectinib worked in adult patients with sarcomas caused by TRK fusion proteins. Over half of patients had a durable response to larotrectinib, with no unexpected side effects. These results show that larotrectinib is safe and effective in adult patients with TRK fusion sarcomas.

Additionally, one MPT sample harbored a pathogenic NTRK1 fusion (TPM4:NTRK1), and treatment with larotrectinib for over 16 months suggests a clinical response to therapy... Our study demonstrates the importance of employing next generation sequencing (NGS) in MPTs to detect actionable genomic alterations. To effectively analyze fusions, an NGS panel that include RNA sequencing is recommended, considering the occurrence of NTRK1 fusion reported herein. Although HER2 transcriptional expression was low, further investigations examining HER2 IHC in PTs are still necessary.