NTRK fusion

Recent approvals of selective RET inhibitors, pralsetinib and selpercatinib, has shifted the focus of RET kinase drug discovery programs towards the development of selective inhibitors. This selective dual RET/TRK inhibitor can be utilized in tumors with both RET and TRK genetic backgrounds and can also provide blockade of NTRK-fusions that are selected for from RET inhibitor treatments. Efforts towards developing dual RET/TRK inhibitors can be beneficial in terms of encompassing more diverse patient classes while also achieving blockade against emerging resistance mechanisms.

No abstract available

Larotrectinib and entrectinib are first-generation TRK inhibitors that have demonstrated efficacy in patients with TRK fusion lung cancers. Among these assays, RNA-based next-generation sequencing (NGS) can be considered a gold standard for detecting NTRK gene fusions; however, several alternatives with minimally acceptable sensitivity and specificity are also available in areas where widespread access to NGS is unfeasible. This review highlights the importance of testing for NTRK gene fusions in lung cancer, ideally using the gold-standard method of RNA-based NGS, the various assays that are available, and treatment algorithms for patients.

P2, N=27, Active, not recruiting, Abramson Cancer Center at Penn Medicine | Trial primary completion date: Mar 2024 --> Dec 2024

Results The 64 patients with colorectal cancer were at a male-to-female ratio of 1.21∶1,with the mean age of (56.59±13.27) years.The tumors were located in the colon in 46(71.88%) patients and in the rectum in 18(28.12%) patients.Sixty(93.75%) patients presented adenocarcinoma,and 4(6.25%) patients presented other types of tumors.The patients in T1/T2 and T3/T4 phases accounted for 17.19%(n=11) and 82.81%(n=53),respectively.Lymph node metastasis occurred in 24(37.50%) patients.The immunohistochemical staining results showed partially down-regulated or absent expression of SMARCA4 in 1(1.56%) patient,positive BRAF expression in 4(6.25%) patients,and mutant expression of P53 in 35(54.69%) patients.The PD-1-expressing tumor associated immune cell was proportion score<10% in 45(70.31%) patients and≥10% in 19(29.69%) patients.The PD-L1 combined positive score was<10 in 52(81.25%) patients and≥10 in 12(18.75%) patients.The gene fusion of NTRK1,NTRK2,and NTRK3 was negative in all the patients,and BRAF V600E gene mutation was positive in 4(6.25%) patients.The SMARCA4 gene alteration was not detected in the patient with partial expression missing of SMARCA4.The PD-L1 combine positive score was correlated with the deficient mismatch repair(dMMR)/microsatellite instability-high (MSI-H) and the PD-1 expression (χ2=10.223,P=0.001;χ2=11.979,P=0.001). Conclusions The down-regulated or absent SMARCA4 expression and NTRK gene fusion are rare in the patients with colorectal cancer in Tibet.A few patients present BRAF V600E gene mutations,and Pan-TRK and BRAF expression can be used for the primary screening of NTRK gene fusion and BRAF gene mutation.The patients with dMMR/MSI-H are prone to high expression of PD-L1 and expected to benefit from immunotherapy.No significant correlation exists between P53 mutation and PD-L1 expression.The high expression of PD-1 is positively correlated with the high expression of PD-L1.

On the other hand, there are some approved drugs, such as pembrolizumab for TMB-H or entrectinib or larotrectinib for NTRK fusion gene, for which there is no stand-alone companion diagnostics and the eligibility for these drugs cannot be judged without the results of CGP test. This paper discusses the current status and issues of companion diagnostics in cancer genomic medicine.

FISH could complement NGS detection, particularly when NTRK fusion is detected by DNA sequencing. NTRK fusion in GC may not be limited to specific subtypes.

Case Presentation and We report two cases with RAI-resistant lung metastases treated with larotrectinib: 83-year-old male presenting with an ETV6::NTRK3 fusion-positive tumor with the TERT promoter mutation c.-124C>T, and a 31-year-old female presenting with a TPR::NTRK1 fusion-positive tumor (and negative for TERT promoter mutation)...In contrast, the TERT-negative tumor exhibited successful I-131 reuptake with a TDS of -0.060. As observed for RAI-resistance associated with concurrent TERT and BRAF mutations, the co-occurrence of TERT mutations and NTRK fusions may also contribute to re-sensitization failure.

Moreover, so was the case with the concomitant expression of NTRK fusions and EGFR mutations. We present a case report of a patient with concomitant EGFR mutation and NTRK1 fusion.

The follow-up CT scan revealed peritoneal nodules suggestive of peritoneal dissemination, and Entrectinib (a TRK inhibitor) was administered...The present case may offer new insights into the potential introduction of TRK inhibitors as treatments for GISTs with NTRK fusions. Additionally, the presence of abundant lymphoid infiltration in the present case may prompt further research into immunotherapy as a possible additional therapeutic option.

Genetic abnormalities with treatment options were found in 62.7% of advanced thyroid carcinomas. TP53 abnormality was an independent poor prognostic factor for overall survival in differentiated thyroid carcinoma. The time to treatment failure for lenvatinib was not different based on genetic profile.

NTRK+ patients may have an increased risk of death compared with NTRK- patients. When using historic control data to assess the comparative effectiveness of TRK inhibitors, the prognostic value of the NTRK fusion biomarker should therefore be accounted for.

Drug synergy was seen using trametinib and rapamycin in combination with entrectinib.

P=N/A, N=100, Active, not recruiting, Regina Elena Cancer Institute | Recruiting --> Active, not recruiting

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.

P1, N=29, Terminated, Pyramid Biosciences | Phase classification: P1/2 --> P1

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.

Therefore, clinical relevance exists for analyses of MSI and MSI-H-associated genomic alterations in malignancy. In this article, we provide an update on MSI-driven carcinogenesis, with an emphasis on unique landscapes of diagnostic and immunotherapeutic strategies.

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.

P1/2; Trial completion date: Apr 2027 --> Dec 2027 | Trial primary completion date: Apr 2027 --> Dec 2027

P1/2, N=29, Terminated, Pyramid Biosciences | N=74 --> 29 | Trial completion date: Jun 2024 --> Jul 2023 | Active, not recruiting --> Terminated | Trial primary completion date: Jun 2024 --> Jul 2023; Sponsor terminated development of PBI-200

This study highlights the benefits of combining morphological and immunohistochemical analyses for gene detection and posits that lymph node metastases are more suitable for genetic analysis owing to their mild calcification. Our results emphasize the importance of accurate sample processing in diagnosing and treating thyroid carcinomas.

From 2019 to 2022, 1387 patients with STS were registered in C-CAT. The histological types included leiomyosarcoma in 357 patients, dedifferentiated liposarcoma in 178 patients, and undifferentiated pleomorphic sarcoma in 82 patients, and the others. The most commonly altered genes included TP53, CDKN2A, Rb1, and CDKN2B.

Immune checkpoint inhibitors have proven to be effective for patients with alveolar soft part sarcoma and targeted therapies with NTRK-inhibitors should be evaluated in patients with NTRK-fusions. This article focuses on current standards and developments in the treatment of soft tissue sarcomas.

P=N/A, N=88, Active, not recruiting, iOMEDICO AG | Recruiting --> Active, not recruiting

This review provides a succinct overview of the application of NTRK inhibitors in various types of cancer by emphasizing the critical clinical significance of NTRK fusion gene detection. The discussion also provides a solid foundation for understanding the current challenges and potential changes for improving the efficacy of NTRK inhibitor therapy to treat different malignancies.

The patient showed significant tumor response to single-agent treatment with alectinib, an ALK-tyrosine kinase inhibitor...The benefit of the early detection of CD30 expression by FCM for a prompt diagnosis and treatment is highlighted in the context of an aggressive clinical course. This case represents a learning experience regarding the need to the check the status of CD30 expression in these tumors and suggests the potential clinical benefits of CD30-targeted therapy.

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.

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.

Actionable alterations were identified in 53.4% of the patients, and KRAS was the most common oncogenic driver alteration. Our study revealed a lower prevalence of patients whose tumor harbors ALK, ROS1, and RET fusions, compared with similar data sets.

P2, N=27, Active, not recruiting, Abramson Cancer Center at Penn Medicine | Recruiting --> Active, not recruiting

In conclusion, NTRK gene fusion is infrequent in patients with PTC. Linkage of biobank samples to EHRs is feasible in describing the characteristics and outcomes of patients with PTC and potentially other cancer types.

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.

To our knowledge, this is the first reported cervical neoplasm exhibiting a SMARCB1 pathogenic variant and the first NTRK fusion sarcoma showing SMARCB1 protein loss. We discuss the diagnostic challenges and complexities of the molecular findings.

Repotrectinib in a patient with NTRK fusion-positive pancreatic carcinoma and congenital long QT syndrome.

In this population, 42% have received standard lenvatinib and 13% have received genotype-matched targeted therapy... In our real-world study, NGS testing revealed high rates of Tier I-II actionable genomic alterations in PTC (77%), MTC (81%), and ATC (31%). NGS-identified BRAF V600E mutations in ATC has a high rate of triggering matched targeted therapy. NGS identification of RET-mutated MTC facilitated use of RET inhibitors.

Our study indicates that NTRK fusion is rare in early-stage lung cancer. Due to the high level of false positive cases with IHC, Pan-TRK IHC is less suited as a screening tool for NTRK-fusions in LUSC and adenoid cystic carcinoma.

Currently, Lenvatinib and Sorafenib, multitargeted TKIs, represent the standard first-line systemic treatment options for RAIR thyroid carcinoma, while Cabozantinib is the standard second-line treatment option. Furthermore, targeted therapies for patients with specific targetable molecular abnormalities include Latrectinib or Entrectinib for patients with NTRK gene fusions and Selpercatinib or Pralsetinib for patients with RET gene fusions. Dabrafenib plus Trametinib currently only have tumor agnostic approval in the USA for patients with BRAF V600E mutations, including thyroid cancer. Redifferentiation therapy is an area of active research, with promising initial results, while immunotherapy studies with checkpoint inhibitors in combination with tyrosine kinase inhibitors are underway.

P=N/A, N=825, Active, not recruiting, Dana-Farber Cancer Institute | Recruiting --> Active, not recruiting

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.

Pan-TRK IHC shows some utility as a diagnostic and surrogate marker for NTRK screening however, physiologic or non-specific expression may lead to false-positive results.

We also advocate the use of molecular techniques in rare tumors of uncertain type or differentiation, to increase understanding and possibilities of reproducible classification of these rare neoplasms. Pathologists and oncologists should recognize this entity, which leads to a direct approach for detecting NTRK fusion for appropriate treatment.