Stereoselective synthesis of 3,4-dihydropyrrolo[1,2-a]pyrazin-1(2H)-one derivatives as PIM kinase inhibitors inspired from marine alkaloids.

We previously demonstrated that natural product-inspired 3,4-dihydropyrrolo[1,2-a]pyrazin-1(2H)-ones derivatives delivered potent and selective PIM kinases inhibitors however with non-optimal ADME/PK properties and modest oral bioavailability. Herein, we describe a structure-based scaffold decoration and a stereoselective approach to this chemical class. The synthesis, structure-activity relationship studies, chiral analysis, and pharmacokinetic data of compounds from this inhibitor class are presented herein. Compound 20c demonstrated excellent potency on PIM1 and PIM2 with exquisite kinases selectivity and PK properties that efficiently and dose-dependently promoted c-Myc degradation and appear to be promising lead compounds for further development.

Identification and characterization of a novel SCYL3-NTRK1 rearrangement in a colorectal cancer patient.

In colorectal cancer patients, chromosomal rearrangements involving NTRK1 gene (encoding the TRKA protein) are shown in a small subset of patients and are associated with the constitutive activation of the kinase domain of TRKA. In turn, activated TRKA-fusion proteins are associated with proliferation and survival in colorectal cancer tumors. Here we report the identification and functional characterization of a new SCYL3-NTRK1 fusion gene in a 61-year-old colorectal cancer patient. To our knowledge, this fusion protein has never been previously documented in oncological patients. We show that this novel fusion is oncogenic and sensitive to TRKA inhibitors. As suggested by other pieces of evidence, entrectinib - an orally available pan-TRK, ROS1 and ALK inhibitor - may have particular efficacy in patients with NTRK rearrangements. Therefore, screening for rearrangements involving NTRK genes may help identifying a subset of patients able to derive benefit from treatment with entrectinib or other targeted inhibitors.

Safety and Antitumor Activity of the Multitargeted Pan-TRK, ROS1, and ALK Inhibitor Entrectinib: Combined Results from Two Phase I Trials (ALKA-372-001 and STARTRK-1).

Entrectinib, a potent oral inhibitor of the tyrosine kinases TRKA/B/C, ROS1, and ALK, was evaluated in two phase I studies in patients with advanced or metastatic solid tumors, including patients with active central nervous system (CNS) disease. Here, we summarize the overall safety and report the antitumor activity of entrectinib in a cohort of patients with tumors harboring NTRK1/2/3, ROS1, or ALK gene fusions, naïve to prior TKI treatment targeting the specific gene, and who were treated at doses that achieved therapeutic exposures consistent with the recommended phase II dose. Entrectinib was well tolerated, with predominantly Grades 1/2 adverse events that were reversible with dose modification. Responses were observed in non-small cell lung cancer, colorectal cancer, mammary analogue secretory carcinoma, melanoma, and renal cell carcinoma, as early as 4 weeks after starting treatment and lasting as long as >2 years. Notably, a complete CNS response was achieved in a patient with SQSTM1-NTRK1-rearranged lung cancer.Significance: Gene fusions of NTRK1/2/3, ROS1, and ALK (encoding TRKA/B/C, ROS1, and ALK, respectively) lead to constitutive activation of oncogenic pathways. Entrectinib was shown to be well tolerated and active against those gene fusions in solid tumors, including in patients with primary or secondary CNS disease. Cancer Discov; 7(4); 400-9. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 339.

Discovery of Entrectinib: A New 3-Aminoindazole As a Potent Anaplastic Lymphoma Kinase (ALK), c-ros Oncogene 1 Kinase (ROS1), and Pan-Tropomyosin Receptor Kinases (Pan-TRKs) inhibitor.

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase responsible for the development of different tumor types. Despite the remarkable clinical activity of crizotinib (Xalkori), the first ALK inhibitor approved in 2011, the emergence of resistance mutations and of brain metastases frequently causes relapse in patients. Within our ALK drug discovery program, we identified compound 1, a novel 3-aminoindazole active on ALK in biochemical and in cellular assays. Its optimization led to compound 2 (entrectinib), a potent orally available ALK inhibitor active on ALK-dependent cell lines, efficiently penetrant the blood-brain barrier (BBB) in different animal species and highly efficacious in in vivo xenograft models. Moreover, entrectinib resulted to be strictly potent on the closely related tyrosine kinases ROS1 and TRKs recently found constitutively activated in several tumor types. Entrectinib is currently undergoing phase I/II clinical trial for the treatment of patients affected by ALK-, ROS1-, and TRK-positive tumors.

Entrectinib, a Pan-TRK, ROS1, and ALK Inhibitor with Activity in Multiple Molecularly Defined Cancer Indications.

Activated ALK and ROS1 tyrosine kinases, resulting from chromosomal rearrangements, occur in a subset of non-small cell lung cancers (NSCLC) as well as other tumor types and their oncogenic relevance as actionable targets has been demonstrated by the efficacy of selective kinase inhibitors such as crizotinib, ceritinib, and alectinib. More recently, low-frequency rearrangements of TRK kinases have been described in NSCLC, colorectal carcinoma, glioblastoma, and Spitzoid melanoma. Entrectinib, whose discovery and preclinical characterization are reported herein, is a novel, potent inhibitor of ALK, ROS1, and, importantly, of TRK family kinases, which shows promise for therapy of tumors bearing oncogenic forms of these proteins. Proliferation profiling against over 200 human tumor cell lines revealed that entrectinib is exquisitely potent in vitro against lines that are dependent on the drug's pharmacologic targets. Oral administration of entrectinib to tumor-bearing mice induced regression in relevant human xenograft tumors, including the TRKA-dependent colorectal carcinoma KM12, ROS1-driven tumors, and several ALK-dependent models of different tissue origins, including a model of brain-localized lung cancer metastasis. Entrectinib is currently showing great promise in phase I/II clinical trials, including the first documented objective responses to a TRK inhibitor in colorectal carcinoma and in NSCLC. The drug is, thus, potentially suited to the therapy of several molecularly defined cancer settings, especially that of TRK-dependent tumors, for which no approved drugs are currently available. Mol Cancer Ther; 15(4); 628-39. ©2016 AACR.

Sensitivity to Entrectinib Associated With a Novel LMNA-NTRK1 Gene Fusion in Metastatic Colorectal Cancer.

In metastatic colorectal cancer (CRC), actionable genetic lesions represent potential clinical opportunities. NTRK1, 2, and 3 gene rearrangements encode oncogenic fusions of the tropomyosin-receptor kinase (TRK) family of receptor tyrosine kinases in different tumor types. The TPM3-NTRK1 rearrangement is a recurring event in CRC that renders tumors sensitive to TRKA kinase inhibitors in preclinical models. We identified abnormal expression of the TRKA protein in tumor and liver metastases of a CRC patient refractory to standard therapy. Molecular characterization unveiled a novel LMNA-NTRK1 rearrangement within chromosome 1 with oncogenic potential, and the patient was treated with the pan-TRK inhibitor entrectinib, achieving partial response with decrease in hepatic target lesions from 6.8 and 8.2cm in longest diameter to 4.7 and 4.3cm, respectively. To our knowledge, this is the first clinical evidence of efficacy for therapeutic inhibition of TRKA in a solid tumor, illuminating a genomic-driven strategy to identify CRCs reliant on this oncogene to be clinically targeted with entrectinib.

Novel CAD-ALK gene rearrangement is drugable by entrectinib in colorectal cancer.

BACKGROUND: Activated anaplastic lymphoma kinase (ALK) gene fusions are recurrent events in a small fraction of colorectal cancers (CRCs), although these events have not yet been exploited as in other malignancies. METHODS: We detected ALK protein expression by immunohistochemistry and gene rearrangements by fluorescence in situ hybridisation in the ALKA-372-001 phase I study of the pan-Trk, ROS1, and ALK inhibitor entrectinib. One out of 487 CRCs showed ALK positivity with a peculiar pattern that prompted further characterisation by targeted sequencing using anchored multiplex PCR. RESULTS: A novel ALK fusion with the carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase (CAD) gene (CAD-ALK fusion gene) was identified. It resulted from inversion within chromosome 2 and the fusion of exons 1-35 of CAD with exons 20-29 of ALK. After failure of previous standard therapies, treatment of this patient with the ALK inhibitor entrectinib resulted in a durable objective tumour response. CONCLUSIONS: We describe the novel CAD-ALK rearrangement as an oncogene and provide the first evidence of its drugability as a new molecular target in CRC.

The TPM3-NTRK1 rearrangement is a recurring event in colorectal carcinoma and is associated with tumor sensitivity to TRKA kinase inhibition.

The NTRK1 gene encodes Tropomyosin-related kinase A (TRKA), the high-affinity Nerve Growth Factor Receptor. NTRK1 was originally isolated from a colorectal carcinoma (CRC) sample as component of a somatic rearrangement (TPM3-NTRK1) resulting in expression of the oncogenic chimeric protein TPM3-TRKA, but there has been no subsequent report regarding the relevance of this oncogene in CRC. The KM12 human CRC cell line expresses the chimeric TPM3-TRKA protein and is hypersensitive to TRKA kinase inhibition. We report the detailed characterization of the TPM3-NTRK1 genomic rearrangement in KM12 cells and through a cellular screening approach, the identification of NMS-P626, a novel highly potent and selective TRKA inhibitor. NMS-P626 suppressed TPM3-TRKA phosphorylation and downstream signaling in KM12 cells and showed remarkable antitumor activity in mice bearing KM12 tumors. Finally, using quantitative reverse transcriptase PCR and immunohistochemistry (IHC) we identified the TPM3-NTRK1 rearrangement in a CRC clinical sample, therefore suggesting that this chromosomal translocation is indeed a low frequency recurring event in CRC and that such patients might benefit from therapy with TRKA kinase inhibitors.