ABSTRACT
In this study, we described a series of 2,8-diazaspiro[4.5]decan-1-one derivatives as selective TYK2/JAK1 inhibitors. Systematic exploration of the structure-activity relationship through the introduction of spirocyclic scaffolds based on the reported selective TYK2 inhibitor 14l led to the discovery of the superior derivative compound 48. Compound 48 showed excellent potency on TYK2/JAK1 kinases with IC50 values of 6 and 37 nM, respectively, and exhibited more than 23-fold selectivity for JAK2. Compound 48 also demonstrated excellent metabolic stability and more potent anti-inflammatory efficacy than tofacitinib in acute ulcerative colitis models. Moreover, the excellent anti-inflammatory effect of compound 48 was mediated by regulating the expression of related TYK2/JAK1-regulated genes, as well as the formation of Th1, Th2, and Th17 cells. Taken together, these findings suggest that compound 48 is a selective dual TYK2/JAK inhibitor, deserving to be developed as a clinical candidate.
Subject(s)
Inflammatory Bowel Diseases/drug therapy , Janus Kinase 1/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , TYK2 Kinase/antagonists & inhibitors , Animals , Drug Evaluation, Preclinical , Mice , Molecular Docking Simulation , Piperidines/therapeutic use , Protein Kinase Inhibitors/therapeutic use , Pyrimidines/therapeutic use , Structure-Activity Relationship , T-Lymphocytes/drug effects , T-Lymphocytes/immunologyABSTRACT
The predominant assay detection methodologies used for enzyme inhibitor identification during early-stage drug discovery are fluorescence-based. Each fluorophore has a characteristic fluorescence decay, known as the fluorescence lifetime, that occurs throughout a nanosecond-to-millisecond timescale. The measurement of fluorescence lifetime as a reporter for biological activity is less common than fluorescence intensity, even though the latter has numerous issues that can lead to false-positive readouts. The confirmation of hit compounds as true inhibitors requires additional assays, cost, and time to progress from hit identification to lead drug-candidate optimization. To explore whether the use of fluorescence lifetime technology (FLT) can offer comparable benefits to label-free-based approaches such as RapidFire mass spectroscopy (RF-MS) and a superior readout compared to time-resolved fluorescence resonance energy transfer (TR-FRET), three equivalent assays were developed against the clinically validated tyrosine kinase 2 (TYK2) and screened against annotated compound sets. FLT provided a marked decrease in the number of false-positive hits when compared to TR-FRET. Further cellular screening confirmed that a number of potential inhibitors directly interacted with TYK2 and inhibited the downstream phosphorylation of the signal transducer and activator of transcription 4 protein (STAT4).
Subject(s)
Drug Discovery/methods , Drug Discovery/standards , Drug Evaluation, Preclinical/methods , Drug Evaluation, Preclinical/standards , Fluorescent Dyes , TYK2 Kinase/antagonists & inhibitors , TYK2 Kinase/chemistry , Fluorescence Resonance Energy Transfer , High-Throughput Screening Assays , Mass Spectrometry , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
A series of potent dual JAK1/3 inhibitors have been developed from a moderately selective JAK3 inhibitor. Substitution at the C6 position of the pyrrolopyridazine core with aryl groups provided exceptional biochemical potency against JAK1 and JAK3 while maintaining good selectivity against JAK2 and Tyk2. Translation to in vivo efficacy was observed in a murine model of chronic inflammation. X-ray co-crystal structure determination confirmed the presumed inhibitor binding orientation in JAK3. Efforts to reduce hERG channel inhibition will be described.
Subject(s)
Janus Kinase 1/antagonists & inhibitors , Janus Kinase 3/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Pyridazines/chemistry , Pyrroles/chemistry , Animals , Binding Sites , Catalytic Domain , Cell Line , Crystallography, X-Ray , Disease Models, Animal , Drug Evaluation, Preclinical , Half-Life , Humans , Inflammation/prevention & control , Inhibitory Concentration 50 , Janus Kinase 1/metabolism , Janus Kinase 2/antagonists & inhibitors , Janus Kinase 2/metabolism , Janus Kinase 3/metabolism , Mice , Mice, Inbred BALB C , Molecular Conformation , Molecular Dynamics Simulation , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Pyridazines/chemical synthesis , Pyridazines/pharmacokinetics , Pyrroles/chemical synthesis , Pyrroles/pharmacokinetics , Rats , Rats, Sprague-Dawley , Structure-Activity Relationship , TYK2 Kinase/antagonists & inhibitors , TYK2 Kinase/metabolismABSTRACT
AIMS AND BACKGROUND: The introduction of agents targeting vascular endothelial growth factor has radically changed the approach to metastatic renal cell carcinoma (mRCC): sunitinib and pazopanib are now the standard first-line therapy in mRCC. At sunitinib failure, second-line axitinib or everolimus or sorafenib should be considered to improve the clinical outcome. No data are available for a third-line tyrosine kinase inhibitor (TKI) after 2 previous lines of therapy with TKIs. At pazopanib failure, no prospective data are available. STUDY DESIGN: The TOKIO study was designed to evaluate progression-free survival, safety, and efficacy of third-line therapy with TKI in 44 patients already treated with 2 previous lines of TKIs in 10 Italian centers, and relapsed from sunitinib-axitinib (group A) or pazopanib-sorafenib (group B). Standard treatment is sorafenib in group A and sunitinib in group B, administered until disease progression or unacceptable toxicity. Secondary endpoints include the evaluation of overall survival, safety, and quality of life.
Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma, Renal Cell/drug therapy , Kidney Neoplasms/drug therapy , Protein Kinase Inhibitors/therapeutic use , TYK2 Kinase/antagonists & inhibitors , Adult , Aged , Antineoplastic Agents/adverse effects , Axitinib , Carcinoma, Renal Cell/mortality , Carcinoma, Renal Cell/secondary , Clinical Protocols , Disease-Free Survival , Everolimus/administration & dosage , Female , Humans , Imidazoles/administration & dosage , Indazoles/administration & dosage , Indoles/administration & dosage , Kaplan-Meier Estimate , Kidney Neoplasms/mortality , Kidney Neoplasms/pathology , Male , Middle Aged , Niacinamide/administration & dosage , Niacinamide/analogs & derivatives , Phenylurea Compounds/administration & dosage , Prospective Studies , Protein Kinase Inhibitors/adverse effects , Pyrimidines/administration & dosage , Pyrroles/administration & dosage , Quality of Life , Sorafenib , Sulfonamides/administration & dosage , Sunitinib , Treatment OutcomeABSTRACT
Herein, we describe the synthesis and SAR of a series of small molecule macrocycles that selectively inhibit JAK2 kinase within the JAK family and FLT3 kinase. Following a multiparameter optimization of a key aryl ring of the previously described SB1518 (pacritinib), the highly soluble 14l was selected as the optimal compound. Oral efficacy in the murine collagen-induced arthritis (CIA) model for rheumatoid arthritis (RA) supported 14l as a potential treatment for autoimmune diseases and inflammatory disorders such as psoriasis and RA. Compound 14l (SB1578) was progressed into development and is currently undergoing phase 1 clinical trials in healthy volunteers.