RESUMEN
PURPOSE: Chronic graft-versus-host disease (cGVHD) remains the major cause of late morbidity after allogeneic hematopoietic cell transplantation. Colony-stimulating factor 1 receptor (CSF-1R)-dependent macrophages promote cGVHD fibrosis, and their elimination in preclinical studies ameliorated cGVHD. Axatilimab is a humanized monoclonal antibody that inhibits CSF-1R signaling and restrains macrophage development. PATIENTS AND METHODS: This phase I (phI)/phase II (phII) open-label study (ClinicalTrials.gov identifier: NCT03604692) evaluated safety, tolerability, and efficacy of axatilimab in patients age ≥ 6 years with active cGVHD after ≥ 2 prior systemic therapy lines. Primary objectives in phI were to identify the optimal biologic and recommended phII dose and in phII to evaluate the overall (complete and partial) response rate (ORR) at the start of treatment cycle 7. RESULTS: Forty enrolled patients (17 phI; 23 phII) received at least one axatilimab dose. In phI, a dose of 3 mg/kg given once every 4 weeks met the optimal biologic dose definition. Two dose-limiting toxicities occurred at the 3 mg/kg dose given once every 2 weeks. At least one treatment-related adverse event (TRAE) was observed in 30 patients with grade ≥ 3 TRAEs in eight patients, the majority known on-target effects of CSF-1R inhibition. No cytomegalovirus reactivations occurred. With the 50% ORR at cycle 7 day 1, the phII cohort met the primary efficacy end point. Furthermore, the ORR in the first six cycles, an end point supporting regulatory approvals, was 82%. Responses were seen in all affected organs regardless of prior therapy. Fifty-eight percent of patients reported significant improvement in cGVHD-related symptoms using the Lee Symptom Scale. On-target activity of axatilimab was suggested by the decrease in skin CSF-1R-expressing macrophages. CONCLUSION: Targeting profibrotic macrophages with axatilimab is a therapeutically promising novel strategy with a favorable safety profile for refractory cGVHD.
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Productos Biológicos , Síndrome de Bronquiolitis Obliterante , Enfermedad Injerto contra Huésped , Humanos , Niño , Enfermedad Injerto contra Huésped/tratamiento farmacológico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Productos Biológicos/uso terapéutico , Enfermedad CrónicaRESUMEN
Spleen tyrosine kinase (SYK) is a critical regulator of signaling in a variety of immune cell types such as B-cells, monocytes, and macrophages. Accordingly, there have been numerous efforts to identify compounds that selectively inhibit SYK as a means to treat autoimmune and inflammatory diseases. We previously disclosed GS-9973 (entospletinib) as a selective SYK inhibitor that is under clinical evaluation in hematological malignancies. However, a BID dosing regimen and drug interaction with proton pump inhibitors (PPI) prevented development of entospletinib in inflammatory diseases. Herein, we report the discovery of a second-generation SYK inhibitor, GS-9876 (lanraplenib), which has human pharmacokinetic properties suitable for once-daily administration and is devoid of any interactions with PPI. Lanraplenib is currently under clinical evaluation in multiple autoimmune indications.
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We describe the discovery of three structurally differentiated potent and selective MTH1 inhibitors and their subsequent use to investigate MTH1 as an oncology target, culminating in target (in)validation. Tetrahydronaphthyridine 5 was rapidly identified as a highly potent MTH1 inhibitor (IC50 = 0.043 nM). Cocrystallization of 5 with MTH1 revealed the ligand in a Φ-cis-N-(pyridin-2-yl)acetamide conformation enabling a key intramolecular hydrogen bond and polar interactions with residues Gly34 and Asp120. Modification of literature compound TH287 with O- and N-linked aryl and alkyl aryl substituents led to the discovery of potent pyrimidine-2,4,6-triamine 25 (IC50 = 0.49 nM). Triazolopyridine 32 emerged as a highly selective lead compound with a suitable in vitro profile and desirable pharmacokinetic properties in rat. Elucidation of the DNA damage response, cell viability, and intracellular concentrations of oxo-NTPs (oxidized nucleoside triphosphates) as a function of MTH1 knockdown and/or small molecule inhibition was studied. Based on our findings, we were unable to provide evidence to further pursue MTH1 as an oncology target.
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In our continued effort to discover and develop best-in-class Bruton's tyrosine kinase (Btk) inhibitors for the treatment of B-cell lymphomas, rheumatoid arthritis, and systemic lupus erythematosus, we devised a series of novel tricyclic compounds that improved upon the druglike properties of our previous chemical matter. Compounds exemplified by G-744 are highly potent, selective for Btk, metabolically stable, well tolerated, and efficacious in an animal model of arthritis.
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BTK inhibitor GDC-0834 (1) was found to be rapidly metabolized in human studies, resulting in a suspension of clinical trials. The primary route of metabolism was through cleavage of the acyclic amide bond connecting the terminal tetrahydrobenzothiophene with the central linker aryl ring. SAR studies were focused on reducing metabolic cleavage of this amide, and resulted in the identification of several central aryl linker substituents that conferred improved stability. The most promising substituted aryl linkers were then incorporated into an optimized pyridazinone scaffold, resulting in the identification of lead analog 23, possessing improved potency, metabolic stability and preclinical properties.
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Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Piridazinas/química , Piridazinas/farmacología , Pirimidinonas/química , Pirimidinonas/farmacología , Tiofenos/química , Tiofenos/farmacología , Agammaglobulinemia Tirosina Quinasa , Animales , Perros , Humanos , Ratones , Microsomas Hepáticos/metabolismo , Modelos Moleculares , Inhibidores de Proteínas Quinasas/metabolismo , Inhibidores de Proteínas Quinasas/farmacocinética , Proteínas Tirosina Quinasas/metabolismo , Piridazinas/metabolismo , Piridazinas/farmacocinética , Pirimidinonas/metabolismo , Pirimidinonas/farmacocinética , Ratas , Tiofenos/metabolismo , Tiofenos/farmacocinéticaRESUMEN
SAR studies focused on improving the pharmacokinetic (PK) properties of the previously reported potent and selective Btk inhibitor CGI-1746 (1) resulted in the clinical candidate GDC-0834 (2), which retained the potency and selectivity of CGI-1746, but with much improved PK in preclinical animal models. Structure based design efforts drove this work as modifications to 1 were investigated at both the solvent exposed region as well as 'H3 binding pocket'. However, in vitro metabolic evaluation of 2 revealed a non CYP-mediated metabolic process that was more prevalent in human than preclinical species (mouse, rat, dog, cyno), leading to a high-level of uncertainly in predicting human pharmacokinetics. Due to its promising potency, selectivity, and preclinical efficacy, a single dose IND was filed and 2 was taken in to a single dose phase I trial in healthy volunteers to quickly evaluate the human pharmacokinetics. In human, 2 was found to be highly labile at the exo-cyclic amide bond that links the tetrahydrobenzothiophene moiety to the central aniline ring, resulting in insufficient parent drug exposure. This information informed the back-up program and discovery of improved inhibitors.
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Inhibidores de Proteínas Quinasas/química , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Pirimidinonas/química , Tiofenos/química , Agammaglobulinemia Tirosina Quinasa , Animales , Benzamidas/química , Benzamidas/metabolismo , Sitios de Unión , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Compuestos Bicíclicos Heterocíclicos con Puentes/metabolismo , Cristalografía por Rayos X , Perros , Semivida , Humanos , Ratones , Microsomas Hepáticos/metabolismo , Simulación de Dinámica Molecular , Unión Proteica , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacocinética , Estructura Terciaria de Proteína , Proteínas Tirosina Quinasas/metabolismo , Pirimidinonas/síntesis química , Pirimidinonas/farmacocinética , Ratas , Relación Estructura-Actividad , Tiofenos/síntesis química , Tiofenos/farmacocinéticaRESUMEN
Bicyclic pyrazinone and pyrimidinone amides were designed and synthesized as potent TF-FVIIa inhibitors. SAR demonstrated that the S2 and S3 pockets of FVIIa prefer to bind small, lipophilic groups. An X-ray crystal structure of optimized compound 9b bound in the active site of FVIIa showed that the bicyclic scaffold provides 5 hydrogen bonding interactions in addition to projecting groups for interactions within the S1, S2 and S3 pockets. Compound 9b showed excellent FVIIa potency, good selectivity against FIXa, Xa, XIa and chymotrypsin, and good clotting activity.
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Amidas/química , Amidinas/síntesis química , Diseño de Fármacos , Factor VIIa/antagonistas & inhibidores , Pirazinas/química , Pirazinas/síntesis química , Pirimidinonas/química , Inhibidores de Serina Proteinasa/síntesis química , Amidas/síntesis química , Amidas/metabolismo , Amidinas/química , Amidinas/metabolismo , Sitios de Unión , Compuestos Bicíclicos con Puentes/química , Dominio Catalítico , Cristalografía por Rayos X , Factor VIIa/metabolismo , Unión Proteica , Pirazinas/metabolismo , Inhibidores de Serina Proteinasa/química , Inhibidores de Serina Proteinasa/metabolismo , Relación Estructura-ActividadRESUMEN
Starting from a hexapeptide boronic acid lead, 3-amino bicyclic pyrazinones as novel beta-sheet dipeptide mimetics have been designed and synthesized. Side-chain manipulation of this scaffold generated a series of potent, nonpeptidic inhibitors of HCV NS3 protease.