RESUMEN
High levels of Pim expression have been implicated in several hematopoietic and solid tumor cancers, suggesting that inhibition of Pim signaling could provide patients with therapeutic benefit. Herein, we describe our progress towards this goal using a screening hit (rac-1) as a starting point. Modification of the indazole ring resulted in the discovery of a series of imidazopyridazine-based Pim inhibitors exemplified by compound 22m, which was found to be a subnanomolar inhibitor of the Pim-1 and Pim-2 isoforms (IC50 values of 0.024nM and 0.095nM, respectively) and to potently inhibit the phosphorylation of BAD in a cell line that expresses high levels of all Pim isoforms, KMS-12-BM (IC50=28nM). Profiling of Pim-1 and Pim-2 expression levels in a panel of multiple myeloma cell lines and correlation of these data with the potency of compound 22m in a proliferation assay suggests that Pim-2 inhibition would be advantageous for this indication.
Asunto(s)
Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-pim-1/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Piridazinas/química , Piridazinas/farmacología , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Modelos Moleculares , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-pim-1/metabolismo , Relación Estructura-ActividadRESUMEN
PIM kinases are a family of Ser/Thr kinases that are implicated in tumorigenesis. The discovery of a new class of PIM inhibitors, 5-(1H-indol-5-yl)-1,3,4-thiadiazol-2-amines, is discussed with optimized compounds showing excellent potency against all three PIM isoforms.
Asunto(s)
Aminas/química , Aminas/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-pim-1/antagonistas & inhibidores , Aminas/síntesis química , Carbolinas/síntesis química , Carbolinas/química , Carbolinas/farmacología , Línea Celular Tumoral , Descubrimiento de Drogas , Humanos , Modelos Moleculares , Inhibidores de Proteínas Quinasas/síntesis química , Proteínas Proto-Oncogénicas c-pim-1/química , Relación Estructura-ActividadRESUMEN
The three Pim kinases are a small family of serine/threonine kinases regulating several signaling pathways that are fundamental to tumorigenesis. As such, the Pim kinases are a very attractive target for pharmacological inhibition in cancer therapy. Herein, we describe our efforts toward the development of a potent, pan-Pim inhibitor. The synthesis and hit-to-lead SAR development from a 3-(pyrazin-2-yl)-1H-indazole derived hit 2 to the identification of a series of potent, pan-Pim inhibitors such as 13o are described.
Asunto(s)
Indazoles/química , Indazoles/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-pim-1/antagonistas & inhibidores , Descubrimiento de Drogas , Humanos , Relación Estructura-ActividadRESUMEN
High levels of Pim expression have been implicated in several hematopoietic and solid tumor cancers. These findings suggest that inhibition of Pim signaling by a small molecule Pim-1,2 inhibitor could provide patients with therapeutic benefit. Herein, we describe our progress towards this goal starting from the highly Pim-selective indole-thiadiazole compound (1), which was derived from a nonselective hit identified in a high throughput screening campaign. Optimization of this compound's potency and its pharmacokinetic properties resulted in the discovery of compound 29. Cyclopropane 29 was found to exhibit excellent enzymatic potency on the Pim-1 and Pim-2 isoforms (Ki values of 0.55nM and 0.28nM, respectively), and found to inhibit the phosphorylation of BAD in the Pim-overexpressing KMS-12 cell line (IC50=150nM). This compound had moderate clearance and bioavailability in rat (CL=2.42L/kg/h; %F=24) and exhibited a dose-dependent inhibition of p-BAD in KMS-12 tumor pharmacodynamic (PD) model with an EC50 value of 6.74µM (18µg/mL) when dosed at 10, 30, 100 and 200mg/kg po in mice.
Asunto(s)
Oxadiazoles/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-pim-1/antagonistas & inhibidores , Cristalografía por Rayos X , Descubrimiento de Drogas , Estructura Molecular , Oxadiazoles/químicaRESUMEN
Despite advances in the treatment of acute myeloid leukemia (AML), novel therapies are needed to induce deeper and more durable clinical response. Bispecific T-cell Engager (BiTE) molecules, which redirect patient T cells to lyse tumor cells, are a clinically validated modality for hematologic malignancies. Due to broad AML expression and limited normal tissue expression, fms-related tyrosine kinase 3 (FLT3) is proposed to be an optimal BiTE molecule target. Expression profiling of FLT3 was performed in primary AML patient samples and normal hematopoietic cells and nonhematopoietic tissues. Two novel FLT3 BiTE molecules, one with a half-life extending (HLE) Fc moiety and one without, were assessed for T-cell-dependent cellular cytotoxicity (TDCC) of FLT3-positive cell lines in vitro, in vivo, and ex vivo FLT3 protein was detected on the surface of most primary AML bulk and leukemic stem cells but only a fraction of normal hematopoietic stem and progenitor cells. FLT3 protein detected in nonhematopoietic cells was cytoplasmic. FLT3 BiTE molecules induced TDCC of FLT3-positive cells in vitro, reduced tumor growth and increased survival in AML mouse models in vivo Both molecules exhibited reproducible pharmacokinetic and pharmacodynamic profiles in cynomolgus monkeys in vivo, including elimination of FLT3-positive cells in blood and bone marrow. In ex vivo cultures of primary AML samples, patient T cells induced TDCC of FLT3-positive target cells. Combination with PD-1 blockade increased BiTE activity. These data support the clinical development of an FLT3 targeting BiTE molecule for the treatment of AML.
Asunto(s)
Anticuerpos Biespecíficos/administración & dosificación , Inhibidores de Puntos de Control Inmunológico/administración & dosificación , Leucemia Mieloide Aguda/tratamiento farmacológico , Tirosina Quinasa 3 Similar a fms/metabolismo , Animales , Anticuerpos Biespecíficos/farmacología , Ciclo Celular , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular , Citotoxicidad Inmunológica , Sinergismo Farmacológico , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacología , Células K562 , Leucemia Mieloide Aguda/metabolismo , Macaca fascicularis , Ratones , Resultado del Tratamiento , Tirosina Quinasa 3 Similar a fms/antagonistas & inhibidoresRESUMEN
Pim kinases are a family of constitutively active serine/threonine kinases that are partially redundant and regulate multiple pathways important for cell growth and survival. In human disease, high expression of the three Pim isoforms has been implicated in the progression of hematopoietic and solid tumor cancers, which suggests that Pim kinase inhibitors could provide patients with therapeutic benefit. Herein, we describe the structure-guided optimization of a series of quinazolinone-pyrrolodihydropyrrolone analogs leading to the identification of potent pan-Pim inhibitor 28 with improved potency, solubility, and drug-like properties. Compound 28 demonstrated on-target Pim activity in an in vivo pharmacodynamic assay with significant inhibition of BAD phosphorylation in KMS-12-BM multiple myeloma tumors for 16 h postdose. In a 2-week mouse xenograft model, daily dosing of compound 28 resulted in 33% tumor regression at 100 mg/kg.
Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias Hematológicas/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Proto-Oncogénicas c-pim-1/antagonistas & inhibidores , Pirroles/uso terapéutico , Quinazolinonas/uso terapéutico , Animales , Antineoplásicos/síntesis química , Antineoplásicos/farmacocinética , Femenino , Humanos , Ratones SCID , Estructura Molecular , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacocinética , Pirroles/síntesis química , Pirroles/farmacocinética , Quinazolinonas/síntesis química , Quinazolinonas/farmacocinética , Relación Estructura-Actividad , Porcinos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Proteolysis targeting chimeras (PROTACs) are bispecific molecules containing a target protein binder and an ubiquitin ligase binder connected by a linker. By recruiting an ubiquitin ligase to a target protein, PROTACs promote ubiquitination and proteasomal degradation of the target protein. The generation of effective PROTACs depends on the nature of the protein/ligase ligand pair, linkage site, linker length, and linker composition, all of which have been difficult to address in a systematic way. Herein, we describe a "click chemistry" approach for the synthesis of PROTACs. We demonstrate the utility of this approach with the bromodomain and extraterminal domain-4 (BRD4) ligand JQ-1 (3) and ligase binders targeting cereblon (CRBN) and Von Hippel-Lindau (VHL) proteins. An AlphaScreen proximity assay was used to determine the ability of PROTACs to form the ternary ligase-PROTAC-target protein complex and a MSD assay to measure cellular degradation of the target protein promoted by PROTACs.
Asunto(s)
Química Clic , Evaluación Preclínica de Medicamentos , Proteínas Nucleares , Proteolisis , Factores de Transcripción , Humanos , Proteínas Adaptadoras Transductoras de Señales , Proteínas de Ciclo Celular , Química Clic/métodos , Evaluación Preclínica de Medicamentos/métodos , Ligandos , Proteínas Nucleares/metabolismo , Péptido Hidrolasas/genética , Péptido Hidrolasas/metabolismo , Péptidos/farmacología , Proteolisis/efectos de los fármacos , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacología , Factores de Transcripción/metabolismo , Ubiquitina-Proteína Ligasas , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismoRESUMEN
The identification of Pim-1/2 kinase overexpression in B-cell malignancies suggests that Pim kinase inhibitors will have utility in the treatment of lymphoma, leukemia, and multiple myeloma. Starting from a moderately potent quinoxaline-dihydropyrrolopiperidinone lead, we recognized the potential for macrocyclization and developed a series of 13-membered macrocycles. The structure-activity relationships of the macrocyclic linker were systematically explored, leading to the identification of 9c as a potent, subnanomolar inhibitor of Pim-1 and -2. This molecule also potently inhibited Pim kinase activity in KMS-12-BM, a multiple myeloma cell line with relatively high endogenous levels of Pim-1/2, both in vitro (pBAD IC50 = 25 nM) and in vivo (pBAD EC50 = 30 nM, unbound), and a 100 mg/kg daily dose was found to completely arrest the growth of KMS-12-BM xenografts in mice.
RESUMEN
The high expression of proviral insertion site of Moloney murine leukemia virus kinases (Pim-1, -2, and -3) in cancers, particularly the hematopoietic malignancies, is believed to play a role in promoting cell survival and proliferation while suppressing apoptosis. The three isoforms of Pim protein appear largely redundant in their oncogenic functions. Thus, a pan-Pim kinase inhibitor is highly desirable. However, cell active pan-Pim inhibitors have proven difficult to develop because Pim-2 has a low Km for ATP and therefore requires a very potent inhibitor to effectively block the kinase activity at cellular ATP concentrations. Herein, we report a series of quinazolinone-pyrrolopyrrolones as potent and selective pan-Pim inhibitors. In particular, compound 17 is orally efficacious in a mouse xenograft model (KMS-12 BM) of multiple myeloma, with 93% tumor growth inhibition at 50 mg/kg QD upon oral dosing.