RESUMEN
Mutations in calreticulin (mutCALR) are the second most common drivers of myeloproliferative neoplasms (MPNs) and yet, the current therapeutic landscape lacks a selective agent for mutCALR-expressing MPNs. Here we show that the monoclonal antibody INCA033989 selectively targets mutCALR-positive cells. INCA033989 antagonized mutCALR-driven signaling and proliferation in engineered cell lines and primary CD34+ cells from patients with MPN. No antibody binding or functional activity was observed in cells lacking mutCALR. In a mouse model of mutCALR-driven MPN, treatment with a INCA033989 mouse surrogate antibody effectively prevented the development of thrombocytosis and accumulation of megakaryocytes in the bone marrow. INCA033989 reduced the pathogenic self-renewal of mutCALR-positive disease-initiating cells in both primary and secondary transplantations, illustrating its disease-modifying potential. In summary, we describe a novel mutCALR-targeted therapy for MPNs, a monoclonal antibody that selectively inhibits the oncogenic function of MPN cells without interfering with normal hematopoiesis.
RESUMEN
11ß-hydroxysteroid dehydrogenase 1 (11ß-HSD1) has been identified as the primary enzyme responsible for the activation of hepatic cortisone to cortisol in specific peripheral tissues, resulting in the concomitant antagonism of insulin action within these tissues. Dysregulation of 11ß-HSD1, particularly in adipose tissues, has been associated with a variety of ailments including metabolic syndrome and type 2 diabetes mellitus. Therefore, inhibition of 11ß-HSD1 with a small nonsteroidal molecule is therapeutically desirable. Implementation of a scaffold-hopping approach revealed a 3-point pharmacophore for 11ß-HSD1 that was utilized to design a 2-spiroproline derivative as a steroid mimetic scaffold. Reiterative optimization provided valuable insight into the bioactive conformation of our novel scaffold and led to the discovery of several leads, such as compounds 39 and 51. Importantly, deleterious hERG inhibition and pregnane X receptor induction were mitigated by the introduction of a 4-hydroxyl group to the proline ring system.
Asunto(s)
Diabetes Mellitus Tipo 2 , Síndrome Metabólico , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/metabolismo , Inhibidores Enzimáticos/farmacología , Humanos , Hidrocortisona/metabolismoRESUMEN
Inhibiting signal transduction induced by inflammatory cytokines offers a new approach for the treatment of autoimmune diseases such as rheumatoid arthritis. Kinase inhibitors have shown promising oral disease-modifying antirheumatic drug potential with efficacy similar to anti-TNF biologics. Direct and indirect inhibition of the JAKs, with small molecule inhibitors like CP-690,550 and INCB018424 or neutralizing Abs, such as the anti-IL6 receptor Ab tocilizumab, have demonstrated rapid and sustained improvement in clinical measures of disease, consistent with their respective preclinical experiments. Therefore, it is of interest to identify optimized JAK inhibitors with unique profiles to maximize therapeutic opportunities. INCB028050 is a selective orally bioavailable JAK1/JAK2 inhibitor with nanomolar potency against JAK1 (5.9 nM) and JAK2 (5.7 nM). INCB028050 inhibits intracellular signaling of multiple proinflammatory cytokines including IL-6 and IL-23 at concentrations <50 nM. Significant efficacy, as assessed by improvements in clinical, histologic and radiographic signs of disease, was achieved in the rat adjuvant arthritis model with doses of INCB028050 providing partial and/or periodic inhibition of JAK1/JAK2 and no inhibition of JAK3. Diminution of inflammatory Th1 and Th17 associated cytokine mRNA levels was observed in the draining lymph nodes of treated rats. INCB028050 was also effective in multiple murine models of arthritis, with no evidence of suppression of humoral immunity or adverse hematologic effects. These data suggest that fractional inhibition of JAK1 and JAK2 is sufficient for significant activity in autoimmune disease models. Clinical evaluation of INCB028050 in RA is ongoing.
Asunto(s)
Artritis Experimental/tratamiento farmacológico , Artritis Experimental/enzimología , Janus Quinasa 1/antagonistas & inhibidores , Janus Quinasa 2/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/administración & dosificación , Animales , Artritis Experimental/inmunología , Enfermedades Autoinmunes/tratamiento farmacológico , Enfermedades Autoinmunes/enzimología , Enfermedades Autoinmunes/inmunología , Línea Celular , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos/métodos , Femenino , Humanos , Mediadores de Inflamación/antagonistas & inhibidores , Mediadores de Inflamación/fisiología , Janus Quinasa 1/fisiología , Janus Quinasa 2/fisiología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos DBA , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacocinética , Distribución Aleatoria , Ratas , Ratas Endogámicas Lew , Transducción de Señal/efectos de los fármacos , Transducción de Señal/inmunologíaRESUMEN
This report describes the design and synthesis of a series of CCR2 antagonists incorporating novel non-aryl/heteroaryl RHS (right hand side) motifs. Previous SAR in the area has suggested an aryl/heteroaryl substituent as a necessary structural feature for binding to the CCR2 receptor. Herein we describe the SAR with regards to potency (binding to hCCR2), dofetilide activity and metabolic stability (in vitro HLM) for this series. The resulting outcome was the identification of compounds with excellent properties for the investigation of the role of CCR2 in disease.
Asunto(s)
Diseño de Fármacos , Receptores CCR2/antagonistas & inhibidores , Sitios de Unión , Modelos Moleculares , Relación Estructura-ActividadRESUMEN
The chemokine receptor 2 (CCR2) directs migration of monocytes and has been proposed to be a drug target for chronic inflammatory diseases. INCB3344 was first published as a small molecule nanomolar inhibitor of rodent CCR2. Here, we show that INCB3344 can also bind human CCR2 (hCCR2) with high affinity, having a dissociation constant (K(d)) of approximately 5nM. The binding of the compound to the receptor is rapid and reversible. INCB3344 potently inhibits hCCR2 binding of monocyte chemoattractant protein-1 (MCP-1) and MCP-1-induced signaling and function in hCCR2-expressing cells, including ERK phosphorylation and chemotaxis, and is competitive against MCP-1 in vitro. INCB3344 also blocks MCP-1 binding to monocytes in human whole blood, with potency consistent with in vitro studies. The whole blood binding assay described here can be used for monitoring pharmacodynamic activity of CCR2 antagonists in both preclinical models and in the clinic.
Asunto(s)
Pirrolidinas/farmacología , Receptores CCR2/antagonistas & inhibidores , Bioensayo , Células Cultivadas , Quimiocina CCL2/metabolismo , Quimiotaxis , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Citometría de Flujo/métodos , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/metabolismo , Fosforilación , Pirrolidinas/metabolismoRESUMEN
A novel series of carbamates was discovered as potent and selective HER-2 sheddase inhibitors. Significant enhancement in potency and selectivity was achieved through attenuating the P1 moiety, which was conventionally believed to be exposed to solvent.
Asunto(s)
Carbamatos/química , Inhibidores de Proteínas Quinasas/química , Receptor ErbB-2/antagonistas & inhibidores , Carbamatos/síntesis química , Carbamatos/farmacología , Colagenasas/metabolismo , Humanos , Microsomas Hepáticos/metabolismo , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Receptor ErbB-2/metabolismo , Relación Estructura-ActividadRESUMEN
A serendipitous discovery that the metalloprotease binding profile of a novel class of 2-carboxamide-3-hydroxamic acid piperidines could be significantly attenuated by the modification of the unexplored P1 substituent enabled the design and synthesis of a novel 2-carboxamide-1-hydroxamic acid cyclohexyl scaffold core that exhibited excellent HER-2 potency and unprecedented MMP-selectivity that we believe would not have been possible via conventional P1' perturbations.
Asunto(s)
Proteínas ADAM/metabolismo , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Antineoplásicos/síntesis química , Ácidos Hidroxámicos/síntesis química , Proteínas de la Membrana/metabolismo , Receptor ErbB-2/metabolismo , Proteína ADAM10 , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Diseño de Fármacos , Humanos , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/farmacología , Metaloproteinasa 2 de la Matriz/metabolismo , Unión Proteica , Relación Estructura-Actividad , Especificidad por SustratoRESUMEN
Potent and selective inhibitors of tumor necrosis factor-alpha converting enzyme (TACE) were discovered with several new heterocyclic P1' groups in conjunction with cyclic beta-amino hydroxamic acid scaffolds. Among them, the pyrazolopyridine provided the best overall profile when combined with tetrahydropyran beta-amino hydroxamic acid scaffold. Specifically, inhibitor 49 showed IC(50) value of 1 nM against porcine TACE and 170 nM in the suppression of LPS-induced TNF-alpha of human whole blood. Compound 49 also displayed excellent selectivity over a wide panel of MMPs as well as excellent oral bioavailability (F%>90%) in rat n-in-1 PK studies.
Asunto(s)
Proteínas ADAM/antagonistas & inhibidores , Benzofuranos/química , Imidazoles/química , Indoles/química , Inhibidores de Proteasas/farmacología , Pirazoles/química , Piridinas/química , Proteínas ADAM/metabolismo , Proteína ADAM17 , Administración Oral , Animales , Disponibilidad Biológica , Humanos , Ácidos Hidroxámicos/química , Lipopolisacáridos/farmacología , Inhibidores de la Metaloproteinasa de la Matriz , Estructura Molecular , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/farmacocinética , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Two novel oxaspiro[4.4]nonane beta-benzamido hydroxamic scaffolds have been synthesized in enantio- and diasteriomerically pure form. These templates proved to be exceptional platforms that have led to the discovery of potent inhibitors of TACE that are active in a cellular assay measuring suppression of LPS-induced TNF-alpha. Furthermore, these inhibitors are selective against related MMPs, demonstrate permeability in a Caco-2 assay, and display good oral bioavailability.
Asunto(s)
Proteínas ADAM/antagonistas & inhibidores , Alcanos/química , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/farmacología , Inhibidores de Proteasas/química , Inhibidores de Proteasas/farmacología , Compuestos de Espiro/química , Proteína ADAM17 , Administración Oral , Alcanos/síntesis química , Alcanos/farmacocinética , Alcanos/farmacología , Animales , Disponibilidad Biológica , Células CACO-2 , Humanos , Ácidos Hidroxámicos/síntesis química , Ácidos Hidroxámicos/farmacocinética , Inhibidores de la Metaloproteinasa de la Matriz , Metaloproteinasas de la Matriz/metabolismo , Modelos Moleculares , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/farmacocinética , Ratas , Ratas Sprague-Dawley , Compuestos de Espiro/síntesis química , Compuestos de Espiro/farmacocinética , Compuestos de Espiro/farmacologíaRESUMEN
Novel ((2-substituted-1H-benzo[d]imidazol-1-yl)methyl)benzamides were found to be excellent P1' substituents in conjunction with unique constrained beta-amino hydroxamic acid scaffolds for the discovery of potent selective inhibitors of TNF-alpha Converting Enzyme (TACE). Optimized examples proved potent for TACE, exceptionally selective over a wide panel of MMP and ADAM proteases, potent in the suppression of LPS-induced TNF-alpha in human whole blood and orally bioavailable.
Asunto(s)
Proteínas ADAM/antagonistas & inhibidores , Benzamidas/química , Benzamidas/farmacología , Proteína ADAM17 , Animales , Área Bajo la Curva , Benzamidas/sangre , Benzamidas/farmacocinética , Disponibilidad Biológica , Perros , Semivida , Estructura Molecular , Ratas , Relación Estructura-ActividadRESUMEN
Selective inhibitors of TNF-alpha Converting Enzyme (TACE) based on (1R,2S)-cyclopentyl, (3S,4S)-pyrrolidinyl, and (3R,4S)-tetrahydrofuranyl beta-benzamido hydroxamic acids have been synthesized and evaluated. This study has led to the discovery of novel inhibitors whose profiles include activity against TACE in an enzyme assay, potency in the suppression of LPS-stimulated TNF-alpha in human whole blood, selectivity against a panel of MMPs and oral bioavailability.
Asunto(s)
Proteínas ADAM/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/farmacología , Proteína ADAM17 , Administración Oral , Animales , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión , Inhibidores Enzimáticos/síntesis química , Humanos , Ácidos Hidroxámicos/administración & dosificación , Ácidos Hidroxámicos/síntesis química , Ácidos Hidroxámicos/farmacocinética , Ratas , EstereoisomerismoRESUMEN
Beta-benzamido hydroxamic acids were discovered as potent TACE inhibitors. A computer model was constructed to help understanding the binding activities and guiding SAR study. SAR optimization led to the discovery of compound 30 which met all in vitro and in vivo criteria for the program and was selected for further evaluation.
Asunto(s)
Proteínas ADAM/antagonistas & inhibidores , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/farmacología , Inhibidores de Proteasas/química , Inhibidores de Proteasas/farmacología , Proteínas ADAM/química , Proteínas ADAM/metabolismo , Proteína ADAM17 , Administración Oral , Animales , Benzamidas/química , Benzamidas/farmacocinética , Benzamidas/farmacología , Sitios de Unión , Disponibilidad Biológica , Perros , Ácidos Hidroxámicos/farmacocinética , Modelos Moleculares , Inhibidores de Proteasas/farmacocinética , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , PorcinosRESUMEN
In an effort to obtain a MMP selective and potent inhibitor of HER-2 sheddase (ADAM-10), the P1' group of a novel class of (6S,7S)-7-[(hydroxyamino)carbonyl]-6-carboxamide-5-azaspiro[2.5]octane-5-carboxylates was attenuated and the structure-activity relationships (SAR) will be discussed. In addition, it was discovered that unconventional perturbation of the P2' moiety could confer MMP selectivity, which was hypothesized to be a manifestation of the P2' group effecting global conformational changes.
Asunto(s)
Proteínas ADAM/antagonistas & inhibidores , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Ácidos Hidroxámicos/química , Proteínas de la Membrana/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/química , Receptor ErbB-2/antagonistas & inhibidores , Proteínas ADAM/metabolismo , Proteína ADAM10 , Amidas/síntesis química , Amidas/química , Amidas/farmacología , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Compuestos Aza/síntesis química , Compuestos Aza/química , Compuestos Aza/farmacología , Diseño de Fármacos , Ácidos Hidroxámicos/síntesis química , Ácidos Hidroxámicos/farmacología , Proteínas de la Membrana/metabolismo , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Estructura Terciaria de Proteína , Receptor ErbB-2/metabolismo , Compuestos de Espiro/síntesis química , Compuestos de Espiro/química , Compuestos de Espiro/farmacología , Relación Estructura-Actividad , Especificidad por SustratoRESUMEN
The design, synthesis, evaluation, and identification of a novel class of (6S,7S)-N-hydroxy-6-carboxamide-5-azaspiro[2.5]octane-7-carboxamides as the first potent and selective inhibitors of human epidermal growth factor receptor-2 (HER-2) sheddase is described. Several compounds were identified that possess excellent pharmacodynamic and pharmacokinetic properties and were shown to decrease tumor size, cleaved HER-2 extracellular domain plasma levels, and potentiate the effects of the humanized anti-HER-2 monoclonal antibody (trastuzumab) in vivo in a HER-2 overexpressing cancer murine xenograft model.
Asunto(s)
Amidas/síntesis química , Antineoplásicos/síntesis química , Ácidos Hidroxámicos/síntesis química , Piperidinas/síntesis química , Receptor ErbB-2/antagonistas & inhibidores , Compuestos de Espiro/síntesis química , Administración Oral , Amidas/farmacocinética , Amidas/farmacología , Animales , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales Humanizados , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Sinergismo Farmacológico , Humanos , Ácidos Hidroxámicos/farmacocinética , Ácidos Hidroxámicos/farmacología , Ratones , Conformación Molecular , Piperidinas/química , Piperidinas/farmacología , Compuestos de Espiro/química , Compuestos de Espiro/farmacología , Estereoisomerismo , Relación Estructura-Actividad , Trasplante Heterólogo , TrastuzumabRESUMEN
New gamma-lactam TACE inhibitors were designed from known MMP inhibitors. A homology model of TACE was built and examined to identify the S1' site as the key area for TACE selectivity over MMPs. Rational exploration of the P1'-S1' interactions resulted in the discovery of the 3,5-disubstituted benzyl ether as a TACE-selective P1' group. Further optimization led to the discovery of IK682 as a selective and orally bioavailable TACE inhibitor.
Asunto(s)
Ácidos Hidroxámicos/síntesis química , Lactamas/síntesis química , Metaloendopeptidasas/antagonistas & inhibidores , Inhibidores de Proteasas/síntesis química , Proteínas ADAM , Proteína ADAM17 , Administración Oral , Animales , Disponibilidad Biológica , Perros , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/farmacología , Lactamas/química , Lactamas/farmacología , Metaloproteinasa 3 de la Matriz/química , Modelos Moleculares , Inhibidores de Proteasas/química , Inhibidores de Proteasas/farmacología , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , PorcinosRESUMEN
In this communication we describe the design, synthesis, and evaluation of novel sultam hydroxamates 4 as MMP-2, -9, and -13 inhibitors. Compound 26 was found to be an active inhibitor (MMP-2 IC(50) = 1 nM) with 1000-fold selectivity over MMP-1 and good oral bioavailability (F = 43%) in mouse. An X-ray crystal structure of 26 in MMP-13 confirms the key hydrogen bonds and prime side binding in the active site.
Asunto(s)
Ácidos Hidroxámicos/síntesis química , Inhibidores de la Metaloproteinasa de la Matriz , Sulfonamidas/síntesis química , Administración Oral , Animales , Disponibilidad Biológica , Cristalografía por Rayos X , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/farmacología , Metaloproteinasa 13 de la Matriz , Ratones , Modelos Moleculares , Relación Estructura-Actividad , Sulfonamidas/química , Sulfonamidas/farmacologíaRESUMEN
Elevated levels of tumor necrosis factor-alpha (TNF-alpha) have been associated with several inflammatory diseases, and therefore, strategies for its suppression have become important targets in drug discovery. Our efforts to suppress TNF-alpha have centered on the inhibition of TNF-alpha converting enzyme (TACE) through the use of hydroxamate inhibitors. Starting from broad-spectrum matrix metalloproteinase (MMP) inhibitors, we have designed and synthesized novel benzothiadiazepines as potent and selective TACE inhibitors. The benzothiadiazepines were synthesized with variation in P1 and P1' in order to effect potency and selectivity. The inhibitors were evaluated versus porcine TACE (pTACE), and the initial selectivity was assessed with counterscreens of MMP-1, -2, and -9. Several potent and selective inhibitors were discovered with compound 41 being the most active against pTACE (K(i) = 5 nM) while still maintaining good selectivity versus the MMP's (at least 75-fold). Most compounds were assessed in the human peripheral blood mononuclear cell assay (PBMC) and the human whole blood assay (WBA) to determine their ability to suppress TNF-alpha. Compound 32 was the most potent compound in the PBMC assay (IC(50) = 0.35 microM), while compound 62 was the most active in the WBA (IC(50) = 1.4 microM).
Asunto(s)
Benzodiazepinonas/síntesis química , Inhibidores Enzimáticos/síntesis química , Ácidos Hidroxámicos/síntesis química , Metaloendopeptidasas/antagonistas & inhibidores , Tiazepinas/síntesis química , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Proteínas ADAM , Proteína ADAM17 , Animales , Benzodiazepinonas/química , Benzodiazepinonas/farmacología , Proteínas Sanguíneas/metabolismo , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Humanos , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/farmacología , Leucocitos Mononucleares/efectos de los fármacos , Inhibidores de la Metaloproteinasa de la Matriz , Modelos Moleculares , Unión Proteica , Relación Estructura-Actividad , Porcinos , Tiazepinas/química , Tiazepinas/farmacología , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
A series of novel hydantoins was designed and synthesized as structural alternatives to hydroxamate inhibitors of TACE. 5-Mono- and di-substituted hydantoins exhibited activity with IC50 values of 11-60 nM against porcine TACE in vitro and excellent selectivity against other MMPs.
Asunto(s)
Proteínas ADAM/antagonistas & inhibidores , Hidantoínas/síntesis química , Hidantoínas/farmacología , Proteína ADAM17 , Animales , Diseño de Fármacos , Concentración 50 Inhibidora , Relación Estructura-Actividad , Especificidad por Sustrato , PorcinosRESUMEN
Using a pyrimidine-2,4,6-trione motif as a zinc-binding group, a series of selective inhibitors of tumor necrosis factor-alpha converting enzyme (TACE) was discovered. Optimization of initial lead 1 resulted in a potent inhibitor (51), with an IC(50) of 2 nM in a porcine TACE assay. To the best of our knowledge, compound 51 and related analogues represent first examples of non-hydroxamate-based inhibitors of TACE with single digit nanomolar potency.
Asunto(s)
Proteínas ADAM/antagonistas & inhibidores , Barbitúricos/química , Barbitúricos/farmacología , Benzamidas/química , Benzamidas/farmacología , Inhibidores de Proteasas/química , Inhibidores de Proteasas/farmacología , Proteína ADAM17 , Barbitúricos/síntesis química , Benzamidas/síntesis química , Ácidos Hidroxámicos/química , Concentración 50 Inhibidora , Inhibidores de Proteasas/síntesis químicaRESUMEN
DPC 333 ((2R)-2-((3R)-3-amino-3{4-[2-methyl-4-quinolinyl) methoxy] phenyl}-2-oxopyrrolidinyl)-N-hydroxy-4-methylpentanamide)) is a potent and selective inhibitor of tumor necrosis factor (TNF)-alpha-converting enzyme (TACE). It significantly inhibits lipopolysaccharide-induced soluble TNF-alpha production in blood from rodents, chimpanzee, and human, with IC(50) values ranging from 17 to 100 nM. In rodent models of endotoxemia, DPC 333 inhibited the production of TNF-alpha in a dose-dependent manner, with an oral ED(50) ranging from 1.1 to 6.1 mg/kg. Oral dosing of DPC 333 at 5.5 mg/kg daily for 2 weeks in a rat collagen antibody-induced arthritis model suppressed the maximal response by approximately 50%. DPC 333 was distributed widely to tissues including the synovium, the site of action for antiarthritic drugs. Pharmacokinetic and pharmacodynamic studies in chimpanzee revealed a systemic clearance of 0.4 l/h/kg, a V(ss) of 0.6 l/kg, an oral bioavailability of 17%, and an ex vivo IC(50) for the suppression of TNF-alpha production of 55 nM (n = 1). In a phase I clinical trial with male volunteers after single escalating doses of oral DPC 333, the terminal half-life was between 3 and 6 h and the ex vivo IC(50) for suppressing TNF-alpha production was 113 nM. Measurement of the suppression of TNF-alpha production ex vivo may serve as a good biomarker in evaluating the therapeutic efficacy of TACE inhibitors. Overall, the pharmacological profiles of DPC 333 support the notion that suppression of TNF-alpha with TACE inhibitors like DPC 333 may provide a novel approach in the treatment of various inflammatory diseases including rheumatoid arthritis, via control of excessive TNF-alpha production.