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1.
Mov Disord ; 38(2): 313-320, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36444905

RESUMO

BACKGROUND: MOXIe was a two-part study evaluating the safety and efficacy of omaveloxolone in patients with Friedreich's ataxia, a rare, progressive neurological disease with no proven therapy. MOXIe part 2, a randomized double-blind placebo-controlled trial, showed omaveloxolone significantly improved modified Friedreich's Ataxia Rating Scale (mFARS) scores relative to placebo. Patients who completed part 1 or 2 were eligible to receive omaveloxolone in an open-label extension study. OBJECTIVE: The delayed-start study compared mFARS scores at the end of MOXIe part 2 with those at 72 weeks in the open-label extension period (up to 144 weeks) for patients initially randomized to omaveloxolone versus those initially randomized to placebo. METHODS: We performed a noninferiority test to compare the difference between treatment groups (placebo to omaveloxolone versus omaveloxolone to omaveloxolone) using a single mixed model repeated measures (MMRM) model. In addition, slopes of the change in mFARS scores were compared between both groups in the open-label extension. RESULTS: The noninferiority testing demonstrated that the difference in mFARS between omaveloxolone and placebo observed at the end of placebo-controlled MOXIe part 2 (-2.17 ± 1.09 points) was preserved after 72 weeks in the extension (-2.91 ± 1.44 points). In addition, patients previously randomized to omaveloxolone in MOXIe part 2 continued to show no worsening in mFARS relative to their extension baseline through 144 weeks. CONCLUSIONS: These results support the positive results of MOXIe part 2 and indicate a persistent benefit of omaveloxolone treatment on disease course in Friedreich's ataxia. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Assuntos
Ataxia de Friedreich , Triterpenos , Humanos , Ataxia de Friedreich/tratamento farmacológico , Triterpenos/uso terapêutico , Método Duplo-Cego , Progressão da Doença
2.
Ann Neurol ; 89(2): 212-225, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33068037

RESUMO

OBJECTIVE: Friedreich ataxia (FA) is a progressive genetic neurodegenerative disorder with no approved treatment. Omaveloxolone, an Nrf2 activator, improves mitochondrial function, restores redox balance, and reduces inflammation in models of FA. We investigated the safety and efficacy of omaveloxolone in patients with FA. METHODS: We conducted an international, double-blind, randomized, placebo-controlled, parallel-group, registrational phase 2 trial at 11 institutions in the United States, Europe, and Australia (NCT02255435, EudraCT2015-002762-23). Eligible patients, 16 to 40 years of age with genetically confirmed FA and baseline modified Friedreich's Ataxia Rating Scale (mFARS) scores between 20 and 80, were randomized 1:1 to placebo or 150mg per day of omaveloxolone. The primary outcome was change from baseline in the mFARS score in those treated with omaveloxolone compared with those on placebo at 48 weeks. RESULTS: One hundred fifty-five patients were screened, and 103 were randomly assigned to receive omaveloxolone (n = 51) or placebo (n = 52), with 40 omaveloxolone patients and 42 placebo patients analyzed in the full analysis set. Changes from baseline in mFARS scores in omaveloxolone (-1.55 ± 0.69) and placebo (0.85 ± 0.64) patients showed a difference between treatment groups of -2.40 ± 0.96 (p = 0.014). Transient reversible increases in aminotransferase levels were observed with omaveloxolone without increases in total bilirubin or other signs of liver injury. Headache, nausea, and fatigue were also more common among patients receiving omaveloxolone. INTERPRETATION: In the MOXIe trial, omaveloxolone significantly improved neurological function compared to placebo and was generally safe and well tolerated. It represents a potential therapeutic agent in FA. ANN NEUROL 2021;89:212-225.


Assuntos
Ataxia de Friedreich/tratamento farmacológico , Triterpenos/uso terapêutico , Acidentes por Quedas , Atividades Cotidianas , Adolescente , Adulto , Antioxidantes/metabolismo , Método Duplo-Cego , Teste de Esforço , Feminino , Ataxia de Friedreich/metabolismo , Ataxia de Friedreich/fisiopatologia , Humanos , Masculino , Mitocôndrias/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Transdução de Sinais , Resultado do Tratamento , Adulto Jovem
3.
Am J Nephrol ; 52(3): 180-189, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33789284

RESUMO

INTRODUCTION: Alport syndrome is a rare genetic disorder that affects as many as 60,000 persons in the USA and a total of 103,000 persons (<5 per 10,000) in the European Union [1, 2]. It is the second most common inherited cause of kidney failure and is characterized by progressive loss of kidney function that often leads to end-stage kidney disease. Currently, there are no approved disease-specific agents for therapeutic use. We designed a phase 3 study (CARDINAL; NCT03019185) to evaluate the safety, tolerability, and efficacy of bardoxolone methyl in patients with Alport syndrome. METHODS: The CARDINAL phase 3 study is an international, multicenter, double-blind, placebo-controlled, randomized registrational trial. Eligible patients were of ages 12-70 years with confirmed genetic or histologic diagnosis of Alport syndrome, eGFR 30-90 mL/min/1.73 m2, and urinary albumin to creatinine ratio (UACR) ≤3,500 mg/g. Patients with B-type natriuretic peptide values >200 pg/mL at baseline or with significant cardiovascular histories were excluded. Patients were randomized 1:1 to bardoxolone methyl or placebo, with stratification by baseline UACR. RESULTS: A total of 371 patients were screened, and 157 patients were randomly assigned to receive bardoxolone methyl (n = 77) or placebo (n = 80). The average age at screening was 39.2 years, and 23 (15%) were <18 years of age. Of the randomized population, 146 (93%) had confirmed genetic diagnosis of Alport syndrome, and 62% of patients had X-linked mode of inheritance. Mean baseline eGFR was 62.7 mL/min/1.73 m2, and the geometric mean UACR was 141.0 mg/g. The average annual rate of eGFR decline prior to enrollment in the study was -4.9 mL/min/1.73 m2 despite 78% of the patient population receiving ACE inhibitor (ACEi) or ARB therapy. DISCUSSION/CONCLUSION: CARDINAL is one of the largest interventional, randomized controlled trials in Alport syndrome conducted to date. Despite the use of ACEi or ARB, patients were experiencing significant loss of kidney function prior to study entry.


Assuntos
Nefrite Hereditária/tratamento farmacológico , Ácido Oleanólico/análogos & derivados , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Oleanólico/efeitos adversos , Ácido Oleanólico/uso terapêutico , Projetos de Pesquisa , Resultado do Tratamento
4.
Kidney Int ; 96(4): 1030-1036, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31377056

RESUMO

Bardoxolone methyl attenuates inflammation by inducing nuclear factor erythroid-derived 2-related factor 2 and suppressing nuclear factor κB. The Bardoxolone Methyl Evaluation in Patients With Chronic Kidney Disease and Type 2 Diabetes (BEACON) trial was a phase 3 placebo-controlled, randomized, double-blind, parallel-group, international, multicenter trial in 2185 patients with type 2 diabetes mellitus and stage 4 chronic kidney disease. BEACON was terminated because of safety concerns, largely related to a significant increase in early heart failure events in patients randomized to bardoxolone methyl. Bardoxolone methyl resulted in increased estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio. Herein, we present post hoc analyses characterizing the relation between the urine albumin-to-creatinine ratio and eGFR. The urine albumin-to-creatinine ratio and eGFR were assessed every four weeks through Week 12, followed by assessments every eight weeks thereafter, and 4 weeks after the last dose of bardoxolone methyl was administered. The initial increases in urine albumin-to-creatinine ratio observed in patients randomized to bardoxolone methyl were attenuated after six months. Multivariable regression analysis identified baseline eGFR and eGFR over time as the dominant factors associated with change in the urine albumin-to-creatinine ratio. Relative to placebo, bardoxolone methyl resulted in a significant decrease in albuminuria when indexed to eGFR (least-squared means: -0.035 [95% confidence interval -0.031 to -0.039]). Thus, among patients with type 2 diabetes mellitus and stage 4 chronic kidney disease treated with bardoxolone methyl, changes in albuminuria are directly related to changes in eGFR, challenging the conventional construct that increases in albuminuria universally reflect kidney injury and denote harm.


Assuntos
Albuminúria/diagnóstico , Creatinina/urina , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/tratamento farmacológico , Falência Renal Crônica/tratamento farmacológico , Ácido Oleanólico/análogos & derivados , Adulto , Albuminúria/tratamento farmacológico , Albuminúria/etiologia , Diabetes Mellitus Tipo 2/urina , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/urina , Método Duplo-Cego , Término Precoce de Ensaios Clínicos , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Insuficiência Cardíaca/induzido quimicamente , Insuficiência Cardíaca/epidemiologia , Humanos , Falência Renal Crônica/etiologia , Falência Renal Crônica/urina , Masculino , Pessoa de Meia-Idade , Ácido Oleanólico/administração & dosagem , Ácido Oleanólico/efeitos adversos , Resultado do Tratamento
5.
Am J Nephrol ; 47(1): 40-47, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29402767

RESUMO

BACKGROUND: Increases in measured inulin clearance, measured creatinine clearance, and estimated glomerular filtration rate (eGFR) have been observed with bardoxolone methyl in 7 studies enrolling approximately 2,600 patients with type 2 diabetes (T2D) and chronic kidney disease (CKD). The largest of these studies was Bardoxolone Methyl Evaluation in Patients with Chronic Kidney Disease and Type 2 Diabetes (BEACON), a multinational, randomized, double-blind, placebo-controlled phase 3 trial which enrolled patients with T2D and CKD stage 4. The BEACON trial was terminated after preliminary analyses showed that patients randomized to bardoxolone methyl experienced significantly higher rates of heart failure events. We performed post-hoc analyses to characterize changes in kidney function induced by bardoxolone methyl. METHODS: Patients in -BEACON (n = 2,185) were randomized 1: 1 to receive once-daily bardoxolone methyl (20 mg) or placebo. We compared the effects of bardoxolone methyl and placebo on a post-hoc composite renal endpoint consisting of ≥30% decline from baseline in eGFR, eGFR <15 mL/min/1.73 m2, and end-stage renal disease (ESRD) events (provision of dialysis or kidney transplantation). RESULTS: Consistent with prior studies, patients randomized to bardoxolone methyl experienced mean increases in eGFR that were sustained through study week 48. Moreover, increases in eGFR from baseline were sustained 4 weeks after cessation of treatment. Patients randomized to bardoxolone methyl were significantly less likely to experience the composite renal endpoint (hazards ratio 0.48 [95% CI 0.36-0.64]; p < 0.0001). CONCLUSIONS: Bardoxolone methyl preserves kidney function and may delay the onset of ESRD in patients with T2D and stage 4 CKD.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Taxa de Filtração Glomerular/efeitos dos fármacos , Falência Renal Crônica/prevenção & controle , Rim/efeitos dos fármacos , Ácido Oleanólico/análogos & derivados , Idoso , Diabetes Mellitus Tipo 2/fisiopatologia , Progressão da Doença , Método Duplo-Cego , Feminino , Insuficiência Cardíaca/induzido quimicamente , Insuficiência Cardíaca/epidemiologia , Humanos , Rim/fisiopatologia , Falência Renal Crônica/complicações , Falência Renal Crônica/patologia , Falência Renal Crônica/fisiopatologia , Transplante de Rim/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Ácido Oleanólico/administração & dosagem , Ácido Oleanólico/efeitos adversos , Diálise Renal/estatística & dados numéricos , Resultado do Tratamento
6.
J Card Fail ; 20(12): 953-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25307295

RESUMO

BACKGROUND: A phase 3 randomized clinical trial was designed to test whether bardoxolone methyl, a nuclear factor erythroid-2-related factor 2 (Nrf2) activator, slows progression to end-stage renal disease in patients with stage 4 chronic kidney disease and type 2 diabetes mellitus. The trial was terminated because of an increase in heart failure in the bardoxolone methyl group; many of the events were clinically associated with fluid retention. METHODS AND RESULTS: We randomized 2,185 patients with type 2 diabetes mellitus (T2DM) and stage 4 chronic kidney disease (CKD) (estimated glomerular filtration rate 15 to <30 mL min(-1) 1.73 m(-2)) to once-daily bardoxolone methyl (20 mg) or placebo. We used classification and regression tree analysis to identify baseline factors predictive of heart failure or fluid overload events. Elevated baseline B-type natriuretic peptide and previous hospitalization for heart failure were identified as predictors of heart failure events; bardoxolone methyl increased the risk of heart failure by 60% in patients with these risk factors. For patients without these baseline characteristics, the risk for heart failure events among bardoxolone methyl- and placebo-treated patients was similar (2%). The same risk factors were also identified as predictors of fluid overload and appeared to be related to other serious adverse events. CONCLUSIONS: Bardoxolone methyl contributed to events related to heart failure and/or fluid overload in a subpopulation of susceptible patients with an increased risk for heart failure at baseline. Careful selection of participants and vigilant monitoring of the study drug will be required in any future trials of bardoxolone methyl to mitigate the risk of heart failure and other serious adverse events.


Assuntos
Diabetes Mellitus Tipo 2/diagnóstico , Término Precoce de Ensaios Clínicos , Insuficiência Cardíaca/induzido quimicamente , Ácido Oleanólico/análogos & derivados , Insuficiência Renal Crônica/tratamento farmacológico , Idoso , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/mortalidade , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Seguimentos , Taxa de Filtração Glomerular , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Ácido Oleanólico/administração & dosagem , Ácido Oleanólico/efeitos adversos , Segurança do Paciente , Valor Preditivo dos Testes , Valores de Referência , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/mortalidade , Fatores de Risco , Índice de Gravidade de Doença , Taxa de Sobrevida , Resultado do Tratamento
7.
Am J Nephrol ; 39(6): 499-508, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24903467

RESUMO

BACKGROUND: Bardoxolone methyl, an Nrf2-activating and nuclear factor-κB-inhibiting semisynthetic oleanane triterpenoid compound, was evaluated in a phase 3 trial (BEACON) in patients with type 2 diabetes mellitus (T2DM) and stage 4 chronic kidney disease (CKD). The trial was terminated because of an increase in heart failure events in the bardoxolone methyl group, many of which appeared related to fluid retention. Thus, additional analyses were conducted to explain these serious adverse events. METHODS: Patients (n = 2,185) were randomized to receive once-daily bardoxolone methyl (20 mg) or placebo. Twenty-four-hour urine collections were analyzed in a subset of the BEACON population and from a separate, open-label pharmacology study in patients with stage 3b/4 CKD and T2DM administered 20 mg bardoxolone methyl once daily for 56 consecutive days. RESULTS: Bardoxolone-methyl-treated patients in the BEACON substudy had a clinically meaningful reduction in urine volume and sodium excretion at week 4 relative to baseline (p < 0.05), and a separate study revealed that decreased sodium excretion and urine output occurred in some patients with stage 4 CKD but not those with stage 3b CKD. The clinical phenotype of fluid overload and heart failure in BEACON was similar to that observed with endothelin receptor antagonists in advanced CKD patients, and preclinical data demonstrate that bardoxolone methyl modifies endothelin signaling. CONCLUSIONS: The totality of the evidence suggests that through modulation of the endothelin pathway, bardoxolone methyl may pharmacologically promote acute sodium and volume retention and increase blood pressure in patients with more advanced CKD.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Término Precoce de Ensaios Clínicos , Insuficiência Cardíaca/induzido quimicamente , Ácido Oleanólico/análogos & derivados , Insuficiência Renal Crônica/tratamento farmacológico , Desequilíbrio Hidroeletrolítico/induzido quimicamente , Animais , Método Duplo-Cego , Humanos , Macaca fascicularis , Masculino , Ácido Oleanólico/efeitos adversos , Ratos , Insuficiência Renal Crônica/complicações , Sódio/urina , Urina
8.
Clin J Am Soc Nephrol ; 17(12): 1763-1774, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36411058

RESUMO

BACKGROUND AND OBJECTIVES: Alport syndrome is an inherited disease characterized by progressive loss of kidney function. We aimed to evaluate the safety and efficacy of bardoxolone methyl in patients with Alport syndrome. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We randomly assigned patients with Alport syndrome, ages 12-70 years and eGFR 30-90 ml/min per 1.73 m2, to bardoxolone methyl (n=77) or placebo (n=80). Primary efficacy end points were change from baseline in eGFR at weeks 48 and 100. Key secondary efficacy end points were change from baseline in eGFR at weeks 52 and 104, after an intended 4 weeks off treatment. Safety was assessed by monitoring for adverse events and change from baseline in vital signs, 12-lead electrocardiograms, laboratory measurements (including, but not limited to, aminotransferases, urinary albumin-creatinine ratio, magnesium, and B-type natriuretic peptide), and body weight. RESULTS: Patients randomized to bardoxolone methyl experienced preservation in eGFR relative to placebo at 48 and 100 weeks (between-group differences: 9.2 [97.5% confidence interval, 5.1 to 13.4; P<0.001] and 7.4 [95% confidence interval, 3.1 to 11.7; P=0.0008] ml/min per 1.73 m2, respectively). After a 4-week off-treatment period, corresponding mean differences in eGFR were 5.4 (97.5% confidence interval, 1.8 to 9.1; P<0.001) and 4.4 (95% confidence interval, 0.7 to 8.1; P=0.02) ml/min per 1.73 m2 at 52 and 104 weeks, respectively. In a post hoc analysis with no imputation of missing eGFR data, the difference at week 104 was not statistically significant (1.5 [95% confidence interval, -1.9 to 4.9] ml/min per 1.73 m2). Discontinuations from treatment were more frequent among patients randomized to bardoxolone methyl; most discontinuations were due to protocol-specified criteria being met for increases in serum transaminases. Serious adverse events were more frequent among patients randomized to placebo. Three patients in each group developed kidney failure. CONCLUSIONS: In adolescent and adult patients with Alport syndrome receiving standard of care, treatment with bardoxolone methyl resulted in preservation in eGFR relative to placebo after a 2-year study period; off-treatment results using all available data were not significantly different. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: A Phase 2/3 Trial of the Efficacy and Safety of Bardoxolone Methyl in Patients with Alport Syndrome - CARDINAL (CARDINAL), NCT03019185.


Assuntos
Diabetes Mellitus Tipo 2 , Nefrite Hereditária , Ácido Oleanólico , Adulto , Adolescente , Humanos , Criança , Adulto Jovem , Pessoa de Meia-Idade , Idoso , Nefrite Hereditária/tratamento farmacológico , Nefrite Hereditária/complicações , Diabetes Mellitus Tipo 2/complicações , Ácido Oleanólico/efeitos adversos , Taxa de Filtração Glomerular , Método Duplo-Cego
9.
Clin Transl Sci ; 14(1): 299-309, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32860734

RESUMO

In a multinational placebo-controlled phase III clinical trial in 2,185 patients with type 2 diabetes mellitus and stage 4 chronic kidney disease, treatment with the Nrf2 activator bardoxolone methyl increased estimated glomerular filtration rate, a measure of kidney function, but also resulted in increases in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma glutamyl transferase. These increases in liver enzyme level(s) were maximal after 4 weeks of treatment and reversible, trending back toward baseline through week 48. Total bilirubin concentrations did not increase, and no cases met Hy's Law criteria, although two subjects had ALT concentrations that exceeded 10 × the upper limit of the population reference range leading to discontinuation of treatment. Animal and cell culture experiments suggested that the increases in ALT and AST induced by bardoxolone methyl may be related to its pharmacological activity. Bardoxolone methyl significantly induced the mRNA expression of ALT and AST isoforms in cultured cells. Expression of ALT and AST isoforms in liver and kidney also positively correlated with Nrf2 status in mice. Overall, these data suggest that the increases in ALT and AST observed clinically were, at least in part, related to the pharmacological induction of aminotransferases via Nrf2 activation, rather than to any intrinsic form of hepatotoxicity.


Assuntos
Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Diabetes Mellitus Tipo 2/complicações , Falência Renal Crônica/tratamento farmacológico , Ácido Oleanólico/análogos & derivados , Idoso , Alanina Transaminase/genética , Alanina Transaminase/metabolismo , Aspartato Aminotransferases/genética , Aspartato Aminotransferases/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Taxa de Filtração Glomerular/efeitos dos fármacos , Taxa de Filtração Glomerular/fisiologia , Humanos , Rim/efeitos dos fármacos , Rim/fisiopatologia , Falência Renal Crônica/sangue , Falência Renal Crônica/etiologia , Falência Renal Crônica/fisiopatologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Pessoa de Meia-Idade , Fator 2 Relacionado a NF-E2/metabolismo , Ácido Oleanólico/farmacologia , Ácido Oleanólico/uso terapêutico
11.
Chem Res Toxicol ; 23(4): 778-87, 2010 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-20201482

RESUMO

Knowledge of the rates at which macrophages and epithelial cells synthesize NO is critical for predicting the concentrations of NO and other reactive nitrogen species in colonic crypts during inflammation, and elucidating the linkage between inflammatory bowel disease, NO, and cancer. Macrophage-like RAW264.7 cells, primary bone marrow-derived macrophages (BMDM), and HCT116 colonic epithelial cells were subjected to simulated inflammatory conditions, and rates of formation and consumption were determined for NO, O(2), and O(2)(-). Production rates of NO were determined in either of two ways: continuous monitoring of NO concentrations in a closed chamber with corrections for autoxidation, or NO(2)(-) accumulation measurements in an open system with corrections for diffusional losses of NO. The results obtained using the two methods were in excellent agreement. Rates of NO synthesis (2.3 +/- 0.6 pmol s(-1) 10(6) cells(-1)), NO consumption (1.3 +/- 0.3 s(-1)), and O(2) consumption (59 +/- 17 pmol s(-1) 10(6) cells(-1) when NO is negligible) for activated BMDM were indistinguishable from those of activated RAW264.7 cells. NO production rates calculated from NO(2)(-) accumulation data for HCT116 cells infected with Helicobacter cinaedi (3.9 +/- 0.1 pmol s(-1) 10(6) cells(-1)) were somewhat greater than those of RAW264.7 macrophages infected under similar conditions (2.6 +/- 0.1 pmol s(-1) 10(6) cells(-1)). Thus, RAW264.7 cells have NO kinetics nearly identical to those of primary macrophages, and stimulated epithelial cells are capable of synthesizing NO at rates comparable to those of macrophages. Using these cellular kinetic parameters, simulations of NO diffusion and reaction in a colonic crypt during inflammation predict maximum NO concentrations of about 0.2 microM at the base of a crypt.


Assuntos
Colo/metabolismo , Células Epiteliais/metabolismo , Macrófagos/metabolismo , Óxido Nítrico/metabolismo , Oxigênio/metabolismo , Superóxidos/metabolismo , Animais , Linhagem Celular , Colo/citologia , Helicobacter/crescimento & desenvolvimento , Doenças Inflamatórias Intestinais/metabolismo , Camundongos , Óxido Nítrico/biossíntese , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Nitrogênio/toxicidade
12.
Nitric Oxide ; 23(4): 319-26, 2010 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-20854923

RESUMO

The presence of iNOS and nitrotyrosine in cutaneous melanomas has been correlated with poor survival rates of patients, suggesting that NO plays a role in the tumor pathophysiology. However, the concentrations of NO that melanoma cells are exposed to in vivo have been unknown. To provide cell kinetic data for use in predicting those concentrations, synthesis and consumption of NO was examined in A375 melanoma cells. Nitric oxide synthesis was undetectable. The rate of intracellular NO consumption was determined by continuous monitoring of NO concentrations following injection of NO solutions in a closed chamber. After correcting for autoxidation and consumption from media-generated O(2)(-), the rate constant obtained for cellular consumption was 7.1±1.1 s(-1). This information was combined with previous data on macrophage NO kinetics to develop a mathematical model to predict NO levels in cutaneous melanomas. Synthesis of NO by macrophages in the stroma was found to give a maximum concentration at the tumor periphery of 0.2 µM. Because of the high rates of cellular consumption, the elevation in NO concentration is predicted to be very localized, approximately 90% of the concentration decay occurring within 30 µm of the tumor edge. High NO concentrations at the periphery of a melanoma may contribute to metastasis by stimulating cell proliferation, inhibiting apoptosis, or acting as a lymphangiogenic factor.


Assuntos
Melanoma/metabolismo , Óxido Nítrico/metabolismo , Neoplasias Cutâneas/metabolismo , Simulação por Computador , Difusão , Humanos , Cinética , Macrófagos/metabolismo , Macrófagos/patologia , Melanoma/patologia , Óxido Nítrico/biossíntese , Neoplasias Cutâneas/patologia , Células Tumorais Cultivadas
13.
Cardiorenal Med ; 9(5): 326-333, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31158840

RESUMO

BACKGROUND: Bardoxolone methyl has been shown to increase eGFR in several clinical trials, including a phase 3 trial in patients with type 2 diabetes and stage 4 CKD (BEACON), which was terminated early due to an increase in heart failure events in bardoxolone methyl-treated patients. A separate, "thorough QT" study was conducted in parallel with BEACON to evaluate the cardiovascular safety of bardoxolone methyl in healthy subjects. METHODS: Subjects in the "thorough QT" study were randomized to receive bardoxolone methyl 20 mg (therapeutic dose) or 80 mg (supratherapeutic dose), placebo, or moxifloxacin (400 mg; an active comparator). ECG results and supine blood pressure measurements were analyzed. The effects of bardoxolone methyl on QT interval changes from baseline were quantified compared to the effect of placebo by calculating mean, time-matched, placebo-corrected, baseline-adjusted QTcF values (ΔΔQTcF) after 6 days of daily administration of bardoxolone methyl. RESULTS: The study was halted early due to emerging safety information from the BEACON trial; however, 142/179 patients received all doses of the study drug and completed the study. For both bardoxolone methyl-treated groups (20 and 80 mg), the upper limits of the 2-sided 90% confidence interval for ΔΔQTcF were less than the significance limit (10 ms) at all time points. Changes in blood pressure were similar in all treatment groups, and no serious adverse events were reported. CONCLUSIONS: In healthy subjects, treatment with 20 or 80 mg bardoxolone methyl did not affect the QTcF interval.


Assuntos
Eletrocardiografia/efeitos dos fármacos , Ácido Oleanólico/análogos & derivados , Adolescente , Adulto , Pressão Sanguínea/efeitos dos fármacos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Moxifloxacina/efeitos adversos , Moxifloxacina/farmacologia , Ácido Oleanólico/administração & dosagem , Ácido Oleanólico/efeitos adversos , Ácido Oleanólico/farmacologia , Adulto Jovem
14.
Cardiorenal Med ; 9(5): 316-325, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31170712

RESUMO

BACKGROUND: Treatment with bardoxolone methyl (Bard) in a multinational phase 3 trial, Bardoxolone Methyl Evaluation in Patients with Chronic Kidney Disease and Type 2 Diabetes (BEACON), resulted in increases in estimated glomerular filtration rate with concurrent reductions in serum magnesium. We analyzed data from several trials to characterize reductions in magnesium with Bard. METHODS: BEACON randomized patients (n = 2,185) with type 2 diabetes (T2DM) and stage 4 chronic kidney disease (CKD) 1:1 to receive Bard (20 mg) or placebo once daily. In a separate open-label study, magnesium levels from 24-hour urine and sublingual epithelial cell samples were analyzed in patients with stage 3b-4 CKD and T2DM administered 20 mg Bard for 56 consecutive days. RESULTS: BEACON patients randomized to Bard experienced significant reductions in serum magnesium from baseline relative to patients randomized to placebo (-0.17 mEq/L, 95% CI -0.18 to -0.60 mEq/L; p < 0.001). A separate study showed intracellular and urinary magnesium levels were unchanged with Bard treatment. CONCLUSIONS: Bard treatment results in significant decreases in serum magnesium that are not associated with changes in intracellular and urinary magnesium levels, indicating that magnesium decreases are not due to renal magnesium wasting or total body magnesium depletion. Importantly, the decreases in serum magnesium with Bard are not associated with adverse effects on QT interval.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Nefropatias Diabéticas/metabolismo , Magnésio/metabolismo , Ácido Oleanólico/análogos & derivados , Insuficiência Renal Crônica/metabolismo , Idoso , Diabetes Mellitus Tipo 2/fisiopatologia , Nefropatias Diabéticas/fisiopatologia , Método Duplo-Cego , Eletrocardiografia/efeitos dos fármacos , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Magnésio/sangue , Masculino , Pessoa de Meia-Idade , Ácido Oleanólico/farmacocinética , Ácido Oleanólico/farmacologia , Insuficiência Renal Crônica/fisiopatologia
15.
Nitric Oxide ; 19(3): 266-75, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18501201

RESUMO

Nitric oxide production in the colon has been linked to inflammatory bowel disease (IBD) and increased risk for colon cancer. However, measurements of NO concentration in the inflamed colon have not been available and it is not known what NO levels are pathophysiological. A computational model, based on anatomical length scales and rates of NO production measured in cell cultures, was used to predict spatially varying NO concentrations within a colonic crypt under inflammatory conditions. A variety of scenarios were considered, including different spatial distributions of macrophages and a range of possible macrophage and epithelial synthesis rates for NO. Activated macrophages arranged as a monolayer at the base of the crypt elicited maximum NO concentrations of approximately 0.3 microM. The epithelial contribution to NO synthesis was calculated to be negligible. Assuming a uniform macrophage layer, NO synthesis rates greater than 20 microM/s, or more than three times that measured in vitro, would be necessary to achieve maximum NO concentrations of 1 microM in the crypt. Thus, unless NO synthesis rates in macrophages and/or epithelial cells greatly exceed those measured in cell cultures, NO concentrations will remain submicromolar in the crypt during inflammation. Additionally, the results were used to predict the range of NO concentrations (<0.3 microM) and cumulative NO dose (560 microM min) experienced by a given epithelial cell migrating from the base to the top of the crypt. These estimates of NO concentrations in inflamed crypts should facilitate efforts to elucidate the molecular biological linkage between NO exposure and carcinogenesis in IBD.


Assuntos
Colo/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , Óxido Nítrico/metabolismo , Animais , Colo/citologia , Neoplasias do Colo/etiologia , Células Epiteliais/metabolismo , Humanos , Mucosa Intestinal/citologia , Macrófagos/metabolismo , Camundongos , Modelos Biológicos
16.
J Diabetes Complications ; 32(12): 1113-1117, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30318163

RESUMO

AIMS: Obesity is associated with progression of chronic kidney disease (CKD). Treatment with bardoxolone methyl in a multinational phase 3 trial, Bardoxolone Methyl Evaluation in Patients with Chronic Kidney Disease and Type 2 Diabetes (BEACON), resulted in increases in estimated glomerular filtration rate (eGFR) with concurrent reductions in body weight. We performed post-hoc analyses to further characterize reductions in body weight with bardoxolone methyl. METHODS: Eligible patients with type 2 diabetes (T2DM) and CKD stage 4 (eGFR 15 to <30 mL/min/1.73 m2) were randomized 1:1 to receive once-daily oral dose of bardoxolone methyl (20 mg) or placebo. RESULTS: BEACON enrolled 2185 patients. Patients randomized to bardoxolone methyl experienced significant reductions in body weight from baseline relative to patients randomized to placebo (-5.7 kg; 95% CI: -6.0 to -5.3 kg; p < 0.001). In patients randomized to bardoxolone methyl, rate and magnitude of body weight loss were proportional to baseline BMI. Bardoxolone methyl resulted in significant reductions in waist circumference and improved glycemic control. CONCLUSIONS: Bardoxolone methyl resulted in significant weight loss in a generally obese patient population with T2DM and stage 4 CKD, with the magnitude and rate dependent on baseline BMI.


Assuntos
Glicemia/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Obesidade/tratamento farmacológico , Ácido Oleanólico/análogos & derivados , Insuficiência Renal Crônica/tratamento farmacológico , Circunferência da Cintura/efeitos dos fármacos , Idoso , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/sangue , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/patologia , Progressão da Doença , Método Duplo-Cego , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Hemoglobinas Glicadas/efeitos dos fármacos , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade/complicações , Ácido Oleanólico/farmacologia , Ácido Oleanólico/uso terapêutico , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/patologia
17.
Onco Targets Ther ; 10: 4239-4250, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28919776

RESUMO

BACKGROUND: Omaveloxolone is a semisynthetic oleanane triterpenoid that potently activates Nrf2 with subsequent antioxidant function. We conducted a first-in-human Phase I clinical trial (NCT02029729) with the primary objectives to determine the appropriate dose for Phase II studies, characterize pharmacokinetic and pharmacodynamic parameters, and assess antitumor activity. METHODS: Omaveloxolone was administered orally once daily continuously in a 28-day cycle for patients with stage 4 relapsed/refractory melanoma or non-small cell lung cancer. An accelerated titration design was employed until a grade 2-related adverse event (AE) occurred. A standard 3+3 dose escalation was employed. Single-dose and steady-state plasma pharmacokinetics of the drug were characterized. Downstream Nrf2 activation was assessed in peripheral blood mononuclear cells by quantification of target gene mRNA expression. RESULTS: Omaveloxolone was tested at four dose levels up to 15 mg given orally once daily. No dose-limiting toxicities were detected, and the maximum tolerated dose was not determined. All drug-related AEs were either grade 1 or 2 in severity, and none required clinical action. The most common drug-related AEs were elevated alkaline phosphatase (18%) and anemia (18%). No drug interruptions or reductions were required. Omaveloxolone was rapidly absorbed and exhibited proportional increases in exposure across dose levels. With some exceptions, an overall trend toward time-dependent and dose-dependent activation of Nrf2 antioxidant genes was observed. No confirmed radiologic responses were seen, although one lung cancer subject did have stable disease exceeding 1 year. CONCLUSIONS: Omaveloxolone has favorable tolerability at biologically active doses, although this trial had a small sample size which limits definitive conclusions. These findings support further investigation of omaveloxolone in cancer.

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