Bardoxolone methyl was associated with improvement in the estimated GFR in patients with advanced CKD and type 2 diabetes at 24 weeks. The improvement persisted at 52 weeks, suggesting that bardoxolone methyl may have promise for the treatment of CKD. (Funded by Reata Pharmaceuticals; BEAM ClinicalTrials.gov number, NCT00811889.).

BACKGROUND Although inhibitors of the renin–angiotensin–aldosterone system can slow the progression of diabetic kidney disease, the residual risk is high. Whether nuclear 1 factor (erythroid-derived 2)–related factor 2 activators further reduce this risk is unknown. METHODS We randomly assigned 2185 patients with type 2 diabetes mellitus and stage 4 chronic kidney disease (estimated glomerular filtration rate [GFR], 15 to <30 ml per minute per 1.73 m2 of body-surface area) to bardoxolone methyl, at a daily dose of 20 mg, or placebo. The primary composite outcome was end-stage renal disease (ESRD) or death from cardiovascular causes. RESULTS The sponsor and the steering committee terminated the trial on the recommendation of the independent data and safety monitoring committee; the median follow-up was 9 months. A total of 69 of 1088 patients (6%) randomly assigned to bardoxolone methyl and 69 of 1097 (6%) randomly assigned to placebo had a primary composite outcome (hazard ratio in the bardoxolone methyl group vs. the placebo group, 0.98; 95% confidence interval [CI], 0.70 to 1.37; P = 0.92). In the bardoxolone methyl group, ESRD developed in 43 patients, and 27 patients died from cardiovascular causes; in the placebo group, ESRD developed in 51 patients, and 19 patients died from cardiovascular causes. A total of 96 patients in the bardoxolone methyl group were hospitalized for heart failure or died from heart failure, as compared with 55 in the placebo group (hazard ratio, 1.83; 95% CI, 1.32 to 2.55; P<0.001). Estimated GFR, blood pressure, and the urinary albumin-to-creatinine ratio increased significantly and body weight decreased significantly in the bardoxolone methyl group, as compared with the placebo group. CONCLUSIONS Among patients with type 2 diabetes mellitus and stage 4 chronic kidney disease, bardoxolone methyl did not reduce the risk of ESRD or death from cardiovascular causes. A higher rate of cardiovascular events with bardoxolone methyl than with placebo prompted termination of the trial. (Funded by Reata Pharmaceuticals; BEACON ClinicalTrials.gov number, NCT01351675.)

OBJECTIVEOxidative stress is implicated in cardiac insulin resistance, a critical risk factor for cardiac failure, but the direct evidence remains missing. This study explored a causal link between oxidative stress and insulin resistance with a focus on a regulatory role of redox sensitive transcription factor NF-E2–related factor 2 (Nrf2) in the cardiac cells in vitro and in vivo.RESEARCH DESIGN AND METHODSChronic treatment of HL-1 adult cardiomyocyte with hydrogen peroxide led to insulin resistance, reflected by a significant suppression of the insulin-induced glucose uptake. This was associated with an exaggerated phosphorylation of extracellular signal–related kinase (ERK). Although U0126, an ERK inhibitor, enhanced insulin sensitivity and attenuated oxidative stress–induced insulin resistance, LY294002, an inhibitor of phosphoinositide 3-kinase (PI3K), worsened the insulin resistance. Moreover, insulin increased Nrf2 transcriptional activity, which was blocked by LY294002 but enhanced by U0126. Forced activation of Nrf2 by adenoviral over-expression of Nrf2 inhibited the increased ERK activity and recovered the blunted insulin sensitivity on glucose uptake in cardiomyocytes that were chronically treated with H2O2. In the hearts of streptozotocin-induced diabetic mice and diabetic patients Nrf2 expression significantly decreased along with significant increases in 3-nitrotyrosine accumulation and ERK phosphorylation, whereas these pathogenic changes were not observed in the heart of diabetic mice with cardiac-specific overexpression of a potent antioxidant metallothionein. Upregulation of Nrf2 by its activator, Dh404, in cardiomyocytes in vitro and in vivo prevented hydrogen peroxide– and diabetes-induced ERK activation and insulin-signaling downregulation.CONCLUSIONSERK-mediated suppression of Nrf2 activity leads to the oxidative stress–induced insulin resistance in adult cardiomyocytes and downregulated glucose utilization in the diabetic heart.

Purpose: Myeloid-derived suppressor cells (MDSC) are one of the major factors responsible for immune suppression in cancer. Therefore, it would be important to identify effective therapeutic means to modulate these cells.Experimental Design: We evaluated the effect of the synthetic triterpenoid C-28 methyl ester of 2-cyano-3,12-dioxooleana-1,9,-dien-28-oic acid (CDDO-Me; bardoxolone methyl) in MC38 colon carcinoma, Lewis lung carcinoma, and EL-4 thymoma mouse tumor models, as well as blood samples from patients with renal cell cancer and soft tissue sarcoma. Samples were also analyzed from patients with pancreatic cancer treated with CDDO-Me in combination with gemcitabine.Results: CDDO-Me at concentrations of 25 to 100 nmol/L completely abrogated immune suppressive activity of MDSC in vitro. CDDO-Me reduced reactive oxygen species in MDSCs but did not affect their viability or the levels of nitric oxide and arginase. Treatment of tumor-bearing mice with CDDO-Me did not affect the proportion of MDSCs in the spleens but eliminated their suppressive activity. This effect was independent of antitumor activity. CDDO-Me treatment decreased tumor growth in mice. Experiments with severe combined immunodeficient-beige mice indicated that this effect was largely mediated by the immune system. CDDO-Me substantially enhanced the antitumor effect of a cancer vaccines. Treatment of pancreatic cancer patients with CDDO-Me did not affect the number of MDSCs in peripheral blood but significantly improved the immune response.Conclusions: CDDO-Me abrogated the immune suppressive effect of MDSCs and improved immune responses in tumor-bearing mice and cancer patients. It may represent an attractive therapeutic option by enhancing the effect of cancer immunotherapy.

Background/Aims: Bardoxolone methyl, a novel synthetic triterpenoid, induces Nrf2, a transcription factor known to play a key role in decreasing oxidative stress and the production of pro-inflammatory molecules. Methods: This exploratory multi-center, open-label study assessed the clinical activity and safety of bardoxolone methyl in 20 patients with moderate to severe chronic kidney disease and type 2 diabetes. Patients received 25 mg of bardoxolone methyl daily for 28 days, followed by 75 mg daily for another 28 days. Results: The study achieved its primary efficacy endpoint, as demonstrated by a significant increase from baseline in estimated glomerular filtration rate (eGFR) of 7.2 ml/min/1.73 m² (p < 0.001). Improvements were seen in approximately 90% of patients and showed a dose- and time-dependent increase in eGFR. The eGFR change paralleled a significant reduction in serum creatinine (–0.3 mg/dl) and blood urea nitrogen (–4.9 mg/dl), along with an increase in creatinine clearance (+14.6 ml/min/1.73 m²), without a change in the 24-hour creatinine excretion rate. Markers of vascular injury and inflammation were improved by treatment with bardoxolone. No life-threatening adverse events or drug-related serious adverse events were reported. Conclusions: The results describe an apparent increase in kidney function following relatively short-term treatment with bardoxolone methyl, a promising new agent that warrants placebo-controlled studies to define its long-term effects on renal function.

The novel oleanane triterpenoid 2-cyano-3,12-dioxooleana-1,9,-dien-28-oic acid (CDDO) and the C-28 methyl ester (CDDOMe) induce apoptosis of human tumor cells by disruption of redox balance and are currently in clinical trials. The present studies show that CDDO and CDDO-Me block tumor necrosis factor ␣-induced targeting of NF-B p65 to the nucleus. CDDO-Me also blocked tumor necrosis factor ␣-induced phosphorylation of IB␣. In concert with these results, we found that CDDO-Me inhibits IB␣ kinase ␤ (IKK␤) activity in cells. In support of a direct mechanism, CDDO-Me inhibited recombinant IKK␤ activity in vitro. The results also demonstrate that (i) CDDO and CDDO-Me form adducts with IKK␤, but not IKK␤ with mutation of Cys-179 to Ala, and (ii) CDDO-Me inhibits IKK␤ by a mechanism dependent on oxidation of Cys-179. These findings indicate that CDDO and CDDO-Me directly block IKK␤ activity and thereby the NF-B pathway by interacting with Cys-179 in the IKK␤ activation loop.The synthetic triterpenoid CDDO 2 induces differentiation of human myeloid leukemia cells and mouse 3T3-Li fibroblasts (1). CDDO also inhibits cytokine-mediated induction of nitricoxide synthase and functions as a ligand for peroxisome proliferator-activated receptor ␥ (1, 2). Other studies have demonstrated that CDDO and its derivatives at the C-28 position induce apoptosis of human myeloid leukemia (3-7), osteosarcoma (8), multiple myeloma (9), lung cancer (10, 11), breast cancer (12, 13), and pancreatic cancer (14) cells. CDDO, the C-28 methyl ester (CDDO-Me), and the C-28 imidazolide ester induce apoptosis by increasing reactive oxygen species and decreasing intracellular glutathione (6,9,14,15). How the CDDO triterpenoids disrupt redox balance is not known. However, the A-ring of these triterpenoids contains an ␣,␤-unsaturated carbonyl moiety that can form reversible adducts with reactive thiol groups in dithiothreitol (DTT) (16) or with specific cysteine-rich protein targets (17). These findings have indicated that the CDDO triterpenoids increase reactive oxygen species and induce apoptosis by oxidizing critical cysteines in proteins that regulate redox balance and survival.NF-B activates the transcription of diverse genes that regulate cell proliferation and survival (18). In the absence of stimulation, the NF-B proteins (RelA/p65, RelB, c-Rel, NF-B1/ p50, and NF-B1/p52) localize to the cytoplasm in complexes with members of the IB family of inhibitor proteins (19). Phosphorylation of IB␣ induces ubiquitination and degradation of IB␣ and release of NF-B p65 to the nucleus. In the classical NF-B pathway, the IB kinase ␤ (IKK␤) in a complex with the regulatory IKK␥ subunit is the major kinase responsible for phosphorylation of IB␣ (20) EXPERIMENTAL PROCEDURESCell Culture-Human U-937 myeloid leukemia cells were grown in RPMI 1640 medium containing 10% heat-inactivated fetal bovine serum, 100 units/ml penicillin, 100 g/ml streptomycin, and 2 mM L-glutamine. 293 cells were grown in Dulbecco's modified Eagle's medium containing 10% heat-inactivat...

Purpose Bardoxolone methyl, a novel synthetic triterpenoid and antioxidant inflammation modulator, potently induces Nrf2 and inhibits NF-κB and Janus-activated kinase/STAT signaling. This first-in-human phase I clinical trial aimed to determine the dose-limiting toxicities (DLT), maximum tolerated dose (MTD), and appropriate dose for phase II studies; characterize pharmacokinetic and pharmacodynamic parameters; and assess antitumor activity. Experimental Design Bardoxolone methyl was administered orally once daily for 21 days of a 28-day cycle. An accelerated titration design was employed until a grade 2–related adverse event occurred. A standard 3 + 3 dose escalation was then employed until the MTD was reached. Single dose and steady-state plasma pharmacokinetics of the drug were characterized. Assessment of Nrf2 activation was examined in peripheral blood mononuclear cells (PBMC) by measuring NAD(P)H:quinone oxidoreductase (NQO1) mRNA levels. Immunohistochemical assessment of markers of inflammation, cell cycle, and apoptosis was carried out on tumor biopsies. Results The DLTs were grade 3 reversible liver transaminase elevations. The MTD was established as 900 mg/d. A complete tumor response occurred in a mantle cell lymphoma patient, and a partial response was observed in an anaplastic thyroid carcinoma patient. NQO1 mRNA levels increased in PBMCs, and NF-κB and cyclin D1 levels decreased in tumor biopsies. Estimated glomerular filtration rate (eGFR) was also increased. Conclusions Bardoxolone methyl was well tolerated with an MTD of 900 mg/d. The increase in eGFR suggests that bardoxolone methyl might be beneficial in chronic kidney disease. Objective tumor responses and pharmacodynamic effects were observed, supporting continued development of other synthetic triterpenoids in cancer.

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