Upadacitinib in Rheumatoid Arthritis and Inadequate Response to Conventional Synthetic Disease-Modifying Antirheumatic Drugs: Efficacy and Safety Through 5 Years (SELECT-NEXT)

OBJECTIVE

To report 5-year efficacy and safety of upadacitinib in rheumatoid arthritis (RA) from the phase 3 long-term extension (LTE) of SELECT-NEXT.

METHODS

Patients on stable conventional synthetic disease-modifying antirheumatic drugs were randomized to upadacitinib 15 mg, upadacitinib 30 mg once daily (UPA15/30), or placebo for 12 weeks. Following this, placebo-randomized patients were switched to UPA15 or UPA30 in the LTE; upadacitinib-randomized patients continued their original dose. Blinding remained until dose switching from UPA30 to UPA15 due to approval of UPA15; the earliest switch occurred at week 168. Efficacy (as observed) and treatment-emergent adverse events (TEAEs) are reported through 5 years.

RESULTS

Overall, 611 (92%) randomized patients entered the LTE; 271 (44%) discontinued study drug by 5 years, primarily due to adverse events (16%). Clinical outcomes improved or were maintained at 5 years; 51% and 43% of patients achieved Clinical Disease Activity Index remission and 75% and 66% achieved 28-joint Disease Activity Score-C-reactive protein < 2.6 among those initially randomized to UPA15 and UPA30, respectively. Proportions of patients achieving ≥ 20/50/70% improvement in American College of Rheumatology criteria responses increased from week 60 through 5 years. Results were similar regardless of initial randomization to upadacitinib or placebo. TEAEs, including TEAEs of special interest, were consistent with earlier analyses and other SELECT studies. Malignancies (excluding non-melanoma skin cancer), major adverse cardiovascular events, and venous thromboembolic events were reported infrequently. No new safety signals were observed.

CONCLUSION

The 5-year benefit-risk profile for upadacitinib in RA remains favorable.

Economic Burden among Patients with Vitiligo in the United States: A Retrospective Database Claims Study

Patients with vitiligo incur direct and indirect costs associated with their condition; however, data regarding the economic burden of vitiligo are scarce and outdated. In this retrospective cohort analysis of the Merative MarketScan Commercial Database, healthcare costs and healthcare resource utilization (HCRU) were evaluated among United States patients with vitiligo. Patients with vitiligo were matched (1:2) with individuals without vitiligo (controls) between January 2007 and December 2021. Outcomes included all-cause and vitiligo-related costs (2021 dollars) and all-cause HCRU, including mental health-related HCRU, during a 1-year postindex period. Subgroup analyses were completed for patients on vitiligo treatments with systemic effects (such as phototherapy and oral steroids) or a new mental health diagnosis. The analysis was focused solely on direct costs. Baseline demographics were well-balanced between matched vitiligo (49,512) and control (99,024) cohorts. Patients with vitiligo incurred significantly higher all-cause ($15,551 vs $7735) and vitiligo-related ($3490 vs $54) costs than controls (P < .0001). All-cause and mental health-related HCRU were also significantly higher among patients with vitiligo (P < .0001). Differences in all-cause and vitiligo-related healthcare costs remained significantly higher in patients on treatments with systemic effects/mental health diagnoses than in controls (P < .0001). Taken together, healthcare costs and HCRU were significantly higher among patients with vitiligo than among controls.

Comorbidity Burden Among Patients with Vitiligo in the United States: A Large-Scale Retrospective Claims Database Analysis

INTRODUCTION

Vitiligo is often associated with comorbid conditions that may increase economic burden and affect patients' health-related quality of life. No large-scale study has been published to date using claims databases to evaluate the burden of comorbidities among patients with vitiligo. Herein, we evaluate the comorbidity burden among patients diagnosed with vitiligo from the US.

METHODS

This retrospective cohort analysis used the Merative MarketScan Commercial Database. Eligible patients were diagnosed with vitiligo between January 2008 and December 2020 and matched 1:4 (vitiligo:control) with control subjects with no diagnosis of vitiligo between January 2007 and December 2021. Study outcomes were the incidence of comorbidities after matching, adjusted hazard ratios of comorbidity incidence among patients with vitiligo relative to matched control subjects, and time to comorbidity diagnosis or incidence.

RESULTS

Baseline demographics were well balanced between matched vitiligo (n = 13,687) and control cohorts (n = 54,748). Incidence rates of comorbidities were higher among patients compared with control subjects (psychiatric, 28.4% vs 22.8%; autoimmune, 13.4% vs 5.1%; and non-autoimmune, 10.0% vs 7.0%). The most common psychiatric and autoimmune comorbidities in patients with vitiligo compared with control subjects included anxiety (14.3% vs 11.0%, respectively), sleep disturbance (9.1% vs 7.1%), depression (8.0% vs 6.3%), atopic dermatitis (3.1% vs 1.1%), psoriasis (2.7% vs 0.6%), and linear morphea (1.5% vs 0.1%). The risk of developing any psychiatric (hazard ratio 1.31; P < 0.01), autoimmune (hazard ratio 2.77; P < 0.01), or non-autoimmune (hazard ratio 1.45; P < 0.01) comorbidity was significantly higher among patients with vitiligo. Time to diagnosis of most vitiligo comorbidities was 1-3 years, although linear morphea was diagnosed at < 1 year.

CONCLUSION

Results of this retrospective analysis demonstrated that patients were much more likely to be diagnosed with autoimmune or psychiatric comorbidities following a vitiligo diagnosis, which likely contributed to increased economic burden and lower quality of life.

Incidence and risk factors for herpes zoster in patients with rheumatoid arthritis receiving upadacitinib: a pooled analysis of six phase III clinical trials

Background

Upadacitinib (UPA) is an oral Janus kinase (JAK) inhibitor approved for the treatment of rheumatoid arthritis (RA). JAK inhibitors have been associated with an increased risk of herpes zoster (HZ) in patients with RA.

Objectives

To evaluate the incidence and risk factors for HZ in UPA-treated patients with RA from the UPA phase III clinical trial programme.

Methods

Exposure-adjusted incidence/event rates for HZ were determined in patients receiving UPA (monotherapy or combination therapy) in six randomised phase III trials (data cut-off on 30 June 2020). HZ incidence and event rates were also determined in patients receiving methotrexate (MTX) monotherapy or adalimumab (ADA) + MTX. Multivariable Cox regression analysis was used to identify HZ risk factors in UPA-treated patients.

Results

A total of 5306 patients were included in this analysis. The incidence rate of HZ/100 patient-years (95% CI) was 0.8 (0.3 to 1.9), 1.1 (0.5 to 1.9), 3.0 (2.6 to 3.5) and 5.3 (4.5 to 6.2), in the MTX monotherapy, ADA + MTX, UPA 15 mg and UPA 30 mg groups, respectively. The majority of HZ cases with UPA (71%) involved a single dermatome. Prior history of HZ and Asian region were HZ risk factors in UPA-treated patients.

Conclusion

In the UPA phase III RA clinical programme, HZ incidence and event rates were higher with UPA versus ADA + MTX or MTX monotherapy, and higher with the 30 mg versus 15 mg dose. Patients from Asia and those with a history of HZ may be at increased risk of HZ while receiving UPA.

Upadacitinib monotherapy improves patient-reported outcomes in rheumatoid arthritis: results from SELECT-EARLY and SELECT-MONOTHERAPY

OBJECTIVE

To evaluate the effect of upadacitinib (UPA) monotherapy vs MTX on patient-reported outcomes (PROs) in patients with RA who were MTX-naïve or who had an inadequate response to MTX (MTX-IR).

METHODS

PROs from the SELECT-EARLY and SELECT-MONOTHERAPY randomized controlled trials were evaluated at Weeks 2 and 12/14. Patients were ≥18 years of age with RA symptoms for ≥6 weeks (SELECT-EARLY, MTX-naïve) or diagnosed RA for ≥3 months (SELECT-MONOTHERAPY, MTX-IR) and received UPA monotherapy (15 or 30 mg) or MTX. PROs included Patient Global Assessment of Disease Activity (PtGA), pain visual analogue scale, HAQ Disability Index (HAQ-DI), morning stiffness duration/severity, Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue (SELECT-EARLY), health-related quality of life (HRQOL) by the 36-iem Short Form Health Survey and Work Productivity and Activity Impairment (WPAI; SELECT-EARLY). Least square mean (LSM) changes and proportions of patients reporting improvements greater than or equal to the minimum clinically important differences and normative values were determined.

RESULTS

In 945 MTX-naïve and 648 MTX-IR patients, UPA monotherapy (15 mg, 30 mg) vs MTX resulted in greater reported LSM changes from baseline at Weeks 12/14 in PtGA, pain, HAQ-DI, morning stiffness duration/severity, FACIT-F (SELECT-EARLY), HRQOL and WPAI (SELECT-EARLY). These changes were statistically significant with both doses of UPA vs MTX at Weeks 12/14 in both RCTs. Improvements were reported as early as week 2. Compared with MTX, more UPA-treated MTX-naïve and MTX-IR patients reported improvements greater than or equal to the minimum clinically important differences and scores greater than or equal to normative values.

CONCLUSION

Among MTX-naïve and MTX-IR patients with active RA, UPA monotherapy at 15 or 30 mg for 12/14 weeks resulted in statistically significant and clinically meaningful improvements in pain, physical function, morning stiffness, HRQOL and WPAI compared with MTX alone.

CLINICAL TRIAL REGISTRATION NUMBER

SELECT-EARLY (NCT02706873) and SELECT-MONOTHERAPY (NCT02706951) are registered with ClinicalTrials.gov.

Effect of Upadacitinib on the Pharmacokinetics of Rosuvastatin or Atorvastatin in Healthy Subjects

This phase 1, 2‐part, 2‐period, open‐label, drug‐drug interaction study evaluated the potential for pharmacokinetic interactions between upadacitinib and rosuvastatin, an organic anion transporting polypeptide (OATP) 1B1 and breast cancer resistance protein substrate, or atorvastatin, a cytochrome P450 3A, OATP1B1, and OATP1B3 substrate, in 36 healthy volunteers. During period 1, a single dose of rosuvastatin (5 mg; part 1) or atorvastatin (10 mg; part 2) was administered on day 1, followed by a washout period of 5 days. During period 2, once‐daily doses of upadacitinib extended‐release (30 mg) were administered on days 1 to 10, and a single dose of rosuvastatin (5 mg; part 1) or atorvastatin (10 mg; part 2) was administered 1 hour after the upadacitinib dose on day 7. Serial blood samples were collected for assays of drug concentrations. In Part 1, rosuvastatin maximum observed plasma concentration (C_max) and area under the plasma concentration–time curve from time 0 to infinity (AUC_inf) were 23% and 33% lower, respectively, when administered with upadacitinib relative to when administered alone. In part 2, atorvastatin C_max and AUC_inf was 11% and 23% lower, respectively, when administered with upadacitinib relative to when administered alone. The C_max and AUC_inf of the active metabolite ortho‐hydroxyatorvastatin remained unchanged. Administration of a single 5‐mg dose of rosuvastatin or a single 10‐mg dose of atorvastatin had no relevant effect on upadacitinib C_max or area under the plasma concentration–time curve. These results demonstrated that upadacitinib has no clinically relevant effect on the pharmacokinetics of rosuvastatin and atorvastatin or on substrates transported by OATP1B or breast cancer resistance protein.

Preferential Inhibition of JAK1 Relative to JAK3 by Upadacitinib: Exposure-Response Analyses of Ex Vivo Data From 2 Phase 1 Clinical Trials and Comparison to Tofacitinib

Upadacitinib is a selective Janus kinase (JAK) 1 inhibitor being developed for treatment of rheumatoid arthritis. This study characterizes the relationships between upadacitinib exposure and interleukin (IL)-6-induced signal transducer and activator of transcription proteins 3 (STAT3) phosphorylation (pSTAT3) and IL-7-induced STAT5 phosphorylation (pSTAT5) in the ex vivo setting as measures for JAK1 and JAK1/JAK3 inhibition, respectively, with comparison to tofacitinib. Drug plasma concentrations and ex vivo IL-6-induced pSTAT3 and IL-7-induced pSTAT5 in blood from subjects evaluated in 2 phase 1 studies who received immediate-release 1 mg to 48 mg upadacitinib, 5 mg twice daily (BID) tofacitinib, or placebo were determined. Exposure-response models were developed, and the effects of different upadacitinib doses on ex vivo biomarker responses were simulated and compared to tofacitinib. Upadacitinib (and tofacitinib) reversibly inhibited IL-6-induced pSTAT3 and IL-7-induced pSTAT5 in a concentration-dependent manner. Model-estimated values of 50% of the maximum effect were 60.7 nM for upadacitinib and 119 nM for tofacitinib for IL-6-induced pSTAT3 inhibition, and 125 nM for upadacitinib and 79.1 nM for tofacitinib for IL-7-induced pSTAT5 inhibition. Tofacitinib 5 mg BID is estimated to have a similar magnitude of effect on IL-6-induced pSTAT3 to ∼3 mg BID of upadacitinib (immediate-release formulation), whereas a 4-fold higher dose of upadacitinib (∼12 mg BID), is estimated to show a similar magnitude of inhibition on IL-7-induced pSTAT5 as tofacitinb 5 mg BID. This study confirms that in humans, upadacitinib has greater selectivity for JAK1 vs JAK3 relative to the rheumatoid arthritis approved dose of tofacitinib, and results from these analyses informed the selection of upadacitinib IR doses evaluated in phase 2.

Upadacitinib improves patient-reported outcomes in patients with rheumatoid arthritis and inadequate response to conventional synthetic disease-modifying antirheumatic drugs: results from SELECT-NEXT

Background

To evaluate the effect of upadacitinib on patient-reported outcomes (PROs) in patients with RA who had an inadequate response to csDMARDs.

Methods

Patients in SELECT-NEXT, a randomised controlled trial, were on a background of csDMARDs and received upadacitinib 15 mg and 30 mg or placebo daily for 12 weeks. PROs included Patient Global Assessment of Disease Activity (PtGA), pain, Health Assessment Questionnaire-Disability Index (HAQ-DI), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), duration and severity of morning (AM) joint stiffness, Short Form 36 Health Survey (SF-36), and Work Instability Scale for RA (RA-WIS). Least squares mean (LSM) changes were based on mixed-effect repeated measure models. Percentages of patients reporting improvements ≥ minimum clinically important differences (MCIDs) and scores ≥ normative values and number needed to treat (NNT) were determined; group comparisons used chi-square tests.

Results

Data from 661 patients were analysed. Compared with placebo, patients receiving upadacitinib reported statistically significant improvements (both doses, P < 0.05) in PtGA, pain, HAQ-DI, FACIT-F, duration and severity of AM stiffness, SF-36 (PCS and 6/8 domains), and RA-WIS at week 12. Significantly, more upadacitinib-treated patients (both doses, P < 0.05) reported improvements ≥ MCID in PtGA, pain, HAQ-DI, FACIT-F, AM stiffness, SF-36 (PCS and 4 or 7/8 domains), and RA-WIS and scores ≥ normative values in HAQ-DI, FACIT-F, and SF-36 (PCS and 4 or 5/8 domains). For most PROs, the incremental NNT with upadacitinib to report clinically meaningful improvement from baseline ranged from 4 to 8 patients.

Conclusions

Upadacitinib 15 mg or 30 mg daily for 12 weeks resulted in significant and clinically meaningful improvements in global disease activity, pain, physical function, fatigue, duration and severity of AM stiffness, HRQOL, and work instability among csDMARD-IR patients with RA.

Trial registration

Clinicaltrials.gov, NCT02675426. Retrospectively registered 5 February 2016.

Exposure-Response Analyses of Upadacitinib Efficacy in Phase II Trials in Rheumatoid Arthritis and Basis for Phase III Dose Selection

The relationships between upadacitinib, an oral selective Janus kinase 1 inhibitor, plasma exposures, and its efficacy (assessed by the American College of Rheumatology 20%/50%/70% responses over time) in moderate‐to‐severe active rheumatoid arthritis (RA) were characterized using data from 574 patients, on background methotrexate and inadequate response to methotrexate or anti‐TNF therapy, from two phase II trials conducted with twice‐daily dosing of an immediate‐release formulation. The developed time‐continuous Markov models were used to simulate efficacy of once‐daily (q.d.). regimens of upadacitinib extended‐release incorporating sources of uncertainty. Upadacitinib plasma concentrations associated with 15 and 30 mg extended‐release q.d. doses were predicted to achieve that plateau of response across RA subpopulations. Results from these analyses provided the rationale that supported selection and de‐risked evaluation of upadacitinib extended‐release doses for the first time in >4,000 patients in five large phase III trials.

Upadacitinib as monotherapy in patients with active rheumatoid arthritis and inadequate response to methotrexate (SELECT-MONOTHERAPY): a randomised, placebo-controlled, double-blind phase 3 study

BACKGROUND

Upadacitinib, an oral Janus kinase (JAK)1-selective inhibitor, showed efficacy in combination with stable background conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) in patients with rheumatoid arthritis who had an inadequate response to DMARDs. We aimed to evaluate the safety and efficacy of upadacitinib monotherapy after switching from methotrexate versus continuing methotrexate in patients with inadequate response to methotrexate.

METHODS

SELECT-MONOTHERAPY was conducted at 138 sites in 24 countries. The study enrolled adults (≥18 years) who fulfilled the 2010 American College of Rheumatology (ACR)-European League Against Rheumatism (EULAR) classification criteria for rheumatoid arthritis. Patients with active rheumatoid arthritis despite stable methotrexate were randomly assigned 2:2:1:1 to switch to once-daily monotherapy of of upadacitinib or to continue methotrexate at their existing dose as blinded study drug; starting from week 14, patients assigned to continue methotrexate were switched to 15 mg or 30 mg once-daily upadacitinib per prespecified random assignment at baseline. The primary endpoints in this report are proportion of patients achieving 20% improvement in the ACR criteria (ACR20) at week 14, and proportion achieving low disease activity defined as 28-joint Disease Activity Score using C-reactive protein (DAS28[CRP]) of 3·2 or lower, both with non-responder imputation at week 14. Outcomes were assessed in patients who received at least one dose of study drug. This study is active but not recruiting and is registered with ClinicalTrials.gov, number NCT02706951.

FINDINGS

Patients were screened between Feb 23, 2016, and May 19, 2017 and 648 were randomly assigned to treatment. 598 (92%) completed week 14. At week 14, an ACR20 response was achieved by 89 (41%) of 216 patients (95% CI 35-48) in the continued methotrexate group, 147 (68%) of 217 patients (62-74) receiving upadacitinib 15 mg, and 153 (71%) of 215 patients (65-77) receiving upadacitinib 30 mg (p<0·0001 for both doses vs continued methotrexate). DAS28(CRP) 3·2 or lower was met by 42 (19%) of 216 (95% CI 14-25) in the continued methotrexate group, 97 (45%) of 217 (38-51) receiving upadacitinib 15 mg, and 114 (53%) of 215 (46-60) receiving upadacitinib 30 mg (p<0·0001 for both doses vs continued methotrexate). Adverse events were reported in 102 patients (47%) on continued methotrexate, 103 (47%) on upadacitinib 15 mg, and 105 (49%) on upadacitinib 30 mg. Herpes zoster was reported by one (<1%) patient on continued methotrexate, three (1%) on upadacitinib 15 mg, and six (3%) on upadacitinib 30 mg. Three malignancies (one [<1%] on continued methotrexate, two [1%] on upadacitinib 15 mg), three adjudicated major adverse cardiovascular events (one [<1%] on upadacitinib 15 mg, two [<1%] on upadacitinib 30 mg), one adjudicated pulmonary embolism (<1%; upadacitinib 15 mg), and one death (<1%; upadacitinib 15 mg, haemorrhagic stroke [ruptured aneurysm]) were reported in the study.

INTERPRETATION

Upadacitinib monotherapy showed statistically significant improvements in clinical and functional outcomes versus continuing methotrexate in this methotrexate inadequate-responder population. Safety observations were similar to those in previous upadacitinib rheumatoid arthritis studies.

FUNDING

AbbVie Inc, USA.

In vitro and in vivo characterization of the JAK1 selectivity of upadacitinib (ABT-494)

Background

Anti-cytokine therapies such as adalimumab, tocilizumab, and the small molecule JAK inhibitor tofacitinib have proven that cytokines and their subsequent downstream signaling processes are important in the pathogenesis of rheumatoid arthritis. Tofacitinib, a pan-JAK inhibitor, is the first approved JAK inhibitor for the treatment of RA and has been shown to be effective in managing disease. However, in phase 2 dose-ranging studies tofacitinib was associated with dose-limiting tolerability and safety issues such as anemia. Upadacitinib (ABT-494) is a selective JAK1 inhibitor that was engineered to address the hypothesis that greater JAK1 selectivity over other JAK family members will translate into a more favorable benefit:risk profile. Upadacitinib selectively targets JAK1 dependent disease drivers such as IL-6 and IFNγ, while reducing effects on reticulocytes and natural killer (NK) cells, which potentially contributed to the tolerability issues of tofacitinib.

Methods

Structure-based hypotheses were used to design the JAK1 selective inhibitor upadacitinib. JAK family selectivity was defined with in vitro assays including biochemical assessments, engineered cell lines, and cytokine stimulation. In vivo selectivity was defined by the efficacy of upadacitinib and tofacitinib in a rat adjuvant induced arthritis model, activity on reticulocyte deployment, and effect on circulating NK cells. The translation of the preclinical JAK1 selectivity was assessed in healthy volunteers using ex vivo stimulation with JAK-dependent cytokines.

Results

Here, we show the structural basis for the JAK1 selectivity of upadacitinib, along with the in vitro JAK family selectivity profile and subsequent in vivo physiological consequences. Upadacitinib is ~ 60 fold selective for JAK1 over JAK2, and > 100 fold selective over JAK3 in cellular assays. While both upadacitinib and tofacitinib demonstrated efficacy in a rat model of arthritis, the increased selectivity of upadacitinib for JAK1 resulted in a reduced effect on reticulocyte deployment and NK cell depletion relative to efficacy. Ex vivo pharmacodynamic data obtained from Phase I healthy volunteers confirmed the JAK1 selectivity of upadactinib in a clinical setting.

Conclusions

The data presented here highlight the JAK1 selectivity of upadacinitinib and supports its use as an effective therapy for the treatment of RA with the potential for an improved benefit:risk profile.

Electronic supplementary material

The online version of this article (10.1186/s41927-018-0031-x) contains supplementary material, which is available to authorized users.

Safety and efficacy of upadacitinib in patients with rheumatoid arthritis and inadequate response to conventional synthetic disease-modifying anti-rheumatic drugs (SELECT-NEXT): a randomised, double-blind, placebo-controlled phase 3 trial

BACKGROUND

Upadacitinib is a selective inhibitor of Janus kinase 1 and was efficacious in phase 2 studies in patients with moderate-to-severe rheumatoid arthritis. We aimed to assess the efficacy of upadacitinib in patients with inadequate response to conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs).

METHODS

This study is a double-blind, placebo-controlled trial at 150 sites in 35 countries. We enrolled patients aged 18 years or older with active rheumatoid arthritis for 3 months or longer, who had received csDMARDs for at least 3 months with a stable dose for at least 4 weeks before study entry, and had an inadequate response to at least one of the following csDMARDs: methotrexate, sulfasalazine, or leflunomide. Using interactive response technology, we randomly assigned patients receiving stable background csDMARDs (2:2:1:1) to receive a once-daily extended-release formulation of upadacitinib 15 mg or 30 mg, or placebo, for 12 weeks. Patients, investigators, and the funder were masked to allocation. After 12 weeks, patients taking placebo received 15 mg or 30 mg of upadacitinib once daily, according to the prespecified randomisation assignment. The primary endpoints were the proportion of patients at week 12 who achieved 20% improvement in American College of Rheumatology criteria (ACR20), and a 28-joint disease activity score using C-reactive protein (DAS28[CRP]) of 3·2 or less. We did efficacy analyses in the full analysis set of all randomly assigned patients who received at least one dose of study drug, and used non-responder imputation for assessment of the primary outcomes. This study is registered with ClinicalTrials.gov, number NCT02675426.

FINDINGS

Between Dec 17, 2015, and Dec 22, 2016, 1083 patients were assessed for eligibility, of whom 661 were recruited and randomly assigned to receive upadacitinib 15 mg (n=221), upadacitinib 30 mg (n=219), or placebo (n=221). All patients received at least one dose of study drug, and 618 (93%) completed 12 weeks of treatment. At week 12, ACR20 was achieved by 141 (64%; 95% CI 58-70) of 221 patients receiving upadacitinib 15 mg and 145 (66%; 60-73) of 219 patients receiving upadacitinib 30 mg, compared with 79 (36%; 29-42) of 221 patients receiving placebo (p<0·0001 for each dose vs placebo). DAS28(CRP) of 3·2 or less was met by 107 (48%; 95% CI 42-55) patients receiving upadacitinib 15 mg and 105 (48%; 41-55) patients receiving upadacitinib 30 mg, compared with 38 (17%; 12-22) patients receiving placebo (p<0·0001 for each dose vs placebo). Adverse events were reported in 125 (57%) of 221 patients receiving upadacitinib 15 mg, 118 (54%) of 219 patients receiving upadacitinib 30 mg, and 108 (49%) of 221 patients receiving placebo. The most frequently reported adverse events (≥5% of patients in any group) were nausea (16 [7%] of 221 in the upadacitinib 15 mg group; three [1%] of 219 in the upadacitinib 30 mg group; and seven [3%] of 221 in the placebo group), nasopharyngitis (12 [5%]; 13 [6%]; and nine [4%]), upper respiratory tract infection (12 [5%]; 12 [5%]; and nine [4%]), and headache (nine [4%]; seven [3%]; and 12 [5%]). More infections were reported for upadacitinib (64 [29%] of 221 patients receiving 15 mg and 69 [32%] of 219 patients receiving 30 mg) versus placebo (47 [21%] of 221 patients). There were three herpes zoster infections (one [<1%] in the placebo group, one [<1%] in the upadacitinib 15 mg group, and one [<1%] in the upadacitinib 30 mg group) and one primary varicella zoster virus infection (one [<1%] in the upadacitinib 30 mg group), two malignancies (both in the upadacitinib 30 mg group), one adjudicated major adverse cardiovascular event (in the upadacitinib 30 mg group), and five serious infections (one [<1%] in the placebo group, one [<1%] in the upadacitinib 15 mg group, three [1%] in the upadacitinib 30 mg group). No deaths were reported during the trial.

INTERPRETATION

Patients with moderately to severely active rheumatoid arthritis who received upadacitinib (15 mg or 30 mg) in combination with csDMARDs showed significant improvements in clinical signs and symptoms.

FUNDING

AbbVie Inc.

A Phase IIb Study of ABT-494, a Selective JAK-1 Inhibitor, in Patients With Rheumatoid Arthritis and an Inadequate Response to Anti-Tumor Necrosis Factor Therapy

Objective

To compare the efficacy and safety of ABT‐494, a novel selective JAK‐1 inhibitor, with placebo in patients with moderate‐to‐severe rheumatoid arthritis (RA) and an inadequate response or intolerance to at least 1 anti–tumor necrosis factor (anti‐TNF) agent.

Methods

In this 12‐week, double‐blind, placebo‐controlled, dose‐ranging study, 276 RA patients receiving a stable dose of methotrexate (MTX) who had previously received treatment with at least 1 anti‐TNF agent were randomized equally to receive immediate‐release ABT‐494 at 3, 6, 12, or 18 mg twice daily or matching placebo twice daily. The primary end point was the proportion of patients meeting the American College of Rheumatology 20% improvement criteria (achieving an ACR20 response) at week 12.

Results

At week 12, significantly more patients receiving ABT‐494 (53–71%) than those receiving placebo (34%) achieved an ACR20 response (by nonresponder imputation analysis) (P < 0.05), with a dose‐response relationship among all ABT‐494 doses (P < 0.001). ACR50 and ACR70 response rates were significantly higher in those receiving ABT‐494 (36–42% and 22–26%, respectively) than in those receiving placebo (16% and 4%, respectively). Changes from baseline in the Disease Activity Score in 28 joints using the C‐reactive protein level (DAS28‐CRP) were significantly greater for all doses of ABT‐494 than for placebo (P ≤ 0.01). Onset of action of ABT‐494 was rapid, with significant differences from placebo at week 2 both in ACR20 response rate (for 12 and 18 mg) and in change in the DAS28‐CRP (P < 0.001 for 6–18 mg). The most frequent adverse events (AEs) were headache, nausea, upper respiratory tract infection, and urinary tract infection. Infection rates were higher at higher doses of ABT‐494, but no infections were serious. No deaths were reported among those receiving ABT‐494.

Conclusion

In patients with an inadequate response or intolerance to anti‐TNF agents, ABT‐494 added to MTX showed rapid, dose‐dependent improvements in RA signs and symptoms, with safety and tolerability similar to those of other drugs of this class. No new AEs were identified.

Efficacy and Safety of ABT-494, a Selective JAK-1 Inhibitor, in a Phase IIb Study in Patients With Rheumatoid Arthritis and an Inadequate Response to Methotrexate

OBJECTIVE

To evaluate the efficacy and safety of ABT-494, a selective JAK-1 inhibitor, in patients with moderate-to-severe rheumatoid arthritis (RA) and an inadequate response to methotrexate (MTX).

METHODS

Three hundred RA patients receiving stable doses of MTX were randomly assigned equally to receive immediate-release ABT-494 at 3, 6, 12, or 18 mg twice daily, 24 mg once daily, or placebo for 12 weeks. The primary efficacy end point was the proportion of patients meeting the American College of Rheumatology 20% improvement criteria (achieving an ACR20 response) at week 12, as determined using the last observation carried forward method.

RESULTS

At week 12, the proportion of ACR20 responses was higher with ABT-494 (62%, 68%, 80%, 64%, and 76% for the 3, 6, 12, 18, and 24 mg doses, respectively) than with placebo (46%) (using nonresponder imputation) (P < 0.05 for the 6, 12, and 24 mg doses). There was a significant dose-response relationship among all ABT-494 doses (P < 0.001). The proportions of patients achieving ACR50 and ACR70 responses were significantly higher for all ABT-494 doses (except the 12 mg dose for the ACR70 response) than for placebo, as were changes in the Disease Activity Score in 28 joints using the C-reactive protein level (DAS28-CRP). Rapid improvement was demonstrated by significant differences in ACR20 response rates and changes in the DAS28-CRP for all doses compared with placebo at week 2 (the first postbaseline visit). The incidence of adverse events was similar across groups; most were mild, and infections were the most frequent. One serious infection (community-acquired pneumonia) occurred with ABT-494 at 12 mg. There were dose-dependent increases in high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, but the LDL cholesterol:HDL cholesterol ratios were unchanged through week 12. Mean hemoglobin levels remained stable at lower doses, but decreases were observed at higher doses.

CONCLUSION

This study evaluated a broad range of doses of ABT-494 in RA patients with an inadequate response to MTX. ABT-494 demonstrated efficacy, with a safety and tolerability profile similar to that of other JAK inhibitors.

Effects of fenofibric acid on carotid intima-media thickness in patients with mixed dyslipidemia on atorvastatin therapy: randomized, placebo-controlled study (FIRST)

OBJECTIVE

To assess whether adding a fibrate to statin therapy reduces residual cardiovascular risk associated with elevated triglycerides and low high-density lipoprotein cholesterol, The Evaluation of Choline Fenofibrate (ABT-335) on Carotid Intima-Media Thickness (cIMT) in Subjects with Type IIb Dyslipidemia with Residual Risk in Addition to Atorvastatin Therapy (FIRST) trial evaluated the effects of fenofibric acid (FA) treatment on cIMT in patients with mixed dyslipidemia on atorvastatin.

APPROACH AND RESULTS

This multicenter, double-blind, placebo-controlled study was performed in patients with mixed dyslipidemia (fasting triglycerides, ≥150 mg/dL; high-density lipoprotein cholesterol, ≤45 [men] or 55 mg/dL [women]; low-density lipoprotein cholesterol, ≤100 mg/dL once and averaging ≤105 mg/dL) and a history of coronary heart disease or risk equivalent. Patients on background atorvastatin (continued on starting dose or titrated to 40 mg, if needed) were randomized to FA 135 mg or placebo. The primary end point was rate of change from baseline through week 104 of the mean posterior-wall cIMT, measured by ultrasound. In patients with controlled low-density lipoprotein cholesterol while on atorvastatin background therapy, rate of change in posterior-wall cIMT was similar with FA plus atorvastatin (-0.006 mm/y) versus atorvastatin monotherapy (0.000 mm/y; P=0.22). FA plus atorvastatin was favored (P<0.05) in 5 of 24 prespecified subgroups: age ≥60 years, history of coronary artery disease, cIMT >0.795 mm, triglycerides 170 to 235 mg/dL, and statin use at entry. Adverse events were consistent with the known safety profiles of both drugs; however, FA plus atorvastatin was associated with a greater incidence of renal-related adverse events compared with atorvastatin monotherapy (6.5% versus 0.9%).

CONCLUSIONS

Compared with atorvastatin monotherapy, FA plus atorvastatin did not further decrease cIMT progression in high-risk patients with mixed dyslipidemia.

Selective activation of PPARgamma in skeletal muscle induces endogenous production of adiponectin and protects mice from diet-induced insulin resistance

The nuclear receptor peroxisome proliferator-activated receptor (PPAR)gamma plays a key role in regulating whole body glucose homeostasis and insulin sensitivity. Although it is expressed most highly in adipose, it is also present at lower levels in many tissues, including skeletal muscle. The role muscle PPARgamma plays in metabolic regulation and in mediating the antidiabetic effects of the thiazolidinediones is not understood. The goal of this work was to examine the molecular and physiological effects of PPARgamma activation in muscle cells. We found that pharmacological activation of PPARgamma in primary cultured myocytes, and genetic activation of muscle PPARgamma in muscle tissue of transgenic mice, induced the production of adiponectin directly from muscle cells. This muscle-produced adiponectin was functional and capable of stimulating adiponectin signaling in myocytes. In addition, elevated skeletal muscle PPARgamma activity in transgenic mice provided a significant protection from high-fat diet-induced insulin resistance and associated changes in muscle phenotype, including reduced myocyte lipid content and an increase in the proportion of oxidative muscle fiber types. Our findings demonstrate that PPARgamma activation in skeletal muscle can have a significant protective effect on whole body glucose homeostasis and insulin resistance and that myocytes can produce and secrete functional adiponectin in a PPARgamma-dependent manner. We propose that activation of PPARgamma in myocytes induces a local production of adiponectin that acts on muscle tissue to improve insulin sensitivity.

Quantitative measurements of corticosteroids in ex vivo samples using on-line SPE-LC/MS/MS

Abnormal elevation of 11beta-HSD1 activities in tissues, such as fat and brain, may contribute to the development of the abdominal obesity and Alzheimer disease, and the inhibition of 11beta-HSD1 might be beneficial to the management of these diseases. To assess the effects of pharmacologic inhibitors of 11beta-HSD1, we developed a fast LC/MS/MS method to quantify corticosteroids in minced tissue samples in the presence of 11beta-HSD substrates. The novel on-line SPE-LC/MS/MS method was developed with dual binary gradient and a throughput of 4.5 min/sample. A total of six corticosteroids (cortisol, cortisone, corticosterone, dehydrocorticosterone, dexamethasone, and dehydrodexamethasone) were studied. The lower limit of quantitation from 0.40 to 11.4 fmol and 4.5 orders magnitude of dynamic range were obtained for these six compounds. Three novel enzymatic bi-products, all isomers of cortisol, were observed in the liver or fat samples. Two of them were identified by matching the HPLC retention times and MS/MS spectra with authentic compounds. The potential interferences of these isomers and their removal are discussed.

Discovery of piperidine-aryl urea-based stearoyl-CoA desaturase 1 inhibitors

A series of structurally novel stearoyl-CoA desaturase1 (SCD1) inhibitors has been identified via molecular scaffold manipulation. Preliminary structure-activity relationship (SAR) studies led to the discovery of potent, and orally bioavailable piperidine-aryl urea-based SCD1 inhibitors. 4-(2-Chlorophenoxy)-N-[3-(methyl carbamoyl)phenyl]piperidine-1-carboxamide 4c exhibited robust in vivo activity with dose-dependent desaturation index lowering effects.

Reduced heart size and increased myocardial fuel substrate oxidation in ACC2 mutant mice

The cardiac-enriched isoform of acetyl-CoA carboxylase (ACC2) is a key regulator of mitochondrial fatty acid (FA) uptake via carnitine palmitoyltransferase 1 (CPT1). To test the hypothesis that oxidative metabolism is upregulated in hearts from animals lacking ACC2 (employing a transgenic Acc2-mutant mouse), we assessed cardiac function in vivo and determined rates of myocardial substrate oxidation ex vivo. When examined by echocardiography, there was no difference in systolic function, but left ventricular mass of the Acc2-mutant (MUT) mouse was significantly reduced ( approximately 25%) compared with wild-types (WT). Reduced activation of the mammalian target of rapamycin (mTOR) and its downstream target p70S6K was found in MUT hearts. Exogenous oxidation rates of oleate were increased approximately 22%, and, unexpectedly, exogenous glucose oxidation rates were also increased in MUT hearts. Using a hyperinsulinemic-euglycemic clamp, we found that glucose uptake in MUT hearts was increased by approximately 83%. Myocardial triglyceride levels were significantly reduced in MUT vs. WT while glycogen content was the same. In parallel, transcript levels of PPARalpha and its target genes, pyruvate dehydrogenase kinase-4 (PDK-4), malonyl-CoA decarboxylase (MCD), and mCPT1, were downregulated in MUT mice. In summary, we report that 1) Acc2-mutant hearts exhibit a marked preference for the oxidation of both glucose and FAs coupled with greater utilization of endogenous fuel substrates (triglycerides), 2) attenuated mTOR signaling may result in reduced heart sizes observed in Acc2-mutant mice, and 3) Acc2-mutant hearts displayed normal functional parameters despite a significant decrease in size.

4-Anilino-5-carboxamido-2-pyridone Derivatives as Noncompetitive Inhibitors of Mitogen-Activated Protein Kinase Kinase

A new series of MEK1 inhibitors, the 4-anilino-5-carboxamido-2-pyridones, were designed and synthesized using a combination of medicinal chemistry, computational chemistry, and structural elucidation. The effect of variation in the carboxamide side chain, substitution on the pyridone nitrogen, and replacement of the 4'-iodide were all investigated. This study afforded several compounds which were either equipotent or more potent than the clinical candidate CI-1040 (1) in an isolated enzyme assay, as well as murine colon carcinoma (C26) cells, as measured by suppression of phosphorylated ERK substrate. Most notably, pyridone 27 was found to be more potent than 1 in vitro and produced a 100% response rate at a lower dose than 1, when tested for in vivo efficacy in animals bearing C26 tumors.

Discovery of 1-(4-phenoxypiperidin-1-yl)-2-arylaminoethanone stearoyl-CoA desaturase 1 inhibitors

A series of novel stearoyl-CoA desaturase 1 (SCD1) inhibitors were identified by scaffold design based on known SCD1 inhibitors. Large structural changes were made leading to multiple analogs with comparable or improved potency. This approach is valuable for generation of proprietary compounds without conducting a costly high-throughput screening.

Discovery of potent, selective, orally bioavailable stearoyl-CoA desaturase 1 inhibitors

Stearoyl-CoA desaturase 1 (SCD1) catalyzes the committed step in the biosynthesis of monounsaturated fatty acids from saturated, long-chain fatty acids. Studies with SCD1 knockout mice have established that these animals are lean and protected from leptin deficiency-induced and diet-induced obesity, with greater whole body insulin sensitivity than wild-type animals. In this work, we have discovered a series of potent, selective, orally bioavailable SCD1 inhibitors based on a known pyridazine carboxamide template. The representative lead inhibitor 28c also demonstrates excellent cellular activity in blocking the conversion of saturated long-chain fatty acid-CoAs (LCFA-CoAs) to monounsaturated LCFA-CoAs in HepG2 cells.

Phenoxy thiazole derivatives as potent and selective acetyl-CoA carboxylase 2 inhibitors: Modulation of isozyme selectivity by incorporation of phenyl ring substituents

A phenyl ring substitution strategy was employed to optimize the ACC2 potency and selectivity profiles of a recently discovered phenoxy thiazolyl series of acetyl-CoA carboxylase inhibitors. Ring substituents were shown to dramatically affect isozyme selectivity. Modifications that generally impart high levels of ACC2 selectivity (>3000-fold) while maintaining excellent ACC2 potency (IC50s approximately 9-20 nM) were identified.

Simultaneous quantification of malonyl-CoA and several other short-chain acyl-CoAs in animal tissues by ion-pairing reversed-phase HPLC/MS

Malonyl-CoA is a key intermediate involved in lipid synthesis and lipid oxidation. Here, we report on a novel method for the quantification of malonyl-CoA and seven other short-chain acyl-CoAs in various rat and mouse tissues using ion-pairing reversed-phase HPLC/MS. This method is capable of measuring malonyl-CoA, free coenzyme A (CoASH), acetyl-CoA, beta-hydroxyl-butyryl-CoA (HB-CoA), 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA), propionyl-CoA, succinyl-CoA, and isobutyryl-CoA simultaneously with a dynamic linear range over two orders of magnitude in a 7.0 min HPLC gradient run. The lower limit of quantification (LLOQ) was 0.225 pmol for all acyl-CoAs studied, except for HMG-CoA which had a higher LLOQ of 0.90 pmol. The interference of HB-CoA on the quantification of malonyl-CoA in animal tissues was also explored for the first time.

N-{3-[2-(4-Alkoxyphenoxy)thiazol-5-yl]-1-methylprop-2-ynyl}carboxy Derivatives as Acetyl-CoA Carboxylase InhibitorsImprovement of Cardiovascular and Neurological Liabilities via Structural Modifications

A preliminary safety evaluation of ACC2 inhibitor 1-(S) revealed serious neurological and cardiovascular liabilities of this chemotype. A systematic structure-toxicity relationship study identified the alkyne linker as the key motif responsible for these adverse effects. Toxicogenomic studies in rats showed that 1-(R) and 1-(S) induced gene expression patterns similar to that seen with several known cardiotoxic agents such as doxorubicin. Replacement of the alkyne with alternative linker groups led to a new series of ACC inhibitors with drastically improved cardiovascular and neurological profiles.

The synthesis and structure-activity relationship studies of selective acetyl-CoA carboxylase inhibitors containing 4-(thiazol-5-yl)but-3-yn-2-amino motif: polar region modifications

The structure-activity relationship study focused on the polar region of the HTS hit A-80040 (1) producing several series of potent and selective ACC2 inhibitors. The SAR suggests a compact lipophilic pocket that does not tolerate polar and ionic groups. Replacement of the hydroxyurea group with isoxazoles improves ACC2 selectivity while maintaining potency. Variations at the propargylic site of 11a reduce ACC2 potency.

Discovery and Metabolic Stabilization of Potent and Selective 2-Amino-N-(adamant-2-yl) Acetamide 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitors

Starting from a rapidly metabolized adamantane 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) inhibitor 22a, a series of E-5-hydroxy-2-adamantamine inhibitors, exemplified by 22d and (+/-)-22f, was discovered. Many of these compounds are potent inhibitors of 11beta-HSD1 and are selective over 11beta-HSD2 for multiple species (human, mouse, and rat), unlike other reported species-selective series. These compounds have good cellular potency and improved microsomal stability. Pharmacokinetic profiling in rodents indicated moderate to large volumes of distribution, short half-lives, and a pharmacokinetic species difference with the greatest exposure measured in rat with 22d. One hour postdose liver, adipose, and brain tissue 11beta-HSD1 inhibition was confirmed with (+/-)-22f in a murine ex vivo assay. Although 5,7-disubstitued-2-adamantamines provided greater stability, a single, E-5-position, polar functional group afforded inhibitors with the best combination of stability, potency, and selectivity. These results indicate that adamantane metabolic stabilization sufficient to obtain short-acting, potent, and selective 11beta-HSD1 inhibitors has been discovered.

Synthesis and structure-activity relationships of N-{3-[2-(4-alkoxyphenoxy)thiazol-5-yl]-1- methylprop-2-ynyl}carboxy derivatives as selective acetyl-CoA carboxylase 2 inhibitors

A structurally novel acetyl-CoA carboxylase (ACC) inhibitor is identified from high-throughput screening. A preliminary structure-activity relationship study led to the discovery of potent dual ACC1/ACC2 and ACC2 selective inhibitors against human recombinant ACC1 and ACC2. Selective ACC2 inhibitors exhibited IC50<20 nM and >1000-fold selectivity against ACC1. (S)-Enantiomer 9p exhibited high ACC2 activity and lowered muscle malonyl-CoA dose-dependently in acute rodent studies, whereas (R)-enantiomer 9o was weak and had no effect on the malonyl-CoA level.

Identification and characterization of a small molecule AMPK activator that treats key components of type 2 diabetes and the metabolic syndrome

AMP-activated protein kinase (AMPK) is a key sensor and regulator of intracellular and whole-body energy metabolism. We have identified a thienopyridone family of AMPK activators. A-769662 directly stimulated partially purified rat liver AMPK (EC50 = 0.8 microM) and inhibited fatty acid synthesis in primary rat hepatocytes (IC50 = 3.2 microM). Short-term treatment of normal Sprague Dawley rats with A-769662 decreased liver malonyl CoA levels and the respiratory exchange ratio, VCO2/VO2, indicating an increased rate of whole-body fatty acid oxidation. Treatment of ob/ob mice with 30 mg/kg b.i.d. A-769662 decreased hepatic expression of PEPCK, G6Pase, and FAS, lowered plasma glucose by 40%, reduced body weight gain and significantly decreased both plasma and liver triglyceride levels. These results demonstrate that small molecule-mediated activation of AMPK in vivo is feasible and represents a promising approach for the treatment of type 2 diabetes and the metabolic syndrome.

Review: peroxisome proliferator-activated receptor-gamma and its role in the development and treatment of diabetes

Since its identification as the receptor for antidiabetic thiazolidinedione drugs, peroxisome proliferator-activated receptor-γ (PPARγ) has been the focus of pharmaceutical drug discovery programs directed toward finding better drugs for the treatment of diabetes, as well as the object of basic research aimed at understanding its role in the regulation of metabolism. We now understand a great deal about the crucial role that PPARγ plays in adipocyte differentiation and development, and are rapidly gaining knowledge about the role of the receptor in the regulation of metabolism. However, many crucial aspects of the molecular mechanism by which modulation of PPARγ activity affects insulin resistance and glucose homeostasis are still not clearly understood. Here the authors review the current status of PPARγ research, with an emphasis on its role in the causes and treatment of type 2 diabetes.

Thiazolidinediones in diabetes: current status and future outlook

Thiazolidinediones have recently emerged as promising antidiabetic drugs. Unlike other oral antidiabetic drugs, thiazolidinediones function to ameliorate insulin resistance, a primary factor for the development of type 2 diabetes. Thiazolidinediones are ligands of the nuclear receptor, peroxisome proliferator-activated receptor-gamma, and their antidiabetic effects appear to be mediated by activation of this receptor. The two currently marketed thiazolidinediones, rosiglitazone and pioglitazone, display similar efficacies in their glucose lowering activities, but interestingly display slightly different clinical and side effect profiles. Understanding the molecular basis for these differences will help in the development of next generation thiazolidinediones that are more efficacious and safer for the treatment of type 2 diabetes.

Adipogenesis and fat-cell function in obesity and diabetes

Normal metabolic balance is maintained by a complex homeostatic system involving multiple tissues and organs. Acquired or inherited defects in any part of this system can lead to metabolic disorders, such as diabetes and obesity. Adipose tissue, once thought to function primarily as a passive depot for the storage of excess lipid, is now understood to play a much more active role in metabolic regulation, secreting a variety of metabolic hormones and actively functioning to prevent deleterious lipid accumulation in other tissues. Here, we review new advances in our understanding of adipogenesis and fat-cell function, primarily from the perspective of the transcription factor peroxisome proliferator-activated receptor gamma.

PPARgamma knockdown by engineered transcription factors: exogenous PPARgamma2 but not PPARgamma1 reactivates adipogenesis

To determine functional differences between the two splice variants of PPARgamma (gamma1 and gamma2), we sought to selectively repress gamma2 expression by targeting engineered zinc finger repressor proteins (ZFPs) to the gamma2-specific promoter, P2. In 3T3-L1 cells, expression of ZFP55 resulted in >50% reduction in gamma2 expression but had no effect on gamma1, whereas adipogenesis was similarly reduced by 50%. However, ZFP54 virtually abolished both gamma2 and gamma1 expression, and completely blocked adipogenesis. Overexpression of exogenous gamma2 in the ZFP54-expressing cells completely restored adipogenesis, whereas overexpression of gamma1 had no effect. This finding clearly identifies a unique role for the PPARgamma2 isoform.

Regulation of transcription by AMP-activated protein kinase: phosphorylation of p300 blocks its interaction with nuclear receptors

AMP-activated protein kinase (AMP-kinase) modulates many metabolic processes in response to fluctuations in cellular energy status. Although most of its known targets are metabolic enzymes, it has been proposed that AMP-kinase might also regulate gene expression. Here we demonstrate that the transcriptional coactivator p300 is a substrate of AMP-kinase. Phosphorylation of p300 at serine 89 by AMP-kinase dramatically reduced its interaction, in vitro and in vivo, with the nuclear receptors peroxisome proliferator-activated receptor gamma, thyroid receptor, retinoic acid receptor, and retinoid X receptor, but did not affect its interaction with the non-nuclear receptor transcription factors E1a, p53, or GATA4. These findings indicate that the AMP-kinase signaling pathway selectively modulates a subset of p300 activities and represent the first example of a transcriptional component regulated by AMP-kinase. Our results suggest a direct link between cellular energy metabolism and gene expression.

A novel potent antagonist of peroxisome proliferator-activated receptor gamma blocks adipocyte differentiation but does not revert the phenotype of terminally differentiated adipocytes

The antidiabetic thiazolidinediones, which include troglitazone and rosiglitazone, are ligands for the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma). Their antihyperglycemic effects seem to be linked to the regulation of PPARgamma-responsive genes. Here, we report the characterization of a specific PPARgamma antagonist that blocks several of the biological activities of the PPARgamma agonist rosiglitazone. PD068235 inhibited rosiglitazone-dependent PPARgamma transcriptional activity with an IC(50) of 0.8 microM and rosiglitazone-stimulated in vitro coactivator association. The role of PPARgamma in the initiation of differentiation is well documented. In this study, we used PD068235 as a tool to evaluate the functional role of PPARgamma in the maintenance of the terminally differentiated state. Treatment of confluent, growth-arrested 3T3-L1 preadipocytes with PD068235 blocked adipocyte differentiation induced by the standard adipogenic hormonal mixture (insulin/dexamethasone/isobutylmethylxanthin) and fully antagonized rosiglitazone-induced adipogenesis. In contrast, long-term treatment of terminally differentiated 3T3-L1 adipocytes with PD068235 did not induce any obvious morphological changes and had no effect on basal lipolysis rates. In addition, in fully differentiated adipocytes PD068235 did not alter the basal expression of PPARgamma target genes aP2 and CAP, but it effectively blocked rosiglitazone-induced expression of both genes. These results suggest that in terminally differentiated adipocytes, the PPARgamma activity is minimal and may not be required for the maintenance of PPARgamma target gene expression.

Differential activation of peroxisome proliferator-activated receptor-gamma by troglitazone and rosiglitazone

The antidiabetic thiazolidinediones, which include troglitazone and rosiglitazone, are ligands for the nuclear receptor peroxisome proliferator-activated receptor (PPAR)-gamma and exert their antihyperglycemic effects by regulation of PPAR-gamma-responsive genes. We report here that PPAR-gamma activation by troglitazone depends on the experimental setting. Troglitazone acts as a partial agonist for PPAR-gamma in transfected muscle (C2C12) and kidney (HEK 293T) cells, producing a submaximal transcriptional response (1.8- to 2.5-fold activation) compared with rosiglitazone (7.4- to 13-fold activation). Additionally, troglitazone antagonizes rosiglitazone-stimulated PPAR-gamma transcriptional activity. Limited protease digestion of PPAR-gamma suggests conformational differences in the receptor bound to troglitazone versus rosiglitazone. Consistent with this finding, an in vitro coactivator association assay demonstrated that troglitazone-bound PPAR-gamma recruited the transcriptional coactivators p300 and steroid receptor coactivator 1 less efficiently than rosiglitazone-bound receptor. In contrast to these observations, troglitazone behaves as a full agonist of PPAR-gamma in 3T3L1 adipocytes. Two-dimensional protein gel electrophoresis demonstrated that troglitazone and rosiglitazone regulated distinct but overlapping sets of genes in several cell types. Thus, troglitazone may behave as a partial agonist under certain physiological circumstances and as a full agonist in others. These differences could be caused by variations in the amount of specific cofactors, differences in PPAR response elements, or the presence of different isoforms of PPAR-gamma.

PPARgamma activators down-regulate the expression of PPARgamma in 3T3-L1 adipocytes

Transcriptional activation of PPARgamma by the anti-diabetic compound troglitazone enhances the rate of 3T3-L1 adipocyte differentiation. In this study, we examined the effects of troglitazone, a specific PPARgamma ligand, on the expression of PPARgamma during and after 3T3-L1 adipocyte differentiation. Troglitazone treatment caused a significant decrease in PPARgamma proteins and DNA binding activity. This reduction was associated with a similar decrease in transcription of PPARgamma mRNA. These data suggest that in 3T3-L1 cells, the expression of PPARgamma is auto-regulated.

c-Jun N-terminal kinase phosphorylates peroxisome proliferator-activated receptor-gamma1 and negatively regulates its transcriptional activity

The peroxisome proliferator-activated receptor-gamma (PPARgamma) transcription factor plays a pivotal role in adipocyte differentiation and metabolic regulation. The transcriptional activity of PPARgamma is positively modulated by ligand binding and negatively regulated by phosphorylation mediated by the MEK/ERK signaling pathway. The phosphorylation of mouse PPARgamma1 at Ser82 by ERK causes a decrease in both basal and ligand-dependent transcriptional activity. In this report we examined the ability of other mitogen-activated protein kinase family members to phosphorylate PPARgamma1. We demonstrate that in vitro, PPARgamma1 is efficiently phosphorylated by JNK/SAPK (c-Jun N-terminal kinase or stress-activated protein kinase) but only weakly phosphorylated by p38. In transfected 293T cells, PPARgamma1 is phosphorylated at Ser82 in response to known JNK activators such as UV irradiation and anisomycin treatment. This phosphorylation is not blocked by either the specific MEK inhibitor PD98059 or the p38 inhibitor SB203580, indicating that it is independent of the MEK/ERK and p38 signaling pathways. Finally, in transient transfection reporter assays, activation of JNK by anisomycin or by overexpression of MKK4 (the upstream JNK kinase) decreased ligand-dependent PPARgamma1 transcriptional activity. These results suggest that the activation of the JNK/SAPK pathway by extracellular signals, perhaps by inflammatory cytokines such as tumor necrosis factor-alpha, would result in a reduction of PPARgamma transcriptional activity and reduce the effects of PPARgamma ligands.

Thiazolidinediones and insulin resistance: peroxisome proliferatoractivated receptor gamma activation stimulates expression of the CAP gene

c-Cbl-associated protein (CAP) is a signaling protein that interacts with both c-Cbl and the insulin receptor that may be involved in the specific insulin-stimulated tyrosine phosphorylation of c-Cbl. The restricted expression of CAP in cells metabolically sensitive to insulin suggests an important potential role in insulin action. The expression of CAP mRNA and proteins are increased in 3T3-L1 adipocytes by the insulin sensitizing thiazolidinedione drugs, which are activators of the peroxisome proliferator-activated receptor gamma (PPARgamma). The stimulation of CAP expression by PPARgamma activators results from increased transcription. This increased expression of CAP was accompanied by a potentiation of insulin-stimulated c-Cbl tyrosine phosphorylation. Administration of the thiazolidinedione troglitazone to Zucker (fa/fa) rats markedly increased the expression of the major CAP isoform in adipose tissue. This effect was sustained for up to 12 weeks of treatment and accompanied the ability of troglitazone to prevent the onset of diabetes and its complications. Thus, CAP is the first PPARgamma-sensitive gene identified that participates in insulin signaling and may play a role in thiazolidinedione-induced insulin sensitization.

Regulation of peroxisome proliferator-activated receptor gamma activity by mitogen-activated protein kinase

Adipocyte differentiation is regulated both positively and negatively by external growth factors such as insulin, platelet-derived growth factor (PDGF), and epidermal growth factor (EGF). A key component of the adipocyte differentiation process is PPARgamma, peroxisomal proliferator-activated receptor gamma. To determine the relationship between PPARgamma activation and growth factor stimulation in adipogenesis, we investigated the effects of PDGF and EGF on PPARgamma1 activity. PDGF treatment decreased ligand-activated PPARgamma1 transcriptional activity in a transient reporter assay. In vivo [32P]orthophosphate labeling experiments demonstrated that PPARgamma1 is a phosphoprotein that undergoes EGF-stimulated MEK/mitogen-activated protein (MAP) kinase-dependent phosphorylation. Purified PPARgamma1 protein was phosphorylated in vitro by recombinant activated MAP kinase. Examination of the PPARgamma1 sequence revealed a single MAP kinase consensus recognition site at Ser82. Mutation of Ser82 to Ala inhibited both in vitro and in vivo phosphorylation and growth factor-mediated transcriptional repression. Therefore, phosphorylation of PPARgamma1 by MAP kinase contributes to the reduction of PPARgamma1 transcriptional activity by growth factor treatment.

Modulation of angiotensin II receptor (AT2) mRNA levels in R3T3 cells

R3T3 cells, a mouse fibroblast cell line, express the type 2 angiotensin II receptor (AT2), but not the AT1 subtype. We previously reported that expression of AT2 sites in these cells were regulated by various conditions: 1. The number of AT2 sites increased considerably when cells were contact-inhibited; 2. Stimulation of R3T3 cells with various mitogens caused a rapid decline of AT2 binding sites; and 3. Stimulation of cells with angiotensin ligands resulted in upregulation of the AT2 sites. In this study, to determine if altered AT2 expression is under transcriptional, posttranscriptional, or translational control, we examined the level of AT2 mRNA in R3T3 cells in response to various treatments. There was a 200-fold increase in AT2 mRNA levels in quiescent cells as compared to growing cells. Results from nuclear run-on assays suggested that the differences in AT2 mRNA levels were primarily caused by changes in the rate of AT2 gene transcription. Stimulation of cells with fibroblast growth factor caused an approximate threefold reduction of AT2 mRNA levels, and also increased the rate of degradation of AT2 mRNA, which correlated with the decrease in AT2 binding activity seen under these conditions. However, whereas treatment with angiotensin ligands increased AT2 binding activity, the level of AT2 transcripts did not increase. This pattern of expression implies that regulation of AT2 receptors occurs at multiple levels, involving translational and/or posttranslational as well as transcriptional control, and further affords the cell the ability to rapidly modulate the number of AT2 binding sites in response to changing extracellular conditions.

Defective Marek's disease virus DNA contains a gene encoding a potential nuclear DNA binding protein and a HSV a-like sequence

Four RNA transcripts from chicken embryo fibroblast cells infected with Marek's disease virus (MDV) strain 281Ml/1 hybridized to the 4-kbp MDV replicon DNA. In an attempt to identify open reading frames coding for the four transcripts, we determined the nucleotide sequences of 4-kbp replicon DNA (represents a single monomeric repeat unit of defective MDV genome). Computer analysis indicates that the 4-kbp MDV replicon DNA contains two intact open reading frames (ORFs) with common promoter regulatory elements. ORF-A codes for a putative 204 amino acid protein that shares 21 and 36% amino acid sequence identity to nuclear DNA binding proteins such as the EBNA-1 of Epstein-Barr virus and galline, a chicken sperm histone protein, respectively. ORF-B encodes for a potential 350 amino acid protein, which did not show any significant amino acid sequence identity to known protein sequences within Swiss-Protein data base. ORF-B may, therefore, encode a MDV specific protein. The 5'-region of MDV replicon DNA revealed seven reiterated copies of an 11-bp motif sharing 8 out of 11 nucleotide sequence identity to DR2 elements of the herpes simplex virus strain USA-8 a sequence.