Boehringer Ingelheim (Switzerland)

BACKGROUND: Interstitial lung disease (ILD) is a common manifestation of systemic sclerosis and a leading cause of systemic sclerosis-related death. Nintedanib, a tyrosine kinase inhibitor, has been shown to have antifibrotic and antiinflammatory effects in preclinical models of systemic sclerosis and ILD. METHODS: We conducted a randomized, double-blind, placebo-controlled trial to investigate the efficacy and safety of nintedanib in patients with ILD associated with systemic sclerosis. Patients who had systemic sclerosis with an onset of the first non-Raynaud's symptom within the past 7 years and a high-resolution computed tomographic scan that showed fibrosis affecting at least 10% of the lungs were randomly assigned, in a 1:1 ratio, to receive 150 mg of nintedanib, administered orally twice daily, or placebo. The primary end point was the annual rate of decline in forced vital capacity (FVC), assessed over a 52-week period. Key secondary end points were absolute changes from baseline in the modified Rodnan skin score and in the total score on the St. George's Respiratory Questionnaire (SGRQ) at week 52. RESULTS: A total of 576 patients received at least one dose of nintedanib or placebo; 51.9% had diffuse cutaneous systemic sclerosis, and 48.4% were receiving mycophenolate at baseline. In the primary end-point analysis, the adjusted annual rate of change in FVC was -52.4 ml per year in the nintedanib group and -93.3 ml per year in the placebo group (difference, 41.0 ml per year; 95% confidence interval [CI], 2.9 to 79.0; P = 0.04). Sensitivity analyses based on multiple imputation for missing data yielded P values for the primary end point ranging from 0.06 to 0.10. The change from baseline in the modified Rodnan skin score and the total score on the SGRQ at week 52 did not differ significantly between the trial groups, with differences of -0.21 (95% CI, -0.94 to 0.53; P = 0.58) and 1.69 (95% CI, -0.73 to 4.12 [not adjusted for multiple comparisons]), respectively. Diarrhea, the most common adverse event, was reported in 75.7% of the patients in the nintedanib group and in 31.6% of those in the placebo group. CONCLUSIONS: Among patients with ILD associated with systemic sclerosis, the annual rate of decline in FVC was lower with nintedanib than with placebo; no clinical benefit of nintedanib was observed for other manifestations of systemic sclerosis. The adverse-event profile of nintedanib observed in this trial was similar to that observed in patients with idiopathic pulmonary fibrosis; gastrointestinal adverse events, including diarrhea, were more common with nintedanib than with placebo. (Funded by Boehringer Ingelheim; SENSCIS ClinicalTrials.gov number, NCT02597933.).

BACKGROUND: It is not known whether prehospital fibrinolysis, coupled with timely coronary angiography, provides a clinical outcome similar to that with primary percutaneous coronary intervention (PCI) early after acute ST-segment elevation myocardial infarction (STEMI). METHODS: Among 1892 patients with STEMI who presented within 3 hours after symptom onset and who were unable to undergo primary PCI within 1 hour, patients were randomly assigned to undergo either primary PCI or fibrinolytic therapy with bolus tenecteplase (amended to half dose in patients ≥75 years of age), clopidogrel, and enoxaparin before transport to a PCI-capable hospital. Emergency coronary angiography was performed if fibrinolysis failed; otherwise, angiography was performed 6 to 24 hours after randomization. The primary end point was a composite of death, shock, congestive heart failure, or reinfarction up to 30 days. RESULTS: The primary end point occurred in 116 of 939 patients (12.4%) in the fibrinolysis group and in 135 of 943 patients (14.3%) in the primary PCI group (relative risk in the fibrinolysis group, 0.86; 95% confidence interval, 0.68 to 1.09; P=0.21). Emergency angiography was required in 36.3% of patients in the fibrinolysis group, whereas the remainder of patients underwent angiography at a median of 17 hours after randomization. More intracranial hemorrhages occurred in the fibrinolysis group than in the primary PCI group (1.0% vs. 0.2%, P=0.04; after protocol amendment, 0.5% vs. 0.3%, P=0.45). The rates of nonintracranial bleeding were similar in the two groups. CONCLUSIONS: Prehospital fibrinolysis with timely coronary angiography resulted in effective reperfusion in patients with early STEMI who could not undergo primary PCI within 1 hour after the first medical contact. However, fibrinolysis was associated with a slightly increased risk of intracranial bleeding. (Funded by Boehringer Ingelheim; ClinicalTrials.gov number, NCT00623623.).

The impact of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) in the pathology of Parkinson's disease (PD) and in MPTP neurotoxicity remains unclear. Here, male TNF-alpha (-/-) deficient mice and C57bL/6 mice were treated with MPTP (4 x 15 mg/kg, 24 h intervals) and in one series, thalidomide was administered to inhibit TNF-alpha synthesis. Real-time RT-PCR revealed that the striatal mRNA levels of TNF-alpha, of the astrocytic marker glial fibrillary acidic protein (GFAP) and of the marker for activated microglia, macrophage antigen complex-1 (MAC-1), were significantly enhanced after MPTP administration. Thalidomide (50 mg/kg, p.o.) partly protected against the MPTP-induced dopamine (DA) depletion, and TNF-alpha (-/-) mice showed a significant attenuation of striatal DA and DA metabolite loss as well as striatal tyrosine hydroxylase (TH) fiber density, but no difference in nigral TH and DA transporter immunoreactivity. TNF-alpha deficient mice suffered a lower mortality (10%) compared to the high mortality (75%) seen in wild-type mice after acute MPTP treatment (4 x 20 mg/kg, 2 h interval). HPLC measurement of MPP(+) levels revealed no differences in TNF-alpha (-/-), wild-type and thalidomide treated mice. This study demonstrates that TNF-alpha is involved in MPTP toxicity and that inhibition of TNF-alpha response may be a promising target for extending beyond symptomatic treatment and developing anti-parkinsonian drugs for the treatment of the inflammatory processes in PD.

Hypertrophic scars and Dupuytren's disease are characterized by the presence of modified fibroblasts or myofibroblasts which are allegedly responsible for tissue retraction and excessive connective tissue production. gamma-Interferon, a cytokine produced by T-helper lymphocytes, has been shown to decrease fibroblast replication, alpha-smooth-muscle actin (the actin isoform characterizing myofibroblasts) expression, and collagen production. We have investigated in an open pilot study the possibility that intralesional injections of gamma-interferon exert a beneficial effect on the evolution of hypertrophic scars and Dupuytren's disease. In the 14 selected patients, gamma-interferon decreased the symptoms and the size of the lesions of both diseases; in hypertrophic scars, immunofluorescence examination showed that alpha-smooth-muscle actin expression also was decreased in myofibroblasts. Moreover, in fibroblasts cultured from 4 patients with hypertrophic scars, gamma-interferon decreased replication and alpha-smooth-muscle actin expression in vitro. Our results suggest that gamma-interferon could represent a useful adjunct to the nonsurgical therapy of hypertrophic scars and Dupuytren's disease. Larger controlled clinical studies, however, should test the validity of these preliminary observations.

Hepatitis B virus (HBV) has been infecting humans for millennia and remains a global health problem, but its past diversity and dispersal routes are largely unknown. We generated HBV genomic data from 137 Eurasians and Native Americans dated between ~10,500 and ~400 years ago. We date the most recent common ancestor of all HBV lineages to between ~20,000 and 12,000 years ago, with the virus present in European and South American hunter-gatherers during the early Holocene. After the European Neolithic transition, Mesolithic HBV strains were replaced by a lineage likely disseminated by early farmers that prevailed throughout western Eurasia for ~4000 years, declining around the end of the 2nd millennium BCE. The only remnant of this prehistoric HBV diversity is the rare genotype G, which appears to have reemerged during the HIV pandemic.

Torsade de Pointes (TdP) is a lethal arrhythmia that is often drug-induced, thus there is an urgent need for development of models to test or predict the drug sensitivity of human cardiac tissue. Here, we present an in vitro TdP model using 3D cardiac tissue sheets (CTSs) that contain a mixture of human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes and non-myocytes. We simultaneously monitor the extracellular field potential (EFP) and the contractile movement of the CTSs. Upon treatment with IKr channel blockers, CTSs exhibit tachyarrhythmias with characteristics of TdP, including both a typical polymorphic EFP and meandering spiral wave re-entry. The TdP-like waveform is predominantly observed in CTSs with the cell mixture, indicating that cellular heterogeneity and the multi-layered 3D structure are both essential factors for reproducing TdP-like arrhythmias in vitro. This 3D model could provide the mechanistic detail underlying TdP generation and means for drug discovery and safety tests.

Alzheimer's disease (AD) is characterized by the invariant accumulation of senile plaques predominantly composed of the pathologically relevant 42-amino acid amyloid beta-peptide (Abeta42). The presenilin (PS) proteins play a key role in Abeta generation. FAD-associated mutations in PS1 and PS2 enhance the production of Abeta42, and PS1 is required for physiological Abeta production, since a gene knockout of PS1 and dominant negative mutations of PS1 abolish Abeta generation. PS proteins undergo endoproteolytic processing, and current evidence indicates that fragment formation may be required for the amyloidogenic function of PS. We have now determined the sequence requirements for endoproteolysis of PS1. Mutagenizing amino acids at the previously determined major cleavage site (amino acid 298) had no effect on PS1 endoproteolysis. In contrast, mutations or deletions at the additional cleavage site around amino acid 292 blocked endoproteolysis. The uncleavable PS1 derivatives accumulated as full-length proteins and replaced the endogenous PS1 proteins. In contrast to the previously described aspartate mutations within transmembrane domains 6 and 7, the uncleaved PS1 variants do not act as dominant negative inhibitors of Abeta production. Moreover, when a FAD-associated mutation (M146L) was combined with a mutation blocking endoproteolysis, Abeta42 production still reached pathological levels. These data therefore demonstrate that endoproteolysis of presenilins is not an absolute prerequisite for the amyloidogenic function of PS1. These data also show that accumulation of the PS1 holoprotein is not associated with the pathological activity of PS1 mutations as suggested previously.

Using a 4D-QSAR approach (software Quasar) allowing for multiple-conformation, orientation, and protonation-state ligand representation as well as for the simulation of local induced-fit phenomena, we have validated a family of receptor surrogates for the neurokinin-1 (NK-1) receptor system. The evolution was based on a population of 500 receptor models and simulated during 40 000 crossover steps, corresponding to 80 generations. It yielded a cross-validated r(2) of 0.887 for the 50 ligands of the training set (represented by a total of 218 conformers and protomers) and a predictive r(2) of 0.834 for the 15 ligands of the test set (70 conformers and protomers). A series of five "scramble tests" (with an average predictive r(2) of -0.438) demonstrates the sensitivity of the surrogate toward the biological data, for which it should establish a QSAR. On the basis of this model, the activities of 12 new compounds - four of which have been synthesized and tested in the meantime - are predicted. For most of the NK-1 antagonists, the genetic algorithm selected a single entity - out of the up to 12 conformers or protomers - to preferably bind to the receptor surrogate. Moreover, the evolution converged at an identical protonation scheme for all NK-1 antagonists. This indicates that 4D-QSAR techniques may, indeed, reduce the bias associated with the choice of the bioactive conformation as each ligand molecule can be represented by an ensemble of conformations, orientations, and protonation states.

Signal-transducing adaptor protein-2 (STAP-2) is a recently identified adaptor protein that contains pleckstrin and Src homology 2-like domains as well as a YXXQ motif in its C-terminal region. Our previous studies have demonstrated that STAP-2 binds to STAT3 and STAT5, and regulates their signaling pathways. In the present study, STAP-2 was found to positively regulate LPS/TLR4-mediated signals in macrophages. Disruption of STAP-2 resulted in impaired LPS/TLR4-induced cytokine production and NF-kappaB activation. Conversely, overexpression of STAP-2 enhanced these LPS/TLR4-induced biological activities. STAP-2, particularly its Src homology 2-like domain, bound to both MyD88 and IkappaB kinase (IKK)-alphabeta, but not TNFR-associated factor 6 or IL-1R-associated kinase 1, and formed a functional complex composed of MyD88-STAP-2-IKK-alphabeta. These interactions augmented MyD88- and/or IKK-alphabeta-dependent signals, leading to enhancement of the NF-kappaB activity. These results demonstrate that STAP-2 may constitute an alternative LPS/TLR4 pathway for NF-kappaB activation instead of the TNFR-associated factor 6-IL-1R-associated kinase 1 pathway.

Daxx has been shown to play an essential role in type I IFN-alphabeta-mediated suppression of B cell development and apoptosis. Recently, we demonstrated that Tyk2 is directly involved in IFN signaling for the induction and translocation of Daxx, which may result in growth arrest and/or apoptosis of B lymphocyte progenitors. To clarify how Daxx regulates B cell development, we examined Daxx interacting partners by yeast two-hybrid screening. DNA methyltransferase 1 (DNMT1)-associated protein (DMAP1) was identified and demonstrated to interact with Daxx. The interaction regions in both proteins were mapped, and the cellular localization of the interaction was examined. Both Daxx and DMAP1 formed a complex with DNMT1 and colocalized in the nucleus. DMAP1 enhanced Daxx-mediated repression of glucocorticoid receptor transcriptional activity. Furthermore, Daxx protected protein degradation of DMAP1 in vivo. These results provide the novel molecular link between Daxx and DNMT1, which establishes a repressive transcription complex in the nucleus.

This randomized, placebo-controlled within dose groups, double-blind, single rising dose study investigated the safety, tolerability, pharmacokinetics and pharmacodynamics of 1 mg to 100 mg doses of empagliflozin in 48 healthy Japanese male subjects. Empagliflozin was rapidly absorbed, reaching peak levels in 1.25 to 2.50 h; thereafter, plasma concentrations declined in a biphasic fashion, with mean terminal elimination half-life ranging from 7.76 to 11.7 h. Increase in empagliflozin exposure was proportional to dose. Oral clearance was dose independent and ranged from 140 to 172 mL/min. In the 24 h following 100 mg empagliflozin administration, the mean (%CV) amount of glucose excreted in urine was 74.3 (17.1) g. The amount and the maximum rate of glucose excreted via urine increased with dose of empagliflozin. Nine adverse events, all of mild intensity, were reported by 8 subjects (7 with empagliflozin and 1 with the placebo). No hypoglycemia was reported. In conclusion, 1 mg to 100 mg doses of empagliflozin had a good safety and tolerability profile in healthy Japanese male subjects. Exposure to empagliflozin was dose proportional. The amount and rate of urinary glucose excretion were higher with empagliflozin than with the placebo, and increased with empagliflozin dose.

Avidin, a basic protein isolated from egg white, was employed as a chiral selector in affinity electrokinetic chromatography (EKC) for the separation of acidic enantiomers. Optical isomers of vanilmandelic acid, warfarin, ibuprofen, ketoprofen, flurbiprofen, and folinic acid were successfully resolved within 20 min with 25 microM avidin in a linear polyacrylamide-coated capillary under weakly acidic conditions. The effects of pH, the concentration of avidin, addition of an organic solvent such as ethanol and 2-propanol, and temperature on enantioselectivity were investigated. The choice of pH and the organic solvent additive was critical to improve the separation. Some general considerations about affinity EKC are also described, based on a simple one-site interaction model.

OBJECTIVES: To characterise the safety and tolerability of nintedanib and the dose adjustments used to manage adverse events in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD). METHODS: In the SENSCIS trial, patients with SSc-ILD were randomised to receive nintedanib 150 mg two times per day or placebo. To manage adverse events, treatment could be interrupted or the dose reduced to 100 mg two times per day. We assessed adverse events and dose adjustments over 52 weeks. RESULTS: A total of 576 patients received nintedanib (n=288) or placebo (n=288). The most common adverse event was diarrhoea, reported in 75.7% of patients in the nintedanib group and 31.6% in the placebo group; diarrhoea led to permanent treatment discontinuation in 6.9% and 0.3% of patients in the nintedanib and placebo groups, respectively. In the nintedanib and placebo groups, respectively, 48.3% and 12.2% of patients had ≥1 dose reduction and/or treatment interruption, and adverse events led to permanent discontinuation of the trial drug in 16.0% and 8.7% of patients. The adverse events associated with nintedanib were similar across subgroups defined by age, sex, race and weight. The rate of decline in forced vital capacity in patients treated with nintedanib was similar irrespective of dose adjustments. CONCLUSIONS: The adverse event profile of nintedanib in patients with SSc-ILD is consistent with its established safety and tolerability profile in patients with idiopathic pulmonary fibrosis. Dose adjustment is important to minimise the impact of adverse events and help patients remain on therapy.

The pharmacokinetic profile of recombinant human erythropoietin (rHuEpo) was studied after a single intravenous dose of 150 U/kg in ten patients with various degrees of renal function: group I, creatinine clearance greater than 80 ml/min, n = 2; group II, creatinine clearance 10-50 ml/min, n = 6; group III, creatinine clearance less than 3 ml/min (patients undergoing haemodialysis) n = 2. Erythropoietin concentrations in serum and urine samples obtained over 48 h were measured by RIA. rHuEpo was cleared from circulation in an exponential fashion, the half-life ranged from 6.5 to 12.7 h (mean 9.03 h) and was not different between the groups. The apparent volume of distribution varied from 0.041 to 0.099 l/kg (mean 0.070 l/kg) this corresponds to 1.5 times the plasma volume and was unrelated to kidney function. Renal clearance (groups I, II) accounted for less than 3% of total body clearance, both parameters were unaffected by decreasing renal function. These results indicate that, in accordance with animal data, the elimination of rHuEpo occurs mainly through non-renal mechanisms.

Background Childhood interstitial lung disease (ILD) comprises a spectrum of rare ILDs affecting infants, children and adolescents. Nintedanib is a licensed treatment for pulmonary fibrosis in adults. The primary objectives of the InPedILD trial were to determine the dose-exposure and safety of nintedanib in children and adolescents with fibrosing ILD. Methods Patients aged 6–17 years with fibrosing ILD on high-resolution computed tomography and clinically significant disease were randomised 2:1 to receive nintedanib or placebo for 24 weeks and then open-label nintedanib. Dosing was based on weight-dependent allometric scaling. Co-primary end-points were the area under the plasma concentration–time curve at steady state (AUC τ,ss ) at weeks 2 and 26 and the proportion of patients with treatment-emergent adverse events at week 24. Results 26 patients received nintedanib and 13 patients received placebo. The geometric mean (geometric coefficient of variation) AUC τ,ss for nintedanib was 175 µg·h·L −1 (85.1%) in patients aged 6–11 years and 167 µg·h·L −1 (83.6%) in patients aged 12–17 years. In the double-blind period, adverse events were reported in 84.6% of patients in each treatment group. Two patients discontinued nintedanib due to adverse events. Diarrhoea was reported in 38.5% and 15.4% of the nintedanib and placebo groups, respectively. Adjusted mean± se changes in percentage predicted forced vital capacity at week 24 were 0.3±1.3% in the nintedanib group and −0.9±1.8% in the placebo group. Conclusions In children and adolescents with fibrosing ILD, a weight-based dosing regimen resulted in exposure to nintedanib similar to adults and an acceptable safety profile. These data provide a scientific basis for the use of nintedanib in this patient population.

This article reports the clinical investigation of a probe drug cocktail containing substrates of key drug transporters. Single oral doses of 0.25 mg digoxin (P-gp), 5 mg furosemide (OAT1 and OAT3), 500 mg metformin (OCT2, MATE1, and MATE2-K), and 10 mg rosuvastatin (OATP1B1, OATP1B3, and BCRP) were administered separately or as a cocktail in a randomized six-period crossover trial in 24 healthy male volunteers. As a cocktail, relative bioavailabilities of digoxin and metformin and furosemide AUC0-tz were similar to separate dosing. However, when administered as a cocktail the Cmax of furosemide was 19.1% lower and the Cmax and AUC0-tz of rosuvastatin were 38.6% and 43.4% higher, respectively. In addition, the effects of increased doses of metformin or furosemide on the cocktail were investigated in 11 and 12 subjects, respectively. The cocktail explored in this trial has the potential to be used for the in vivo screening of transporter-mediated drug-drug interactions. © 2016 American Society for Clinical Pharmacology and Therapeutics.

OBJECTIVES: Nintedanib is a tyrosine kinase inhibitor approved for the treatment of idiopathic pulmonary fibrosis (IPF). The pathological pathways involved in fibrogenesis in IPF and interstitial lung disease associated with systemic sclerosis (SSc-ILD) show commonalities; both involve fibroblast activation, myofibroblast accumulation and deposition of extracellular matrix. The SENSCIS™ trial is a randomised, placebo-controlled Phase III trial that will evaluate the efficacy and safety of nintedanib in patients with SSc-ILD (NCT02597933). METHODS: Approximately 520 patients with SSc (based on 2013 American College of Rheumatology/European League Against Rheumatism criteria) and ILD (≥10% fibrosis of the lungs, confirmed by central assessment of chest high resolution computed tomography), forced vital capacity (FVC) ≥40% predicted and diffusing capacity for carbon monoxide of 30-89% predicted will be enrolled. Patients will be randomised (1:1) to nintedanib 150 mg twice daily or placebo, stratified by the presence of anti-topoisomerase I antibody. To reflect real-world management, patients receiving prednisone (≤10 mg/day) and/or a stable dose of mycophenolate or methotrexate, will be eligible. The primary endpoint is the annual rate of decline in FVC (mL/ year) assessed over 52 weeks. Patients will remain on blinded study treatment until the last patient completes 52 weeks of treatment or for a maximum of 100 weeks of treatment. Key secondary endpoints are absolute changes from baseline in modified Rodnan skin score and St George's Respiratory Questionnaire at week 52. RESULTS: Recruitment for the trial began in November 2015. CONCLUSIONS: This trial will assess the efficacy and safety of nintedanib in patients with SSc-ILD.

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the CNS and a leading cause of lasting neurologic disabilities in young adults. Although the precise mechanism remains incompletely understood, Ag presentation and subsequent myelin-reactive CD4(+) T cell activation/differentiation are essential for the pathogenesis of MS. Although semaphorins were initially identified as axon guidance cues during neural development, several semaphorins are crucially involved in various phases of immune responses. Sema4A is one of the membrane-type class IV semaphorins, which we originally identified from the cDNA library of dendritic cell (DC). Sema4A plays critical roles in T cell activation and Th1 differentiation during the course of experimental autoimmune encephalomyelitis, an animal model of MS; however, its pathological involvement in human MS has not been determined. In this study, we report that Sema4A is increased in the sera of patients with MS. The expression of Sema4A is increased on DCs in MS patients and shed from these cells in a metalloproteinase-dependent manner. DC-derived Sema4A is not only critical for Th1 but also for Th17 cell differentiation, and MS patients with high Sema4A levels exhibit Th17 skewing. Furthermore, patients with high Sema4A levels have more severe disabilities and are unresponsive to IFN-β treatment. Taken together, our results suggest that Sema4A is involved in the pathogenesis of MS by promoting Th17 skewing.

Signal-transducing adaptor protein-2 (STAP-2) is a recently identified adaptor protein that contains pleckstrin homology- and Src homology 2-like domains as well as a YXXQ motif in its C-terminal region. Our previous studies demonstrated that STAP-2 binds to STAT3 and STAT5, and regulates their signaling pathways. In the present study, we find that STAP-2-deficient splenocytes or T cells exhibit enhanced cell adhesion to fibronectin after PMA treatment, and that STAP-2-deficient T cells contain the increased protein contents of focal adhesion kinase (FAK). Furthermore, overexpression of STAP-2 induces a dramatic decrease in the protein contents of FAK and integrin-mediated T cell adhesion to fibronectin in Jurkat T cells via the degradation of FAK. Regarding the mechanism for this effect, we found that STAP-2 associates with FAK and enhances its degradation, proteasome inhibitors block FAK degradation, and STAP-2 recruits an endogenous E3 ubiquitin ligase, Cbl, to FAK. These results reveal a novel regulation mechanism for integrin-mediated signaling in T cells via STAP-2, which directly interacts with and degrades FAK.

OBJECTIVE: Telmisartan is mainly taken up into the liver by organic anion transporting polypeptide (OATP) 1B3, conjugated with glucuronate, and excreted into the bile. We investigated the relationship between genotypes of metabolizing enzymes and transporters and pharmacokinetics of telmisartan in clinical study. We also checked which enzymes are responsible for telmisartan glucuronidation. MATERIALS AND METHODS: We collected blood samples from 57 healthy volunteers who had participated in a clinical trial of telmisartan and examined the relationship between 14 mutations in six transporters/metabolic enzymes and pharmacokinetics of telmisartan. We also performed an in-vitro glucuronidation assay with recombinant uridine 5'-diphospho-glucuronosyltransferases isoforms and human liver microsomes. RESULTS: In the clinical study, area under the plasma concentration-time curve value from time zero to infinity, of telmisartan in heterozygotes of SLCO1B3 (encoding protein: OATP1B3) rs11045585 tended to be larger than that in homozygotes of wild-type alleles. Unexpectedly, 19 heterozygotes of UGT1A1*28, whose function was decreased, significantly increased its oral clearance compared with homozygotes of UGT1A1*1 alleles (1090±690 vs. 620±430 ml/min/body). Metabolic clearance of telmisartan in human liver microsomes obtained from individuals with UGT1A1*28/*28 was higher compared with that of UGT1A1*1/*1 (168±33 vs. 93.3±27.3 μl/min/mg protein). Although telmisartan was metabolized by multiple UGT isoforms, in-vitro experiments revealed that UGT1A3 was estimated to be predominantly involved in telmisartan glucuronidation in human hepatocytes. CONCLUSION: UGT1A1*28 was thought to enhance the protein expression of UGT1A3 as reported most recently (Riedmaier et al. Clin Pharmacol Ther 2010; 87:65-73) and thereby increase glucuronidation activity of telmisartan and decrease the plasma concentration of telmisartan.