Evaluation of the drug-drug interaction potential for trazpiroben (TAK-906), a D2/D3 receptor antagonist for gastroparesis, towards cytochrome P450s and transporters.

Trazpiroben (TAK-906), a peripherally selective dopamine D2/D3 receptor antagonist, is being developed for the treatment of patients with gastroparesis. The potential of trazpiroben to act as a perpetrator or a victim for cytochrome P450 (CYP)- or transporter- mediated drug-drug interactions (DDIs) was evaluated following the latest regulatory guidelines.In vitro studies revealed that trazpiroben is metabolised mainly through a non-CYP pathway (56.7%) by multiple cytosolic, NADPH-dependent reductase, such as aldo-keto reductase and short-chain dehydrogenase/reductase including carbonyl reductases. Remaining metabolism occurs through CYP3A4 and CYP2C8 (43.3%). Trazpiroben is neither an inhibitor nor an inducer of major CYP enzymes at a clinically relevant dose. It is a substrate of P-glycoprotein (P-gp) and organic anion transporting polypeptide (OATP) 1B1/1B3, but is not an inhibitor of transporters listed in the DDI guidelines at a clinically relevant dose. This is consistent with findings from CYP3A and P-gp-based clinical assessment showing no substantial change (≤2-fold) in trazpiroben exposure when co-administered with itraconazole.Collectively, trazpiroben has low potential of enzyme-mediated DDIs and is unlikely to act as a perpetrator of transporter-mediated DDIs but there may be a potential to act as a victim of OATP1B1/1B3 DDI that will be evaluated clinically.

Differences in nonclinical pharmacokinetics between species and prediction of human pharmacokinetics of TAK-272 (SCO-272), a novel orally active renin inhibitor.

In the search for orally available drugs, the prediction of human pharmacokinetics (PK) is essential for successfully selecting compounds that will be clinically useful. This report describes the selection of TAK-272 (SCO-272), a novel orally active renin inhibitor, as a clinical candidate via the detailed investigation of nonclinical PK data and human PK prediction. The bioavailability (BA) of TAK-272 after oral administration to rats and monkeys was low, especially in fasted monkeys, and the systemic exposure of TAK-272 was highly variable in monkeys. The results of mass balance studies in animals suggested that the absorbed TAK-272 was largely eliminated by metabolism. In vitro studies revealed that TAK-272 was mainly metabolized by CYP3A4/5 in humans, and it was a P-glycoprotein substrate. PK analysis suggested that the factors responsible for the low BA were different in rats and monkeys. First-pass hepatic extraction was high in rats, while the fraction absorbed from the gastrointestinal tract (Fa * Fg ) was low in monkeys. It was predicted that humans would have a higher BA and a longer half-life in the plasma compared with the animals by a simple calculation using intrinsic hepatic clearance in monkeys, which correlates well with human values for CYP3A4 substrates, and Fa * Fg in rats, which correlates relatively well with human values. TAK-272 was finally selected as a clinical candidate based on the result of human PK prediction. The actual human PK after oral administration of TAK-272 was comparable to the predicted profile and was preferable for clinical usage.

Long-Term Stability of Cryopreserved Human Hepatocytes: Evaluation of Phase I and II Drug-Metabolizing Enzyme Activities and CYP3A4/5 Induction for More than a Decade.

We evaluated the long-term stability of hepatocytes stored in the vapor phase of liquid nitrogen for their viability, cytochrome P450 (CYP) 1A2 activity, CYP3A4/5 activity, uridine diphosphate-glucuronosyl transferase (UGT) activity, sulfotransferase (SULT) activity, and CYP3A4/5 induction during 14 years of preservation. No substantial degradation of viability, CYP1A2 activity, UGT activity, or CYP3A4/5 induction was observed. CYP3A4/5 activity showed a slight decrease after 7 years of storage, and SULT activity gradually decreased during storage, although substantial activities remained even after 14 years. These results indicate that cryopreserved human hepatocytes can be stored stably for more than a decade with little or no change in viability, activity of drug-metabolizing enzymes, or CYP3A4/5 induction, and can be widely applicable to qualitative research in drug metabolism.

The effect of genetic polymorphisms in UGT2B15 on the pharmacokinetic profile of sipoglitazar, a novel anti-diabetic agent.

PURPOSE: Sipoglitazar was a novel, azolealkanoic acid derivative that possesses selective activity for the peroxisome proliferator-activated receptors (PPAR) PPARγ, PPARα, and PPARδ. The compound undergoes phase II biotransformation by conjugation catalyzed by UDP-glucuronosyltransferase (UGT). The aim of this analysis was to explore the influence of genetic polymorphism in UGT on the pharmacokinetics of sipoglitazar. METHODS: Three preliminary phase I clinical pharmacology studies were conducted in tandem in healthy human subjects. Genotyping was undertaken in a total of 82 subjects in the phase I program for the purpose of genotyping UGT polymorphisms. Plasma samples were collected for up to 48 h post-dose to characterize the pharmacokinetic profile following a single oral dose of the drug. RESULTS: Plasma concentrations of sipoglitazar and the distribution of dose-normalized individual values for area under the plasma concentration-time curve from time 0 to infinity (AUC(0-∞)) before any stratification were considerably skewed with a multi-modal distribution. The proportion of variability in AUC(0-∞) explained by UGT2B15 was 66.7 % (P < 0.0001); the addition of other genetic or demographic factors was not statistically significant. Subjects homozygous for the UGT2B15 D85Y variant (UGT2B15*2/*2) were exposed to greater plasma concentrations of sipoglitazar than subjects homozygous for the wild-type allele UGT2B15*1/*1 (3.26-fold higher) or heterozygous allele UGT2B15*1/*2 (2.16-fold higher). CONCLUSIONS: These results indicate that sipoglitazar clearance is substantially modified by UGT2B15 enzyme variants, with higher exposure observed in the UGT2B15*2/*2 genotype group.

An unusual metabolic pathway of sipoglitazar, a novel antidiabetic agent: cytochrome P450-catalyzed oxidation of sipoglitazar acyl glucuronide.

Animal pharmacokinetic studies of sipoglitazar, a novel antidiabetic agent, showed that the deethylated metabolite (M-I) and the glucuronide conjugate of sipoglitazar (sipoglitazar-G) appeared to be the key metabolites in the elimination process. M-I was also measured as the main metabolite in the plasma of humans administered sipoglitazar. In vitro metabolic studies were performed to investigate the metabolic pathways from sipoglitazar to M-I in humans. The metabolic profile with human hepatocytes and hepatic microsomes indicated that M-I was not formed directly from sipoglitazar and that sipoglitazar-G was involved in the metabolism from sipoglitazar to M-I. Further studies of the metabolism of sipoglitazar-G revealed that the properties of the glucuronide conjugate and its metabolism are as follows: high-performance liquid chromatography, liquid chromatography-tandem mass spectrometry, and NMR analyses showed that sipoglitazar-G was composed of two glucuronides, sipoglitazar-G1, a ß-1-O-acyl glucuronide, and sipoglitazar-G2, an α-2-O-acyl glucuronide. The stability study of these glucuronides suggested that sipoglitazar-G1 could be converted to sipoglitazar-G2 and sipoglitazar, but sipoglitazar-G2 could not be converted to sipoglitazar-G1. The oxidative metabolic study of sipoglitazar-G1 and -G2 with human hepatic microsomes and cytochrome P450-expressing microsomes revealed that M-I was formed only from sipoglitazar-G1, not from sipoglitazar-G2, and that CYP2C8 was mainly involved in this process. From these results, it is shown that the metabolic pathway from sipoglitazar to M-I is an unusual one, in which sipoglitazar is initially metabolized to sipoglitazar-G1 by UDP-glucuronosyltransferase and then sipoglitazar-G1 is metabolized to M-I by O-dealkylation by CYP2C8 and deconjugation. Sipoglitazar-G2 is sequentially formed by the migration of the ß-site of sipoglitazar-G1.

Discovery of the investigational drug TAK-441, a pyrrolo[3,2-c]pyridine derivative, as a highly potent and orally active hedgehog signaling inhibitor: modification of the core skeleton for improved solubility.

We recently reported the discovery of the novel pyrrolo[3,2-c]quinoline-4-one derivative 1 as a potent inhibitor of Hedgehog (Hh) pathway signaling. However, the PK evaluation of 1 at high dosage (100 mg/kg) revealed the C(max) value 3.63 µg/mL, likely due to poor solubility of this compound. Efforts to improve solubility by reducing the aromatic ring count of the core system led to N-methylpyrrolo[3,2-c]pyridine derivative 11. Further optimization of the 3-alkoxy group led to compound 11d with acceptable solubility and potent Hh inhibitory activity. Compound 11d suppressed transcription factor Gli1 mRNA expression in tumor-associated stromal tissue and inhibited tumor growth (treatment/control ratio, 3%) in a mouse medulloblastoma allograft model owing to the improved PK profile based on increased solubility. Compound 11d (TAK-441) is currently in clinical trials for the treatment of advanced solid tumors.

Evaluation of the pharmacokinetics of trazpiroben (TAK-906) in the presence and absence of the proton pump inhibitor esomeprazole.

Trazpiroben, a dopamine D2 /D3 receptor antagonist under development to treat gastroparesis, displays decreasing solubility with increasing pH. This single-sequence, open-label, two-period, crossover study evaluated the effect of esomeprazole, a proton pump inhibitor that raises gastric pH, on the single-dose pharmacokinetics, safety, and tolerability of trazpiroben in healthy adults (NCT03849690). In total, 12 participants were enrolled and entered period 1 (days 1-3), receiving a single oral dose of trazpiroben 25 mg on day 1. After a 4-day washout, participants then entered period 2 (days 8-13) and received esomeprazole 40 mg once daily on days 8-12, with a single oral dose of trazpiroben 25 mg co-administered 1 h post esomeprazole dosing on day 11. Geometric mean area under the curve from time 0 extrapolated to infinity (AUC∞ ) and maximum plasma concentration (Cmax ) values were generally similar when trazpiroben was administered alone versus alongside esomeprazole (AUC∞ , 44.03 vs. 38.85 ng h/ml; Cmax , 19.76 vs. 17.24 ng/ml). Additionally, the associated geometric mean ratio (GMR; co-administration: administration alone) 90% confidence intervals (CIs) suggested no clinically meaningful difference between treatment groups (AUC∞ , GMR 0.88, 90% CI 0.78-1.00; Cmax , 0.87, 90% CI 0.70-1.09). Mean apparent first-order terminal elimination half-life values were similar between treatments, illustrating co-administration with esomeprazole had minimal effect on trazpiroben elimination. Trazpiroben was well-tolerated in healthy adults following administration alone and alongside esomeprazole, with no clinically relevant adverse events reported. The lack of evidence of any clinically meaningful drug-drug interaction supports the co-administration of esomeprazole with trazpiroben.

The pharmacokinetics of oral trazpiroben (TAK-906) after organic anion transporting polypeptide 1B1/1B3 inhibition: A phase I, randomized study.

Trazpiroben is a dopamine D2 /D3 receptor antagonist under development for the treatment of gastroparesis. This phase I, open-label, randomized, two-way crossover study (NCT04121078) evaluated the effect of single-dose intravenous rifampin, a potent inhibitor of the organic anion transporting polypeptides (OATPs) 1B1 and 1B3, on the pharmacokinetics and safety of trazpiroben in healthy adults. The utility of coproporphyrin (CP) I and CPIII as biomarkers of OATP inhibition was also assessed. Overall, 12 participants were enrolled and randomized (1:1) into one of two treatment sequences (AB and BA). Participants received either a single oral dose of trazpiroben 25 mg (treatment A) or a single oral dose of trazpiroben 25 mg immediately after a single 30-min intravenous infusion of rifampin 600 mg (treatment B). After a washout period of at least 7 days, participants received the other treatment. Geometric mean area under the curve from time 0 extrapolated to infinity (AUC∞ ) and maximum serum concentration (Cmax ) of plasma trazpiroben were higher in participants receiving treatment B than those receiving treatment A (AUC∞ , 168.5 vs. 32.68 ng*h/ml; Cmax , 89.62 vs. 14.37 ng/ml); corresponding geometric mean ratios (90% confidence interval) showed 5.16 (4.25-6.25) and 6.24 (4.62-8.42)-fold increases in these parameters, respectively. In this study, trazpiroben was confirmed as a substrate of OATP1B1/1B3, and therefore co-administration of trazpiroben with moderate to strong inhibitors of OATP1B1/1B3 is not recommended. This is also the first assessment of the utility of CPI and CPIII as endogenous biomarkers of OATP1B1/1B3 inhibition after a single intravenous dose of rifampin.

Inhibitory Effect of Vonoprazan on the Metabolism of [14C]Prasugrel in Human Liver Microsomes.

BACKGROUND AND OBJECTIVES: A recent report indicated that the pharmacodynamic interaction between clopidogrel and vonoprazan leading to attenuation of the anti-platelet effect of clopidogrel was unlikely to be caused by the inhibition of cytochrome P450 (CYP) 2B6, CYP2C19, or CYP3A4/5 by vonoprazan, based on in vitro CYP inhibition data. The current report investigates another important antiplatelet inhibitor, prasugrel, that is also activated through metabolism by CYP2B6, CYP2C19 and CYP3A4/5, for its CYP-based DDI potential with vonoprazan. The report describes in vitro metabolic inhibition assessments using radiolabeled prasugrel and human liver microsomes (HLMs). METHODS: Reversible and time-dependent inhibition studies of vonoprazan as well as esomeprazole on the formation of the active metabolite R-138727 of prasugrel were conducted using HLMs. RESULTS: Vonoprazan up to 10 µM, a concentration over 100-fold higher than the clinical maximum plasma concentration (Cmax) of 75.9 nM after 20 mg once daily for 7 days, did not significantly affect the formation of R-138727 from [14C]prasugrel via reversible or time-dependent inhibition. CONCLUSIONS: The in vitro data show that the pharmacodynamic interaction reported in the literature between vonoprazan and prasugrel is unlikely to be caused by CYP inhibition by vonoprazan. The results were similar to those obtained from the study with clopidogrel.

In Vitro Assessment of Potential for CYP-Inhibition-Based Drug-Drug Interaction Between Vonoprazan and Clopidogrel.

BACKGROUND AND OBJECTIVES: It was recently proposed that CYP-mediated drug-drug interactions (DDIs) of vonoprazan with clopidogrel and prasugrel can attenuate the antiplatelet actions of the latter two drugs. Clopidogrel is metabolized to the pharmacologically active metabolite H4 and its isomers by multiple CYPs, including CYP2C19 and CYP3A4. Therefore, to investigate the possibility of CYP-based DDIs, in vitro metabolic inhibition studies using CYP probe substrates or radiolabeled clopidogrel and human liver microsomes (HLMs) were conducted in this work. METHODS: Reversible inhibition studies focusing on the effects of vonoprazan on CYP marker activities and the formation of the [14C]clopidogrel metabolite H4 were conducted with and without pre-incubation using HLMs. Time-dependent inhibition (TDI) kinetics were also measured. RESULTS: It was found that vonoprazan is not a significant direct inhibitor of any CYP isoforms (IC50 ≥ 16 µM), but shows the potential for TDI of CYP2B6, CYP2C19, and CYP3A4/5. This TDI was weaker than the inhibition induced by the corresponding reference inhibitors ticlopidine, esomeprazole, and verapamil, based on the measured potencies (kinact/KI ratio and the R2 value). In a more direct in vitro experiment, vonoprazan levels of up to 10 µM (a 100-fold higher concentration than the plasma Cmax of 75.9 nM after taking 20 mg once daily for 7 days) did not suppress the formation of the active metabolite H4 or other oxidative metabolites of [14C]clopidogrel in a reversible or time-dependent manner. Additionally, an assessment of clinical trials and post-marketing data suggested no evidence of a DDI between vonoprazan and clopidogrel. CONCLUSIONS: The body of evidence shows that the pharmacodynamic DDI reported between vonoprazan and clopidogrel is unlikely to be caused by the inhibition of CYP2B6, CYP2C19, or CYP3A4/5 by vonoprazan.

UDP-glucuronosyltransferase 2B15 (UGT2B15) is the major enzyme responsible for sipoglitazar glucuronidation in humans: retrospective identification of the UGT isoform by in vitro analysis and the effect of UGT2B15*2 mutation.

Recently, genotyping in clinical studies has revealed that UGT2B15 genetic polymorphism has an influence on the clinical pharmacokinetics of sipoglitazar. In this study, the UGT responsible for sipoglitazar was retrospectively identified by in vitro analysis. A study using UGT-expressing supersomes revealed that sipoglitazar glucuronidation was more extensively catalyzed by UGT1A1, 1A3, 1A6, 2B4, and 2B15 than by other UGTs. Enzyme kinetic studies for sipoglitazar glucuronidation and recent findings related to mRNA expression analysis of UGTs narrowed the involved isoforms down to UGT1A1 and UGT2B15 among these five human UGTs. In a correlation study between sipoglitazar glucuronidation and UGT isoform-specific activities, the glucuronidation of S-oxazepam, a specific substrate for UGT2B15, strongly correlated with that of sipoglitazar, as compared with that of ß-estradiol, a representative UGT1A1 substrate. The analysis of the species difference strengthens the possibility of UGT2B15 rather than that of UGT1A1. These in vitro findings indicate that UGT2B15 is principally responsible for sipoglitazar glucuronidation. Moreover, the UGT2B15*2 mutation significantly increased the Km value of sipoglitazar in the kinetic analysis using recombinant His-tag UGT2B15*1- or *2-membrane fractions. These results show that sipoglitazar is a good example to elucidate the relationship between phenotype and genotype for UGT2B15 from in vitro analysis.

Metabolic fate of sipoglitazar, a novel oral PPAR agonist with activities for PPAR-γ, -α and -δ, in rats and monkeys and comparison with humans in vitro.

Sipoglitazar is a novel anti-diabetic agent with triple agonistic activities on the human peroxisome proliferator-activated receptors, hPPAR-γ, -α, and -δ. The bioavailability for sipoglitazar was 95.0% and 72.6% in rats and monkeys respectively and sipoglitazar is hardly subject to first pass metabolism in either species. Following oral administration of [¹4C]sipoglitazar to rats, sipoglitazar and its metabolites were distributed to the rat tissues with relatively high concentrations in the liver and also to the target tissue, the adipose tissue. The major component was sipoglitazar in the plasma of rats and monkeys. In rats, sipoglitazar was mainly excreted into the feces via biliary excretion as sipoglitazar-G, while the major component was M-I-G in the urine and M-I in the feces of monkeys. In hepatocytes, the metabolism was not extensively advanced in rats and the main metabolites were M-I and sipoglitazar-G in humans, similar to the metabolic profile in monkeys. There was no metabolite specific for humans in vitro. In conclusion, the formation of M-I, M-I-G and sipoglitazar-G is considered to be crucial and sipoglitazar is presumed to be cleared primarily by oxidation and glucuronidation in humans, when examined in vivo and in vitro.