Pharmacokinetics, mass balance, and metabolism of [14C]vicagrel, a novel irreversible P2Y12 inhibitor in humans

Application of Electro-Activated Dissociation Fragmentation Technique to Identifying Glucuronidation and Oxidative Metabolism Sites of Vepdegestrant by Liquid Chromatography-High Resolution Mass Spectrometry

Drug metabolite identification is an integrated part of drug metabolism and pharmacokinetics studies in drug discovery and development. Definitive identification of metabolic modification sides of test compounds such as screening metabolic soft spots and supporting metabolite synthesis are often required. Currently, liquid chromatography-high resolution mass spectrometry is the dominant analytical platform for metabolite identification. However, the interpretation of product ion spectra generated by commonly used collision-induced disassociation (CID) and higher-energy collisional dissociation (HCD) often fails to identify locations of metabolic modifications, especially glucuronidation. Recently, a ZenoTOF 7600 mass spectrometer equipped with electron-activated dissociation (EAD-HRMS) was introduced. The primary objective of this study was to apply EAD-HRMS to identify metabolism sites of vepdegestrant (ARV-471), a model compound that consists of multiple functional groups. ARV-471 was incubated in dog liver microsomes and 12 phase I metabolites and glucuronides were detected. EAD generated unique product ions via orthogonal fragmentation, which allowed for accurately determining the metabolism sites of ARV-471, including phenol glucuronidation, piperazine N-dealkylation, glutarimide hydrolysis, piperidine oxidation, and piperidine lactam formation. In contrast, CID and HCD spectral interpretation failed to identify modification sites of three O-glucuronides and three phase I metabolites. The results demonstrated that EAD has significant advantages over CID and HCD in definitive structural elucidation of glucuronides and phase I metabolites although the utility of EAD-HRMS in identifying various types of drug metabolites remains to be further evaluated. SIGNIFICANCE STATEMENT: Definitive identification of metabolic modification sites by liquid chromatography-high resolution mass spectrometry is highly needed in drug metabolism research, such as screening metabolic soft spots and supporting metabolite synthesis. However, commonly used collision-induced dissociation (CID) and higher-energy collisional dissociation (HCD) fragmentation techniques often fail to provide critical information for definitive structural elucidation. In this study, the electron-activated dissociation (EAD) was applied to identifying glucuronidation and oxidative metabolism sites of vepdegestrant, which generated significantly better results than CID and HCD.

Influence of Genetic and Epigenetic Factors of P2Y12 Receptor on the Safety and Efficacy of Antiplatelet Drugs

PURPOSE

P2Y12 receptor inhibitors are drugs that decrease the risk of stent thrombosis and lower the long-term risk of non-stent-related myocardial infarction and stroke. They inhibit the binding of adenosine diphosphate (ADP) to the P2Y12 receptor and effectively reduce platelet reactivity. However, considerable variability in the pharmacodynamics response contributes to a failure of antiplatelet therapy; this phenomenon is especially notorious for older drugs, such as clopidogrel. Some genetic polymorphisms associated with these drugs' metabolic pathway, especially in the CYP2C19 gene, can significantly decrease antiplatelet efficacy. There are few reports on the variability stemming from the target of this drug class that is the P2Y12 receptor itself.

RESULTS AND CONCLUSION

This review summarizes the results of research that focus on the influence of P2Y12 genetic polymorphisms on the pharmacodynamics and the efficacy of P2Y12 inhibitors. We found that the conclusions of the studies are unequivocal, and despite several strong candidates, such as G52T (rs6809699) or T744C (rs2046934), they may not be independent predictors of the inadequate response to the drug. Most probably, P2Y12 genetic polymorphisms contribute to the effect exerted by other gene variants (such as CYP2C19*2/*3/*17), drug interactions, or patient habits, such as smoking. Also, epigenetic modifications, such as methylation or miRNA levels, may play a role in the efficacy of antiplatelet treatment.

Metabolism investigation of the peptide-drug conjugate LN005 in rats using UHPLCHRMS

LN005, as a peptide-drug conjugate (PDC), is a conjugate of the homing peptide VAP and doxorubicin (DOX). The exceptional targeting ability of the homing peptide VAP is directed toward glucose-regulated protein (GRP78), a highly expressed protein primarily found in the endoplasmic reticulum of various solid tumors. However, there are limited reports regarding the metabolism of peptide-drug conjugates (PDCs), and the in vivo metabolism of LN005 has yet to be investigated. After intravenous injection of 18 mg/kg LN005 in SD rats, biological samples including plasma, urine, fecal, and bile samples, were collected and analyzed by ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). A total of 11 possible metabolites of LN005 were identified. Unchanged LN005 was found to be the main component in rat blood and urine, accounting for 46.46% and 63.79% of the total peak areas, respectively. M1057 was the most abundant metabolite in feces, accounting for 57.65% of the total peak area. Only one metabolite, M398, was identified in rat bile. The metabolism of LN005 is closely related to DOX, and the primary metabolic pathways involved oxidative deamination or hydrolysis, reductive glycosidic cleavage, hydrolytic glycosidic cleavage, and dehydrogenation.

Absorption, Distribution, Metabolism, and Excretion of [14C]BS1801, a Selenium-Containing Drug Candidate, in Rats

BS1801 is a selenium-containing drug candidate with potential for treating liver and lung fibrosis. To fully elucidate the biotransformation of BS1801 in animals and provide sufficient preclinical drug metabolism data for human mass balance study, the metabolism of BS1801 in rats was investigated. We used radiolabeling techniques to investigate the mass balance, tissue distribution, and metabolite identification of BS1801 in Sprague-Dawley/Long-Evans rats after a single oral dose of 100 mg/kg (100 μCi/kg) [14C]BS1801: 1. The mean recovery of radioactive substances in urine and feces was 93.39% within 168 h postdose, and feces were the main excretion route. 2. Additionally, less than 1.00% of the dose was recovered from either urine or bile. 3. BS1801-related components were widely distributed throughout the body. 4. Fifteen metabolites were identified in rat plasma, urine, feces, and bile, and BS1801 was detected only in feces. 5. BS1801-M484, the methylation product obtained via a N-Se bond reduction in BS1801, was the most abundant drug-related component in plasma. The main metabolic pathways of BS1801 were reduction, amide hydrolysis, oxidation, and methylation. Overall, BS1801 was distributed throughout the body, and excreted mainly as an intact BS1801 form through feces. No differences were observed between male and female rats in distribution, metabolism, and excretion of BS1801.

Pharmacokinetics, Mass Balance and Metabolism of [14C]HSK21542, a Novel Kappa Opioid Receptor Agonist, in Humans

BACKGROUND AND OBJECTIVE

HSK21542, a synthetic short-chain polypeptide, is a selective peripheral kappa opioid receptor (KOR) agonist. In this single-centre, non-randomized, open-label study, the pharmacokinetics, mass balance, metabolism and excretion of HSK21542 were investigated.

METHODS

A single intravenous dose of 2 μg/0.212 μCi/kg [14C]HSK21542 was administered to six healthy male subjects. Samples of blood, urine and faeces were collected for quantitative determination of total radioactivity and unchanged HSK21542, and identification of metabolites.

RESULTS

The mean total recovery was 81.89% of the radiolabelled dose over 240 h post-dose, with 35.60% and 46.30% excreted in faeces and urine, respectively. The mean maximum concentration (Cmax), the half-life (t1/2) and the area under the concentration-time curve (AUC0-t) of total radioactivity (TRA) in plasma were 20.4 ±4.16 ng Eq./g, 1.93 ± 0.322 h and 21.8 ± 2.93 h·ng Eq./g, respectively, while the Cmax, t1/2 and the AUC0-t of unchanged HSK21542 were 18.3 ± 3.36 ng/mL, 1.66 ± 0.185 h and 18.4 ± 2.24 h·ng/mL, respectively. The blood-to-plasma ratios of TRA at several times ranged from 0.46 to 0.54. [14C]HSK21542 was detected as the main circulating substance in plasma, accounting for 92.17% of the AUC of TRA. The unchanged parent compound was the only major radioactive chemical in urine (100.00% of TRA) and faeces (93.53% of TRA). Metabolites were very minor components.

CONCLUSIONS

HSK21542 was barely metabolized in vivo and mainly excreted with unchanged HSK21542 as its main circulating component in plasma. It was speculated that renal excretion was the principal excretion pathway, and faecal excretion was the secondary pathway.

CLINICAL TRIAL REGISTRATION NUMBER

NCT05835934.

A mass balance study of [14C]SHR6390 (dalpiciclib), a selective and potent CDK4/6 inhibitor in humans

SHR6390 (dalpiciclib) is a selective and effective cyclin-dependent kinase (CDK) 4/6 inhibitor and an effective cancer therapeutic agent. On 31 December 2021, the new drug application was approved by National Medical Product Administration (NMPA). The metabolism, mass balance, and pharmacokinetics of SHR6390 in 6 healthy Chinese male subjects after a single oral dose of 150 mg [14C]SHR6390 (150 µCi) in this research. The Tmax of SHR6390 was 3.00 h. In plasma, the t1/2 of SHR6390 and its relative components was approximately 17.50 h. The radioactivity B/P (blood-to-plasma) AUC0-t ratio was 1.81, indicating the preferential distribution of drug-related substances in blood cells. At 312 h after administration, the average cumulative excretion of radioactivity was 94.63% of the dose, including 22.69% in urine and 71.93% in stool. Thirteen metabolites were identified. In plasma, because of the low level of radioactivity, only SHR6390 was detected in pooled AUC0-24 h plasma. Stool SHR6390 was the main component in urine and stool. Five metabolites were identified in urine, and 12 metabolites were identified in stool. Overall, faecal clearance is the main method of excretion.

Mass balance study of [14C]SHR0302, a selective and potent JAK1 inhibitor in humans

SHR0302, a selective JAK1 inhibitor developed by Jiangsu Hengrui Pharmaceutical Co., was intended for the treatment of rheumatoid arthritis. In this study, we evaluated the pharmacokinetics, mass balance, and metabolism of SHR0302 in six healthy Chinese male subjects after a single 8 mg (80 µCi) oral dose of [¹⁴C]SHR0302.SHR0302 was absorbed rapidly (T_max = 0.505 h), and the average t_1/2 of the SHR0302-related components in plasma was approximately 9.18 h. After an oral dose was administered, the average cumulative excretion of the radioactive components was 100.56% ± 1.51%, including 60.95% ± 11.62% in urine and 39.61% ± 10.52% in faeces.A total of 16 metabolites were identified. In plasma, the parent drug SHR0302 accounted for 90.42% of the total plasma radioactivity. In urine, SHR161279 was the main metabolite, accounting for 33.61% of the dose, whereas the parent drug SHR0302 only accounted for 5.1% of the dose. In faeces, the parent drug SHR0302 accounted for 23.73% of the dose, and SHR161279 was the significant metabolite, accounting for 5.67% of the dose. In conclusion, SHR0302-related radioactivity was mainly excreted through urine (60.95%) and secondarily through faeces (39.61%).The metabolic reaction of SHR0302 in the human body is mainly through mono-oxidation and glucuronidation. The main metabolic location of SHR0302 in the human body is the pyrrolopyrimidine ring.

Pharmacokinetics, mass balance, and metabolism of [14C]TPN171, a novel PDE5 inhibitor, in humans for the treatment of pulmonary arterial hypertension

TPN171 is a novel phosphodiesterase-5 (PDE5) inhibitor used to treat pulmonary arterial hypertension (PAH) and erectile dysfunction (ED), which currently is undergoing phase II clinical trials in China. In this single-center, single-dose, nonrandomized, and open design study, radiolabeled [¹⁴C]TPN171 was used to investigate the metabolic mechanism, pharmacokinetic characteristics, and clearance pathways of TPN171 in 6 healthy Chinese male volunteers. Each volunteer was administered a single oral suspension of 10 mg (100 μCi) of [¹⁴C]TPN171. We found that TPN171 was absorbed rapidly in humans with a peak time (T_max) of 0.667 h and a half-life (t_1/2) of approximately 9.89 h in plasma. Excretion of radiopharmaceutical-related components was collected 216 h after administration, accounting for 95.21% of the dose (46.61% in urine and 48.60% in feces). TPN171 underwent extensive metabolism in humans. Twenty-two metabolites were detected in human plasma, urine, and feces using a radioactive detector combined with a high-resolution mass spectrometer. According to radiochromatograms, a glucuronide metabolite of O-dealkylated TPN171 exceeded 10% of the total drug-related components in human plasma. However, according to the Food and Drug Administration (FDA) guidelines, no further tests are needed to evaluate the safety of this metabolite because it is a phase II metabolite, but the compound is still worthy of attention. The main metabolic biotransformation of TPN171 was mono-oxidation (hydroxylation and N-oxidation), dehydrogenation, N-dealkylation, O-dealkylation, amide hydrolysis, glucuronidation, and acetylation. Cytochrome P450 3A4 (CYP3A4) mainly catalyzed the formation of metabolites, and CYP2E1 and CYP2D6 were involved in the oxidative metabolism of TPN171 to a lesser extent. According to the incubation data, M1 was mainly metabolized to M1G by UDP-glucuronosyltransferase 1A9 (UGT1A9), followed by UGT1A7 and UGT1A10.

Antiplatelet effect, safety, and pharmacokinetics of vicagrel in patients with coronary artery disease undergoing percutaneous coronary intervention

AIMS

Vicagrel, a novel antiplatelet prodrug to overcome the residual high platelet reactivity of clopidogrel induced by inactive metabolism and cytochrome P450 (CYP) 2C19 polymorphisms, provides favourable antiplatelet inhibition in healthy volunteers. However, its antiplatelet effect and safety in patients with coronary artery disease (CAD) are unclear.

METHODS AND RESULTS

This was a multicentre, randomized, double-blind, triple-dummy, dose-exploring phase II trial comparing the antiplatelet activity and safety of vicagrel at different doses vs. those of clopidogrel in patients with CAD undergoing percutaneous coronary intervention (PCI). The primary endpoint was inhibition of adenosine diphosphate (ADP)-induced platelet aggregation (%IPA) after loading and maintenance doses (LD/MD) at 28 days. Safety endpoints included adverse events (AEs) and Bleeding Academic Research Consortium-defined any bleeding. Pharmacokinetic (PK) profiles and the influence of CYP2C19 polymorphisms were explored in subgroup analysis. Two hundred and seventy-nine patients diagnosed with stable CAD (51.97%), unstable angina (40.86%), and myocardial infarction (7.17%) were randomized to receive vicagrel 20/5 mg (LD/MD), 24/6 mg, or 30/7.5 mg or clopidogrel 300/75 mg in combination with aspirin. %IPAs on Day 28 were 30.19%, 35.02%, 45.61%, and 32.55% for vicagrel 20/5, 24/6, and 30/7.5 mg and clopidogrel, respectively, and were comparable across all groups (P = 0.0694). The plasma concentration of the vicagrel active metabolite M15-2 had a similar area under curve and Tmax to those of clopidogrel. There were no significant differences in AEs (4.35%, 0%, 1.45%, and 5.56% for vicagrel 20/5, 24/6, and 30/7.5 mg and clopidogrel, P = 0.6667) or any bleeding (13.04%, 14.06%, 11.59%, and 11.11% for vicagrel 20/5, 24/6, and 30/7.5 mg and clopidogrel, respectively, P = 0.95) across four groups. %IPAs and PK profiles of vicagrel did not vary significantly among different CYP2C19 metabolizers.

CONCLUSION

Vicagrel had comparable antiplatelet effect and safety to clopidogrel in patients with CAD undergoing PCI.

Inhibition of calpain reduces cell apoptosis by suppressing mitochondrial fission in acute viral myocarditis

Cardiomyocyte apoptosis is critical for the development of viral myocarditis (VMC), which is one of the leading causes of cardiac sudden death in young adults. Our previous studies have demonstrated that elevated calpain activity is involved in the pathogenesis of VMC. This study aimed to further explore the underlying mechanisms. Neonatal rat cardiomyocytes (NRCMs) and transgenic mice overexpressing calpastatin were infected with coxsackievirus B3 (CVB3) to establish a VMC model. Apoptosis was detected with flow cytometry, TUNEL staining, and western blotting. Cardiac function was measured using echocardiography. Mitochondrial function was measured using ATP assays, JC-1, and MitoSOX. Mitochondrial morphology was observed using MitoTracker staining and transmission electron microscopy. Colocalization of dynamin-related protein 1 (Drp-1) in mitochondria was examined using immunofluorescence. Phosphorylation levels of Drp-1 at Ser637 site were determined using western blotting analysis. We found that CVB3 infection impaired mitochondrial function as evidenced by increased mitochondrial ROS production, decreased ATP production and mitochondrial membrane potential, induced myocardial apoptosis and damage, and decreased myocardial function. These effects of CVB3 infection were attenuated by inhibition of calpain both by PD150606 treatment and calpastatin overexpression. Furthermore, CVB3-induced mitochondrial dysfunction was associated with the accumulation of Drp-1 in the outer membrane of mitochondria and subsequent increase in mitochondrial fission. Mechanistically, calpain cleaved and activated calcineurin A, which dephosphorylated Drp-1 at Ser637 site and promoted its accumulation in the mitochondria, leading to mitochondrial fission and dysfunction. In summary, calpain inhibition attenuated CVB3-induced myocarditis by reducing mitochondrial fission, thereby inhibiting cardiomyocyte apoptosis.