Effect of Hepatic Impairment on the Pharmacokinetics and Pharmacodynamics of SHR4640, a Selective Human Urate Transporter 1 Inhibitor

This parallel-group, open-label Phase I study evaluated the effect of mild to moderate hepatic impairment on pharmacokinetics (PK), pharmacodynamics (PD), and safety of a single oral dose of SHR4640. Participants with mild or moderate hepatic impairment were enrolled, with each cohort consisting of eight individuals, alongside eight well-matched controls with normal hepatic function. The participants were administered 10 mg SHR4640, and blood samples were collected for PK evaluation over 72 h. Additionally, serum uric acid (sUA) levels were measured to assess PD changes. Safety was evaluated through adverse events, laboratory tests, vital signs, and electrocardiograms. The Cmax of SHR4640 decreased by 15.0% in the mild hepatic impairment group (geometric least squares means of the ratios [GMR] = 0.850, 90% CI: 0.701-1.03) and by 17.5% in the moderate hepatic impairment group (GMR = 0.825, 90% CI: 0.681-1.00). These reductions were not statistically significant compared to the normal hepatic function group. AUC0-t and AUC0-inf were similar across all groups, indicating that overall exposure to the drug was not clinical significantly affected by hepatic impairment. Apparent clearance and volume of distribution of SHR4640 showed no association with the severity of hepatic impairment as measured by the Child-Pugh score. There were no significant differences in the changes in sUA levels from baseline across different levels of hepatic function. SHR4640 is well tolerated in participants with mild or moderate hepatic impairment. Mild and moderate hepatic impairment did not have a clinically relevant impact on PK, PD, and safety of SHR4640. SHR4640 can be used in patients with mild to moderate hepatic impairment without the need for dose adjustment.

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.