Population pharmacokinetics and pharmacogenetics of apatinib in adult cancer patients.

AIMS: Apatinib is widely used in Chinese cancer patients. As the in vivo drug disposition of apatinib has large individual differences, adverse events are prone to occur. Cytochrome P450 (CYP)3A5 and cancer types maybe the main factors affecting this individual differences. The objective of our study was to establish a population pharmacokinetics (PK) model of apatinib in adult cancer patients, and to explore optimal dosage regimens for individualized treatment. METHODS: Adult patients with various types of cancer treated with apatinib were enrolled. The concentration of apatinib in plasma was determined by high-performance liquid chromatography-tandem mass spectrometry. CYP3A5 genotype was determined using TaqMan allelic discrimination technique. The population PK model was developed by NONMEM V7.4. The dosing regimen was optimized based on Monte Carlo simulations. RESULTS: A population PK model of apatinib in adult cancer patient was established. CYP3A5 genotype and systemic cancer type (digestive system cancers, nondigestive system cancers) were the most significant covariates for PK parameters. Patients with CYP3A5*1 expressers (CYP3A5*1/*1 and CYP3A5*1/*3) had lower apparent clearance and apparent volume of distribution than patients who do not express CYP3A5*1 (CYP3A5*3/*3). Patients with nondigestive system cancer had higher apparent volume of distribution and absorption rate constant than digestive system cancer. The results of dose simulation suggest that the apatinib dose in patients who do not express CYP3A5*1 should be 33.33-50.00% higher than that in CYP3A5*1 expressers. CONCLUSIONS: A population PK model of apatinib in adult cancer patients was established. CYP3A5 genotype and systemic cancer type had concurrent effects on PK parameters. CYP3A5 patients who do not express CYP3A5*1 required higher doses.

Drug-drug interactions of simnotrelvir/ritonavir: an open-lable, fixed-sequence, two-period clinical trial.

OBJECTIVES: Simnotrelvir is a small molecule highly specific 3C-like protease inhibitor for anti-SARS-CoV-2 and was approved as a combination drug with ritonavir (simnotrelvir/ritonavir) in China. Simnotrelvir is a substrate of cytochrome P450 3A (CYP3A) and P-glycoprotein (P-gp), and a weak inhibitor of CYP3A. Ritonavir is a substrate and inhibitor of CYP3A and an inhibitor of P-gp. Hence, the drug-drug interaction (DDI) potential of simnotrelvir/ritonavir should be investigated. METHODS: This DDI study was an open-label, fixed-sequence, two-period Phase I clinical trial in Chinese healthy adult subjects, divided into 3 cohorts, including simnotrelvir/ritonavir co-administrated with a strong CYP3A and P-gp inhibitor (itraconazole) and inducer (rifampicin), and with a specific CYP3A substrate (midazolam). RESULTS: The results demonstrated that compared to administration of simnotrelvir/ritonavir alone, the co-administration with itraconazole increased the geometric least-square mean ratio (GMR) of the expose (AUC0-t) of simnotrelvir by 25% (GMR 125%, 90% confidence interval (CI) 114% - 137%), whereas co-administration with rifampicin significantly decreased the AUC0-t of simnotrelvir by 81.5% (GMR 18.5%, 90% CI 16.4% - 20.9%). Notably, simnotrelvir/ritonavir increased the AUC0-t of midazolam by 16.69-fold (GMR 1769%, 90% CI 1551% - 2018%). The co-administration of simnotrelvir/ritonavir and rifampicin caused the increased amount and severity of treatment-emergent adverse events, especially hepatotoxicity. CONCLUSIONS: The co-administration of simnotrelvir/ritonavir with CYP3A and P-gp inhibitors can be safely used, while the co-administration with CYP3A and P-gp strong inducer should be avoided to minimize the risk of under-exposure. Co-administration of midazolam with simnotrelvir/ritonavir increased systemic exposure of midazolam. GOV IDENTIFIER: NCT05665647.

A first-in-human phase I study of SHR-1906, a humanized monoclonal antibody against connective tissue growth factor, in healthy participants.

New therapeutic targets and drugs are urgently needed to halt the fibrosing process in idiopathic pulmonary fibrosis (IPF). SHR-1906 is a novel fully humanized monoclonal antibody against the connective tissue growth factor, which plays an essential role in the genesis of IPF. We assessed the safety, tolerability, pharmacokinetics (PKs), and immunogenicity of single dose SHR-1906 in healthy participants. This was a randomized, double-blind, placebo-controlled, dose-escalation, phase I study. Twelve healthy participants for each dose level were enrolled to receive single ascending doses of SHR-1906 intravenously (1.5, 6, 12, 20, 30, and 45 mg/kg) or placebo and followed for 71 days. The primary end points were safety and tolerability. Treatment-related treatment-emergent adverse events occurred in 25 participants (46.3%) in the SHR-1906 group and 11 (61.1%) in the placebo group. No serious adverse events occurred. Over the dose range investigated, the geometric mean clearance was 0.14-0.63 mL/h/kg, the geometric mean volume of distribution at steady-state was 47.4-75.5 mL/kg, and the terminal elimination half-life was 51.9-349 h. SHR-1906 showed nonlinear PKs. The peak concentration increased in a dose-proportional manner, whereas the area under the concentration-time curve showed a greater than dose-proportional increase. Anti-drug antibodies of SHR-1906 were detected in nine of 54 participants (16.7%). A single dose of SHR-1906 up to 45 mg/kg demonstrated a favorable tolerability profile in healthy participants. The PKs and immunogenicity of SHR-1906 were evaluated, supporting further clinical development.

Pharmacokinetics and bioavailability of a new long-acting insulin analog in healthy Chinese volunteers: an open, randomized, single-dose, two-period and two-sequence cross-over study.

Objectives: INS068 is a novel, soluble, and long-acting insulin analog. In this study, we evaluated the pharmacokinetics and relative bioavailability of two formulations of INS068 in healthy Chinese subjects: a reference formulation packaged in vials and administered via syringe (R), and a test formulation packaged and administered via pen injector (T). Methods: A randomized, open-label, two-period, two-sequence crossover study was conducted with 24 healthy Chinese subjects. Subjects were randomized and administered subcutaneously in the abdomen at 0.4 U/kg of test or reference INS068 injection according to an open crossover design. INS068 concentrations in the serum were measured using LC-MS/MS, and the pharmacokinetic parameters of maximum concentration (Cmax) and area under the concentration-time curve (AUC0-t and AUC0-∞) were used to evaluate relative bioavailability. Results: After a single dose at 0.4 U/kg, the median Tmax of INS068 was 12 h for both formulations, and the mean t1/2 for T and R was 13.0 h and 12.6 h, respectively. The geometric means of Cmax and AUC0-∞ were 3.99 nmol/L and 120 h·nmol/L for the T, and 4.05 nmol/L and 117 h·nmol/L for the R, respectively. The geometric mean ratios of Cmax, AUC0-t and AUC0-∞ of T over R were 98.7% (90% CI: 92.7%-105.2%), 102.6% (90% CI: 100.0%-105.3%) and 102.8% (90% CI: 100.1%-105.5%). Conclusion: The overall PK profile of the two formulations of INS068 injection was comparable in healthy subjects, and the pen injector of INS068 had adequate safety and tolerability, supporting it as a new formulation in a phase III study and bridging PK data from early phase clinical trials. Clinical Trial Registration: clinicaltrials.gov, identifier: NCT05336071.