Population Pharmacokinetics for Pediatric Extrapolation of GenSci006: A 3.75-mg Triptorelin Acetate Microsphere Formulation for Central Precocious Puberty.
Kun Wang, Zhongyi Sun, Fengyan Xu, Lu Liu, Tianhong Luo, Weiwei Gao, Tangping Zhao, Guangli Ma, Xiaoyan Zhu
{"title":"Population Pharmacokinetics for Pediatric Extrapolation of GenSci006: A 3.75-mg Triptorelin Acetate Microsphere Formulation for Central Precocious Puberty.","authors":"Kun Wang, Zhongyi Sun, Fengyan Xu, Lu Liu, Tianhong Luo, Weiwei Gao, Tangping Zhao, Guangli Ma, Xiaoyan Zhu","doi":"10.1007/s40262-026-01634-4","DOIUrl":null,"url":null,"abstract":"<p><strong>Background and objectives: </strong>Triptorelin acetate microspheres are long-acting gonadotropin-releasing hormone (GnRH) agonist used for treating central precocious puberty (CPP). GenSci006 is a newly developed 3.75-mg formulation intended as a local alternative to Diphereline<sup>®</sup>. This study aimed to characterize the pharmacokinetics (PK) of GenSci006 using population pharmacokinetic (PopPK) modeling with pediatric extrapolation, to evaluate pharmacodynamic (PD) comparability, and to support a fixed-dose regimen for CPP.</p><p><strong>Methods: </strong>This study comprised two components: (1) PopPK modeling and model-based simulation to characterize exposure and support pediatric extrapolation; and (2) a comparative pharmacodynamic assessment based on serum luteinizing hormone (LH) responses.</p><p><strong>Results: </strong>The final PopPK model employed a three-compartment structure with mixed sequential absorption phases (two first-order and a zero-order absorption), capturing triptorelin's multiphasic release. Covariates, including weight, age, albumin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), serum creatinine, total bilirubin, and creatinine clearance, showed no significant effect on PK. Allometric scaling (exponents 0.75 for clearance [CL] and 1 for central volume distribution [V<sub>3</sub>]) was applied to simulate pediatric exposure. Simulations indicated that at a fixed 3.75-mg dose, exposure decreased with increasing weight, with an approximately 1.7-fold difference between the 20-30 kg and 40-50 kg groups. In the comparative PD analysis, serum LH exposure profiles were comparable between GenSci006 and the reference product over the 0-672-h assessment period.</p><p><strong>Conclusion: </strong>Model-based simulations predicted approximately two-fold higher exposure in lighter children (20-30 kg) compared with adults. This difference was not clinically meaningful given the plateau PD effect and wide therapeutic range of triptorelin.</p>","PeriodicalId":10405,"journal":{"name":"Clinical Pharmacokinetics","volume":" ","pages":"849-861"},"PeriodicalIF":4.0000,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Clinical Pharmacokinetics","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s40262-026-01634-4","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/4/9 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"PHARMACOLOGY & PHARMACY","Score":null,"Total":0}
引用次数: 0
Abstract
Background and objectives: Triptorelin acetate microspheres are long-acting gonadotropin-releasing hormone (GnRH) agonist used for treating central precocious puberty (CPP). GenSci006 is a newly developed 3.75-mg formulation intended as a local alternative to Diphereline®. This study aimed to characterize the pharmacokinetics (PK) of GenSci006 using population pharmacokinetic (PopPK) modeling with pediatric extrapolation, to evaluate pharmacodynamic (PD) comparability, and to support a fixed-dose regimen for CPP.
Methods: This study comprised two components: (1) PopPK modeling and model-based simulation to characterize exposure and support pediatric extrapolation; and (2) a comparative pharmacodynamic assessment based on serum luteinizing hormone (LH) responses.
Results: The final PopPK model employed a three-compartment structure with mixed sequential absorption phases (two first-order and a zero-order absorption), capturing triptorelin's multiphasic release. Covariates, including weight, age, albumin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), serum creatinine, total bilirubin, and creatinine clearance, showed no significant effect on PK. Allometric scaling (exponents 0.75 for clearance [CL] and 1 for central volume distribution [V3]) was applied to simulate pediatric exposure. Simulations indicated that at a fixed 3.75-mg dose, exposure decreased with increasing weight, with an approximately 1.7-fold difference between the 20-30 kg and 40-50 kg groups. In the comparative PD analysis, serum LH exposure profiles were comparable between GenSci006 and the reference product over the 0-672-h assessment period.
Conclusion: Model-based simulations predicted approximately two-fold higher exposure in lighter children (20-30 kg) compared with adults. This difference was not clinically meaningful given the plateau PD effect and wide therapeutic range of triptorelin.
期刊介绍:
Clinical Pharmacokinetics promotes the continuing development of clinical pharmacokinetics and pharmacodynamics for the improvement of drug therapy, and for furthering postgraduate education in clinical pharmacology and therapeutics.
Pharmacokinetics, the study of drug disposition in the body, is an integral part of drug development and rational use. Knowledge and application of pharmacokinetic principles leads to accelerated drug development, cost effective drug use and a reduced frequency of adverse effects and drug interactions.