General pharmacology PBPK

Pediatric therapeutic-protein PBPK scaling

Reference paper ↗

A reduced pediatric PBPK model connecting body-size-dependent antibody disposition to central and peripheral exposure and optional target binding.

Therapeutic
Palivizumab or bevacizumab, palivizumab; bevacizumab
Modality
Monoclonal antibody
Target
RSV F protein, VEGFA, FcRn
Disease
Pediatric therapeutic-protein dose and exposure scaling
Model type
PBPK

Complete model workspace

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Parameters
18
States
6
Equations
6
Derived outputs
12

Explore this model

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Palivizumab 15 mg/kg nominal-age growth

How does pediatric growth change therapeutic-protein disposition, exposure, and target binding? Explore this intervention regimen through Central antibody concentration, Peripheral antibody concentration, Free target, Drug–target complex, Cumulative exposure.

Starting result

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Starting configuration

Time: 0–120 day; step 1

InputDefaultAvailable range
Body weight7 kg3.5–10.5 kg
Systemic clearance198 mL/day99–297 mL/day
Central distribution volume4.09 L2.045–6.135 L
Intercompartmental clearance879 mL/day439.5–1,319 mL/day
Peripheral distribution volume2.23 L1.115–3.345 L

Expected readouts

Central antibody concentration · Peripheral antibody concentration · Free target concentration (uM) · Drug–target complex concentration (uM) · Exposure (AUC) (ug/mL*day)

Adjustable model parameters

This public explorer exposes 5 curated parameters. Sign in to edit all 18 declared model parameters.

More key parameters (1)

How the model represents the biology

A reduced pediatric PBPK model connecting body-size-dependent antibody disposition to central and peripheral exposure and optional target binding.

How do fixed body size, antibody disposition, and optional target binding shape pediatric exposure?An intravenous antibody dose enters a central compartment and exchanges reversibly with a peripheral compartment while undergoing systemic clearance. Fixed scenario body weight scales clearance, intercompartmental flow, and distribution volumes. An optional free-target module forms and degrades drug–target complex without depleting the antibody PK amount.BIOLOGY OVERVIEWHow do fixed body size, antibody disposition, and optional target binding shapepediatric exposure?IV antibody dosePalivizumab or bevacizumabFixed body weightScenario-specific size scalingCentral antibodyexposureBody-weight-scaled volumePeripheral antibodyReversible distributionSystemic clearanceBody-weight-scaled PK lossOptional free targetTurnover module by scenarioDrug–target complexBinding and degradationPRIMARY READOUTSCentral and peripheral antibodyCentral and peripheral ant…Cumulative exposureCumulative exposureFree targetFree targetDrug–target complexDrug–target complex

Solid arrows show modeled movement or change; two-headed arrows show reversible exchange; dashed arrows show modulation without material transfer.

Model scope: Body weight is fixed within each scenario rather than a dynamic growth trajectory. The model has two PK compartments rather than a 15-organ PBPK system, no named target or clinical PD, and no target-mediated antibody clearance. The entire target module is inactive in palivizumab scenarios.

Modeled relationships (9)
  • IV antibody dose → Central antibody exposure: central bolus (flow)
  • Fixed body weight → Central antibody exposure: scales Vc (modulation)
  • Fixed body weight → Peripheral antibody: scales Q and Vp (modulation)
  • Fixed body weight → Systemic clearance: scales CL (modulation)
  • Central antibody exposure ↔ Peripheral antibody: reversible Q (reversible exchange)
  • Central antibody exposure → Systemic clearance: systemic CL (loss)
  • Central antibody exposure → Drug–target complex: concentration drives kon (modulation)
  • Optional free target → Drug–target complex: kon binding (flow)
  • Drug–target complex → Optional free target: koff returns target (flow)

Modeled relationships: IV antibody dose to Central antibody exposure: central bolus (flow); Fixed body weight to Central antibody exposure: scales Vc (modulation); Fixed body weight to Peripheral antibody: scales Q and Vp (modulation); Fixed body weight to Systemic clearance: scales CL (modulation); Central antibody exposure reversibly exchanges with Peripheral antibody: reversible Q (reversible exchange); Central antibody exposure to Systemic clearance: systemic CL (loss); Central antibody exposure to Drug–target complex: concentration drives kon (modulation); Optional free target to Drug–target complex: kon binding (flow); Drug–target complex to Optional free target: koff returns target (flow).

Primary readouts: Central and peripheral antibody; Cumulative exposure; Free target; Drug–target complex.

Found a scientific issue? Email helpdesk@unibiointelligence.com with model ID pan_2020_pediatric_tp_pbpk_pk_sim.

Research use only — not for patient-specific prediction or dosing advice.

Ubi Biologics