PKPDTMDD

Rituximab exposure and CD19-positive B-cell dynamics

A coupled PK/PD model linking circulating rituximab to CD19-positive B-cell depletion, cell-dependent drug loss, and gradual B-cell repopulation.

Explore and simulate

Therapeutic: Rituximab, RTX
Target: CD20 / MS4A1
Disease: Multiple sclerosis

Biological model

A coupled PK/PD model linking circulating rituximab to CD19-positive B-cell depletion, cell-dependent drug loss, and gradual B-cell repopulation.

Biological schematic for Rituximab exposure and CD19-positive B-cell dynamics — Biology-first schematic of the model structure.

Model details

A coupled PK/PD model linking circulating rituximab to CD19-positive B-cell depletion, cell-dependent drug loss, and gradual B-cell repopulation.

Modeled states

Cmg/L

Modeled dynamic state for c.
Lcell/millimeter^3

Modeled dynamic state for l.
elapsed dayday

Modeled dynamic state for elapsed day.

Key readouts

Rituximab concentrationmg/L

Model-derived readout for rituximab concentration.
CD19-positive B cellscell/millimeter^3

Model-derived readout for cd19-positive b cells.
Linear rituximab lossmg/L/day

Model-derived readout for linear rituximab loss.
B-cell-dependent rituximab lossmg/L/day

Model-derived readout for b-cell-dependent rituximab loss.
Cmg/L

Model-derived readout for c.

Explore this model

Choose a starting point to view its result. Adjust key model inputs when you want to explore a different outcome.

Starting configuration

Typical 1000 mg exposure and B-cell response

How does rituximab exposure control the depth and duration of B-cell depletion and repopulation? Explore this biological starting configuration through Rituximab concentration, CD19-positive B cells, Linear rituximab loss, B-cell-dependent rituximab loss. This is a mechanistic product exploration, not a paper-result reproduction.

Questions to explore

How does rituximab exposure control the depth and duration of B-cell depletion and repopulation?

Starting result

This result reflects the starting settings. Run your changes to update it.

This scenario result is temporarily unavailable.

Model inputs

Five scientist-facing controls at most.

cl day Model parameter controlling cl day. 1/daykdeg1 mm3 mg day Model parameter controlling kdeg1 mm3 mg day. millimeter^3/(cell*day)kdeg2 l mg day Model parameter controlling kdeg2 l mg day. L/(mg*day)kout day Model parameter controlling kout day. 1/dayL0 cells mm3 Model parameter controlling l0 cells mm3. cell/millimeter^3

Compare a parameter

How does one model input change the response?

How does rituximab exposure control the depth and duration of B-cell depletion and repopulation?

Parameter to compare

cl day

Model parameter controlling cl day.

Exploratory range around the default value.

Low High Points

5 evenly spaced values in 1/day. Other model inputs and the simulation window stay fixed.

Interpret with care

Interpret trajectories as deterministic model behavior, not as a patient-specific prediction or dosing recommendation.
Paper-result and exact-anchor checks remain in the private validation lane and are not part of this public scenario.

Review the server-confirmed fixed price before starting the comparison.

Comparative response

End-of-window response across the selected parameter values.

Choose an exploratory range around the default, review the fixed price, and run the comparison.

Scientific reference

Supporting publication

Pharmacokinetic–pharmacodynamic modelling in a clinical pilot study of rituximab in multiple sclerosis: Towards personalized dosing interval

British Journal of Clinical Pharmacology