V2 (Dynamic)v1.0

Neural ODE

Simulates how a tumor responds to treatment over time

Architecture
Continuous-Time Neural ODE with Adjoint Backprop
PDX Validation R²
0.91

Fit to patient-derived xenograft growth curves

Target: > 0.85
Emulator Fidelity
0.997

Fast emulator matches numerical solver

Target: > 0.99
Solver Stability
100%

No NaN/Inf in 10,000 simulations

Target: 100%
Speed
< 50ms

Single trajectory inference time

Target: < 100ms
Physics Violations
< 0.1%

Predictions that violate biological constraints

Target: < 1%

Overview

A physics-based simulation — like the equations that describe population dynamics in ecology — but parameterized individually for each patient. It models tumor growth, drug effect, and immune response as competing forces over time. Given a patient's parameters and a treatment schedule, it simulates what happens over the next 12-18 months: when does the tumor respond, when does resistance emerge, and through which mechanism. Supports sequential treatments, combinations, and pulsed chemotherapy schedules.

Inputs

5 inputs
N0[K]

Initial clone populations

Source: hypernet
rho[K]

Clone growth rates

Source: hypernet
beta[K, D]

Drug sensitivity coefficients

Source: hypernet
omega[1]

Immune killing coefficient

Source: hypernet
treatment_schedule[T, D]

Drug dosing over time

Source: Clinical input

Outputs

3 outputs
trajectory[T, K]

Clone populations over time

Consumers: evosim
tumor_burden[T]

Total tumor burden over time

clone_fractions[T, K]

Relative clone proportions

Consumers: evosim

Mathematical Formulation

Tumor Dynamics

Lotka-Volterra with drug and immune effects

Immune Dynamics

Immune effector cell dynamics

Adjoint Equation

Backward sensitivity for gradients

Key Features

  • Lotka-Volterra competition dynamics
  • Drug effect as multiplicative kill term
  • Immune effect as predator-prey interaction
  • Dopri5 adaptive solver
  • Adjoint method for O(1) memory backprop

Key Innovations

  • 1Interpretable ODE dynamics with biological meaning
  • 2Treatment schedule integration in continuous time
  • 3Stable numerical integration with adaptive stepping
  • 4Gradient computation without storing full trajectory

Hyperparameters

Solver
Dopri5 (adaptive RK4/5)
rtol
1e-5
atol
1e-6
Max Steps
10,000
Adjoint
True
dt_min
1e-6

Training Details

ODE parameters come from Hypernet. Neural ODE is differentiable end-to-end via adjoint sensitivity. Trained jointly with Hypernet using survival and trajectory losses.

Pipeline Position