Loewe

class synergy.combination.Loewe(mode='CI', drug1_model=None, drug2_model=None, **kwargs)[source]

The Loewe additivity non-parametric synergy model for combinations of two drugs.

The Loewe model is used to calculate a dose-dependent scalar value of synergy. Multiple modes are supported:

  • mode=”CI” (default) - calculates synergy using an equation equivalent to combination index

  • mode=”delta_HSA” - calculates synergy as the difference between the measured values and an expected values,

  • mode=”delta_weakest” - calculates synergy as the difference between the measured values and an expected values

  • mode=”delta_nan” - calculates synergy as the difference between the measured values and an expected values,

All delta modes require that the single drug models be Hill models. The CI mode can be used with any single drug models.

All delta modes are identical except for how they handle the case where the effect of one drug exceeds the max effect of the other. “HSA” sets the expected response to be the stronger drug’s effect. “weakest” sets the expected response to be Emax of the weakest drug. “nan” sets the expected response to be nan.

In CI mode, 0 <= Loewe < 1 indicates synergism, while Loewe > 1 indicates antagonism In the delta modes, Loewe > 0 indicates synergism, while Loewe < 0 indicates antagonism

E_reference(d1, d2)[source]

Return the expected effect of the combination of drugs at doses d1 and d2.

Parameters:

  • d1 (ArrayLike) – Concentration of drug 1

  • d2 (ArrayLike) – Concentration of drug 2

Return ArrayLike:

Reference (additive) values of E at the given doses

fit(d1, d2, E, **kwargs)

Fit the model to data.

Parameters:

  • d1 (ArrayLike) – Concentration of drug 1

  • d2 (ArrayLike) – Concentration of drug 2

  • E (ArrayLike) – Effect of the combination of drugs at doses d1 and d2

  • kwargs (dict) –

    • use_jacobian: whether to use the model jacobian when fitting single-drug models

    • Additional keyword arguments for scipy.optimize.curve_fit()

Return ArrayLike:

Synergy values

property is_fit

True if the model has been fit to data.

property is_specified

True if each single-drug model is specified.