Table 1.

Typical goals and objectives for physiologically based pharmacokinetic (PBPK) vs. quantitative systems pharmacology (QSP) models.

Model goals and objectives	Objective class
	PBPK	QSP
FTIH dose prediction	1	2
DDI risk and specific drug interaction potential evaluation	1	N/A (PK interaction) 1 (PD interaction)
FTIP dose prediction	1	2
PK/PD evaluation	1	2
Formulation feasibility/performance evaluation	1	N/A
IVIVC	2	N/A
Biomarker-based evaluation	3	1
Weight/size impact on PK	1	3
Developmental influence on PK	1	3
Proof-of-mechanism evaluation	N/A	1
Proof-of-concept evaluation	N/A	1
Disease progression evaluation	N/A	1

1 = primary; 2 = complementary; 3 = secondary.

FTIH, first time in human; DDI, drug-drug interaction; FTIP, first in patient; PK, pharmacokinetics; PD, pharmacodynamics; IVIVC, in vitro-in vivo correlation; N/A, not applicable.