Modeling Efalizumab Pharmacokinetic and Pharmacodynamic
Aspects in Psoriasis
Title: Pharmacokinetic-pharmacodynamic-efficacy
analysis of efalizumab in patients with moderate to severe psoriasis.
Authors: Ng CM, et al.
Publication: Pharm Res. 2005 Jul;22(7):1088-100.
Epub 2005 Jul 22.
Efalizumab is a human anti-CD11a antibody that has demonstrated
efficacy in psoriasis treatment. The author wanted to determine
the pharmacokinetic and pharmacodynamic efficiency of efalizumab
and its interaction with CD11a T cells.
To do this, the authors analyzed a total of 6,329 blood samples
taken from 240 patients in five Phase I and II clinical studies.
The authors used:
- The plasma or blood concentration of efalizumab to measure
its pharmacokinetic aspect
- Amount of CD11a before treatment to measure the drug’s
pharmacodynamic aspect
- Psoriasis Area and Severity Index (PASI) as a measure of the
efficacy of treatment.
The authors found that the rate of psoriasis lesions is directly
proportional to the amount of free surface CD11a on T cells, which
is offset by the rate of skin healing. The authors were able to
develop a pharmacokinetic-pharmacodynamic model which suggested
that administering less efalizumab more frequently would result
in better convenience with similar efficacy.
Editor’s Note: pharmacokinetic refers to the
process by which a drug is absorbed, distributed, metabolized
and then eliminated from the body. Pharmacodynamic refers to the
action or effects of drugs in the body.
T cells are a subset of white blood cells that mature in the
thymus and regulate the body’s immune system by recognizing
specific antigens.
