Drug Groups

approved; investigational

Description

Lapatinib is an anti-cancer drug developed by GlaxoSmithKline (GSK) as a treatment for solid tumours such as breast and lung cancer. It was approved by the FDA on March 13, 2007, for use in patients with advanced metastatic breast cancer in conjunction with the chemotherapy drug Capecitabine. Lapatinib is human epidermal growth factor receptor type 2 (HER2/ERBB2) and epidermal growth factor receptor (HER1/EGFR/ERBB1) tyrosine kinases inhibitor. It binds to the intracellular phosphorylation domain to prevent receptor autophosphorylation upon ligand binding.

Indication

Indicated in combination with capecitabine for the treatment of patients with advanced or metastatic breast cancer whose tumors overexpress the human epidermal receptor type 2 (HER2) protein and who have received prior therapy including an anthracycline, a taxane, and trastuzuma.

Pharmacology

Lapatinib is a small molecule and a member of the 4-anilinoquinazoline class of kinase inhibitors. An anti-cancer drug, lapatinib was developed by GlaxoSmithKline (GSK) as a treatment for solid tumours such as breast and lung cancer. It was approved by the FDA on March 13, 2007, for use in patients with advanced metastatic breast cancer in conjunction with the chemotherapy drug capecitabine.

Toxicity

There has been a report of one patient who took 3,000 mg of lapatinib for 10 days. This patient had grade 3 diarrhea and vomiting on day 10.

Affected Organisms

Biotransformation

Lapatinib undergoes extensive metabolism, primarily by CYP3A4 and CYP3A5, with minor contributions from CYP2C19 and CYP2C8 to a variety of oxidated metabolites, none of which accounts for more than 14% of the dose recovered in the feces or 10% of lapatinib concentration in plasma.

Absorption

Absorption following oral administration of lapatinib is incomplete and variable.

Half Life

Single-dose terminal half life: 14.2 hours
Effective multiple-dose half life: 24 hours

Protein Binding

Highly bound (>99%) to albumin and alpha-1 acid glycoprotein

Elimination

Lapatinib undergoes extensive metabolism, primarily by CYP3A4 and CYP3A5, with minor contributions from CYP2C19 and CYP2C8 to a variety of oxidated metabolites, none of which accounts for more than 14% of the dose recovered in the feces or 10% of lapatinib concentration in plasma.

References

External Links