[5] In March 2007, the U.S. Food and Drug Administration (FDA) approved lapatinib in combination therapy for breast cancer patients already using capecitabine (Xeloda).

[5] Pharmaceutical company GlaxoSmithKline (GSK) markets the drug under the proprietary names Tykerb (mostly U.S.) and Tyverb (mostly Europe and Russia).

[6] The drug currently has approval for sale and clinical use in the US,[4][6] Australia,[4] Bahrain,[4] Kuwait,[4] Venezuela,[4] Brazil,[7] New Zealand,[7] South Korea,[7] Switzerland,[6] Japan, Jordan, the European Union, Lebanon, India and Pakistan.

[4] Like sorafenib, lapatinib is a protein kinase inhibitor shown to decrease tumor-causing breast cancer stem cells.

The study also reported that risk of disease progression was reduced by 51%, and that the combination therapy was not associated with increases in toxic side effects.

Early clinical trials have been performed suggesting that high dose intermittent lapatinib might have better efficacy with manageable toxicities in the treatment of HER2-overexpressing breast cancers.