The European Medicines Agency (EMEA) has granted GlaxoSmithKline conditional approval to sell their Tykerb for breast cancer, the most common cancer in women. The drug will be marketed under the brand name Tyverb and contains lapatinib.

"Lapatinib represents an important new treatment option for a group of patients in real need of alternative therapies," Martine Piccart, a professor of oncology at Universite Libre de Bruxelles in Brussels, said in a statement released by GlaxoSmithKline.

Lapatinib must be used in patients with advanced metastatic breast cancer in conjunction with other chemotherapy drugs. The EMEA decision is based on results from a Phase III trial. The data showed that the median time to progression (TTP) was 23.9 weeks in patients who took lapatinib and capecitabine versus 18.3 weeks in those who received capecitabine alone.

"This positive opinion is fantastic news for eligible women with ErbB2-positive breast cancer across the European Union. Thousands of women are diagnosed every year in Europe with ErbB2 positive breast cancer and are at a greater risk of disease progression and death compared to women with tumours that do not overexpress this protein," Dr. Piccart said.

ErbB2, also known as HER2/neu, is an epidermal growth factor receptor protein involved in the signal transduction pathways leading to cell growth and differentiation.

Lapatinib inhibits both the epidermal growth factor receptor (EGFR) and the HER2/neu. The amplification of the HER2/neu gene or the overexpression of its protein product have been tied with increased disease recurrence and significantly worse prognosis in breast cancer.

The conditional approval granted by the European Medicines Agency is valid for one year, and it expects more information about the medicine and its effectiveness. Glaxo has announced it will provide the European regulator a data from a late-stage trial and will also conduct an additional study on brain tumors in breast-cancer patients.

Lapatinib is already marketed in the US as Tykerb since March 13, 2007, for use in patients with advanced metastatic breast cancer in conjunction with the chemotherapy drug capecitabine.