GSK’s Tykerb® receives accelerated approval for first-line combination treatment of hormone receptor positive, HER2+/ErbB2+ metastatic breast cancer

Issued 29 January 2010, Philadelphia PA

GlaxoSmithKline announced today that the U.S. Food and Drug Administration (FDA) has granted accelerated approval for a new combination regimen using Tykerb® (lapatinib) as a first-line, all-oral treatment for women with metastatic breast cancer.

Lapatinib is now indicated in combination with letrozole for the treatment of postmenopausal women with hormone receptor positive metastatic breast cancer that overexpresses the HER2 receptor for whom hormonal therapy is indicated. Lapatinib in combination with an aromatase inhibitor has not been compared to a trastuzumab-containing chemotherapy regimen for the treatment of metastatic breast cancer.

“This combination of Tykerb plus Femara® is an example of advancing science and improving patient care. This regimen attacks two specific receptors that drive cancer growth,” said Paolo Paoletti, Senior Vice President, GSK Oncology R&D. “Women battling this disease now have the opportunity to delay the use of traditional cytotoxic-chemotherapy, which is an exciting possibility for them.”

Between 25 and 30 percent of breast cancers overexpress HER2 receptors¹ and 60 to 70 percent of all breast cancer cases in Europe and the U.S. are HR positive.²

Lapatinib was already indicated in combination with Xeloda® (capecitabine) for the treatment of patients with advanced or metastatic breast cancer whose tumours overexpress HER2 and who have received prior therapy including an anthracycline, a taxane, and trastuzumab.³

Tykerb, known as Tyverb in European markets, is currently being reviewed by the EMEA for a comparable indication through a supplemental marketing authorisation.

About the study

In the double-blind, placebo-controlled study, which enrolled 219 women diagnosed with post-menopausal, HR-positive and HER2-positive metastatic breast cancer, women treated with lapatinib and letrozole experienced a 5.2 month increase in median progression-free survival (PFS) compared to women treated with letrozole alone.

The most common (=20%) adverse reactions during treatment with lapatinib plus letrozole were diarrhoea, rash, nausea, and fatigue. The safety profile of lapatinib was consistent with previously reported results from trials of lapatinib in the advanced or metastatic breast cancer population.⁴

About lapatinib

Lapatinib is an oral small-molecule inhibitor of the HER2/ErbB2 tyrosine kinase receptor. Stimulation of HER2/ErbB2 is associated with cell proliferation and with multiple processes involved in tumour progression and metastases. Overexpression of these receptors has been reported in a variety of human tumours and is associated with poor prognosis and reduced overall survival.

Lapatinib, in combination with capecitabine, is approved in 91 countries. On March 13, 2007, the U.S. FDA approved lapatinib in combination with capecitabine for the treatment of patients with advanced or metastatic breast cancer whose tumours overexpress HER2/ErbB2 and who have received prior therapy including an anthracycline, a taxane, and trastuzumab. On June 10, 2008, the European Commission granted a conditional marketing authorisation for lapatinib in all 27 European Union (EU) member states. Other countries in which lapatinib is approved for marketing include Australia, India, Brazil, Russia, Switzerland, Turkey, South Korea, Taiwan and others around the world. Registration dossiers for lapatinib have been filed in Canada, China, Japan, Mexico and a number of countries in Latin America, Middle East, Africa and Asia Pacific.

Dose Modification Guidelines

For dose modification guidelines, please see accompanying complete Prescribing Information.

BOXED WARNING and Important Safety Information

Lapatinib has been associated with hepatotoxicity. The hepatotoxicity may be severe and deaths have been reported. Causality of the deaths is uncertain.

Lapatinib is contraindicated in patients with known hypersensitivity. Patients may experience decreased LVEF, diarrhoea, interstitial lung disease/pneumonitis, QT prolongation, and risk of fetal harm in pregnant women. If lapatinib is to be administered to patients with severe hepatic impairment, dose reduction should be considered.

GSK in Oncology

GSK Oncology is dedicated to producing innovations in cancer that will make profound differences in the lives of patients. Through GSK's revolutionary 'bench to bedside' approach, we are transforming the way treatments are discovered and developed, resulting in one of the most robust pipelines in the oncology sector. Our worldwide research in oncology includes collaborations with more than 160 cancer centres. GSK is closing in on cancer from all sides with a new generation of patient-focused cancer treatments in prevention, supportive care, chemotherapy and targeted therapies.

GlaxoSmithKline – one of the world's leading research-based pharmaceutical and healthcare companies – is committed to improving the quality of human life by enabling people to do more, feel better and live longer.

Notes to Editor:

Tykerb® is a registered trademark of the GlaxoSmithKline group of companies in the United States and the countries outside of Europe.

Femara® is a registered trademark of Novartis International AG.

Xeloda® is a registered trademark of Roche Pharmaceuticals.

References

1.“Glossary – HER2 gene.” American Cancer Society. Available at http://www.cancer.org/. Accessed January 21, 2010.

2. Bedard PE, Freedman OC, Howell A et al. Overcoming endocrine resistance in breast cancer – are signal transduction inhibitors the answer. Breast Cancer Res Treat. 2008 108:307-317.

3. TYKERB Prescribing Information. Available at http://us.gsk.com/products/assets/us_tykerb.pdf. Accessed January 26, 2010.

4. Johnston, S et al. Lapatinib combined with letrozole vs letrozole and placebo as first-line therapy for postmenopausal hormone receptor-positive metastatic breast cancer.”J Clin Oncol 2009 27:5538-5546