GlaxoSmithKline today announced the submission of two simultaneous regulatory applications to expand the use of TYVERB®/TYKERB® (lapatinib)

LONDON, UK and PHILADELPHIA, PA, USA | April 1, 2009 | GlaxoSmithKline (NYSE: GSK – News) today announced the submission of two simultaneous regulatory applications to expand the use of TYVERB®/TYKERB® (lapatinib). If approved, TYVERB®/TYKERB® could be used as a first-line therapy regimen combined with anti-hormonal therapy for patients with hormone-sensitive, metastatic (or advanced) breast cancer in Europe and the United States.

The variation to the EU marketing authorization and the supplemental New Drug Application (sNDA) were submitted respectively to the European Medicines Agency (EMEA) and to the U.S. Food and Drug Administration (FDA) for the combination of TYVERB/TYKERB plus an aromatase inhibitor based on the recent study, EGF30008. This study evaluated TYVERB/TYKERB in combination with letrozole in women whose breast cancer expressed was hormone receptor positive (HR+) and may or may not also over-expressed the HER2+/ErbB2+ receptor.

These data were presented at the San Antonio Breast Cancer Symposium in December 2008.

Breast cancer tumors which initially respond to anti-hormonal therapy such as letrozole can become resistant to treatment, leading to disease progression and ultimately, patient death.1 Between 60-70 percent of all breast cancer cases in Europe and the U.S. are HR+.2

"Tyverb/Tykerb with a hormone therapy is a biologically-rational targeted treatment, since the combination attacks two specific receptors that drive the cancer growth," said Debasish Roychowdhury, MD, Head, Medicines Development, GSK Oncology. "If approved the combination could provide a cytotoxic chemotherapy-free option for these patients and we look forward to working with regulatory agencies to advance the availability of this regimen as a new, oral option for patients in first-line breast cancer."

About TYVERB®/TYKERB® (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 tumor progression and metastases. Overexpression of these receptors has been reported in a variety of human tumors and is associated with poor prognosis and reduced overall survival.

Lapatinib, in combination with capecitabine, is approved in 74 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 tumors 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 authorization 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.

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 centers. 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. For more information please visit us.gsk.com

BOXED WARNING and Additional Important Safety Information for TYKERB

Hepatotoxicity – TYKERB has been associated with hepatotoxicity. Hepatotoxicity (ALT or AST >3 times the upper limit of normal and total bilirubin >1.5 times the upper limit of normal) has been observed in clinical trials (<1% of patients) and postmarketing experience. The hepatotoxicity may be severe and deaths have been reported. Causality of the deaths is uncertain. The hepatotoxicity may occur days to several months after initiation of treatment. Liver function tests should be monitored before initiation of treatment, every 4 to 6 weeks during treatment, and as clinically indicated. If changes in liver function are severe, therapy with TYKERB should be discontinued and patients should not be re-treated with TYKERB.

Decreased Left Ventricular Ejection Fraction – TYKERB has been reported to decrease LVEF. Caution should be taken if TYKERB is to be administered to patients with preexisting cardiac conditions, including uncontrolled or symptomatic angina, arrhythmias, or congestive heart failure. Confirm normal LVEF before starting TYKERB, and continue evaluations during treatment.

Patients with Severe Hepatic Impairment – If TYKERB is to be administered to patients with severe hepatic impairment, dose reduction should be considered.

Diarrhea – Diarrhea, including severe diarrhea, has been reported during treatment with TYKERB and was the most common adverse reaction resulting in discontinuation of TYKERB therapy. Proactive management of diarrhea with anti-diarrheal agents is important, and severe cases of diarrhea may require administration of oral or intravenous electrolytes and fluids, and interruption or discontinuation of therapy with TYKERB.

Interstitial Lung Disease/Pneumonitis – TYKERB has been associated with interstitial lung disease and pneumonitis. Patients should be monitored for pulmonary symptoms indicative of interstitial lung disease or pneumonitis and if symptoms are Grade 3 (NCI CTCAE), TYKERB should be discontinued.

QT Prolongation – TYKERB prolongs the QT interval in some patients. TYKERB should be administered with caution to patients who have or may develop prolongation of QTc. Hypokalemia or hypomagnesemia should be corrected prior to TYKERB administration. Baseline and on-treatment electrocardiograms with QT measurement should be considered.

Pregnancy: Pregnancy D – TYKERB can cause fetal harm when administered to a pregnant woman. Women should be advised not to become pregnant when taking TYKERB. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.

Adverse Reactions – The most common adverse reactions (>20%) during therapy with TYKERB plus capecitabine compared to capecitabine alone were diarrhea (65%, 40%), nausea (44%, 43%), vomiting (26%, 21%), palmar-plantar erythrodysesthesia (53%, 51%), rash (28%, 14%), and fatigue (46%, 47%).

The most common grade 3 and 4 adverse reaction (NCICTC v3) with TYKERB plus capecitabine compared to capecitabine alone were diarrhea (14%, 10%) and palmar-plantar erythrodysesthesia (12%, 14%).

Please see full prescribing information, including BOXED WARNING.

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

TYVERB® is a registered trademark of the GlaxoSmithKline group of companies in European Union.

Cautionary statement regarding forward-looking statements

Under the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995, GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Factors that may affect GSK’ s operations are described under ‘Risk Factors’ in the ‘Business Review’ in the company’ s Annual Report on Form 20-F for 2008.

References

1 Prat, A and Baselga, J. The role of hormonal therapy in the management of hormonal-receptor-positive breast cancer with co-expression of HER2. Nature Clinical Practice Oncology. 2008;5:531-542

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

SOURCE: GSK