GlaxoSmithKline announces start of two phase III studies in advanced/metastatic melanoma

Issued: London, UK and Philadelphia, US

GlaxoSmithKline (GSK) announced today the start of two global Phase III studies in advanced or metastatic melanoma patients with a BRAF V600 mutation. The studies will separately assess the efficacy and safety of two investigational agents, GSK2118436 and GSK1120212, to determine their individual ability to stop or slow the progression of skin cancer in patients whose tumours contain a BRAF V600 mutation, which occurs in 50 to 60 percent of melanoma patients.Commencement of these studies confirms previously announced plans to progress these assets into Phase III.

The BRF113683 Phase III study compares GSK’436, a BRAF inhibitor, to dacarbazine (DTIC) in previously untreated patients with BRAF V600 mutated advanced or metastatic melanoma. The METRIC study compares GSK’212, a MEK inhibitor, to chemotherapy (DTIC or paclitaxel) in advanced or metastatic melanoma patients with a BRAF V600 mutation.

“By focusing our research programme on patients with the V600 mutation, we are striving to understand how our investigational MEK and BRAF inhibitors can best be used to treat patients with metastatic melanomA," said Paolo Paoletti, President, GSK Oncology. “In addition to our ongoing research in metastatic melanoma, we are also studying GSK’212 and GSK’436, both alone and in combination with other agents, in other difficult to treat forms of cancers including pancreatic cancer, refractory or relapsed leukaemias and other solid tumours.”

About Melanoma

Melanoma is a type of cancer which develops when melanocytes (pigment cells in the skin) become malignant and start to grow and divide at an abnormally quick pace, spreading into the surrounding surface layers of skin. Metastatic melanoma occurs when melanoma spreads to other parts of the body. According to the World Health Organization, 132,000 melanoma skin cancers occur globally each year and approximately 19,000 women and 22,000 men die annually from malignant melanoma.

About GSK`212 (investigational MEK inhibitor)

GSK’212 is an investigational orally bioavailable inhibitor of MEK. MEK is a key component of the RAS/RAF/MEK/ERK signalling pathway that regulates cell growth. Constant and unregulated activation of this pathway has been implicated in many cancers. MEK 1 and 2 are thought to play a role in the activation of key signalling pathways that regulate cell growth.In BRAF mutant melanoma, MEK activation is a driver of the disease. GSK’212 may inhibit a critical node on a key pathway underpinning melanoma cell proliferation. By specifically binding to MEK 1 and 2, GSK’212 may result in an inhibition of cellular signalling and cellular growth in certain cancers.

GSK’212 was discovered by Japan Tobacco and in-licensed by GSK in 2006.

About GSK2118436 (Investigational BRAF inhibitor)

GSK’436 is an investigational orally bioavailable inhibitor of BRAF. Mutations in BRAF are present in ~50-60 percent of melanoma and ~8 percent of all cancers. The mutation appears to have a direct role in activating the MAP kinase pathway, which controls processes such as cell proliferation, differentiation, survival and apoptosis (cell death). BRAF belongs to the RAF family of protein kinases. BRAF inhibitor GSK’436 binds to and inhibits the activity of BRAF, which may inhibit the proliferation of tumor cells containing a mutation in BRAF.

About the metric study:

The METRIC Phase III study of GSK’212, a MEK inhibitor, in patients with advanced/metastatic melanoma focuses on patients with BRAF V600 mutation who have had no more than one prior regimen of chemotherapy and no prior BRAF inhibitor treatment. The primary endpoint of the study is progression free survival. Patients in the chemotherapy cohort will be allowed to crossover to receive GSK’212 therapy after their disease progresses. The study will be conducted in Australia, Argentina, Russia and several countries within North America and Europe. The METRIC study has begun dosing patients.

About the BRF113683 study:

BRF113683 is a Phase III, randomised, open-label study comparing the efficacy, safety, and tolerability of GSK’436 to DTIC in patients with advanced (Stage III) or metastatic (Stage IV) melanoma who harbour a BRAF V600 mutation. The primary endpoint of the study will be progression free survival. Patients who progress on DTIC will be allowed to crossover to an optional extension arm of the study to receive GSK’436. The study will be conducted in Russia, Australia and several countries within North America and Europe. The BRR113683 study has centres open and is actively screening and recruiting patients, but has not yet begun dosing.

Notes to Editors:

These compounds are in development and subject to evaluation of the benefits and risks by the regulatory authorities before being made available generally to the public.

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 further information please visit www.gsk.com

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 2009.