LONDON, Oct 10 GlaxoSmithKline Plc has licensed Synta Pharmaceuticals Corp's experimental

LONDON, Oct 10 (Reuters) GlaxoSmithKline Plc has licensed Synta Pharmaceuticals Corp's experimental cancer drug STA-4783 in a deal that could earn the U.S. biotech firm up to $1.01 billion, the two companies said on Wednesday.

Synta will receive $80 million as an upfront payment.

The tie-up on the drug, which is just starting a global Phase III trial for melanoma involving 600 patients, marks a further step by Glaxo to boost its pipeline through outside alliances.

Europe's biggest drugmaker has made cancer medicine a priority area for development.

''It further strengthens our late stage oncology pipeline, which currently includes 10 Phase III programmes,'' Glaxo's research head, Moncef Slaoui, said in a statement.

Under the deal, Glaxo and Synta will share responsibility for development and commercialisation of STA-4783 in the United States and Glaxo will have exclusive rights elsewhere.

In addition to the upfront payment, Synta will be eligible for potential milestone payments of up to $135 million if STA-4783 is approved in melanoma, plus up to $450 million for other indications and up to $300 million based on certain sales targets.

In addition, Glaxo may buy up to $45 million of Synta's common stock upon achievement of specified milestones.

STA-4783 has a new mechanism action, which kills cancer cells by raising oxidative stress levels beyond breaking point, triggering programmed cell death.

This approach has so far shown good promise in melanoma but Synta anticipates it will also work across a variety of tumour types.

REUTERS MP PM1920