GlaxoSmithKline Plc's new breast cancer pill, Tykerb, should become a blockbuster with sales above $1 billion a year, but most of its potential lies beyond 2010, according to industry analysts.

Tykerb is one of three cancer products that Europe's biggest drugmaker hopes to launch next year, signalling its arrival as a major force in oncology. The others are cervical cancer vaccine Cervarix and platelet-booster eltrombopag.

Dresdner Kleinwort Wasserstein said good data presented on Saturday at the American Society of Clinical Oncology meeting confirmed Tykerb's potential to become a $4 billion-a-year seller. But it won't happen overnight.

"If you are looking for the total $4 billion, you could be waiting anywhere between five and 10 years," pharmaceuticals analyst Ben Yeoh said.

Other analysts are more cautious in their forecasts.

ABN AMRO raised its recommendation on Glaxo to "buy" from "hold" following the latest Tykerb news, while predicting sales five years from launch could reach $2 billion. Morgan Stanley, meanwhile, lifted its 2012 sales forecast for the product to one billion pounds from £278 million.

Shares in Glaxo were 0.3 per cent lower at £14.78 by 1015 GMT, in line with a slightly weaker European sector.