Cancer trials show 1 year on Roche's Herceptin is best

LONDON, Oct 1 (Reuters) - Extending treatment with Roche's

breast cancer drug Herceptin to two years from the one year current standard is not worth while, trial data showed on Monday, but shortening treatment to six months also looks unlikely to benefit patients.

The results of two keenly-watched studies on Herceptin, known generically as trastuzumab, banish a downside risk for Roche, but also limit its ability to squeeze more value out of the lucrative drug before it loses its patent from 2014.

Analysts had said the Swiss drugmaker could lose up to $1.5 billion in revenue from the blockbuster medicine in the medium term if six months treatment had been shown to be just as effective.

(Reporting by Kate Kelland; editing by James Jukwey)

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