Shares in German company GPC Biotech are in the ascendancy this morning on the back of Phase III trial results supporting the efficacy of its lead drug satraplatin in hormone-refractory prostate cancer.

GPC now expects to be able to press ahead with filing for approval of satraplatin in the USA before the end of the year and in Europe a few months later.

In the Phase III trial, called SPARC, patients given satraplatin on top of standard treatment with prednisone achieved a 40% reduction in the risk of disease progression and a statistically-significant 89% gain in progression-free survival, from 19 weeks to 36 weeks, compared to patients treated with prednisone plus placebo. At 12 months, 16% of patients who received satraplatin had not progressed, compared to 7% of patients in the control arm.

The results were particularly compelling given that patients enrolled into SPARC had received first-line treatment with taxanes or other chemotherapies.

GPC licenses satraplatin to Pharmion in Europe and various other territories worldwide, but will take on responsibility for securing US approval itself.

Satraplatin is an orally-active platinum-containing cancer drug that has been recommended for 'fast-track' review in the USA. Worldwide sales of platinum cancer drugs exceeded $2.2 billion in 2004, and it is estimated that satraplatin itself could achieve revenues of 500 million euros at peak.

Shares in GPC Biotech were up 40% in late-morning trading today at 15.12 euros.