GPC shares rise 40% on strong satraplatin data

German drugmaker GPC Biotech AG and the USA's Pharmion Corp have reported positive top-line results from their double-blinded, randomized Phase III registrational trial for their co-developed anticancer drug satraplatin. Shares in GPC Biotech soared 40% to 15.05 euros, on the day after the announcement, September 25.

The trial, which is evaluating satraplatin plus prednisone versus placebo plus prednisone as a second-line treatment in 950 hormone-refractory prostate cancer patients, showed highly statistically significant progression-free survival (p<0.00001) using the protocol-specified log-rank test, which is the primary endpoint for submission for accelerated approval in the USA and will also serve as the primary basis for the agent's marketing authorization application in Europe.

Those who received the satraplatin combination had a 40% reduction in the risk of disease progression (hazard ratio of 0.6; 95% confidence interval: 0.5-0.7) compared with prednisone plus placebo patients. The improvement in progression-free survival on satraplatin increased over PFS at the median (50th percentile) demonstrated a 13% improvement for those on satraplatin plus prednisone (11 weeks) compared to patients who received prednisone plus placebo (9.7 weeks).