Shares in Germany’s Schering AG dropped almost 4% on the New York Stock Exchange yesterday after the firm unveiled full data from a late-stage study of its oral anti-angiogenesis agent, PTK/ZK, showing the compound had failed to stop disease progression in first-line colorectal cancer patients. However, the sliding share price may have come as somewhat of a surprise to the firm, which first discussed the findings back in March, along with partner Novartis [[21/03/05a]].

The so-called CONFIRM-1 trial enrolled over 1,100 patients who were given PTK/ZK plus a chemotherapy combination incorporating oxaliplatin, 5-fluorouracil and leucovorin, called FOLFOX-4 - or the latter therapy alone. Results showed a 12% reduction in the risk of disease progression in patients given Schering and Novartis’ drug - a figure that did not achieve statistical significance.

Despite the disappointing results, Schering was keeping optimistic, and in a statement yesterday said: “These new data show that PTK/ZK may improve outcomes for colorectal cancer patients. We eagerly await the findings on overall survival, which will enable us to see how this compound may advance treatment for these patients. The independent Data Safety Monitoring Board reviewed all safety data and recommended continuation of the trial.”

In March, Schering and Novartis said they would push back a regulatory filing for PTK/ZK from the second half of this year to 2007, causing jitters amongst the investment community which had been banking on the drug to replace slowing sales of Schering’s multiple sclerosis treatment Betaferon/Betaseron (interferon beta-1b) [[09/02/05b]]. Chief executive, Hubertus Erlen, last year predicted that PTK/ZK could be a potential blockbuster earner for the firm, with annual sales in excess of one billion euros [[06/01/05d]].

Another ongoing Phase III trial, CONFIRM 2, compares the PTK/ZK combination regimen to FOLFOX-4 alone in patients with metastatic colorectal cancer who have progressed after irinotecan-based first line chemotherapy. An interim analysis is planned in mid-2005 and final overall survival data are expected in mid-2006.