ImClone Systems and Bristol-Myers Squibb have suffered a setback after disappointing data from a late-stage study of the firms’ Erbitux in non-small cell lung cancer.

The more-than-600-patient, open-label Phase III study of Erbitux (cetuximab), plus a taxane and carboplatin in the first-line treatment for metastatic NSCLC did not meet its primary endpoint of progression-free survival (PFS). However, the companies noted that key secondary endpoints of the study, including response rate (as assessed by an independent radiology review committee) and PFS as measured by clinical investigators, “were statistically significant and favoured the Erbitux-containing arm”.

The news led to a 3.3% drop in ImClone’s share price to $34.73 but the firm was quick to point out that the study was just one of several intended to establish the role of Erbitux, which is approved for cancer of the colon and in the head and neck, in the treatment of advanced NSCLC. For example, data from the largest of these trials, an ongoing multinational Phase III study of the drug plus cisplatin and vinorelbine which is “intended to be the pivotal study for the Erbitux NSCLC regulatory strategy”, are not yet available.

That trial, called FLEX, is being carried out by Merck KGaA, ImClone’s European partner, and its shares fell 1.6% on Frankfurt’s Xetra to 99.29 euros, though comparisons with the latest B-MS/ImClone study should not be made, said analyst James Reddoch at Friedman Billings Ramsey. He noted that the design of FLEX is different, it involves different chemotherapy and it is a much bigger trial (over 1,100 patients). The final data from that study are expected in 2008.