The experimental cancer drug at the center of the Sam Waksal insider-trading scandal performed well in a European clinical trial, but it remains hard to gauge the implications for

ImClone Systems

(IMCL)

.

Merck KgaA

said an independent review of the Erbitux trial treating 330 colon-cancer patients confirmed a previous positive assessment and the company plans to file for European approval this summer. It hopes to start selling the drug in 2004. Merck KgaA licenses Erbitux from ImClone.

The upshot for ImClone is unclear because Merck didn't break out the results of the two treatments it examined: Erbitux alone and Erbitux in combination with chemotherapy. ImClone's original filing with the FDA sought clearance for Erbitux with chemo, and if the combination didn't prove superior in the trials that application could be moot. Adam Feuerstein, a columnist on

TheStreet.com's

sister site,

RealMoney.com

,

continues to report that the Merck study found Erbitux with chemotherapy wasn't significantly better than Erbitux alone.

Nevertheless, ImClone was marked up about 7% on the Instinet premarket session at $18.70.

If that were the case, ImClone could still refile Erbitux as a standalone treatment, using both the Merck trial and a study being conducted by partner

Bristol-Myers

(BMY) - Get Report

to back it up.

Merck plans to release results of the trial at the annual meeting of the American Society of Clinical Oncology on June 1.

Erbitux's original rejection triggered an insider trading scandal involving Waksal, ImClone's former chief executive. In October, Waksal pleaded guilty to six of 13 counts in a criminal indictment.