Amgen Inc. and Abgenix Inc. said on Thursday a late-stage study found its experimental drug panitumumab helped slow tumor progression in patients with advanced Colon cancer who had failed multiple other therapies.

In the 463-patient trial, patients who received panitumumab every two weeks showed a 46 percent decrease in tumor progression rate versus those who received best supportive care alone, the companies said.

The result was better than the pre-set goal of a 33 percent decrease in tumor progression, they said.

“We are very encouraged by the results of this pivotal study and what panitumumab could mean for patients with advanced Colorectal cancer,” said Bill Ringo, president and chief executive officer of Abgenix.

The news sent shares of Amgen and Abgenix sharply higher while dragging down shares of ImClone Systems Inc., maker of a rival drug.