XBiotech Plunges on Results of Colorectal Cancer Drug Trial

XBiotech Inc. plunged a record 50 percent after a late-stage study of its lead drug, using an unconventional method to evaluate its cancer-fighting abilities, raised questions about any potential benefit for patients.

Rather than the traditional approach of tracking tumor growth, the study reported on symptoms associated with disease progression, such as pain, fatigue, appetite and muscle loss, according to a company statement distributed Saturday. The study authors didn’t compare survival in patients given the drug -- Xilonix for colorectal cancer -- or placebo, a standard method of assessing effectiveness, because everyone in the trial was offered the drug after eight weeks, XBiotech said.