XBiotech reveals Xilonix trial 'irregularities'

XBiotech Inc. (NASDAQ:XBIT) fell $4.50 (34%) to $8.75 on Tuesday after it said Monday after market close that data were compromised from 72 patients in its Phase III study of Xilonix, its human mAb against IL-1 alpha to treat advanced colorectal cancer. The company said it expects the study to have reduced statistical power, but did not disclose the total number of patients in the study and did not respond to inquiries.

XBiotech said 14 patients were given Xilonix or placebo erroneously, 33 did not receive scheduled scans or properly complete evaluations, and 25 dropped out of the study before dosing. The company said it is still receiving patient data and will provide an update on its analysis in about ten days. ...