European Regulator Calls XBiotech's Phase III Cancer Data Unreliable
July 15, 2016
By Alex Keown, BioSpace.com Breaking News Staff
AUSTIN, Texas – XBiotech faces new problems following an excoriating review of XBiotech’s experimental colorectal cancer drug Xilonix by The Street’s Adam Feuerstein. The latest is the European Society of Medical Oncology’s report that Xilonix is an unreliable drug.
In a report issued by Kirk Arnold of the Instituto CUF de Oncologia in Lisbon, Portugal, the trial data presented earlier this month by XBiotech was re-examined and they came to the conclusion that there were problems with the trial.
“…the jury is still out on whether the study made sense but as the results do not bear close inspection, they also cannot be relied upon. It’s not yet clear whether there is any benefit in translating this trial into practice,” Arnold wrote in his report that was released late Thursday.
Shares of XBiotech dropped about 15 percent following the report’s release—exacerbating a drop that occurred earlier this month following Feuerstein’s questioning of XBiotech’s Phase III data of Xilonix. This morning, share prices of XBiotech are continuing to drop, currently trading at $14.60 per share, down from the opening price of $15 per share.
Mariann Caprino, an XBiotech spokesperson, told Feuerstein Thursday that the company stands behind the Xilonix Phase III data presented at ESMO earlier this month.
“We fundamentally disagree with Dr. Arnold's interpretation of the data and look forward to further discussion in an appropriate scientific forum, “Caprino told Feuerstein.
XBiotech is banking on European regulators to approve Xilonix later this year.
During its presentation to ESMO earlier this month, XBiotech said Xilonix was reason for a 2.7-fold increase in overall survival in patients, about 11.5 months. However, in the same breath the company noted the same response was also seen in the placebo arms of patients as well. That statement is what prompted Feuerstein to closely examine and ultimately challenge the data. Calling the data claims “clinically meaningless sleight of hand,” Feuerstein said company’s claims show it does not care if colon cancer patients in the late-stage clinical trial were treated with the company’s drug or a placebo.
Other claims XBiotech made about Xilonix was that “overall survival was not compared between treatment arms because after 8 weeks, all patients were eligible to receive study drug." In an earlier report, Feuerstein said the claim means that “a credible survival analysis—Xilonix vs. placebo—was impossible to assess because patients randomized to placebo at the start of the trial crossed over to Xilonix after eight weeks.”
In a statement released by the company, Tamas Hickish, chairman of the Xilonix European Phase III Study and Consultant Medical Oncologist at Dorset Cancer Centre, said the late-stage study of Xilonix “has the potential to meet the real and urgent need for more effective, less toxic therapies for patients with advanced colorectal cancer.”
“In addition, this study provides evidence that novel endpoints based on symptom recovery can serve as a predictor of overall survival benefit and thus may be used to evaluate an anti-tumor agent in this disease,” Hickish said in a statement.