XBiotech Cancer Drug Survival Claim in Question

July 6, 2016

Analysts are questioning XBiotech's presentation of data from a Phase III Xilonix study in colon cancer patients. The company made claims about its experimental colon cancer drug, stating, "Among responders (in both treatment and placebo arms), clinical response was associated with a 2.7-fold increase in overall survival (11.5 months vs. 4.2 months in responders vs. non-responders, respectively)."

The issue being that the data only looked at "responders."  This means that the data only shows that those who responded to either treatment (drug or placebo) lived longer. The data fails to give a direct comparison of survival in the Xilonix group versus the placebo group.

According to TheStreet, this is an old data-analysis trick usually attempted by companies when the real survival analysis -- drug vs. placebo or control -- shows nothing.

XBiotech went on to say that responding colon cancer patients -- Xilonix or placebo, doesn't matter -- lived an average of 11.5 months! That's way better than the non-responding patients, who lived only an average of 4.2 months. Read the full story in TheStreet.