XBiotech announced today interim results from its fast-tracked Phase III study being conducted in the US for its anti-cancer agent Xilonix™.
Xilonix, a True Human™ monoclonal antibody therapy, is being evaluated in advanced colorectal cancer patients where disease is further complicated with cachexia. The primary endpoint of the study is overall survival, comparing survival in Xilonix treated patients to a control population provided only palliative therapy for cachexia.
XBiotech recently conducted an interim analysis of the 40 patients that have entered the study to date. Over half of the patients have succumbed to disease, enabling what the Company says is a preliminary analysis of study endpoints. At the time of analysis, patients receiving Xilonix had a hazard ratio for risk of death of 0.33 (p=0.11) compared with controls. The strong hazard ratio reveals a marked trend for improved survival in the Xilonix treated group compared to controls.
The Company disclosed it has used the interim overall survival data in a model to predict the statistical significance of the survival benefit over the projected complete course of the study. This model is said to indicate that, based on the current effect seen with Xilonix, a highly significant result would be obtained upon study completion, well beyond what is necessary for registration.
Key pharmacodynamic measures were also reported to be consistent with the intended biological activity of the therapy; as well, secondary endpoints evaluating life quality were consistent with the observed survival benefit in Xilonix patients. Together, these data are considered to be strong supportive evidence of the drug's clinical activity.
The unscheduled interim analysis was enabled due to a halt in the study for protocol amendments, which the Company says are intended to correct what are believed to be barriers to patient enrollment. The Company reports it is currently collaborating with the FDA on revisions that will ensure the protocol remains suitable for biological licensing applications. The new protocol is said to permit recruitment of all advanced refractory colorectal cancer patients and will be randomized 2:1 against placebo. XBiotech is expecting patients to be enrolled under the revised protocol as early as October this year.
The Company's CEO, John Simard stated, "Enrollment challenges in this highly competitive environment for colorectal cancer patients forced us to reevaluate assumptions for the study design. What was unanticipated was that this problem would enable our team to perform an early evaluation of ongoing study results. What we found was dramatic. These survival results, seen in the context of enhanced patient health and well being as a result of therapy, suggests a quantum advance in the management of advanced cancer."
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