US IDMC recommends termination of phase III XCITE study for Xilonix (Human IgG1 monoclonal antibody) in colorectal cancer- XBiotech

XBiotech announced that a US Independent Data Monitoring Committee (IDMC) has performed its second prospectively planned, unblinded analysis of the Phase III XCITE study for Xilonix (Human IgG1 monoclonal antibody specific for human interleukin-1 alpha) for the treatment of colorectal cancer. The IDMC had no safety concerns from the unblinded analysis. However, the committee recommended the early termination of the study since the findings were not sufficient to meet efficacy or the threshold for continuation, which involved a prospectively defined acceptance boundary for the interim analysis of less than or equal to p = 0.08.

Patients enrolled in the XCITE study were randomized 2:1 to receive Xilonix or placebo plus, in each case, best supportive care. Advanced colorectal cancer patients were required to have previous failed regimens that included flouropyrimidines, oxaliplatin, irinotecan, and Cetuximab (or Panitumumab for patients with KRAS mutation). Patients were expected to continue in the study until there was evidence of radiographic progression. The patients were to be followed for up to 18 months in order to determine overall survival. The primary endpoint of this study was overall survival, with secondary endpoints including objective response rate, progression free survival, change in lean body mass and patient reported quality of life measures.

The Company plans to analyze the data to further understand the primary and secondary endpoint data, as well as to identify populations that may have benefited from the therapy. The company also plans to pursue approval of the therapy based on the successful completion of the European study, which demonstrated control of symptoms in colorectal cancer.