New data on colorectal cancer
AUSTIN, Texas—XBiotech, developer of True Human therapeutic antibodies, has completed data analysis for its Phase 3 European study and held a follow-up conference call to provide additional important information regarding the activity of Xilonix in the treatment of advanced, symptomatic colorectal cancer.
In addition to previously announced positive results regarding the primary endpoint of the pivotal study, complete data analysis further demonstrated that key secondary measures of antibody activity were also improved. Inhibition of IL-1 alpha on the surface of platelets may represent an important antitumor, disease-modifying activity, due to the mechanism of action of Xilonix. In the study, median platelet counts among placebo patients were found to be increased fivefold compared to patients who received Xilonix, whose platelet counts remained near baseline levels during the treatment cycle (p=0.003).
Furthermore, while the study was not powered to demonstrate differences in serious adverse events (SAEs) between treatment and placebo groups, there was a 26-percent reduction in the risk of SAEs in the treatment arm relative to placebo (p=0.062). A treatment-related reduction in SAEs compared to placebo patients is a remarkable and important finding, the company said in a statement. An SAE is defined as a health-related event that is life-threatening, results in persistent or significant disability or death. XBiotech believes this may be the first report of a placebo-controlled, randomized clinical study of an anticancer agent where there was reduced incidence of SAEs in a treatment arm. Finally, patients in the treatment arm were found to be 53 percent more likely to have stable disease compared to placebo at eight weeks (p=0.12).
The trends toward reduced disease progression and a reduction in SAEs is compelling given the small patient population in the study. Together, the company believes that these secondary findings corroborate the therapeutic value of the antibody in advanced, recalcitrant cancer.
John Simard, CEO of XBiotech, stated, “We believe this study serves as a confirmation that Xilonix is a unique anticancer agent for gently treating advanced, even fragile, cancer patients. We are also very proud that the study represents a milestone in the development of new clinical endpoints to assess efficacy of novel treatments that help heal patients with advanced disease.”
The study included only patients with advanced disease with multiple symptoms that were prognosticators of poor outcome. The study was thus performed on a narrowly defined group of patients living with advanced colorectal cancer. The objective response criteria that constituted the primary endpoint were based on findings of a previous study in advanced cancer patients where antibody therapy was associated with recovery from key disease-related symptoms, including objective findings of increased lean body mass, and recovery from appetite loss, fatigue and pain. The company collaborated with the Scientific Advisory Group of the European Medicines Agency (EMA) to use these earlier observations to establish novel objective response criteria to enable evaluation and potential registration of a cancer therapy. Thus, the present findings of the Phase 3 study are believed to provide the first evidence that: (1) new endpoints based on symptom recovery may be used to evaluate an antitumor agent in advanced cancer; (2) in patients with advanced cancer, clinical trajectory can be positively altered in the presence of recalcitrant tumor; and (3) Xilonix, a True Human antibody therapeutic, represents a novel treatment for a serious unmet medical need in advanced colorectal cancer.
Following up on Jan. 23, Dr. Michael Stecher, the company’s medical director, presented a poster as part of the Trials in Progress Poster Session at the American Society of Clinical Oncology 2016 Gastrointestinal Cancers Symposium in San Francisco. The poster presentation, titled “Phase III double-blinded, placebo-controlled study of MABp1 for improving survival in metastatic colorectal cancer,” is part of a special update for the gastrointestinal (GI) oncology community on XCITE, an ongoing FDA Fast Track, pivotal Phase 3 study of XBiotech’s cancer drug Xilonix for the treatment of metastatic colorectal cancer.
The poster outlined the details of XCITE, which is a global study of 600 patients with a primary endpoint of overall survival and secondary endpoints of progression free survival, overall response rate, change in lean body mass and quality of life. The study is powered to show a clinically meaningful improvement in overall survival, evaluated by log- rank test with a one-sided alpha of 0.025. Enrollment is currently underway, and results of the first interim analysis are expected in late 2016.
Stecher stated, “Having successfully completed our European Phase 3 study using novel clinical endpoints developed with the EMA, I am gratified to have this opportunity to continue our positive momentum and highlight our global FDA trial for the GI cancer community.”
XBiotech is pioneering the discovery and development of targeted antibodies based on its True Human technology. The company’s mission is to rethink the way antibody medicines are discovered and commercialized by advancing its robust pipeline of human antibodies for treating serious diseases such as cancer, inflammatory conditions and infectious diseases. XBiotech’s lead product, Xilonix, is a potential breakthrough antibody therapy that is currently the subject of two pivotal clinical studies for treating patients with advanced colorectal cancer. Xilonix specifically targets and neutralizes interleukin-1 alpha, a molecule known to promote angiogenesis and growth and spread of tumors, as well as mediate symptoms such as metabolic dysregulation, fatigue and anxiety associated with advanced cancer. XBiotech’s True Human antibodies are cloned directly from individual donors who possess natural immunity against certain diseases.