XBiotech Inc. (NASDAQ: XBIT) took the opportunity at a meeting of the European Society of Medical Oncology to present data on Phase 3 study of its lead candidate Xilonix. Although the company tried to create an impression that the study was successful, questions quickly arose about the methodology it used in the study.
According to XBiotech Inc. (NASDAQ: XBIT), Xilonix demonstrated significant clinical response rate (CCR) in patients who received it during the trial compared to a placebo. But it immediately turned out that the company used an unconventional methodology in the presentation of the Phase 3 trial data on Xilonix.
The standard methodology in such studies is to assess overall response rate and progression-free survival in patients who received the trial drug. But in its case, XBiotech apparently coined a measure called clinical response rate (CCR) in the trial of Xilonix.
As a result, XBiotech Inc (NASDAQ:XBIT) has created doubt among investors about whether Xilonix has strong data behind it to convince regulators to approve it for marketing. Investors in drug companies are used to endpoint targets that assess the survival rates of a drug candidate compared to a placebo. But XBiotech decided to be unconventional in its Phase 3 study of Xilonix.
What is XBiotech Inc. (NASDAQ: XBIT)’s target market?
XBiotech Inc (NASDAQ: XBIT) is developing Xilonix as a treatment for colorectal cancer. According to its study findings in the Phase 3 trial, responders to the treatment either maintained or exhibited improvement in their lean body mass. The company also cited improvement in anorexia, pain and fatigue among the patients who received its trial drug compared to the placebo group.
Difference between Xilonix and placebo
From the Phase 3 study, it emerged that 33% of patients who received Xilonix exhibited clinical response rate compared to 19% in the placebo group. Despite the difference between Xilonix and placebo performance being statistically significantly, lack of data citing how the drug improved survival or shrunk tumor left much to be desired in the whole study and created a situation of uncertainty that triggered a selloff in the stock.
But XBiotech Inc (NASDAQ: XBIT) is not going to be held back. The company has already applied for regulatory approval to market the drug in Europe. It expects to hear from the regulators there in 4Q2016.
Perhaps to have stronger data backing for Xilonix, XBiotech is enrolling patients for another Phase 3 trial of the drug in study that is expected to measure more traditional endpoint such as survival rate. Enroll to the second Phase 3 study of Xilonix is expected to be completed in December 2016.