Researchers have challenged findings from a Chinese study that concluded Baraclude (entecavir) is associated with a lower risk of liver cancer than Viread (tenofovir disoproxil fumarate) for treatment of hepatitis B virus (HBV), Infectious Disease Advisor reports.

Publishing their opinions in a letter in the journal Gastroenterology, the researchers stated that the Chinese team’s claims about Baraclude’s superior safety run contrary to the findings of previous studies, which found no differences in the long-term risk of liver cancer between people treated for HBV for the first time with Baraclude versus Viread.

Part of the problem with the Chinese study, the letter authors stated, was the multiple differences between the groups that took each of the respective antivirals, including the fact that those who took Baraclude tended to be older and have a higher rate of cirrhosis than those who took Viread. Even with statistical adjustment for these differences, these results could have falsely attributed an excess liver cancer risk to Baraclude rather than to age and cirrhosis status.

The Chinese study, which was a retrospective analysis, assembled a cohort with a lopsided proportion of 95% in the Baraclude group and just 5% in the Viread group, compromising its ability to come up with valid findings. The study may also have suffered from what’s known as selection bias, in which the basis of the cohort members and their physicians’ decisions to have them take one drug over another may have influenced the findings of the analysis.

The study was also missing a considerable amount of data, with 20% of the cohort members lacking data on their HBV “e” antigen status, 36% lacking data on their viral load and 11% lacking data on their serum creatinine levels. Nor were there any data on the cohort members’ body mass index.

The authors of the letter discouraged international guidelines from taking the Chinese study into account before more research can be conducted on the subject.

To read the Infectious Disease Advisor article, click here.

To read the study abstract, click here.

To read the letter, click here.