Brii Biosciences' (HKG:2137) said a group of phase 2 trial enrollees of a chronic hepatitis B treatment plan showed immune responsiveness after taking the company's BRII-179 drug, according to a Thursday filing with the Hong Kong bourse.

The data from cohort 4 of the study are "encouraging," Chief Medical Officer David Margolis said during the presentation of data during a congress in Amsterdam, the Netherlands.

The trial assessed the efficacy of the drug, together with a combination of elebsiran and pegylated interferon alpha in patients with chronic hepatitis B, the filing said.

"We saw in target populations that patients who were immune-responsive through pre-treatment with BRII-179 demonstrated a significant advantage in achieving a higher HBsAg seroclearance rate," said Margolis.