Bepirovirsen produced sustained clearance of hepatitis B virus and hepatitis B surface antigens.
Bepirovirsen is an investigational antisense oligonucleotide, produced sustained clearance of hepatitis B virus (HBV) and hepatitis B surface antigens (HBsAg) in patients on concurrent nucleoside/nucleotide analogues (NA) and in patients not-on-NA therapy, according to results from the B-Clear phase 2B trial.
It has potential as a monotherapy or in combination with NAs, which could result in functional cure.
It was designed to specifically recognize the RNA that HBV uses to replicate in infected liver cells and to make the viral antigens that facilitate the chronicity of the virus by helping to avoid being cleared by the immune system.
It is also able to stimulate immune responses via Toll-like receptor 8 (TLR8), which may enable the immune system to achieve durable clearance of HBV from circulating blood.
The B-Clear phase 2b trial investigated the efficacy in people with chronic HBV on stable NA treatment or not on NA treatment at the start of the study.
24 week treatment resulted in 9% of patients on NA and 10% of patients not on NA achieving the primary endpoint of HBsAg levels below the Lower Limit of Detection and HBV DNA levels below the Lower Limit of Quantification.
Patients with low baseline HBV surface antigen levels had the best response to treatment.
There were no safety signals identified that would preclude further use of the drug development.