Tengsheng Pharmaceutical-B (02137) announced data from its ongoing ENSURE Phase 2 study in the form of the latest breakthrough poster at the 2025 EASL conference

Zhitong Finance App News, Tengsheng Pharmaceutical-B (02137) issued an announcement. The company announced its ongoing ENSURE Phase 2 research data in the form of the latest breakthrough poster at the 2025 European Liver Disease Research Association (EASL) conference held in Amsterdam, the Netherlands.

ENSURE (NCT05970289) is a multi-center, open phase 2 study. Cohort 1-3 aimed to evaluate the role of elebsiran, an investigational small interfering ribonucleic acid (“siRNA”) in patients infected with chronic hepatitis B virus (“HBV”) in combination with polyethylene glycol interferon α (“PEG-IFNα”) with baseline hepatitis B surface antigen (“HBSAG”) levels of 100—3,000 IU/mL.

Cohort 4 enrolled participants who received 9 doses of BRII-179 (a recombinant protein-based therapeutic vaccine) in combination with elebsiran in the previous Asia Pacific study BRII-179-835-001 (NCT04749368) and received a combination of Elebsiran and PEG-IFNα. These participants were grouped according to their previous hepatitis B surface antibody (“anti-HbS”) responses generated after receiving BRII-179 treatment: participants with peak anti-HBS titer values of at least 10 IU/L were defined as anti-HBS responders, and participants with peak anti-HBS titer <10 IU/L were defined as non-responders. The design of this study cohort 4 is based on the opinion that BRII-179 can distinguish between immune responders and non-responders, thus providing the possibility to predict future treatment responses.

Interim data from cohort 4 showed that anti-HBS responders had significantly higher HBsAg serum clearance than non-responders. At the end of treatment (“EOT”) (week 48), 61% (11/18) of anti-HBs responders achieved HBsAg serum clearance, compared to 10% (1/10) of those who did not respond. Among the 11 anti-HBS responders who achieved HBsAg clearance, 91% (10/11) had an anti-HBS titer greater than 100 IU/L at EOT.

Notably, BRII-179 treated participants in Cohort 4 achieved HBsAg clearance faster than BRII-179 untreated participants in Cohort 2 and Cohort 3. 83% (10/12) of BRII-179 treated participants achieved HBsAg clearance at week 24, compared to 55% (6/11) of BRII-179 untreated participants. These findings suggest that rapid HBsAg serum clearance and higher anti-HBS titers can be translated into long-lasting HBsAg clearance, and to evaluate the possibility of shortening PEG-IFNα courses.

Other data from the ENSURE study cohort 1-3 showed that compared with PEG-IFNα monotherapy, 100 or 200 mg of Elebsiran combined with PEG-IFNα can achieve higher HBsAg clearance after 24 weeks of EOT, supporting additional benefits of siRNA.

Dr. David Margolis, the company's chief medical officer, said, “The data from ENSURE Study Cohort 4 is encouraging. We found in the target population that patients who developed an immune response after pre-treatment with BRII-179 showed significant advantages in achieving higher serum clearance of HBsAg. With BRII-179, we can identify patients with low intrinsic immune impairment and further enhance their immune response. This approach allows HBsAg clearance to last longer and has the potential to shorten PEG-IFNα treatment time. We are advancing clinical work at full speed to provide meaningful options for patients with chronic hepatitis B.”