Maintaining Antiviral Efficacy after Switching to Generic Entecavir 1 mg for Antiviral-resistant Chronic Hepatitis B

Young Eun Ahn; Sang Jun Suh; Tae Hyung Kim; Young Kul Jung and Hyung Joon Yim

doi:10.4166/kjg.2020.0144

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Korean J Gastroenterol < Volume (); -0001 < Articles

Korean J Gastroenterol

Maintaining Antiviral Efficacy after Switching to Generic Entecavir 1 mg for Antiviral-resistant Chronic Hepatitis B

Young Eun Ahn, Sang Jun Suh, Tae Hyung Kim, Young Kul Jung, Hyung Joon Yim

Department of Internal Medicine, Korea Universty College of Medicine, Seoul, Korea

Correspondence to: Hyung Joon Yim, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Korea University Ansan Hospital, 123 Jeokgeum-ro, Danwon-gu, Ansan 15355, Korea. Tel: +82-31-412-6565, Fax: +82-31-412-5582, E-mail: gudwns21@korea.ac.kr, ORCID https://orcid.org/0000-0002-6036-2754

Financial support: This project was partly funded by Dong-A Science Technology Research Fund and partly funded by the Korea University Research Grant.

Received: October 11, 2020; Revised: November 16, 2020; Accepted: November 17, 2020; Published online: December 30, 2020.

Abstract: Backgrounds/Aims: Clinical equivalence of generic antiviral agents for chronic hepatitis B (CHB) has not been demonstrated, particularly in cases with previous antiviral resistance. Entecavir 1 mg is prescribed frequently as a mono- or combination therapy in antiviral-resistant CHB patients. This study evaluated the efficacy and safety of switching to generic entecavir 1 mg (Baracle^®) in CHB patients taking brand-name entecavir 1 mg (Baraclude^®) alone or in combination with other nucleotide analogs after the development of antiviral resistance.
Methods: This study was a single-arm prospective study. The primary endpoint was undetectable HBV DNA (<20 IU/mL) at 12 months after switching treatment. The biochemical and serologic responses, virologic breakthrough, and antiviral resistance rates were also evaluated.
Results: Forty CHB patients with undetectable HBV DNA through the brand-name entecavir 1 mg treatment as a mono- or combination therapy after developing antiviral resistance to nucleos(t)ide analogs were enrolled in this study. No significant difference in the HBV DNA non-detection rate was observed between the baseline and 12 months after switching therapy (p=0.324). Furthermore, non-inferiority of the generic entecavir 1 mg to the brand-name entecavir 1 mg with 10% margin in maintaining undetectable HBV DNA was demonstrated (95% CI -2.80 to 8.20%). Similarly, no difference in the biochemical response rate was observed after switching therapy. Serum hepatitis B e antigen loss was observed in 12.5%. No virologic breakthrough was reported.
Conclusions: Generic entecavir 1 mg is a reasonable alternative to the brand-name entecavir 1 mg in antiviral-resistant CHB patients with viral suppression.; Keywords: Entecavir; Hepatitis B, chronic; Therapeutics