Assembly Biosciences announces presentation of ABI-H0731, ABI-H2158 data
Assembly Biosciences (ASMB) announced that data on its lead HBV core inhibitor candidates, ABI-H0731 and ABI-H2158 for the treatment of chronic HBV will be featured in a late-breaking poster session during the American Association for the Study of Liver Diseases Annual Meeting.
A hepatitis B infection can result in either an acute infection or a chronic infection. When a person is first infected with the hepatitis B virus, it is called an “acute infection” (or a new infection). Most healthy adults that are infected do not have any symptoms and are able to get rid of the virus without any problems. Some adults are unable to get rid of the virus after six months and they are diagnosed as having a “chronic infection.”
Title: Continued Therapy with ABI-H0731+Nrtl Results in Sequential Reduction/Loss of HBV DNA, HBV RNA, HBeAg, HBcrAg and HBsAg in HBeAg-Positive Patients.
Abstract Summary: Final results from Phase 2a are reported for HBeAg+ patients with chronic HBV infection treated with 731+Nrtl for 24 weeks.
In Study 202, greater mean log10 declines in HBV DNA and RNA were achieved with 731+Nrtl versus entecavir alone.
In Study 201, the proportion of patients on 731+Nrtl versus Nrtl alone achieving DNA target not detected was 69% vs 0%, and the proportion of patients achieving RNA less than35 U/mL whose RNA was greater than or equal to35 U/mL at baseline was 52% vs 0% respectively.
In Study 211, there are 64 HBeAg+ patients currently on extended treatment beyond 24 weeks. Among the 27 HBeAg+ patients receiving 731+Nrtl in Study 201, 41% have now achieved DNA TND along with RNA less than35 U/mL and HBeAg less than1 IU/mL.
At their last time point, Study 202 patients now in Study 211 have demonstrated mean DNA and RNA declines of 6.1 and 3.0 logs, respectively, with observed mean log changes of greater than or equal to 0.6 for HBeAg, greater than 0.8 log for HBcrAg and greater than or equal to 0.4 log for HBsAg.
731 continues to exhibit a favorable safety and tolerability profile in patients treated for up to 1 year, with only mild/moderate adverse events and lab abnormalities, and only a single discontinuation due to a Grade 1 rash.
The combination of 731+NrtI results in faster and deeper declines in HBV DNA and RNA than NrtI alone, as well as subsequent declines in the surrogate markers of cccDNA predictive of cccDNA pool depletion, and HBsAg.
The emergent data supports the continued development of 731.
Abstract data are as of the time of submission; the poster is expected to include updated safety and efficacy results. Title: The Second-Generation Hepatitis B Virus Core Inhibitor ABI-H2158 is Associated with Potent Antiviral Activity in a 14-Day Monotherapy Study in HBeAg-positive Patients with Chronic Hepatitis B.
Abstract Summary: The Phase 1b study is enrolling sequential cohorts of 9 patients and each cohort will be randomized to receive 2158 or placebo QD for 14 days in a blinded manner.
Dosing in the 1st cohort has been completed. In patients receiving 2158, mean declines from Baseline to Day 15 in HBV DNA and RNA levels were 2.3 log10 and 2.1 log10 IU/mL respectively.
No serious AEs, dose limiting toxicities or premature discontinuations were reported.
Three patients reported a total of 5 mild, drug-related AEs that recovered without intervention; dizziness, fatigue, rash, headache and upper abdominal pain.
Treatment emergent laboratory abnormalities were infrequent, mild and transient, with no ALT elevations Grade greater than or equal to 1 in severity.
Day 14 plasma 2158 Cmax and AUC0-24hr were 3,390 ng/mL and 46,100 hr*ng/mL, respectively.
Results from the initial 100 mg low dose of ABI-H2158 cohort demonstrated potent antiviral activity, a favourable safety profile when administered for 14 days, and support once daily dosing in CHB patients.