Benzinga | Jun 23, 2021 05:49AM EDT

Enanta Pharmaceuticals Reported New Preclinical Data for EDP-721, an Oral Hepatitis B Virus RNA Destabilizer, at EASL International Liver Congress; CEO Said Data Strongly Support the Continued Development of EDP-721

Enanta Pharmaceuticals, Inc. (NASDAQ:ENTA) today reported new preclinical data for EDP-721, a novel, oral hepatitis B virus (HBV) RNA destabilizer being developed for use in an all-oral combination regimen for HBV. The data demonstrate potent, selective and pangenotypic inhibition of HBV surface antigen (HBsAg), with up to a 3-log drop in the AAV-HBV mouse model. The research on EDP-721 was presented in a poster titled Discovery and Characterization of EDP-721, a Novel Hepatitis B Virus RNA Destabilizer, during the EASL International Liver Congress(tm) 2021.

"The data presented today strongly support the continued development of EDP-721 for use in an all-oral regimen to provide a functional cure for HBV," said Jay R. Luly, Ph.D., President and Chief Executive Officer of Enanta Pharmaceuticals. "While existing therapies for chronic HBV are moderately effective at suppressing HBV DNA, high levels of HBsAg present a key barrier to enduring viral clearance. These new preclinical data demonstrate that EDP-721 significantly reduced HBsAg production up to 3 logs and exhibited additive to synergistic activity with antivirals that target different mechanisms. We look forward to initiating a Phase 1 trial evaluating EDP-721 in mid-2021 and subsequently studying the compound in combination with other mechanisms, including our core inhibitor, EDP-514, and nucleoside reverse transcriptase inhibitors."

EDP-721 was shown to be a selective inhibitor of the non-canonical poly(A) polymerases, PAPD5 and PAPD7, host factors critical to the post-transcriptional stabilization of HBV RNA. Inhibition of PAPD5/7 results in potent and pangenotypic reduction in HBsAg production with minimal effects on the host transcriptome in uninfected primary human hepatocytes. Oral administration of EDP-721 demonstrated HBsAg reductions of up to 3 logs following 14 days of once-daily dosing in the AAV-HBV mouse model. EDP-721 was also shown to exhibit synergistic antiviral activity in vitro when combined with nucleos(t)ide reverse transcriptase inhibitors or the HBV core inhibitor EDP-514.

Enanta expects to initiate a Phase 1 single ascending dose (SAD) and multiple ascending dose (MAD) study to evaluate the safety and tolerability of EDP-721 in healthy volunteers in mid-2021.