# Development of a PCR assay for quantitative detection of HBV cccDNA

> **NIH NIH R43** · JBS SCIENCE, INC. · 2024 · $289,302

## Abstract

Development of a PCR assay for quantitative detection of HBV cccDNA
There is an urgent and unmet need for an effective method to detect hepatitis B virus
(HBV) cccDNA in the blood. HBV infection affects nearly 350 million people worldwide. Chronic
HBV infection is a major risk factor for the development of severe liver diseases such as cirrhosis
and hepatocellular carcinoma, which has a poor survival rate. Current therapies are effective
at suppressing viral replication. However, they do not eliminate the virus due to their inability
to eliminate the plasmid-like episome, covalently closed circular DNA (cccDNA) which can serve
as a template for the continuous generation of infectious viruses. This cccDNA, which resides
in the host nucleus, is generated from relaxed circular DNA (rcDNA), a partially double-
stranded DNA found in circulating virions and transmitted into the host hepatocytes. The
need to remove cccDNA to cure HBV infection has prompted drug discovery groups to focus
efforts on developing compounds that can target and eliminate cccDNA. Even with the ongoing
development of novel drugs, there is still an absence of a quantitative, specific, and reliable
cccDNA assay that is both highly sensitive for the detection of cccDNA in the blood, as well as
being specific enough to not detect rcDNA. The goal of this SBIR is to develop an innovative
and sensitive cccDNA assay that would be suitable for routine testing by physicians to manage
patients with chronic HBV infection and facilitate anti-HBV drug development. We have designed
such an assay, and our preliminary studies have indicated specific detection of 1,000 copies of
cccDNA and no detectable amplification of 10,000 copies of rcDNA. Two aims are proposed
in this phase I application. Aim 1 is to develop an innovative quantitative PCR assay that has
a sensitivity of 0.1% of cccDNA to rcDNA. Aim 2 is to perform assay validation with liver biopsies
and serial measurement of cccDNA from peripheral blood of chronic hepatitis B (CHB) patients
on therapy. In phase II, we will further develop and evaluate the assay to monitor therapeutic
efficacy.

## Key facts

- **NIH application ID:** 10804690
- **Project number:** 5R43AI174349-02
- **Recipient organization:** JBS SCIENCE, INC.
- **Principal Investigator:** Selena Lin
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $289,302
- **Award type:** 5
- **Project period:** 2023-03-07 → 2025-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10804690

## Citation

> US National Institutes of Health, RePORTER application 10804690, Development of a PCR assay for quantitative detection of HBV cccDNA (5R43AI174349-02). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10804690. Licensed CC0.

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