China’s BD111 is The Most Advanced Gene-Editing Therapy Targeting HSV in Humans

Chinese biotech company BDgene Therapeutics, based in Shanghai, has developed BD111, a gene-editing therapy using CRISPR-Cas9 technology to target and remove latent herpes simplex virus type 1 (HSV-1) DNA from infected nerve cells.

The therapy employs a proprietary lentivirus-based mRNA delivery system designed to reach the trigeminal ganglion, where HSV-1 establishes lifelong latency.

Clinical trials conducted in China have demonstrated that a single dose of BD111 effectively eliminated detectable HSV-1 DNA in patients with refractory herpes keratitis, a serious viral infection of the cornea.

Follow-up periods extending up to 18 months showed no viral recurrence, indicating a potential functional cure rather than temporary suppression.

How BD111 Works

BD111’s delivery system, known as viroid-like particle mRNA (VLP-mRNA), enables retrograde transport from the cornea to the trigeminal ganglion.

This allows the CRISPR-Cas9 components to excise the viral genome hidden within nerve cells, directly targeting the root cause of HSV-1 persistence and recurrence.

Unlike conventional antiviral drugs that only inhibit viral replication, BD111 aims to remove the latent virus by cutting its DNA.

The therapy delivers Cas9 mRNA transiently, minimizing immune response and reducing the risk of off-target gene editing.

To date, no significant off-target effects on the human genome have been detected.

Regulatory Milestones Ahead of Western Research Efforts

In June 2022, BD111 received orphan drug designation from the U.S.

Food and Drug Administration (FDA), which facilitates accelerated development and review.

As of mid-2026, however, BD111 remains in trials in China only, and no BDgene-sponsored trial has yet opened in the United States.

The orphan drug designation still stands, but it has not yet translated into an active U.S. clinical program.

While several Western companies are developing gene-editing therapies for HSV, most remain in preclinical or early clinical stages.

BD111 currently stands as the most advanced gene-editing treatment targeting HSV in humans.

2026 Trial Status

Two BD111 trials are now running in China.

A Phase I safety and preliminary efficacy study (NCT06474416) began in September 2023 and has an estimated completion date of March 2026.

A larger, randomized, single-blind Phase IIa trial (NCT06474442), which began in April 2025, is enrolling 40 patients aged 18-70 with HSV-1 stromal keratitis and following them for 12 months; it targets primary completion in December 2026, with full study completion expected in March 2027.

Experts caution that further large-scale clinical trials are necessary to confirm long-term safety and efficacy, and formal Phase IIa efficacy results are not expected before late 2026 at the earliest.

Additional challenges remain around manufacturing scalability and expanding treatment to HSV-2, responsible for genital herpes.

BDgene is actively expanding its research pipeline to include gene-editing therapies targeting HSV-2, although these efforts are still in early stages.

As BD111 progresses through its Phase IIa trial, it represents a significant step forward in the global effort to develop curative therapies for herpes infections, which affect millions worldwide. The therapy’s innovative approach offers hope for a functional cure that could improve patient outcomes and reduce the burden of lifelong viral infection, though confirmed efficacy data is still pending.