FDA grants fast track status to gene-editing therapy for hepatitis B
PBGENE-HBV now being tested in patients in Phase 1 clinical trial
The U.S. Food and Drug Administration (FDA) has granted fast track status to PBGENE-HBV, Precision Bioscience’s gene-editing therapy candidate for chronic hepatitis B — now being tested in patients in a Phase 1 clinical trial.
Fast track status aims to expedite the clinical development and regulatory review of treatments with the potential to address an unmet medical need for serious or life-threatening conditions. With this designation, Precision will have access to more frequent communication with the FDA about PBGENE-HBV’s development pathway.
Further, should the company ultimately seek the therapy’s approval, the application would be eligible for rolling review. That means Precision can submit parts of the application as they’re ready, rather than waiting until it’s entirely completed for regulatory consideration to start. If certain criteria are met, the submission may also be eligible for priority review, which shortens the review time from 10 months to six.
“We are pleased to receive fast track designation from the FDA for PBGENE-HBV and believe this classification underscores the urgent need for improved treatment options for patients living with chronic hepatitis B,” Michael Amoroso, president and CEO of Precision, said in a company press release.
The ongoing Phase 1 ELIMINATE-B trial (NCT06680232) is assessing the safety and tolerability of PBGENE-HBV, as well as other secondary markers, in about 45 people with chronic hepatitis B.
Ongoing trial of PBGENE-HBV now cleared to expand into US
That trial, which may still be recruiting, was launched last fall in Moldova, and the FDA has now given clearance for it to expand into the U.S. According to Precision, there also are clinical sites in the U.K., New Zealand, and Hong Kong.
Early data have been promising, per Amoroso.
“We’ve been encouraged by the initial safety and antiviral activity we have observed in the ELIMINATE-B trial and look forward to continuing to work closely with the FDA as we progress PBGENE-HBV through clinical development,” Amoroso said.
In hepatitis B, liver inflammation arises due to an infection with the hepatitis B virus, known as HBV. If the infection doesn’t clear up and becomes chronic — lasting at least six months — it can lead to more serious liver damage.
Available antiviral therapies can’t completely stop HBV from replicating its DNA in the body, and therefore usually have to be taken for life to keep the infection suppressed.
Delivered intravenously, or via infusions into the bloodstream, PBGENE-HBV is a gene-editing therapy designed to eliminate or inactivate two forms of HBV DNA that are key to enabling the virus to replicate and survive in human liver cells. In doing so, its goal is to lead to a functional cure, where HBV is no longer actively replicating and antiviral treatments can be stopped.
We’ve been encouraged by the initial safety and antiviral activity we have observed in the ELIMINATE-B trial and look forward to continuing to work closely with the FDA as we progress PBGENE-HBV through clinical development.
ELIMINATE-B’s participants are adults with chronic hepatitis B who are on stable regimens of antiviral therapies and who test negative for HBeAg, a protein indicating that HBV is actively replicating in the body.
Its first part is testing three doses of PBGENE-HBV in 3-6 participants each, and patients can receive up to three infusions at their assigned dose. The optimal dose will then be selected and tested in a larger group of participants for the study’s second part.
Safety is the study’s main goal, with PGENE-HBV’s antiviral activity and pharmacological properties also being assessed as secondary goals.
Data from the first three participants after their initial infusion of the lowest tested dose showed the gene-editing therapy was well tolerated. For two participants, it also led to substantial reductions in HBsAg — a protein important for HBV’s ability to infect human cells — suggesting that PBGENE-HBV had the expected antiviral effects.
The company plans to share additional data throughout the rest of the year. This will include full data from this low-dose group, including after multiple infusions, as well as data from participants who received PBGENE-HBV at higher dose levels.
ELIMINATE-B findings have been consistent with preclinical studies demonstrating the therapy’s safety profile and ability to reduce HBsAg levels, according to Precision.
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