Gilead Sciences is pursuing a new avenue toward hepatitis B treatment, collaborating on gene therapies aimed at eliminating viral infections in vivo by using Precision BioSciences’ genome editing platform.
Gilead will fully fund the effort and run clinical trials, while Precision will be responsible for early development, formulation and preclinical work. Precision is slated to receive total milestone payments up to $445 million, plus tiered royalties following commercialization.
Current HBV treatments may suppress viral replication, but they do not completely clear out the virus; the infection’s covalently closed circular DNA, or cccDNA, enables HBV replication to restart if treatment is stopped.
Precision’s ARCUS editing platform is derived from a natural enzyme called a homing endonuclease, which can target long sequences and is used to insert or delete DNA. The Durham, North Carolina-based company’s fully synthetic version can be designed to locate and disrupt particular sequences and minimize off-target effects.
Gilead’s preliminary, in vitro studies using ARCUS nucleases have shown significant activity against cccDNA and integrated HBV DNA in human liver cells, the biotech said in a statement.
“Gilead's cure-based approach to hepatitis B is comprehensive and exciting,” said Precision’s chief scientific officer, Derek Jantz. “This is an excellent application for our technology, which has made notable progress toward therapeutic in vivo editing in relevant models over the last year.”
Earlier this month, Precision expanded its collaboration with the University of Pennsylvania focused on in vivo gene editing. The three-year project covers three gene knockout programs and up to three knock-in or gene repair programs, including studies in nonhuman primate models before pursing clinical trials.
And this past summer, Precision raised $110 million to move its off-the-shelf CAR-T cancer treatment into human clinical trials, with Gilead participating in the series B round. Precision’s plan is to use ARCUS to create a CAR-T therapy from T cells from healthy donors, not cancer patients. The company’s previous investors include venBio and the VC arms of Amgen and Baxter.