Intellia Gets Phase III Greenlight from FDA for Gene Editing Therapy

Pictured: FDA headquarters/iStock, JHVEPhoto

Pictured: FDA headquarters/iStock, JHVEPhoto

Massachusetts-based Intellia Therapeutics’ ongoing push for regulatory approval of its genetic liver disease therapy cleared another hurdle on Wednesday, with the FDA giving the genome-editing company clearance to launch a Phase III trial.

The therapy is the first investigational CRISPR therapy candidate “to be administered systemically, or through a vein, to edit genes inside the human body,” Intellia said in its announcement, adding that the FDA go-ahead marks “the first in vivo CRISPR-based candidate to begin late-stage clinical development.”

“This is another important step forward for Intellia and our collaborator, Regeneron, as we aim to establish a new standard of care for the treatment of ATTR amyloidosis,” Intellia CEO John Leonard said in a statement.

Intellia has been studying NTLA-2001, its investigational drug candidate, as a possible treatment for transthyretin (ATTR) amyloidosis cardiomyopathy, a genetic liver disease that causes production and buildup of a faulty protein—transthyretin—in the heart, as a result of mutations in the TTR gene which can ultimately lead to heart failure.

The therapy is intended to knock out the faulty gene and replace it with a functional one. Intellia has been investigating the potential of the therapy alongside Regeneron, with Intellia leading the way on development and commercialization of the therapy, with Regeneron covering about 25% of the costs in exchange for 25% of the profits.

The two companies also announced last September that the Phase I in vivo study of NTLA-2001 showed “deep and sustained mean serum transthyretin (TTR) reductions of 93% and 92% at 0.7 mg/kg and 1.0 mg/kg doses, respectively, at day 28,” and that the therapy was “generally well-tolerated at both dose levels.”

The companies also announced earlier this month that they would be expanding their research partnership to develop CRISPR-based therapies for muscular and neurological diseases.

The two have been working together since 2016, when they first announced a partnership to discover and develop CRISPR and Cas therapeutics.

Leonard said in Wednesday’s announcement that Intellia  looks forward to sharing additional information about the Phase III study at its third-quarter earnings webcast, being held on Nov. 9. Intellia CMO David Lebwohl told investors on a conference call in August 2023 that the late-stage study will be roughly the same size as Alnylam’s HELIOS-B study, which enrolled 164 patients.

Connor Lynch is a freelance writer based in Ottawa, Canada. Reach him at

Back to news