JPM26: Korro Bio Looks To Save Itself Despite Unenviable Position

The game slipped away from Korro Bio, but the company came to JPM26 ready to play.

“We spent the last three months doing a root-cause analysis,” of the recent failed trial of its lead asset—along with some soul searching, CEO Ram Aiyar told BioSpace in an interview on the sidelines of the J.P. Morgan Healthcare Conference. Now, with a new delivery vehicle and a few other tweaks to the product, he sees Korro staging a comeback.

The trouble started this past fall, when Korro suffered a litany of blows as RNA-editing treatment KRRO-110 flunked a Phase I/IIa trial for for alpha-1 antitrypsin deficiency (AATD). The company laid off one-third of its staff, and the chief medical officer resigned. Adding salt to the wound, Novo Nordisk paused a partnership inked in September 2024 for at least a year. The company’s stock crashed 80% on all the news.

The retrospective analysis gave Korro some answers, however. It specifically showed that the therapy’s lipid nanoparticle (LNP) delivery vehicle wasn’t doing its job: only about a quarter of the construct that they were expecting was being expressed in the target cells.

It was a “banging our head against the wall” moment, Aiyar said. “In every patient we dosed, we saw end protein; it just wasn’t at the levels we needed it to be.” Something lurking in the serum of AATD patients, and only AATD patients—not preclinical models, not mice, not monkeys, and not healthy volunteers—was making their construct fall apart.

“If they could work around this issue they would double down likely” on the LNP approach, William Blair analyst Myles Minter told BioSpace in an interview ahead of JPM. Instead, Korro has selected an N-acetylgalactosamine (GalNac) delivery vehicle—used by other biotechs pursuing RNA editing in AATD, including Wave Life Sciences and Beam Therapeutics—that works just as well as it hoped its LNP formulation would.

This week in San Francisco, Aiyar was confident that Korro can soldier forth—“now that I know we can make constructs that are three logs more potent.”

AATD was Korro’s most promising indication and KRRO-110 its most promising candidate, according to Minter. Now that it is essentially starting over in that space with a new formulation, that puts the company about two years behind competitors. “That’s a tough sell,” Minter said.

But Aiyar batted this critique away. The last company Aiyar was a part of, the kidney disease therapeutic developer Corvidia Therapeutics, was similarly behind competitors in its development lifecycle and did quite well from this position; Corvidia was purchased by Novo Nordisk in 2020 for $2.1 billion.

It doesn’t matter if you’re late or early, Aiyar said. “If the compound is best-in-class, that won’t be a problem.”

As for Novo pausing its partnership with Korro, which involved developing multiple central nervous system programs for the Danish pharma, Aiyar is feeling level-headed. He pointed out that the Novo partnership was not terminated, because Novo “need[s] to figure out where they are” as a company more broadly. “They were not in MASH, then they bought Akero,” he pointed out, referring to the $5.2 billion purchase of Akero Therapeutics in October 2025.

“I think they’re working through some stuff,” Aiyar said. “I’m confident they’ll come back.”

The runway for Korro isn’t long, however. The layoffs in the fall helped the company push its viability only into 2027. “We are in a tough cash position to be completely honest,” Aiyar said.

But he came to JPM to find a way to finish the company’s work. “I have a lot of levers to pull,” he noted. “We have two other shots on goal, other assets” to work with. Additionally, Korro’s experience working with Novo on CNS diseases has the company interested in further exploring that space.

While he doesn’t “have enough cash” right now to move forward Korro’s CNS programs—including at least one discovery-stage ALS program—Aiyar said that’s part of why he’s at JPM this year. “We’ll look for partners in the CNS space.”