April 27 (Reuters) – Intellia Therapeutics said on Monday its experimental gene-editing therapy reduced the frequency of swelling attacks in patients with a rare genetic disorder in a late-stage trial, sending its shares up more than 5% in volatile premarket trading.
The therapy lonvoguran ziclumeran is aimed at treating hereditary angioedema (HAE), an inherited disorder that causes recurring episodes of swelling in the limbs, face, gastrointestinal tract and airways, with symptoms including abdominal pain, nausea and vomiting.
In a trial involving 80 patients, a one-time infusion of the therapy reduced swelling episodes by 87% compared to placebo over six months, meeting the main goal.
The therapy also helped 62% of patients remain attack-free without regular preventive therapy during that period, compared with 11% in the placebo group, meeting the secondary goal of the trial.
The company’s shares surged 30% in premarket in anticipation of positive trial data before paring most of those gains.
“The bar for lonvo-z is high given its one-time high-cost profile,” said analyst Debanjana Chatterjee from Jones Trading, adding the muted stock reaction reflects the Street’s misplaced expectations.
Achieving best‑in‑class efficacy with a clean safety profile was always the realistic goal, and the therapy delivered on both, said Chatterjee.
HAE affects about one in 50,000 people, according to the company, and can become life-threatening when swelling affects the throat.
The therapy is administered as a single intravenous infusion and is designed to disable a gene involved in making kallikrein, a protein that plays a role in triggering these attacks.
Side effects seen by the data cutoff were mild or moderate, with no serious adverse events in the treatment arm, the company said.
Intellia said it expects to complete its U.S. regulatory filing for the therapy in the second half of 2026 and a possible U.S. launch in the first half of 2027, pending approval.
(Reporting by Kunal Das and Kamal Choudhury in Bengaluru; Editing by Vijay Kishore)
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