Regeneron stock shifts focus to CIDEB data before webcast

Regeneron Pharmaceuticals said on Sunday, November 8, that a single investigational CIDEB siRNA dose produced sustained liver-fat reductions in adults with metabolic dysfunction-associated steatotic liver disease. The company presented the first-in-human findings at the 2026 meeting of the American Association for the Study of Liver Diseases and published them simultaneously in the New England Journal of Medicine. The Regeneron investor release described the trial results.

Deep Liver-Fat Reduction

The Phase 1/2 trial tested four dose levels in 30 participants receiving CIDEB siRNA and compared them with 10 placebo recipients. Liver fat fell by 58% to 80% at week 36, measured by MRI-PDFF, after reductions of 49% to 72% at week six. The placebo group recorded a mean decrease of 2.9% at week 36.

Liver fat fell below 5% in 62% of treated participants at week 36, compared with none in the placebo group. Regeneron also said 93% of treated participants achieved at least a 30% reduction, a threshold associated with histological MASH resolution. The primary trial goal was safety and tolerability, while liver-fat and liver-injury measures were secondary endpoints.

Early Safety And Next Steps

Overall adverse-event rates were generally similar between the treatment and placebo groups. The company said all adverse events were mild or moderate except for one severe, serious hyperglycemia event that was not attributed to the study drug; no participant discontinued treatment, and no nausea or vomiting events were reported in the CIDEB siRNA groups.

Regeneron is evaluating longer-term safety and histological outcomes in ongoing Phase 2a, Phase 2b and Phase 3 studies. Management will host a virtual Regeneron Roundtable on Tuesday, November 10, at 8:30 a.m. Eastern time to discuss the cardiometabolic and MASH pipeline. CIDEB siRNA remains investigational and has not been evaluated by a regulatory authority.

Regeneron Stock At Lang And Schwarz

Regeneron stock traded at 810.80 euros on Lang & Schwarz at 16:15 CET on Monday, November 9, 2026. That was 1.12% below the 819.95-euro quote in our report at 14:16 CET on the same day; this is a separate comparison from any Xetra close.

Regeneron Pharmaceuticals At A Glance

• Company: Regeneron Pharmaceuticals, Inc.
• ISIN: US75886F1075
• Ticker: REGN
• Home exchange: Nasdaq
• Lang & Schwarz price: 810.80 euros on Monday, November 9, 2026, at 16:15 CET
• Change since the prior report: Down 1.12% from 819.95 euros at 14:16 CET on November 9, 2026

The wider US market context is covered in the S&P 500 market overview.

Further developments around the pipeline, trial progress and investor events are available in more news and analyses on Regeneron stock.