Regeneron stock gains pipeline focus from CIDEB liver-fat data
Published on 11/09/2026 at 14:30 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWSCIDEB data sharpen pipeline focus
- Regeneron reported first-in-human CIDEB siRNA results in adults with MASLD on November 8.
- The investigational treatment normalized liver fat in 62% of treated participants at week 36, versus none in the placebo group.
- Management will discuss the cardiometabolic and MASH pipeline at a virtual investor event on November 10.
Regeneron Pharmaceuticals said on Sunday, November 8, that a single dose of investigational CIDEB siRNA produced sustained reductions in liver fat in adults with metabolic dysfunction-associated steatotic liver disease. The company presented the first-in-human results at the 2026 meeting of the American Association for the Study of Liver Diseases and said the findings were published simultaneously in The New England Journal of Medicine.
The Regeneron investor release said the Phase 1/2 trial tested four dose levels in 30 participants receiving CIDEB siRNA and compared them with 10 placebo recipients. The main goal was safety and tolerability, while changes in liver fat and liver-injury markers were secondary measures.
Deep liver-fat reduction at week 36
Among participants receiving CIDEB siRNA, liver fat fell by 58% to 80% at week 36, measured by MRI-PDFF. The reductions had reached 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 CIDEB siRNA recipients at week 36, compared with none of the placebo recipients. Regeneron also said 93% of treated participants achieved at least a 30% reduction, a threshold associated with histological MASH resolution. Alanine aminotransferase levels declined across all dose groups, with directionally similar changes in aspartate aminotransferase.
The safety profile remains an important development factor because the study is early stage. Overall adverse-event rates were generally similar between the treatment and placebo groups, and all adverse events were mild or moderate except for one severe, serious hyperglycemia event that the company said was not attributed to the study drug. No participant discontinued the trial, and no nausea or vomiting events were reported in the CIDEB siRNA groups.
Next catalyst is a pipeline webcast
Regeneron is evaluating longer-term safety and histological outcomes in ongoing Phase 2a, Phase 2b and Phase 3 studies. The company describes CIDEB siRNA as a first-in-class, liver-targeted small-interfering-RNA treatment based on genetic findings from its Regeneron Genetics Center. Its potential uses remain investigational and have not been evaluated by a regulatory authority.
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. The webcast is the next scheduled event for investors following the AASLD data release.
The real-time quote of Regeneron stock was 819.95 euros on Lang & Schwarz at 14:16 CET on Monday, November 9, 2026.
Regeneron Pharmaceuticals at a glance
- Company: Regeneron Pharmaceuticals, Inc.
- ISIN: US75886F1075
- Ticker: REGN
- Home exchange: Nasdaq
- Lang & Schwarz price: 819.95 euros on November 9, 2026, at 14:16 CET
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.
