A Phase 2 interventional study of ALN-CIDEB and Placebo in Metabolic Dysfunction-Associated Steatohepatitis and MASH, sponsored by Regeneron Pharmaceuticals. Recruiting at 24 sites in 3 countries. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-11-09.
Sponsored by Regeneron Pharmaceuticals · Phase 2, Interventional, and Treatment
This study will test a Regeneron study drug called ALN-CIDEB to find out whether it may help treat a liver disease called MASH.
In this study, researchers are looking at the effect of ALN-CIDEB on reducing liver fat, liver injury, and liver scarring. The study will compare ALN-CIDEB with placebo to understand how well ALN-CIDEB works to lower the amount of fat in the liver.
The study is looking at:
1,617 studies on the registry are indexed under Non-alcoholic Fatty Liver Disease; 324 are open to participants now.
This study's planned enrollment of 360 is above the median of 60 across 1,176 interventional studies indexed under Non-alcoholic Fatty Liver Disease.
Browse Non-alcoholic Fatty Liver Disease studies →Regeneron Pharmaceuticals is the lead sponsor of 411 studies on the registry; 90 are open to participants now.
Of its 125 completed or terminated interventional studies of FDA-regulated products, 79 (63%) have results posted.
Counted across the registry records on this site, refreshed daily.
The criteria were revised on the registry on Nov 9, 2026. See what changed
Key Inclusion Criteria:
Key Exclusion Criteria:
NOTE: Other Protocol-defined Inclusion/Exclusion Criteria Apply
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Drug: ALN-CIDEB
Drug: ALN-CIDEB
Drug: Placebo
Administered per the protocol
Administered per the protocol
Percent Change from Baseline in Liver Fat by Magnetic Resonance Imaging-derived Proton Density Fat Fraction (MRI-PDFF)
Time frame: At week 52
Resolution of MASH with No Worsening of Nonalcoholic Steatohepatitis-Clinical Research Network (NASH-CRN) Fibrosis on Liver Biopsy
Time frame: At week 52
Improvement of NASH-CRN Fibrosis Stage (F) by ≥1 with No Worsening of MASH on Liver Biopsy
Time frame: At week 52
Percent Change from Baseline in Liver Fat by MRI-PDFF
Time frame: At week 26
Achievement of a ≥30% Reduction in Liver Fat by MRI-PDFF Compared to Baseline
Time frame: At week 52
Achievement of ≤5% Liver Fat by MRI-PDFF
Time frame: At week 52
Percent Change from Baseline in Liver Fat by MRI-PDFF for Each Dose Level of ALN-CIDEB Compared to Placebo
Time frame: Up to week 52
Occurrence of Treatment-Emergent Adverse Events (TEAEs)
Time frame: Up to week 64
Severity of TEAEs
Time frame: Up to week 64
Change from Baseline in FibroScan Controlled Attenuation Parameter (CAP)
Time frame: Through week 52
Change from Baseline in FibroScan Liver Stiffness Measurement (LSM) by Vibration Controlled Transient Elastography (VCTE)
Time frame: Through week 52
Change from Baseline in Aspartate Aminotransferase (AST)
Time frame: Up to week 64
Change from Baseline in Alanine Aminotransferase (ALT)
Time frame: Up to week 64
Change from Baseline in Enhanced Liver Fibrosis (ELF)
Time frame: Through week 52
Change from Baseline in PRO-C3
Time frame: Through week 52
Change from Baseline in ADAPT
Time frame: Through week 52
Change from Baseline in NIS2+
Time frame: Through week 52
Percent Change from Baseline in Liver Fat by MRI-PDFF in Genetic Subpopulations
Time frame: At week 52
Plan to share: Yes — All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code
Time frame: When Regeneron has: received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc.) for the product and indication or has globally discontinued development of the product for all indications on or after April 2020 and has no plans for future development made the study results publicly available (e.g., scientific publication, scientific conference, clinical trial registry) the legal authority to share the data, and ensured the ability to protect participant privacy
Access criteria: Qualified researchers can submit a proposal for access to individual patient or aggregate level data from a Regeneron-sponsored clinical trial through Vivli. Regeneron's Independent Research Request Evaluation Criteria can be found at: https://www.regeneron.com/sites/default/files/Regeneron-External-Data-Sharing-Policy-and-Independent-Research-Request-Evaluation-Criteria.pdf
Data sharing details ↗ · vivli.org
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Non-alcoholic Fatty Liver Disease →