# Vlad Ratziu
**Vlad Ratziu** The Assistance Publique – Hôpitaux de Paris directory lists him in gastro-enterology and hepatology in the Service d'Hépato-Gastro-Entérologie of Pitié-Salpêtrière,[2](https://www.aphp.fr/pr-ratiu-vlad) and the French hospital federation directory records him as PUPH (Professeur des Universités – Praticien Hospitalier) and head of a functional unit there, with a specialty line in the diagnosis and prevention of severe liver diseases.[3](https://etablissements.fhf.fr/annuaire/member/structure2048-establishment5783-service38230-member122582) He is affiliated with the Institute for Cardiometabolism and [Nutrition](https://www.edgepedia.org/nutrition) (ICAN), a Sorbonne-affiliated research center.[4](https://hepionpharma.com/about/leadership/vlad-ratziu/) • [5](https://www.santemagazine.fr/experts/pr-vlad-ratziu-1115779)
| Fact | Detail |
|---|---|
| Specialty | Hepatology (gastro-enterology and hepatology), fatty liver disease[2](https://www.aphp.fr/pr-ratiu-vlad) |
| Hospital post | PUPH and became head of a functional unit, Pitié-Salpêtrière, AP-HP[3](https://etablissements.fhf.fr/annuaire/member/structure2048-establishment5783-service38230-member122582) |
| Signature work | MAESTRO-NASH phase 3 resmetirom trial, New England Journal of Medicine, 2024[6](https://www.nejm.org/doi/full/10.1056/NEJMoa2309000) |
| Methodology work | 2005 Gastroenterology study of liver biopsy sampling variability in NAFLD[7](https://doi.org/10.1053/j.gastro.2005.03.084) |
| Guidelines | Panel member, EASL–EASD–EASO NAFLD 2016 and MASLD 2024 guidelines[8](https://easl.eu/wp-content/uploads/2018/10/NAFLD-English-report.pdf) • [9](https://europepmc.org/article/MED/38869512) |
| Regulatory milestone | Resmetirom received FDA accelerated approval in March 2024 for MASH with F2–F3 fibrosis[10](https://doi.org/10.1097/hep.0000000000001112) |
## Career and training
A national thesis catalog record associates him with a thesis on non-alcoholic steatohepatitis.[11](https://theses.fr/069737290) Hepion Pharmaceuticals lists him on its Scientific Advisory Board.[4](https://hepionpharma.com/about/leadership/vlad-ratziu/) According to a 2023 interview in *Gastroenterology & Hepatology*, Ratziu disclosed consulting for [Novo Nordisk](https://www.edgepedia.org/novo-nordisk), Madrigal Pharmaceuticals, Intercept Pharmaceuticals, Terns Pharmaceuticals, ENYO Pharma, Poxel, Bristol Myers Squibb, NGM Bio, and Pfizer, and research grants to his institution from [Gilead Sciences](https://www.edgepedia.org/gilead-sciences) and Intercept.[12](https://www.gastroenterologyandhepatology.net/files/2023/03/0423_NASH_Ratziu_final_r1-1.pdf)
## Liver biopsy sampling variability and trial methodology
In 2005, as corresponding author, Ratziu published in [Gastroenterology](https://www.edgepedia.org/gastroenterology) a study of how much a liver biopsy sample can misrepresent a fatty liver. The design was direct: two distinct liver fragments were taken through the same puncture site, on the same occasion, from each of 51 patients.[7](https://doi.org/10.1053/j.gastro.2005.03.084) Because a percutaneous biopsy fragment is estimated to represent about 1/50,000 of the whole organ, any two fragments can disagree.[13](https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2036.2007.03425.x) Agreement between the paired fragments was 78% for steatosis class, 59% for fibrosis stage, 57% for activity grade, and 67% for ballooning score.[13](https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2036.2007.03425.x)
The consequence was quantitative. Published natural-history studies had reported fibrosis progression on follow-up biopsy of about 20% to 40%; a 2007 reassessment showed these proportions were not statistically different from what a second same-day fragment would show, concluding that sampling variability was an overlooked confounding factor in interpreting histological progression in NAFLD.[13](https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2036.2007.03425.x) The EASL–EASD–EASO 2016 guidelines, on which he sat as a panel member, still called liver biopsy essential for diagnosing NASH and the only procedure that reliably differentiates simple steatosis from steatohepatitis, while acknowledging sampling variability.[8](https://easl.eu/wp-content/uploads/2018/10/NAFLD-English-report.pdf)
## Representative work
The resmetirom MAESTRO-[NASH trial](https://www.edgepedia.org/nash-trial) (New England Journal of Medicine, 2024; [doi:10.1056/NEJMoa2309000](https://doi.org/10.1056/nejmoa2309000)) is the work he is most identified with. According to the phase 3 trial's publication in the *New England Journal of Medicine*, Ratziu, of Sorbonne Université, Inserm UMRS 1138, and AP-HP, participated as co-lead investigator in the MAESTRO-NASH trial funded by Madrigal Pharmaceuticals (NCT03900429).[6](https://www.nejm.org/doi/full/10.1056/NEJMoa2309000) • [1](https://ihuican.org/en/results-of-the-maestro-nash-clinical-trial-a-new-hope-for-the-treatment-of-mash-nash-with-liver-fibrosis/) • [14](https://clinicaltrials.gov/study/NCT03900429) Overall, 966 patients with biopsy-confirmed NASH and fibrosis stage F1B, F2, or F3 were randomized to once-daily resmetirom 80 mg, 100 mg, or placebo.[6](https://www.nejm.org/doi/full/10.1056/NEJMoa2309000) • [18](https://www.nejm.org/doi/abs/10.1056/NEJMoa2309000) Resmetirom is an orally administered, liver-targeted, beta-selective agonist of the thyroid hormone receptor.[1](https://ihuican.org/en/results-of-the-maestro-nash-clinical-trial-a-new-hope-for-the-treatment-of-mash-nash-with-liver-fibrosis/) NASH resolution with no worsening of fibrosis at week 52 was achieved in about 20% (80 mg) and about 30% (100 mg) versus about 10% on placebo (P<0.001); fibrosis improvement by at least one stage without worsening of the activity score occurred in about 25% and 25% versus about 15% (P<0.001).[6](https://www.nejm.org/doi/full/10.1056/NEJMoa2309000)
The aramchol ARREST trial ([Nature Medicine](https://www.edgepedia.org/nature-medicine), 2021; [doi:10.1038/s41591-021-01495-3](https://doi.org/10.1038/s41591-021-01495-3)), on which he was a co-author, tested a different mechanism: aramchol is a partial inhibitor of hepatic stearoyl-CoA desaturase (SCD1).[15](https://www.nature.com/articles/s41591-021-01495-3) In this 52-week phase 2b trial, 247 patients were randomized to aramchol 400 mg, 600 mg, or placebo.[15](https://www.nature.com/articles/s41591-021-01495-3) The primary endpoint missed: the placebo-corrected decrease in liver triglycerides with 600 mg was −3.1 with a 95% confidence interval of −6.4 to 0.2, P=0.066.[15](https://www.nature.com/articles/s41591-021-01495-3) NASH resolution without worsening fibrosis occurred in 16.7% (13/78) of the 600 mg arm versus 5% (2/40) on placebo, an odds ratio of 4.74 with a confidence interval crossing 1.[15](https://www.nature.com/articles/s41591-021-01495-3)
Another work is a 2013 systematic review of follow-up biopsies in the Journal of Hepatology ([doi:10.1016/j.jhep.2013.04.027](https://doi.org/10.1016/j.jhep.2013.04.027)).
## Guidelines and field leadership
According to the 2024 EASL–EASD–EASO MASLD guidelines published in *Diabetologia*, Ratziu served as a panel member of the joint EASL–EASD–EASO NAFLD clinical practice guidelines published in 2016,[8](https://easl.eu/wp-content/uploads/2018/10/NAFLD-English-report.pdf) and of the updated 2024 joint MASLD guidelines published in *Diabetologia*.[9](https://europepmc.org/article/MED/38869512) The 2024 guidelines recommend resmetirom for adults with non-cirrhotic MASH and fibrosis stage ≥2 where locally approved, and state that no MASH-targeted pharmacotherapy can currently be recommended for the cirrhotic stage.[9](https://europepmc.org/article/MED/38869512)
## Recent developments
Resmetirom moved from trial result to approved medicine. The [European Medicines Agency](https://www.edgepedia.org/european-medicines-agency) granted Rezdiffra a conditional marketing authorization valid throughout the EU on 18 August 2025,[16](https://www.ema.europa.eu/en/medicines/human/EPAR/rezdiffra) and the UK MHRA authorized it on 3 June 2026, describing it as the first medicine approved for patients with MASH and moderate to advanced liver fibrosis.[17](https://www.gov.uk/government/news/resmetirom-rezdiffra-authorised-to-treat-metabolic-dysfunction-associated-steatohepatitis-mash-in-adults) According to the October 2024 updates to the AASLD Practice Guidance on resmetirom therapy for metabolic dysfunction-associated steatotic liver disease, the label does not require liver biopsy to confirm fibrotic MASH, though AASLD notes there are no FDA-approved noninvasive tests to diagnose MASH with F2–F3 or to monitor treatment response.[10](https://doi.org/10.1097/hep.0000000000001112)
## References
1. [Results of the MAESTRO-NASH clinical trial, IHU ICAN](https://ihuican.org/en/results-of-the-maestro-nash-clinical-trial-a-new-hope-for-the-treatment-of-mash-nash-with-liver-fibrosis/)
2. [Pr VLAD RATIU, AP-HP](https://www.aphp.fr/pr-ratiu-vlad)
3. [Pr VLAD RATIU, FHF annuaire](https://etablissements.fhf.fr/annuaire/member/structure2048-establishment5783-service38230-member122582)
4. [Vlad Ratziu, M.D., Ph.D., Hepion Pharmaceuticals](https://hepionpharma.com/about/leadership/vlad-ratziu/)
5. [Professeur Vlad Ratziu, Santé Magazine](https://www.santemagazine.fr/experts/pr-vlad-ratziu-1115779)
6. [A Phase 3, Randomized, Controlled Trial of Resmetirom in NASH with Liver Fibrosis, NEJM](https://www.nejm.org/doi/full/10.1056/NEJMoa2309000)
7. [Sampling Variability of Liver Biopsy in Nonalcoholic Fatty Liver Disease, Gastroenterology](https://doi.org/10.1053/j.gastro.2005.03.084)
8. [EASL–EASD–EASO Clinical Practice Guidelines for the management of NAFLD (2016)](https://easl.eu/wp-content/uploads/2018/10/NAFLD-English-report.pdf)
9. [EASL–EASD–EASO Clinical Practice Guidelines on the management of MASLD: Executive Summary, Diabetologia](https://europepmc.org/article/MED/38869512)
10. [Resmetirom therapy for MASH: October 2024 updates to AASLD Practice Guidance, Hepatology](https://doi.org/10.1097/hep.0000000000001112)
11. [Vlad Ratziu, Theses.fr](https://theses.fr/069737290)
12. [NASH in Focus: interview with Vlad Ratziu, Gastroenterology & Hepatology](https://www.gastroenterologyandhepatology.net/files/2023/03/0423_NASH_Ratziu_final_r1-1.pdf)
13. [Histological progression of non-alcoholic fatty liver disease: a critical reassessment, Alimentary Pharmacology & Therapeutics](https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2036.2007.03425.x)
14. [MAESTRO-NASH, ClinicalTrials.gov](https://clinicaltrials.gov/study/NCT03900429)
15. [Aramchol in patients with nonalcoholic steatohepatitis: a randomized, double-blind, placebo-controlled phase 2b trial, Nature Medicine](https://www.nature.com/articles/s41591-021-01495-3)
16. [Rezdiffra, European Medicines Agency](https://www.ema.europa.eu/en/medicines/human/EPAR/rezdiffra)
17. [Resmetirom (Rezdiffra) authorised to treat MASH in adults, MHRA, GOV.UK](https://www.gov.uk/government/news/resmetirom-rezdiffra-authorised-to-treat-metabolic-dysfunction-associated-steatohepatitis-mash-in-adults)
18. [NEJMoa2309000 (nejm.org)](https://www.nejm.org/doi/abs/10.1056/NEJMoa2309000)
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*Topic: Encyclopedia › Life and health › Life and health scientists › Medical and health researchers › Gastroenterology and hepatology researchers › Hepatologists › Fatty liver and alcohol-related disease researchers*
*Initially written Sep 21, 2026 · Reviewed: Sep 25, 2026; Sep 30, 2026 · Edited: Sep 25, 2026; Sep 30, 2026; Oct 11, 2026; Oct 15, 2026 · Last review: Sep 30, 2026*
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