About

Dr. David N. Assis is an Associate Professor of Medicine in the Digestive Diseases section at Yale School of Medicine and serves as the Program Director for the Gastroenterology Fellowship. He received his MD from Jefferson Medical College and completed his internship, residency, and chief residency at Thomas Jefferson University Hospital. His fellowship training in gastroenterology and hepatology, as well as transplant hepatology, was conducted at Yale, where he also completed a T32 research track. His clinical and research interests focus on autoimmune and cholestatic liver diseases, including autoimmune hepatitis, primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC). Dr. Assis treats patients with these conditions and performs translational and basic research using human biospecimens and animal models to investigate disease mechanisms and potential therapies. His research explores the role of inflammatory cytokines, novel biomarkers, and the mechanisms of action of PPARs in cholestatic liver diseases. He is actively involved in professional organizations such as the American Association for the Study of Liver Disease (AASLD), contributing to guidelines and guidance documents. Additionally, Dr. Assis is part of the Yale Adult Cystic Fibrosis Program, evaluating and treating patients with GI or liver complications related to cystic fibrosis, and contributes to the development of clinical guidelines for CF liver disease. Since 2021, he has served as the Fellowship Program Director in the Section of Digestive Diseases.

Research topics

• Internal medicine
• Medicine
• Immunology
• General surgery
• Gastroenterology

Selected publications

• Long‐Term Use of Fenofibrate as Second‐Line Therapy in Primary Biliary Cholangitis: A Retrospective Study

  Alimentary Pharmacology & Therapeutics · 2026-02-18

  articleSenior authorCorresponding

  BACKGROUND AND AIMS: Nearly 40% of patients with primary biliary cholangitis (PBC) have an incomplete response to first-line ursodeoxycholic acid (UDCA) therapy. Fenofibrate, a peroxisome proliferator-activated receptor alpha (PPAR-α) agonist, is an effective second-line treatment for PBC. Compared to the recently FDA-approved PPAR agonists, fenofibrate may provide a more cost-effective and accessible alternative. However, longitudinal data on fenofibrate use in PBC are lacking. Here, we review our experience using fenofibrate in PBC and its long-term effects on cholestatic biomarkers, prognostic scores, and fibrosis indices. APPROACH AND RESULTS: This single-centre retrospective cohort study examined PBC patients prescribed fenofibrate between 2012 and 2024 for persistent elevations in alkaline phosphatase (ALP) despite UDCA therapy. The study included 59 patients treated with fenofibrate for a mean duration of 44.8 months. The overall median time to ALP normalisation was 9.5 months. Of those who did not meet Paris II criteria prior to fenofibrate therapy, the median time to ALP normalisation was 11.2 months. GLOBE prognostic scores significantly improved with fenofibrate therapy, while UK-PBC scores and fibrosis index scores (FIB-4) remained stable. Fenofibrate was well-tolerated by most patients, with only 5% of patients discontinuing therapy due to elevated liver enzymes. CONCLUSIONS: In this long-term cohort of PBC patients with insufficient response to UDCA, fenofibrate significantly improved cholestatic markers and prognostic scores over time. Given this, and its favourable safety profile, fenofibrate should be further considered as an accessible and affordable second-line therapy in PBC.

  PublisherDOI

• Gaps in Guideline Adherence for Primary Sclerosing Cholangitis in North America—A 5‐Year Analysis

  Liver International · 2026-04-10

  article

  BACKGROUND AND AIMS: Primary sclerosing cholangitis (PSC) is a progressive cholestatic liver disease with a high risk of malignancy and limited therapeutic options. Both the American Association for the Study of Liver Diseases (AASLD) and the European Association for the Study of the Liver (EASL) recommend structured baseline evaluation, fibrosis staging and longitudinal surveillance. However, real-world adherence to these practices in North America remains unclear. METHODS: We conducted a retrospective cohort study of 1300 patients with PSC enrolled in the Consortium for Autoimmune Liver Diseases (CALiD) registry between 2018 and 2024 across 19 centres in North America. Guideline adherence was assessed for diagnostic measures at baseline (colonoscopy to establish IBD status and noninvasive fibrosis staging) and longitudinal surveillance (colonoscopy in PSC-IBD, abdominal imaging for hepatobiliary cancer surveillance and CA 19-9 testing). Prescribing patterns for ursodeoxycholic acid (UDCA) were also characterised. Multivariable logistic regression was used to evaluate demographic, clinical and socioeconomic predictors of adherence. RESULTS: At diagnosis, 78.8% of eligible patients with available data underwent colonoscopy to establish IBD status, and 45% underwent noninvasive fibrosis staging. During follow-up, only 30%-35% of patients with PSC-IBD underwent colonoscopy annually, while abdominal imaging for hepatobiliary cancer surveillance declined from 74% at Year 1 to 51% by Year 4. CA 19-9 testing was documented in 47% over 5-year period. UDCA was prescribed in 51% at baseline, with median dose of 12.5 mg/kg/day. Socioeconomic factors, including lower education and household income, were associated with reduced adherence, while cirrhosis strongly predicted completion of surveillance imaging. CONCLUSIONS: Adherence to guideline-based care in PSC remains suboptimal in North America Suboptimal adherence was observed for strongly recommended practices with longstanding guideline support (colonoscopy to establish IBD status; annual CRC surveillance in PSC-IBD) as well as practices where guideline consensus has evolved more recently or where societies differ (baseline fibrosis assessment; hepatobiliary cancer imaging). Efforts to standardise care and address socioeconomic barriers are urgently needed to improve outcomes.

  PublisherDOI

• Corrigendum to ‘A liquid biopsy-RNAseq method for monitoring the expression of genes involved in drug disposition: proof-of-concept application to cholestatic liver disease’ [J. Pharm. Biomed. Anal. (2025) 269: 117244]

  Journal of Pharmaceutical and Biomedical Analysis · 2026-02-02

  article
  PublisherDOI

• Update on Biomarkers in Primary Sclerosing Cholangitis

  Current Hepatology Reports · 2026-01-07

  articleSenior author
  PublisherDOI

• Current opinion in gastroenterology

  Current Opinion in Gastroenterology · 2026-02-05

  article1st authorCorresponding
  PublisherDOI

• Mo1229: GAPS IN GUIDELINE ADHERENCE FOR PRIMARY SCLEROSING CHOLANGITIS IN THE US: A 5-YEAR ANALYSIS OF CALID DATABASE

  Gastroenterology · 2025-05-01

  article
  PublisherDOI

• Phase II clinical trials in primary sclerosing cholangitis: Making the most of every opportunity?

  Journal of Hepatology · 2025-11-04 · 1 citations

  editorial1st authorCorresponding
  PublisherDOI

• Ileal bile acid transporter inhibitors for cholestatic pruritus in primary biliary cholangitis

  ˜The œLancet. Gastroenterology & hepatology · 2025-10-28 · 5 citations

  articleSenior author
  PublisherDOI

• Hepatotoxicity of Chemotherapy and Immune Checkpoint Inhibitors

  Clinics in Liver Disease · 2025-05-12 · 1 citations

  reviewSenior authorCorresponding
  PublisherDOI

• Treatment of pruritus in primary sclerosing cholangitis: Analysis of the consortium for autoimmune liver disease registry

  Hepatology Communications · 2025-05-14 · 1 citations

  articleOpen access

  BACKGROUND: Cholestasis from primary sclerosing cholangitis (PSC) frequently causes pruritus. However, the prevalence of pruritus and its management have not been well studied. Investigating the Cholestatic Pruritus of Primary Sclerosing Cholangitis (ItCh-PSC) includes a retrospective medical record review to determine the prevalence, severity, and treatment patterns of pruritus. METHODS: Data was collected at 5 academic medical centers in the United States. Medical records were searched for the terms "itch" and "pruritus" and data abstracted related to itch severity, number of encounters, and treatment. RESULTS: Among 724 patients with PSC, 359 (50%) of patients had a documented history of pruritus, including 40%, 39%, and 21% with mild, moderate, or severe itch. Itch was less common in those with small ducts compared to large duct PSC (p=0.02) and more frequent in those of Hispanic versus non-Hispanic ethnicity (p=0.001). Compared to patients with mild itch, patients with moderate or severe itch were younger, and had more elevated liver biochemistries, more encounters with itch, and more frequently prescribed 2 or more anti-pruritic medications. Bile acid-binding resins were prescribed in 36%, hydroxyzine in 23%, rifampin in 11%, and fenofibrate in 4% of patients with any itch. The prevalence and severity of pruritus were not affected by cirrhosis, hepatic decompensation, or inflammatory bowel disease. CONCLUSION: Itch is common in patients with PSC and is often associated with multiple prescriptions of antipruritic agents. Effective treatments for pruritus in patients with PSC remain an unmet need.

  PublisherDOI

Recent grants

• The role of macrophage migration inhibitory factor in autoimmune hepatitis

  NIH · $812k · 2015–2019

Frequent coauthors

• Timo Jama

  Päijät-Hämeen Keskussairaala

  72 shared

• Joost P.H. Drenth

  University of Amsterdam

  47 shared

• Ansgar W. Lohse

  38 shared

• Michael Trauner

  Medical University of Vienna

  37 shared

• Viliam Dobias

  Slovak Medical University

  36 shared

• Frank Marx

  36 shared

• Anatolij Truhlás

  University of Lübeck

  36 shared

• Markus Thaler

  Health Service Executive

  36 shared

Education

• M.D.

  Jefferson Medical College

• Other

  Thomas Jefferson University Hospital