A fresh therapy, CNP-104, is showing promise in the treatment of primary biliary cholangitis (PBC), a chronic liver disease, according to results from a U.S.-based Phase 2a clinical trial. The investigational infusion therapy demonstrated reductions in markers of liver damage and scarring—fibrosis—after one year in adults with the condition. The findings, announced earlier this week, offer a potential new avenue for treatment for a disease that currently has limited therapeutic options.
PBC is an autoimmune disease where the body’s immune system attacks the small bile ducts in the liver. This inflammation leads to a buildup of bile, causing liver damage and eventually potentially leading to cirrhosis and liver failure. Currently, treatments focus on managing symptoms and slowing disease progression, but a therapy targeting the underlying immune dysfunction has been a long-sought goal. Liver Disease News first reported on the trial results on March 4, 2026.
How CNP-104 Works
CNP-104, developed by Cour Pharmaceuticals, takes a novel approach to treating PBC. Unlike existing therapies that primarily address symptoms, CNP-104 aims to restore immune tolerance. According to a press release from BioSpace, the therapy is an investigational biodegradable nanoparticle encapsulating the E2 component of the mitochondrial pyruvate dehydrogenase complex (PDC-E2). PDC-E2 is a key autoantigen in PBC, meaning it’s a substance the immune system mistakenly identifies as foreign and attacks.
By delivering PDC-E2 via nanoparticles, CNP-104 seeks to “retrain” the immune system to recognize this liver component as self, thereby reducing the autoimmune attack on the bile ducts. The Phase 2a trial involved a small number of participants with PBC and administered two doses of CNP-104 one week apart. The one-year data revealed durable clinical effects, including stabilization in liver stiffness measurements and validated prognostic risk scores.
Key Findings from the Phase 2a Trial
The trial results, while still preliminary, are encouraging. Researchers observed improvements in key cholestasis endpoints, including a composite serum alkaline phosphatase (ALP) and bilirubin biochemical response. ALP and bilirubin are markers of liver function, and elevated levels indicate liver damage. The observed separation of CNP-104 treated patients from the placebo group on this composite measure suggests a meaningful therapeutic effect.
“CNP-104 demonstrated robust antigen-specific immune modulation consistent with restoration of immune tolerance in PBC,” said Dannielle Appelhans, Chief Executive Officer of COUR Pharma, in the BioSpace press release. “The one-year data confirms continued stabilization in liver stiffness measurements and validated prognostic risk scores, while newly demonstrating achievement of established composite biochemical response criteria at twelve months.”
What’s Next for CNP-104?
While the Phase 2a trial results are positive, it’s critical to note that the study was relatively small. Cour Pharmaceuticals plans to present the full one-year data at a future scientific meeting, providing a more detailed analysis of the findings. The company is likewise evaluating its development strategy for the program, including exploring potential collaborations with strategic partners.
The company did not release specific details regarding the number of patients enrolled in the trial or the magnitude of the observed improvements in the initial announcement. However, the positive trend observed across multiple biomarkers—fibrotic and cholestatic—suggests CNP-104 could represent a significant step forward in the treatment of PBC.
The development of CNP-104 comes as researchers continue to investigate the complex interplay between genetics, environmental factors, and the immune system in the development of PBC. A study published in January 2026 suggested that vitamin D may also play a protective role against liver damage in those with PBC, highlighting the potential for multi-faceted approaches to managing the disease.
The next step for CNP-104 will be the presentation of the full one-year data at an upcoming scientific conference, which will allow for broader scrutiny and discussion within the medical community. Further clinical trials will be necessary to confirm these findings and assess the long-term safety and efficacy of the therapy.
Disclaimer: This article is for informational purposes only and should not be considered medical advice. Please consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
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