Researchers have reported encouraging findings from a clinical study evaluating a novel monoclonal antibody therapy for primary sclerosing cholangitis (PSC), a rare and progressive liver disorder with limited treatment options. The investigational drug, known as nebokitug, demonstrated a strong safety profile along with early signs of effectiveness in reducing liver inflammation and scarring.
The study was conducted by a research team at the University of California–Davis, USA, and its findings were published in the American Journal of Gastroenterology. PSC currently has no approved medical therapy capable of slowing disease progression, and many patients ultimately require a liver transplant. The new data offer renewed hope for an alternative treatment approach.
“In the trial, nebokitug demonstrated that it has the potential to change the lives of patients with PSC by reducing fibrosis and inflammation, which should lead to improved outcomes,” said Christopher Bowlus, chief of Gastroenterology and Hepatology at UC Davis Health.
“These results are good news for patients with PSC, who are in desperate need of an effective, FDA-approved therapy.”
PSC is a long-term liver condition marked by persistent inflammation and scarring of the bile ducts, which transport bile from the liver to the small intestine to aid digestion. As these ducts narrow and become damaged, bile accumulates in the liver, gradually leading to liver injury.
While the precise cause of PSC remains unclear, a significant number of patients also suffer from inflammatory bowel disease, indicating a potential connection between gut inflammation and liver damage.
Patients may experience symptoms such as chronic fatigue, itching, and yellowing of the skin or eyes, although some individuals remain symptom-free in the early stages. Since there is no cure, current care focuses on symptom relief and managing complications. Liver transplantation remains the only option for advanced disease.
Nebokitug is an engineered antibody designed to inhibit CCL24, a protein involved in driving inflammation and fibrotic processes in the liver. Elevated levels of CCL24 have been observed near bile ducts in PSC patients, where they contribute to tissue damage. Previous research suggests that blocking this protein can reduce inflammation and fibrosis.
The Phase 2 clinical trial enrolled 76 patients with PSC across five countries. Participants were randomly assigned to receive either one of two doses of nebokitug or a placebo, administered intravenously every three weeks over a 15-week period. The primary objective was to assess the drug’s safety.
The results showed that nebokitug was safe and generally well tolerated. Patients receiving the treatment—particularly those with more advanced liver scarring—showed improvements in markers related to liver stiffness and fibrosis when compared with those given a placebo.