PBC Liver Drug Nearly Doubles Its Potential Patient Pool in New Trial

Ipsen announced positive results from ELSPIRE, a phase 3b trial testing its drug elafibranor, sold as Iqirvo, in a group of primary biliary cholangitis (PBC) patients who would not have qualified for the trials that led to the drug's original approval. PBC is a rare autoimmune liver disease in which the immune system slowly destroys the small bile ducts inside the liver, causing a buildup of bile and toxins that can eventually lead to scarring, liver failure, and the need for a transplant. Most patients are treated first with a standard drug called ursodeoxycholic acid (UDCA), but a meaningful share do not respond well enough to it alone.

Elafibranor is an oral, once-daily pill that activates two related proteins, PPAR-alpha and PPAR-delta, which help regulate how the liver produces and processes bile acids and reduces the inflammation and scarring that come with chronic bile buildup. It was originally approved based on trials in patients with more significantly elevated levels of alkaline phosphatase (ALP), a liver enzyme that doctors use as a key marker of disease activity and treatment response in PBC. The ELSPIRE trial specifically enrolled a different group: patients whose ALP was only mildly elevated, between one and 1.67 times the upper limit of normal, after already being on UDCA.

The results were strong. By week 52, 85% of patients taking elafibranor had their ALP levels return to a fully normal range, compared to just 23% of those on placebo, a difference that was highly statistically significant. Normalizing ALP is increasingly viewed by liver specialists as one of the best available markers for predicting whether a PBC patient will avoid liver transplant and other serious complications down the road, so a normalization rate this high in a previously untested patient group is a meaningful finding. The safety profile was consistent with what has already been documented for the drug, with no new safety issues identified.

What makes this trial notable isn't just the response rate, it's who was included. Because ELSPIRE specifically enrolled patients with milder ALP elevations who fell outside the criteria for the original approval studies, Ipsen has said the data could support expanding elafibranor's approved use to roughly double the number of PBC patients eligible for it. Ipsen plans to present the full data at an upcoming medical meeting and to submit it to regulators, though any formal label expansion would still need regulatory review and approval before doctors could prescribe the drug to this broader group.