Gastroenterology · Clinical trials
Primary Biliary Cholangitis Clinical Trials
Approved therapies, the pivotal-trial endpoints they were judged on, the magnitude of benefit — and the drugs that failed their endpoints, and why.
Indication overview
About primary biliary cholangitis — and why its trials are hard
Primary biliary cholangitis (PBC) is a chronic autoimmune cholestatic liver disease in which progressive destruction of small intrahepatic bile ducts leads to cholestasis, fibrosis, and potentially cirrhosis; it predominantly affects women and often presents with fatigue and pruritus and a raised alkaline phosphatase (ALP). Ursodeoxycholic acid (UDCA) is first-line and improves survival, but a substantial minority have an inadequate biochemical response and need second-line therapy. Obeticholic acid, an FXR agonist, gained accelerated approval in 2016 based on ALP reduction, but subsequent safety concerns led the FDA to restrict its use in 2024 and the drug was ultimately withdrawn from the US market after its confirmatory trial failed to verify clinical benefit. Two PPAR agonists received accelerated approval in 2024: elafibranor (a PPAR alpha/delta agonist) and seladelpar (a PPAR delta agonist), both used with or without UDCA. Regulatory endpoints use a composite biochemical response built on ALP and bilirubin, with pruritus increasingly assessed as a key patient-reported outcome.
Approved therapies & pivotal evidence
What's been approved — and by how much it moved the endpoint
| Drug (brand) | Approved | Setting | Pivotal trial | Primary endpoint | Magnitude of benefit |
|---|---|---|---|---|---|
| Ursodeoxycholic acid (Actigall/URSO) | 1997 | First-line PBC; hydrophilic bile acid | Pooled analyses of randomized trials and long-term cohorts | Biochemical response (ALP/bilirubin) and transplant-free survival | Improves biochemistry and survival; ~30-40% have inadequate response requiring add-on therapy |
| Obeticholic acid (Ocaliva) | 2016 | Second-line PBC (accelerated approval); FXR agonist. FDA restricted use in advanced cirrhosis in 2024 and the drug was subsequently withdrawn from the US market | POISE (Phase 3) | Composite: ALP <1.67x ULN with >=15% reduction and normal total bilirubin at 12 months | ~46-47% vs ~10% placebo (dose-dependent pruritus a major issue) |
| Elafibranor (Iqirvo) | 2024 | Second-line PBC with UDCA or as monotherapy if UDCA-intolerant (accelerated approval); PPAR alpha/delta agonist | ELATIVE (Phase 3) | Composite biochemical response at week 52 (ALP <1.67x ULN, >=15% ALP decrease, normal total bilirubin) | ~51% vs ~4% placebo |
| Seladelpar (Livdelzi) | 2024 | Second-line PBC with UDCA or as monotherapy if UDCA-intolerant (accelerated approval); PPAR delta agonist | RESPONSE (Phase 3, NEJM 2024) | Composite biochemical response at month 12; key secondaries ALP normalization and pruritus (NRS) change | Composite ~61.7% vs 20% placebo; ALP normalization ~25% vs 0%; significant pruritus improvement |
Where trials have failed
Drugs that missed their endpoint — and what contributed
The most instructive lessons in primary biliary cholangitis development come from programmes that failed the endpoint that mattered.
| Drug / trial | Endpoint outcome | What contributed |
|---|---|---|
| Obeticholic acid (confirmatory) — COBALT confirmatory outcomes trial | Did not verify the predicted clinical benefit required to confirm accelerated approval; combined with hepatotoxicity signals this led to 2024 FDA restrictions and US market withdrawal | Reliance on an ALP-based surrogate, confounding from off-study therapy, and serious liver-injury reports in the post-marketing period |
| Setanaxib (GKT831) — Phase 2 in PBC (NADPH oxidase 1/4 inhibitor) | Did not clearly meet its primary biochemical endpoint across the overall population; further PBC development was not advanced on those results | Modest and subgroup-limited effect on cholestatic markers (exact magnitude unverified) |
Choosing the right endpoint
Primary endpoints that matter in primary biliary cholangitis trials
- Composite biochemical response — ALP threshold (e.g., <1.67x ULN with >=15% reduction) plus normal bilirubin at 12 months; the standard accelerated-approval endpoint.
- ALP normalization — Return of alkaline phosphatase to the normal range, a more stringent secondary marker associated with better prognosis.
- Pruritus (NRS) — Patient-reported itch severity; a key symptom endpoint where PPAR agonists showed benefit and FXR agonists worsened it.
- Transplant-free survival — Long-term clinical outcome underpinning UDCA's benefit and the goal that surrogate endpoints aim to predict.
How iNGENū runs primary biliary cholangitis trials
Physician-led design, built for FDA submission
Endpoint & biomarker strategy
Board-certified specialists design endpoints and patient selection aligned to current FDA guidance for this indication.
FDA-ready data
Built to ICH-GCP and 21 CFR 312.120, with direct FDA submission — data accepted by the FDA, EMA and MHRA.
Faster, lower-cost delivery
~4-week ethics via the TGA CTN scheme, up to 43.5% R&D rebate, and 80–90% below US CRO cost.
Request a fixed-milestone proposal and a tailored endpoint & feasibility summary for this indication.
Frequently asked questions
Primary Biliary Cholangitis clinical trials — FAQs
What is the first-line treatment for PBC?
What changed for obeticholic acid?
How do the 2024 PPAR agonists differ from obeticholic acid on itch?
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