ELATIVE and PBC

The ELATIVE trial was a clinical study designed to evaluate the efficacy and safety of elafibranor, a dual PPAR-α/δ agonist, as a potential second-line treatment for primary biliary cholangitis (PBC). PBC is a chronic autoimmune liver disease characterized by progressive destruction of bile ducts, leading to cholestasis, fibrosis, and eventually cirrhosis. The trial specifically targeted patients with PBC who had an inadequate response or intolerance to ursodeoxycholic acid (UDCA), the current first-line therapy for the disease.

Key Aspects of the ELATIVE Trial:

Objective:

The primary goal of the ELATIVE trial was to determine whether elafibranor could improve biochemical markers of cholestasis and serve as a safe and effective second-line therapy for PBC patients who could not achieve sufficient benefits from UDCA.

Study Design:

• Type: Multicenter, phase 3, double-blind, placebo-controlled trial.
• Duration: 52 weeks, with continuation into a long-term open-label extension.
• Participants: 161 patients randomized in a 2:1 ratio to receive either elafibranor (80 mg once daily) or placebo.
• Conducted across 14 countries.

Patient Demographics:

• Gender: Majority were women (96%), reflecting the typical gender distribution in PBC.
• Age: Average age was 57 years.
• UDCA Use: Approximately 94% of patients continued UDCA during the trial, mimicking real-world management of PBC.
• Disease Severity: Around 39% of participants had ALP levels >3× upper limit of normal (ULN), and 35% had fibrosis or cirrhosis at baseline.

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Primary Endpoint:

The trial’s main endpoint was achieving a biochemical response at week 52, defined as:

1. ALP <1.67× ULN,

2. ≥15% reduction from baseline, and

3. Normal total bilirubin.

This endpoint is strongly predictive of improved transplant-free survival in PBC patients.

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Results and Outcomes:

Primary Outcome:

• Biochemical Response:
• Elafibranor group: 51% achieved biochemical response at week 52.
• Placebo group: Only 4% achieved biochemical response.
• Statistical Significance: Difference of 47 percentage points (P<0.001), demonstrating robust efficacy.

ALP Normalization:

• 15% of elafibranor-treated patients achieved normalization of ALP, compared to none in the placebo group (P=0.002).
• ALP reductions were evident as early as 4 weeks and sustained throughout the trial.

Liver Enzymes and Bilirubin:

• Elafibranor effects:
• Significant reductions in γ-glutamyl transferase (GGT), ALT, and IgM levels.
• Stable bilirubin and albumin levels, indicating improved liver function without hepatotoxicity.

Pruritus (Itch):

• Moderate-to-severe itch: No statistically significant differences in WI-NRS scores at weeks 24 or 52 compared to placebo.
• However, patient-reported outcomes using PBC-40 and 5-D itch scales showed modest improvements favoring elafibranor.
• Unlike obeticholic acid, which tends to worsen pruritus, elafibranor may reduce itch-related burden.

Lipid Metabolism:

• Elafibranor significantly lowered triglycerides, VLDL cholesterol, and total cholesterol, while maintaining stable LDL and HDL cholesterol levels.
• This contrasts favorably with obeticholic acid, which often raises LDL levels.

Fibrosis and Liver Stiffness:

• No significant changes in enhanced liver fibrosis scores or liver stiffness were observed after 52 weeks.
• Longer follow-up is required to assess potential antifibrotic effects.

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Safety Profile:

Adverse Events:

• Overall, adverse events were similar between elafibranor and placebo groups.
• Most common treatment-related side effects were mild gastrointestinal events:
• Abdominal pain, diarrhea, nausea, and vomiting (each reported in ~10–12% of patients).

Muscle-Related Effects:

• Creatine phosphokinase elevations occurred more frequently in the elafibranor group (3.7%), occasionally leading to treatment discontinuation.
• One serious case of rhabdomyolysis was reported in a patient with advanced cirrhosis and concomitant use of atorvastatin.

Hepatic and Renal Safety:

• Drug-induced liver injury was rare and reversible upon discontinuation.
• Slight increases in creatinine were noted in 10% of patients, but without changes in cystatin C or estimated glomerular filtration rate, suggesting no significant renal impairment.

Mortality and Serious Events:

• Two deaths occurred in the elafibranor group:
• One postoperative death.
• One due to biliary sepsis.
• Neither death was considered treatment-related.
• Serious adverse events were similar between elafibranor and placebo groups (10% vs. 13%).

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Comparison to Other Agents:

• Unlike obeticholic acid:
• Elafibranor improved lipid parameters.
• Did not worsen pruritus, suggesting a more favorable tolerability and metabolic profile for long-term management of PBC.

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Mechanism of Action:

Elafibranor works by activating PPAR-α and PPAR-δ, which are nuclear receptors involved in:

1. Bile acid metabolism: Reducing toxic bile acid accumulation.

2. Inflammation: Mitigating liver inflammation associated with PBC.

3. Lipid oxidation: Improving lipid profiles.

This mechanism helps reduce hepatic injury and improve cholestatic liver function.

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Clinical Significance:

• Rapid and sustained biochemical improvements were observed within the first month of treatment and persisted through 52 weeks.
• Normalization of ALP and bilirubin levels correlates with improved long-term outcomes in PBC.
• The ELATIVE trial results position elafibranor as a promising second-line therapy for patients who fail or cannot tolerate UDCA.

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Future Outlook:

• Long-term studies and open-label extensions are ongoing to further evaluate:
• Effects on clinical outcomes.
• Fibrosis regression.
• Overall survival in PBC patients.

Elafibranor represents a significant advancement in the treatment landscape for PBC, offering a safe and effective alternative for patients with unmet therapeutic needs.