Clinical Trials in PBC Going Forward

Liver stiffness measurement by vibration-controlled transient elastography improves outcome prediction in primary biliary cholangitis

BACKGROUND & AIMS

Liver stiffness measurement (LSM) by vibration-controlled transient elastography (VCTE) has been shown to predict outcomes of patients with primary biliary cholangitis (PBC) in small-size studies. We aimed to validate the prognostic value of LSM in a large cohort study.

METHODS

We performed an international, multicentre, retrospective follow-up study of 3,985 patients with PBC seen at 23 centres in 12 countries. Eligibility criteria included at least 1 reliable LSM by VCTE and a follow-up ≥ 1 year. Independent derivation (n = 2,740) and validation (n = 568) cohorts were built. The primary endpoint was time to poor clinical outcomes defined as liver-related complications, liver transplantation, or death. Hazard ratios (HRs) with CIs were determined using a time-dependent multivariable Cox regression analysis.

RESULTS

LSM was independently associated with poor clinical outcomes in the derivation (5,324 LSMs, mean follow-up 5.0 ± 3.1 years) and validation (1,470 LSMs, mean follow-up 5.0 ± 2.8 years) cohorts: adjusted HRs (95% CI) per additional kPa were 1.040 (1.026-1.054) and 1.042 (1.029-1.056), respectively (p <0.0001 for both). Adjusted C-statistics (95% CI) at baseline were 0.83 (0.79-0.87) and 0.92 (0.89-0.95), respectively. Between 5 and 30 kPa, the log-HR increased as a monotonic function of LSM. The predictive value of LSM was stable in time. LSM improved the prognostic ability of biochemical response criteria, fibrosis scores, and prognostic scores. The 8 kPa and 15 kPa cut-offs optimally separated low-, medium-, and high-risk groups. Forty percent of patients were at medium to high risk according to LSM.

CONCLUSIONS

LSM by VCTE is a major, independent, validated predictor of PBC outcome. Its value as a surrogate endpoint for clinical benefit in PBC should be considered.

LAY SUMMARY

Primary biliary cholangitis (PBC) is a chronic autoimmune disease, wherein the body's immune system mistakenly attacks the bile ducts. PBC progresses gradually, so surrogate markers (markers that predict clinically relevant outcomes like the need for a transplant or death long before the event occurs) are often needed to expedite the drug development and approval process. Herein, we show that liver stiffness measurement is a strong predictor of clinical outcomes and could be a useful surrogate endpoint in PBC trials.

Association of bezafibrate with transplant-free survival in patients with primary biliary cholangitis

BACKGROUND & AIMS

A beneficial effect of bezafibrate (BZF) on symptoms and biochemical features of primary biliary cholangitis (PBC) has been reported in patients with an incomplete response to ursodeoxycholic acid (UDCA), but long-term effects on survival remain unknown. In Japan, BZF has been used as a de facto second-line therapy for PBC since 2000. Herein, we compared the survival rates between patients treated with and those without BZF in a large nationwide Japanese PBC cohort.

METHODS

All consecutively registered patients of this cohort who started UDCA therapy from 2000 onwards and had a follow-up ≥1 year were included. Association between BZF exposure and mortality or need for liver transplantation (LT) was assessed using time-dependent, multivariable-and propensity score-adjusted Cox proportional hazards models. Clinical benefit was quantified using the number needed to treat (NNT).

RESULTS

Of 3,908 eligible patients, 3,162 (81%) received UDCA only and 746 (19%) UDCA and BZF over 17,360 and 3,932 patient-years, respectively. During follow-up, 183 deaths (89 liver-related) and 21 LT were registered. Exposure to combination therapy was associated with a significant decrease in all-cause and liver-related mortality or need for LT (adjusted hazard ratios: 0.3253, 95% CI 0.1936-0.5466 and 0.2748, 95% CI 0.1336-0.5655, respectively; p <0.001 for both). This association was consistent across various risk groups at baseline. The NNTs with combination therapy to prevent 1 additional death or LT over 5, 10, and 15 years were 29 (95% CI 22-46), 14 (10-22), and 8 (6-15), respectively.

CONCLUSIONS

In a large retrospective cohort study of treatment effects in patients with PBC, the addition of BZF to UDCA was associated with improved prognosis.

LAY SUMMARY

The long-term efficacy of bezafibrate (BZF) on liver transplantation (LT) - free survival in patients with PBC and an incomplete response to ursodeoxycholic acid (UDCA) remains to be determined. In this Japanese nationwide retrospective cohort study, the use of UDCA-BZF combination therapy, compared to UDCA alone, was associated with a lower risk of all-cause and liver-related mortality or need for LT. These results indicate that BZF is so far the only drug in PBC to have demonstrated efficacy in improving symptoms, biochemical markers, and long-term outcomes.

Liver Stiffness Measured by Either Magnetic Resonance or Transient Elastography Is Associated With Liver Fibrosis and Is an Independent Predictor of Outcomes Among Patients With Primary Biliary Cholangitis

GOALS

We aimed to describe the diagnostic and prognostic performance of transient elastography (TE) and magnetic resonance elastography (MRE) in patients with primary biliary cholangitis (PBC).

BACKGROUND

The diagnostic performance of TE and MRE in detecting advanced fibrosis in PBC and in predicting outcomes independent of existing serologic prognostic markers is incompletely understood.

MATERIALS AND METHODS

Five hundred thirty-eight consecutive patients with PBC at 3 centers with liver stiffness (LS) measurements by TE (n=286) or MRE (n=332) were reviewed. LS cutoffs for predicting fibrosis stages were determined by receiver operating characteristic curves among those with a liver biopsy (TE, n=63; MRE, n=98). Cox proportional hazard regression modeling was used to identify associations between covariates and hepatic decompensation.

RESULTS

The optimal LS thresholds for predicting histologic stage F4 were 14.40 kPa (area under the curve=0.94) for TE and 4.60 kPa (area under the curve=0.82) for MRE. Both TE and MRE outperformed biochemical markers for the prediction of histologic advanced fibrosis. Optimal LS thresholds to predict hepatic decompensation were 10.20 kPa on TE and 4.30 kPa on MRE. LS by TE and MRE (respectively) remained predictors of hepatic decompensation after adjusting for ursodeoxycholic acid responsiveness [hazard ratio (HR), 1.14; 95% confidence interval (CI), 1.05-1.24 and HR, 1.68; 95% CI, 1.28-2.19] and the GLOBE score (HR, 1.13; 95% CI, 1.07-1.19 and HR, 2.09; 95% CI, 1.57-2.78).

CONCLUSION

LS measurement with either TE or MRE can accurately detect advanced fibrosis and offers additional prognostic value beyond existing serologic predictive tools.