Performance of Noninvasive Tests of Fibrosis Among Asians, Hispanic, and non-Hispanic Whites in the STELLAR Trials

Background & Aims: The effect of race on routinely available noninvasive tests of fibrosis is incompletely understood. This study evaluated the performance of noninvasive tests among white and Asian patients in the STELLAR trials (NCT03053050 and NCT03053063), which evaluated selonsertib in patients with advanced (F3-F4) fibrosis due to nonalcoholic steatohepatitis (NASH). Methods: Baseline liver biopsies were centrally read using the NASH Clinical Research Network system, and 4 noninvasive tests (Nonalcoholic fatty liver disease fibrosis score [NFS], Fibrosis-4 index [FIB-4], Enhanced Liver Fibrosis test [ELF], and liver stiffness by vibration-controlled transient elastography) were measured. The performance of these tests to discriminate advanced fibrosis was evaluated using areas under the receiver operating characteristics curves with 5-fold cross-validation repeated 100 times. Results: Among 3207 patients screened with evaluable liver histology, 2281 were whites and 762 were Asians. Seventy-two percent of whites and 67% of Asians had advanced fibrosis. The areas under the receiver operating characteristics curves of the noninvasive tests for advanced fibrosis were similar in whites and Asians: 0.73 and 0.75 for NFS, 0.78 and 0.80 for FIB-4, 0.79 and 0.81 for ELF, and 0.80 and 0.83 for liver stiffness, respectively. At the published cutoffs, the tests had similar sensitivities and specificities in the 2 groups. However, the sensitivities of NFS, FIB-4, and ELF were low in both white and Asian patients younger than 40 years. Conclusions: In the global phase III STELLAR trials, the diagnostic performance of routinely available noninvasive tests for the detection of advanced fibrosis due to NASH was acceptable and similar between white and Asian patients.