Pratt, Daniel S.

Abstract Description PBC is an archetypal autoimmune disease where the dominant autoantigen is mitochondrial PDC-E2. Hitherto, PBC treatment has been neither specific nor directed toward restoration of tolerance. CNP-104, a tolerogenic nanoparticle encapsulating PDC-E2, is hypothesized to restore tolerance to pathogenic T cells. We conducted a Phase 2a First-in-Human randomized controlled trial of CNP-104 in PBC patients unresponsive/intolerant to ursodeoxycholic acid. The 42 enrolled subjects were randomized 2:1 to receive two doses of CNP-104 or placebo (PBO) one week apart and were followed for 120 days to assess safety and treatment durability. CNP-104 was safe and well-tolerated. Compared to PBO, the CNP-104 group had a reduced percentage of antigen-specific Th17 T cells and increased antigen-specific tolerogenic CD8+ T cell counts (TIGIT, GARP). ALP, ALT, and total bilirubin were similar between groups. Clinically relevant effects on albumin levels, liver stiffness, and the rate of change in 5-year UK-PBC risk for liver outcomes were improved in the CNP-104 group compared to PBO. This trial is limited by small size and data variability. Induction of antigen-specific T cell tolerance, shown by reduced Th17 cells and increased TIGIT and GARP cells correlates with improved liver stiffness, albumin, and UK-PBC. These findings suggest the CNP-104 tolerogenic mechanism of action translates to clinical benefits. These data support future studies with this unique therapeutic platform to treat PBC. Topic Categories Therapeutic Approaches to Autoimmunity (THER)

Background: The natural history of primary sclerosing cholangitis (PSC) among African Americans (AA) is not well understood. Methods: Transplant-free survival and hepatic decompensation–free survival were assessed using a retrospective research registry from 16 centers throughout North America. Patients with PSC alive without liver transplantation after 2008 were included. Diagnostic delay was defined from the first abnormal liver test to the first abnormal cholangiogram/liver biopsy. Socioeconomic status was imputed by the Zip code. Results: Among 850 patients, 661 (77.8%) were non-Hispanic Whites (NHWs), and 85 (10.0%) were AA. There were no significant differences by race in age at diagnosis, sex, or PSC type. Inflammatory bowel disease was more common in NHWs (75.8% vs. 51.8% p =0.0001). The baseline (median, IQR) Amsterdam-Oxford Model score was lower in NHWs (14.3, 13.4–15.2 vs. 15.1, 14.1–15.7, p =0.002), but Mayo risk score (0.03, −0.8 to 1.1 vs. 0.02, −0.7 to 1.0, p =0.83), Model for End-stage Liver Disease (5.9, 2.8–10.7 vs. 6.4, 2.6–10.4, p =0.95), and cirrhosis (27.4% vs. 27.1%, p =0.95) did not differ. Race was not associated with hepatic decompensation, and after adjusting for clinical variables, neither race nor socioeconomic status was associated with transplant-free survival. Variables independently associated with death/liver transplant (HR, 95% CI) included age at diagnosis (1.04, 1.02–1.06, p <0.0001), total bilirubin (1.06, 1.04–1.08, p <0.0001), and albumin (0.44, 0.33–0.61, p <0.0001). AA race did not affect the performance of prognostic models. Conclusions: AA patients with PSC have a lower rate of inflammatory bowel disease but similar progression to hepatic decompensation and liver transplant/death compared to NHWs.