Treatment of advanced liver fibrosis in HIV- and HCV-infected adults with simtuzumab, a monoclonal antibody against lysyl oxidase-like 2: Results of a 6-month open-label safety trial

Chronic liver injury can result in fibrosis that may progress over years to end-stage liver disease. The most effective antifibrotic therapy is treatment of the underlying disease, however when this is not possible, interventions to reverse fibrosis are needed. We conducted an open-label pilot trial to study the safety and tolerability of simtuzumab, a monoclonal antibody directed against lysyl oxidase-like 2 (LOXL2) enzyme, in patients with advanced liver disease from hepatitis C virus (HCV), human immunodeficiency virus (HIV), or HCV-HIV co-infection. 18 patients with advanced liver fibrosis received simtuzumab 700mg IV every 2 weeks for 22 weeks. There were no discontinuations due to adverse events. No significant change was seen in hepatic venous pressure gradient or liver biopsy fibrosis score after treatment. Exploratory transcriptional and protein profiling using paired pre- and post-treatment liver biopsies, serum, and whole blood identified upregulation of TGFβ3 and IL-10 pathways with treatment. In summary, simtuzumab was well tolerated in HCV- and HIV-infected patients with advanced liver disease. Modulation of TGFβ3 and IL-10 pathways as a result of simtuzumab treatment merits investigation in future trials. Paired liver biopsy of pre-treatment (PRE) versus post-treatment (POST), and paired blood PRE and POST, in 12 participants.