ARBM-101

In Wilson disease (WD), excess copper provokes hepatocyte death due to impaired copper excretion, ultimately causing either acute or chronic liver damage. Current therapeutic compounds fail to reduce hepatic copper near to physiological levels, leaving lifelong, several times daily treatment as the only choice for patients. We have previously shown that a bacteria-derived methanobactin, termed ARBM-101, most efficiently depleted excess liver copper in still healthy WD rats. Here we report, for the first time, that mechanistically this is due to endosomal/lysosomal/exosomal trafficking of ARBM-101 in WD hepatocytes, allowing for copper mass excretion via the biliary/fecal route. We further show that such liver copper excretion occurs within minutes in vivo to detect copper-bound ARBM-101 in feces. This efficacy allows for specialized treatment regimen to rescue acute liver failure in WD rats. Moreover, also shown for the first time, it avoids fibrosis development in WD mice. Thus, judging from the results in two rodent species and human hepatocytes, this study advocates the development of ARBM-101 for WD therapy.

The Wilson disease (WD) research field is rapidly evolving, and new diagnostic and therapeutical approaches are expected to be change-gamers in the disease for the incoming years, after decades of slow changing options. Non–ceruloplasmin-bound copper assays for circulating bioavailable copper are being tested for use in monitoring therapy and may also help in the diagnosis of new cases of WD. Other diagnostic advances include the use of quantitative detection of ATP7B peptides in dried blood spots, a method that is being tested for use in the newborn screening for WD, and the use of metallothionein immunostaining of liver biopsy specimens to differentiate WD from other liver diseases. Ongoing and future trials of gene therapy and use of methanobactin are expected to restore biliary copper excretion from the liver, thus making a cure for WD a plausible therapeutic objective. With the aim of helping updating physicians, this review summarizes the novel methods for WD diagnosis and future therapies. Advancing understanding of the scientific advances that can be applied to WD will be critical for ensuring that our patients will receive the best current and future care.