4-Week toxicity study of biosimilar natalizumab in comparison to Tysabri® by repeated intravenous infusion to cynomolgus monkeys.

The objective of the study was to obtain information on the toxicity of biosimilar natalizumab (PB006) in comparison to the reference product Tysabri®. Cynomolgus monkeys (15 males and 15 females), three animals per sex and group were treated with either PB006 or the reference product Tysabri® at dose levels of 3 or 30 mg/kg body weight or placebo by intravenous infusion every other day for a period of 4 weeks. The study is also meant to facilitate ethics committee approval in specific countries for the planned confirmatory efficacy and safety study in patients. Based on study findings, it was concluded that there was no noteworthy difference between the animals treated with PB006 and the animals treated with Tysabri®. There were no noteworthy differences between PB006 and Tysabri® with respect to local tolerance, toxicity and pharmacokinetic profile in cynomolgus monkeys. In conclusion, obtained data are valid and suitable to support entry into clinical studies of PB006 in man.

Natalizumab-induced hepatic injury: A case report and review of literature.

Natalizumab is an α4-integrin monoclonal antibody used for treatment of relapsing multiple sclerosis (MS). At least and nearly 30 cases of liver failure in natalizumab-treated patients are listed in the post-marketing FDA adverse event reporting system (FAERS) and twelve patients with severe liver injury, including several after the first infusion, have been reported (Lisotti et al., 2012; Bezabeh et al., 2010; Martinez-Lapiscina et al., 2013; Michael et al., 2007; Hillen et al., 2015). Herein, we describe a case of a young woman with relapsing MS who developed acute liver injury after the second infusion of natalizumab. Liver biopsy demonstrated a mixed pattern of medication-induced injury or partially treated auto-immune hepatitis. Liver function normalized after natalizumab discontinuation and a subsequent liver biopsy showed resolution of hepatitis. The patient's MS has since been successfully treated with rituximab for over a year. We review the published cases of liver injury associated with natalizumab and those in the post-marketing FDA adverse event reporting system (FAERS).