Liver and kidney accumulation, tissue concentrations hundreds-thousands-fold above plasma; tissue t1/2 12.5-32 days
“For all evaluated dose levels, volanesorsen concentrations 48 hours after the last dose (Day 93) were several hundred-to several thousand-fold higher in kidney cortex and liver than in plasma.”
Thrombocytopenia (platelet reduction in all species), ASO class effects in liver, kidney, lymph nodes, skin; complement activation
“The main hazard identified in animals is a reduction in platelet count leading to thrombocytopenia, which has also been observed in humans in the clinical trials.”
Monkeys: ADA increased median plasma trough concentrations ~1.2- to 14-fold from ~3 months of dosing
“The presence of anti-volanesorsen antibodies resulted in an increase in the median plasma trough concentrations of approximately 1.2- to 14-fold in the samples collected approximately 3 months or later after initiation of dosing in all dose groups.”
30% in FCS patients (CS6); 16% to 40% in other studies
“Antibodies to volanesorsen were formed in 30% of the patients with familial chylomicronemia syndrome treated with volanesorsen (study CS6). In the other studies, the formation of anti-drug antibodies ranged from 16% to 40% (studies CS2, CS4, and CS16).”
Main pharmacology-related risk is increased susceptibility to infections (C5 inhibition); no complement activation by the aptamer in monkeys; panuveitis with Lucentis combination