Mechanism of Action
Evinacumab-dgnb is a recombinant human monoclonal antibody that binds to and inhibits ANGPTL3. ANGPTL3 is a member of the angiopoietin-like protein family that is expressed primarily in the liver and plays a role in the regulation of lipid metabolism by inhibiting lipoprotein lipase (LPL) and endothelial lipase (EL). Evinacumab-dgnb inhibition of ANGPTL3 leads to reduction in LDL-C, HDL-C, and triglycerides (TG). Evinacumab-dgnb reduces LDL-C independent of the presence of LDL receptor (LDLR) by promoting very low-density lipoprotein (VLDL) processing and clearance upstream of LDL formation. Evinacumab-dgnb blockade of ANGPTL3 lowers TG and HDL-C by rescuing LPL and EL activities, respectively.
Administration of evinacumab-dgnb in HoFH patients resulted in reductions in LDL-C, total cholesterol (TC), HDL-C, apolipoprotein B and TG [see Clinical Studies].
The pharmacokinetic parameters described in this section are presented following administration of evinacumab-dgnb 15 mg/kg intravenously every 4 weeks, unless otherwise specified.
Steady-state is reached after 4 doses, and the accumulation ratio is 2. According to population pharmacokinetic modeling, the mean (standard deviation) steady-state trough concentration is 241 (96.5) mg/L, whereas the mean (standard deviation) Cmax at the end of infusion is 689 (157) mg/L. Due to non-linear clearance, a 4.3-fold increase in area under the concentration-time curve at steady-state (AUCtau.ss) for a 3-fold increase in evinacumab-dgnb dose up to 15 mg/kg IV every 4 weeks was predicted in patients with HoFH.
The total volume of distribution estimated via population pharmacokinetic analysis was approximately 4.8 L.
Evinacumab-dgnb elimination is mediated via parallel linear and non-linear pathways. At higher concentrations, evinacumab-dgnb elimination is primarily through a non-saturable proteolytic pathway, whereas at lower concentrations, the non-linear, saturable ANGPTL3 target-mediated elimination predominates. The elimination half-life is a function of serum evinacumab-dgnb concentrations and is not a constant.
Based on a population pharmacokinetic analysis, the median time for serum evinacumab-dgnb concentrations to decrease below the lower limit of quantitation (78 ng/mL) is 19 weeks after the last steady-state dose of 15 mg/kg IV every 4 weeks.
The exact pathway through which evinacumab-dgnb is metabolized has not been characterized. As a human monoclonal IgG4 antibody, evinacumab-dgnb is expected to be degraded into small peptides and amino acids via catabolic pathways in the same manner as endogenous IgG.
Evinacumab-dgnb, a monoclonal antibody, is not likely to undergo renal excretion.
A population PK analysis conducted on data from 183 healthy subjects and 95 patients with HoFH suggests that the following factors have no clinically significant effect on the exposure of evinacumab-dgnb: age (12 to 75 years), gender, body weight (42 to 152 kg), and race (White, Asian, Black, and Other).
A 15-year-old patient with HoFH received evinacumab-dgnb at 15 mg/kg IV every 4 weeks. Steady-state trough and end-of-infusion concentrations were within the range observed in adult patients.
Patients with Renal Impairment
Observed trough serum evinacumab-dgnb concentrations at steady-state were comparable between patients with mild or moderate renal impairment and patients with normal renal function. No data are available in patients with severe renal impairment.
Patients with Hepatic Impairment
No data are available in patients with hepatic impairment.
Drug Interaction Studies
Drug interaction studies have not been conducted with evinacumab-dgnb. In a clinical trial, the concentrations of statins (atorvastatin, rosuvastatin, simvastatin) were not meaningfully altered in patients taking statins prior to and post administration of evinacumab-dgnb. Concentrations of evinacumab-dgnb were comparable in patients with HoFH taking or not taking background lipid-lowering therapy.