Pharmacokinetic Time Course Scaling of a Subcutaneously Administered Pegylated Peptide Conjugate for a First-in-Human Investigation

Model-Based Interspecies Scaling for Predicting Human Pharmacokinetics of CB 4332, a Complement Factor I Protein

Interspecies scaling of the pharmacokinetics (PK) of CB 4332, a 150 kDa recombinant complement factor I protein, was performed using traditional and model-based approaches to inform first-in-human dose selection. Plasma concentration versus time data from four preclinical PK studies of single intravenous and subcutaneous (SC) CB 4332 dosing in mice, rats and nonhuman primates (NHPs) were modeled simultaneously using naive pooling including allometric scaling. The human-equivalent dose was calculated using the preclinical no observed adverse effect level (NOAEL) as part of the dose-by-factor approach. Pharmacokinetic modeling of CB 4332 revealed species-specific differences in the elimination, which was accounted for by including an additional rat-specific clearance. Signs of anti-drug antibodies (ADA) formation in all rats and some NHPs were observed. Consequently, an additional ADA-induced clearance parameter was estimated including the time of onset. The traditional dose-by-factor approach calculated a maximum recommended starting SC dose of 0.9 mg/kg once weekly, which was predicted it to result in a trough steady-state concentration lower than the determined efficacy target range for CB 4332 in humans. Model simulations predicted the efficacy target range to be reached using 5 mg/kg once weekly SC dosing.

Pharmacokinetics of 40 kDa Polyethylene glycol (PEG) in mice, rats, cynomolgus monkeys and predicted pharmacokinetics in humans

Conjugation with polyethylene glycol (PEG), PEGylation, has been considered a useful tool to improve drug-like properties of novel small molecules and biologics in drug discovery. PEG40 or 40 kDa PEG is a double-branched PEG, routinely employed to improve the pharmacokinetics (PK) of therapeutics, including successful marketed products such as Pegasys® and Omontys®. However, less is known about the extent of contribution of PEG40 to the overall PK of the PEGylated product. Considering the half-life of PEG40 conjugated PEGylated products ranges from 1 to 14 days in human, this information is immensely valuable. After successfully developing a high sensitivity NMR based analytical method to quantitate PEG40 in mice serum after intravenous (IV) administration (Khandelwal et al., 2019), here, we extend its application to measure PEG40 in serum after IV administration and subcutaneous (SC) absorption in routinely employed non-clinical species in drug discovery, namely, mice, rats and cynomolgus monkeys. We utilized non-compartmental analysis and compartmental modeling to characterize the PK of PEG40 in these non-clinical species. Finally, we employed allometric scaling and Wajima (MRT-Css) method to predict the PK of PEG40 in human after IV administration and SC absorption. In general, our data shows that intrinsic PK parameters of PEG40 in mice, rats and cynomolgus monkeys are in the range of published literature values for PEG40-conjugated products, unless saturable clearance mechanisms are involved. We observed a bioavailability (F) of ~68% in CD-1 mice after SC administration of PEG40. In rats, the clearance (CL) and volume of distribution at steady state (V_ss) after IV infusion of PEG40 were 0.079 mL/min/kg and 0.19 L/kg, respectively; and SC bioavailability was ~20%. In cynomolgus monkeys, after IV infusion, CL and V_ss of PEG40 were 0.037 mL/min/kg and 0.20 L/kg, respectively; and SC bioavailability was ~69%. In addition, our findings indicate flip-flop kinetics of PEG40 in rodents, but not in cynomolgus monkeys. Finally, in human, intrinsic CL and V_ss of PEG40 were projected to be 0.02 mL/min/kg (0.084 L/h) and 0.22 L/kg, respectively. This comprehensive report of PK of PEG40 in non-clinical species and its subsequent prediction in humans is expected to be useful to drug discovery and development scientists for efficient decision-making and optimal resource utilization.

Pharmacokinetics of Polyethylene Glycol-Modified Canine Uricase Following Single and Multiple Intravenous Injections in Cynomolgus Monkeys

BACKGROUND AND OBJECTIVE

Polyethylene glycol-modified canine uricase (PEG-UHC) prepared with a lower-molecular-weight (5 kDa) PEG is used to treat gout. This study investigated the comparative pharmacokinetics of single and multiple doses of PEG-UHC administered intravenously and a single dose of uricase (UHC) administered intravenously in cynomolgus monkeys.

METHODS

A noncompartmental model was used to fit the plasma drug concentration-time curve and calculate the pharmacokinetic parameters of PEG-UHC, which were compared with those obtained for UHC at the equivalent dose (2 mg/kg). To study the pharmacokinetics after multiple dose administration, cynomolgus monkeys were administered five intravenous injections of PEG-UHC (0.5 mg/kg), with one injection performed every 15 days.

RESULTS

The area under the curve (AUC) and the maximum plasma concentration (C_max) of PEG-UHC were positively correlated with dose, whereas plasma half-life (t_1/2) and clearance (CL) did not change significantly with increasing dose, suggesting that these pharmacokinetic characteristics are linear. Intravenous PEG-UHC exhibited an average t_1/2 that was 125.79 times longer and an AUC_0-t that was 64.45 times larger than the corresponding values for UHC at the same dose (2 mg/kg), while the CL of PEG-UHC was 1/72.73 times the CL of intravenous UHC. The plasma drug concentration reached a steady state after five injections, and the t_1/2 values following the first and last drug administration did not differ significantly.

CONCLUSION

Our data show that PEG-UHC is markedly superior to UHC in terms of duration of action, and that the pharmacokinetics of PEG-UHC in cynomolgus monkeys are linear. Sequential administration of PEG-UHC did not accelerate drug clearance. Our findings provide the basis for future clinical studies of PEG-UHC.