A large multicentre, randomized, double-blind, cross-over study in healthy volunteers to compare pharmacokinetics, pharmacodynamics and safety of a pegfilgrastim biosimilar with its US- and EU-reference biologics.

AIMS: Recombinant PEGylated human granulocyte colony-stimulating factor (pegfilgrastim) is indicated for the reduction of chemotherapy-induced neutropenia and prevention of febrile neutropenia. Biosimilar pegfilgrastim is expected to reduce the financial burden of this complication of chemotherapy. The aim of this study was to demonstrate biosimilarity between Sandoz biosimilar pegfilgrastim and its US- and EU-approved reference biologics. METHODS: Phase I, randomized, double-blind, single-dose, 3-period, 6-sequence cross-over, multicentre study to evaluate the pharmacokinetics, pharmacodynamics, safety and immunogenicity of Sandoz biosimilar pegfilgrastim with US- and EU-references in healthy adults. RESULTS: Pharmacokinetic and pharmacodynamic similarity was demonstrated between the 3 biologics, as the 90% confidence interval for all primary pharmacokinetic and pharmacodynamic endpoint comparisons were contained within the predefined similarity margins of 0.80-1.25. Safety, immunogenicity and tolerability were also similar. CONCLUSIONS: Sandoz biosimilar pegfilgrastim demonstrated pharmacokinetic and pharmacodynamic similarity to both US- and EU-reference biologics. No meaningful differences in safety, local tolerability and immunogenicity were identified.

Proposed biosimilar pegfilgrastim shows similarity in pharmacokinetics and pharmacodynamics to reference pegfilgrastim in healthy subjects.

AIMS: This study aimed to demonstrate that the pharmacokinetic (PK) and pharmacodynamic (PD) profile of Sandoz proposed biosimilar pegfilgrastim (LA-EP2006) matches reference pegfilgrastim (Neulasta® ) in healthy subjects. Safety and immunogenicity were also assessed. METHODS: The phase I, randomized, double-blind, two-period crossover study consisted of two treatment periods separated by an 8-week washout period. Healthy subjects aged 18-45 were randomized to either proposed biosimilar/reference pegfilgrastim or reference pegfilgrastim/proposed biosimilar. Proposed biosimilar and reference pegfilgrastim were administered on Day 1 of each treatment period (single 6 mg subcutaneous injection). Blood samples for PK/PD analysis were taken predose and ≤336 h postdose. PK/PD similarity was claimed if 90% (PK) and 95% (PD) confidence intervals (CI) for geometric mean ratios of the area under the serum concentration-time curve (AUC) from time of dosing and extrapolated to infinity (AUC0-inf ), or to the last measurable concentration (AUC0-last ), maximum observed serum concentration (Cmax ), absolute neutrophil count (ANC) area under the effect curve from the time of dosing to the last measurable concentration (AUEC0-last ) and ANC maximum effect attributable to the therapy under investigation (Emax ) were completely contained within the predefined margin (0.8 to 1.25). RESULTS: Overall, 169 subjects completed the study. PK/PD similarity was demonstrated; 90% CIs of geometric mean ratio of proposed biosimilar/reference for PK: AUC0-inf (1.0559-1.2244), AUC0-last (1.0607-1.2328), Cmax (1.0312-1.1909) and 95% CIs for PD (ANC): AUEC0-last (0.9948-1.0366), Emax (0.9737-1.0169) were completely contained within predefined margin of 0.8 to 1.25. Both biologics had similar safety profiles, were well tolerated and had low incidence of anti-drug antibodies. No neutralizing or clinically relevant antibodies were detected. CONCLUSIONS: PK/PD similarity of Sandoz proposed biosimilar pegfilgrastim and reference pegfilgrastim was confirmed. No clinically meaningful differences in safety, tolerability and immunogenicity were observed in healthy subjects.

Preparation and stability of lipid-coated nanocapsules of cisplatin: anionic phospholipid specificity.

Cisplatin nanocapsules represent a novel lipid formulation of the anti-cancer drug cis-diamminedichloroplatinum(II) (cisplatin), in which nanoprecipitates of cisplatin are coated by a phospholipid bilayer consisting of a 1:1 mixture of zwitterionic phosphatidylcholine (PC) and negatively charged phosphatidylserine (PS). Cisplatin nanocapsules are characterized by an unprecedented cisplatin-to-lipid ratio and exhibit increased in vitro cytotoxicity compared to the free drug [Nat. Med. 8, (2002) 81]. In the present study, the stability of the cisplatin nanocapsules was optimized by varying the lipid composition of the bilayer coat and monitoring in vitro cytotoxicity and the release of contents during incubations in water and in mouse serum. The release of cisplatin from the PC/PS (1:1) nanocapsules in water increased with increasing temperature with a t(1/2) of 6.5 h at 37 degrees C. At 4 degrees C, cisplatin was retained in the nanocapsules for well over 8 days. Replacement of PS by either phosphatidylglycerol or phosphatidic acid revealed that nanocapsules prepared of PS were more stable, which was found to be due to the ability of PS to form a stable cisplatin-PS coordination complex. Mouse serum had a strong destabilizing effect on the cisplatin nanocapsules. The PC/PS formulation lost over 80% of cisplatin within minutes after resuspension in serum. Incorporation of poly(ethylene glycol 2000) (PEG)-derivatized phosphatidylethanolamine and cholesterol in the bilayer coat extended the lifetime of the cisplatin nanocapsules in mouse serum to almost an hour. The results demonstrate that specificity in the interaction of cisplatin with anionic phospholipids is an important criterium for the formation and stability of cisplatin nanocapsules.

Ultrastructural analysis of DNA complexes during transfection and intracellular transport.

We present a simple method based on transmission electron microscopy that allows investigation of the early steps of polyplex-mediated transfection without the use of labeled DNA. The ultrastructural analysis showed internalization of 0.2-1-micro m aggregates composed of 30-50-nm subunits. In addition, new details of the internalization process were revealed, suggesting an unspecific cell entry mechanism of large DNA aggregates.

Nanocapsules: lipid-coated aggregates of cisplatin with high cytotoxicity.

Cisplatin is one of the most widely used agents in the treatment of solid tumors, but its clinical utility is limited by toxicity. The development of less toxic, liposomal formulations of cisplatin has been hampered by the low water solubility and low lipophilicity of cisplatin, resulting in very low encapsulation efficiencies. We describe a novel method allowing the efficient encapsulation of cisplatin in a lipid formulation; it is based on repeated freezing and thawing of a concentrated solution of cisplatin in the presence of negatively charged phospholipids. The method is unique in that it generates nanocapsules, which are small aggregates of cisplatin covered by a single lipid bilayer. The nanocapsules have an unprecedented drug-to-lipid ratio and an in vitro cytotoxicity up to 1000-fold higher than the free drug. Analysis of the mechanism of nanocapsule formation suggests that the method may be generalized to other drugs showing low water solubility and lipophilicity.