title: Nano-encapsulation of plitidepsin: in vivo pharmacokinetics, biodistribution, and efficacy in a renal xenograft tumor model.
abstract: OBJECTIVE
  Plitidepsin is an antineoplasic currently in clinical evaluation in a phase III trial in multiple myeloma (ADMYRE). Presently, the hydrophobic drug plitidepsin is formulated using Cremophor®, an adjuvant associated with unwanted hypersensitivity reactions. In search of alternatives, we developed and tested two nanoparticle-based formulations of plitidepsin, aiming to modify/improve drug biodistribution and efficacy.
  
  
  METHODS
  Using nanoprecipitation, plitidepsin was loaded in polymer nanoparticles made of amphiphilic block copolymers (i.e. PEG-b-PBLG or PTMC-b-PGA). The pharmacokinetics, biodistribution and therapeutic efficacy was assessed using a xenograft renal cancer mouse model (MRI-H-121 xenograft) upon administration of the different plitidepsin formulations at maximum tolerated multiple doses (0.20 and 0.25 mg/kg for Cremophor® and copolymer formulations, respectively).
  
  
  RESULTS
  High plitidepsin loading efficiencies were obtained for both copolymer formulations. Considering pharmacokinetics, PEG-b-PBLG formulation showed lower plasma clearance, associated with higher AUC and Cmax than Cremophor® or PTMC-b-PGA formulations. Additionally, the PEG-b-PBLG formulation presented lower liver and kidney accumulation compared with the other two formulations, associated with an equivalent tumor distribution. Regarding the anticancer activity, all formulations elicited similar efficacy profiles, as compared to the Cremophor® formulation, successfully reducing tumor growth rate.
  
  
  CONCLUSIONS
  Although the nanoparticle formulations present equivalent anticancer activity, compared to the Cremophor® formulation, they show improved biodistribution profiles, presenting novel tools for future plitidepsin-based therapies.
authors.affiliation: Université de Bordeaux/IPB, ENSCBP, 16 avenue Pey Berland, 33607, Pessac Cedex, France, hugo.de-oliveira@inserm.fr.
authors.forename: Hugo
authors.initials: H
authors.lastname: Oliveira
authors.forename: Julie
authors.initials: J
authors.lastname: Thevenot
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Garanger
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Ibarboure
authors.forename: Pilar
authors.initials: P
authors.lastname: Calvo
authors.forename: Pablo
authors.initials: P
authors.lastname: Aviles
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Guillen
authors.forename: Sébastien
authors.initials: S
authors.lastname: Lecommandoux
mesh_terms: D000818:Animals; D047630:Depsipeptides / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004337:Drug Carriers / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005260:Female; D007680:Kidney Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000008:administration & dosage / Q000378:metabolism*; D010456:Peptides, Cyclic; D014018:Tissue Distribution / Q000187:drug effects / Q000502:physiology; D016896:Treatment Outcome; D023041:Xenograft Model Antitumor Assays / Q000379:methods*
chemical_list: D047630:Depsipeptides; D004337:Drug Carriers; D010456:Peptides, Cyclic; C098980:plitidepsin