title: Preclinical pharmacology and safety of a novel avidin derivative for tissue-targeted delivery of radiolabelled biotin.
abstract: We recently described an oxidized avidin variant, named AvidinOX(®) , which is a product that chemically links to tissue proteins while maintaining the capacity to uptake intravenously administered biotin. Such product proved to be successful in targeting radionuclide therapy in a mouse model of inoperable breast cancer. Here, we show that the uptake of a single or multiple doses of biotin (up to five times), by the tissue-bound AvidinOX(®) , is stable for 2 weeks. Taking into account that oxidized avidin is the first chemically reactive protein to be proposed for clinical use, we evaluated its tolerability, immunogenicity and mutagenicity. Present in vitro data indicate that AvidinOX(®) (up to 10 μg/5 × 10(5) cells) does not affect cell viability or proliferation of PC3 human prostate cancer or 3T3 mouse fibroblast cell lines as well as primary mouse spleen cells. Safety pharmacology and toxicology studies were conducted using AvidinOX(®) up to the highest concentration compatible with its solubility (about 12 mg/mL), representing four times the product concentration intended for human use, and in the maximum administrable volume compatible with each study system. The intramuscular administration in rat and monkey induced a moderate to strong inflammatory response particularly after a second administration and consistently with the induction of an immune response. Interestingly, the intramuscular administration of AvidinOX(®) to rodents and monkeys exhibiting very high anti-avidin antibody titres was well tolerated with no systemic symptoms of any kind. Intravenous administration of AvidinOX(®) , performed to mimic an accidental injection of the dose intended for a local administration (15 μL of 3.3 mg/mL solution), showed significant localization of the product into the spleen not associated with uptake of the radiolabelled biotin intravenously injected after 24 hr, thus suggesting rapid inactivation. No mutagenic activity was induced by oxidized avidin in prokaryotic and eukaryotic cells. Overall, the present data indicate that AvidinOX(®) is well tolerated in rodents and non-human primates, thus supporting its clinical use within protocols of radionuclide therapy of inoperable tumour lesions.
authors.affiliation: Sigma-Tau SpA R&D, Pomezia, Rome, Italy.
authors.forename: Fiorella
authors.initials: F
authors.lastname: Petronzelli
authors.forename: Anna M
authors.initials: AM
authors.lastname: Anastasi
authors.forename: Angela
authors.initials: A
authors.lastname: Pelliccia
authors.forename: Daniela
authors.initials: D
authors.lastname: Santapaola
authors.forename: Claudio
authors.initials: C
authors.lastname: Albertoni
authors.forename: Antonio
authors.initials: A
authors.lastname: Rosi
authors.forename: Barbara
authors.initials: B
authors.lastname: Leoni
authors.forename: Liliana E
authors.initials: LE
authors.lastname: Ferrari
authors.forename: Giovanni
authors.initials: G
authors.lastname: Paganelli
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Gramiccioli
authors.forename: Daniela
authors.initials: D
authors.lastname: Pesce
authors.forename: Anna M
authors.initials: AM
authors.lastname: Alfano
authors.forename: Maria A
authors.initials: MA
authors.lastname: Stasi
authors.forename: Rita
authors.initials: R
authors.lastname: De Santis
mesh_terms: D016475:3T3 Cells; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001360:Avidin / Q000276:immunology / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000633:toxicity*; D001710:Biotin / Q000008:administration & dosage*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D006801:Humans; D007205:Indium Radioisotopes; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008252:Macaca fascicularis; D008297:Male; D051379:Mice; D018482:Muscle, Skeletal / Q000187:drug effects / Q000473:pathology; D009152:Mutagenicity Tests / Q000379:methods; D019275:Radiopharmaceuticals / Q000276:immunology / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000633:toxicity*; D051381:Rats; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D018675:Toxicity Tests / Q000379:methods
chemical_list: D007205:Indium Radioisotopes; D019275:Radiopharmaceuticals; D001360:Avidin; D001710:Biotin