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dc.contributor.authorShetty, Krithika Arun
dc.date.accessioned2016-04-05T19:59:06Z
dc.date.available2016-04-05T19:59:06Z
dc.date.issued2015
dc.identifier.isbn9781321922790
dc.identifier.other1709470149
dc.identifier.urihttp://hdl.handle.net/10477/51564
dc.description.abstractFactor VIII (FVIII) is an essential blood clotting protein, the genetic deficiency or dysfunction of which leads to the bleeding condition Hemophilia A (HA). This dissertation builds on previous work in our lab that uses multifunctional lipidic nanoparticles and excipients to address the clinical delivery issues of FVIII. These lipidic delivery approaches include phosphatidylinositol (PI) containing nanoparticles, phosphatidylserine (PS) containing lipid nanoparticles, and the head group of PS O-Phospho-L-Serine (OPLS). In Chapter 1 of this dissertation, we evaluated the pharmacokinetics (PK), hemostatic efficacy and immunogenicity of BDD FVIII associated with PI nanoparticles (PI-BDD FVIII) in HA mice. PI association reduced the development of inhibitory and binding antibodies against BDD FVIII after a series of i.v. injections. The combined improvements in circulating half-life and hemostatic efficacy could significantly prolong the time above clinically established therapeutic thresholds of prophylactic FVIII replacement therapy in humans. In Chapter 2, we evaluated whether PI-BDD FVIII could serve as an efficacious replacement FVIII therapy in the presence of inhibitors against the protein. We hypothesized that the lipid particle sterically shields the protein from binding to inhibitors permitting retention of biological activity under bleeding conditions. Mathematical modeling of the data supports the hypotheses that a greater fraction of the lipid-associated FVIII remains unbound to inhibitors, and that PI-BDD FVIII has lower binding affinity to inhibitors than the free protein. In Chapters 3 and 4 we conducted complete toxicological evaluations of OPLS and PS liposomes in rodents and in non-human primates. The goal of these studies was to establish a No Observed Adverse Effect Level (NOAEL) of OPLS and PS liposomes in each of these species, to guide first-in-human dosing. Based on the findings of these systematic toxicological assessments, OPLS and PS liposomes have wide margins of safety around their anticipated clinical doses. In Chapter 5A we studied the comparative plasma survival and ex vivo efficacy of free and PI associated recombinant canine FVIII (PI-rcFVIII) in HA dogs. The data indicate that PI association prolongs the plasma survival of rcFVIII. PI-rcFVIII treated animals had prolonged improvements in WBCTs and TEG parameters compared to free rcFVIII treated animals. Based on the results of these studies we expect that our findings with human BDD FVIII in mice will translate to higher species. Chapter 5B reports the findings of our comparative PK, efficacy and immunogenicity studies with free and PI associated full length FVIII (FL FVIII) in HA dogs and rhesus macaques. Potential hypotheses for these findings are discussed. Immunogenicity studies in rhesus macaques were inconclusive with the small sample size given the high inherent variability in immunological responses. In summary, this dissertation furthers the development of next generation FVIII products that could fulfill large unmet medical needs, and it also serves to bridge key gaps in scientific knowledge. BDD FVIII was identified as the form of FVIII more likely to succeed using the lipidic delivery approach, and the data suggest that that lipidic FVIII is more potent that the free protein. A critical application of lipidic FVIII in inhibitor-positive HA subjects was identified. Mathematical models to facilitate understanding of the impact of immunogenicity on FVIII efficacy were described. Rigorous toxicological evaluations of the lipidic entities OPLS and PS liposomes were conducted, which are key prerequisites to first-in-human studies with these entities. Finally, and perhaps most importantly, proof of principal of the translational efficacy PI associated BDD FVIII was demonstrated with rcFVIII in HA dogs. (Abstract shortened by UMI.)
dc.languageEnglish
dc.sourceDissertations & Theses @ SUNY Buffalo,ProQuest Dissertations & Theses Global
dc.subjectHealth and environmental sciences
dc.subjectSafety
dc.subjectEfficacy
dc.subjectLipidic formulations
dc.subjectTherapeutic proteins
dc.titleSafety and efficacy of lipidic formulations of therapeutic proteins
dc.typeDissertation/Thesis


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