The development of antibody responses against therapeutic proteins such as Factor VIII (FVIII) is a major clinical complication that compromises the safety and efficacy of protein based therapeutics. Our goal is to improve upon the therapeutic efficacy of proteins by developing non-immunogenic forms of the molecules. FVIII is a multi-domain protein that plays a critical role in blood coagulation cascade. The deficiency and dysfunction of FVIII causes Hemophilia A, a bleeding disorder. Administration of recombinant FVIII is the first line of therapy for Hemophilia A (HA) patients. The safety and efficacy of this replacement therapy is severely compromised by the development of inhibitory antibody responses that occur in 15-30% of HA patients treated with FVIII. We have established that the antibody response to FVIII is reduced significantly by complexing the protein with phosphatidylserine (FVIII-PS) or phosphatidylinositol (FVIII-PI). To exploit this novel finding for developing a more therapeutically effective form of FVIII, and to determine how such lipid modifications may be used with other therapeutic proteins, it is imperative to determine the mechanisms by which the reduction of immunogenicity is achieved. Therefore, in Aim 1 we propose to establish whether the decrease in the antibody response is due to the lipid complexes'ability to alter antigen processing and presentation of the protein, resulting in active induction of immunological tolerance in HA mice. Alternatively we will determine whether it is due to a passive process that results from lipid shielding of immunogenic determinants. These studies will reveal the robustness, specificity, safety and durability of the reduced antibody responses observed, and will establish the degree to which the lipid complexes reduce or eliminate an already-established anti-FVIII antibody response. Because the frequency of administration increases immunogenic response, long acting lipid-FVIII complexes that reduce the frequency of administration are useful.
In Aim 2, the effect of lipid headgroup and PEG modification upon the pharmacokinetics (PK) of FVIII will be investigated. PK properties, such as circulation half-life, mean residence time and exposure of FVIII following iv or sc injection, will be established by quantifying and comparing the FVIII levels achieved with lipidic FVIII formulations to those observed with FVIII alone. The haemostatic efficacy of FVIII is the key endpoint of clinical significance.
Aim 3 will establish how lipid complexation affects the pharmacodynamics and therapeutic efficacy of the lipid- complexed FVIII by using an in vivo standardized tail vein transection assay. In SA 4, the translational utility of reduction in immunogenicity and PK of FVIII-lipid complex will be tested in a primate model, Macaque mulatta. These studies are expected to elucidate the mechanistic basis by which lipidic FVIII complexes decrease immunogenicity, and improve pharmacokinetics and therapeutic efficacy in animal models, so that this observation may be extended to clinical trial, and applied also to the design, formulation and delivery of other therapeutic proteins, so as to overcome issues that negatively impact their clinical use.
Development of inhibitory antibody against FVIII is a major clinical complication that impacts safety and efficacy of the replacement therapy for Hemophilia A, a bleeding disorder. The proposed research is relevant to public health because the proposal is focused on developing lipidic FVIII as therapeutic preparations that are less immunogenic and long acting FVIII to improve safety and therapeutic efficacy of FVIII replacement therapy. The experimental design involves an interdisciplinary approach involving biophysics, immunology, pharmacokinetics and pharmacodynamics.
|Shetty, Krithika A; Merricks, Elizabeth P; Raymer, Robin et al. (2016) Soy Phosphatidylinositol-Containing Lipid Nanoparticle Prolongs the Plasma Survival and Hemostatic Efficacy of B-domain-Deleted Recombinant Canine Factor VIII in Hemophilia A Dogs. J Pharm Sci 105:2459-64|
|Ramakrishnan, Radha; Balu-Iyer, Sathy V (2016) Effect of Biophysical Properties of Phosphatidylserine Particle on Immune Tolerance Induction Toward Factor VIII in a Hemophilia A Mouse Model. J Pharm Sci 105:3039-45|
|Schneider, Jennifer L; Balu-Iyer, Sathy V (2016) Phosphatidylserine Converts Immunogenic Recombinant Human Acid Alpha-Glucosidase to a Tolerogenic Form in a Mouse Model of Pompe Disease. J Pharm Sci 105:3097-104|
|Shetty, Krithika A; Kosloski, Matthew P; Mager, Donald E et al. (2016) Factor VIII associated with lipidic nanoparticles retains efficacy in the presence of anti-factor VIII antibodies in hemophilia A mice. Biopharm Drug Dispos 37:409-420|
|Shetty, Krithika A; Kosloski, Matthew P; Mager, Donald E et al. (2015) Soy phosphatidylinositol containing nanoparticle prolongs hemostatic activity of B-domain deleted factor VIII in hemophilia A mice. J Pharm Sci 104:388-95|
|Ramakrishnan, Radha; Davidowitz, Andrew; Balu-Iyer, Sathy V (2015) Exposure of FVIII in the Presence of Phosphatidyl Serine Reduces Generation of Memory B-Cells and Induces Regulatory T-Cell-Mediated Hyporesponsiveness in Hemophilia A Mice. J Pharm Sci 104:2451-6|
|Gaitonde, Puneet; Purohit, Vivek S; Balu-Iyer, Sathy V (2015) Intravenous administration of Factor VIII-O-Phospho-L-Serine (OPLS) complex reduces immunogenicity and preserves pharmacokinetics of the therapeutic protein. Eur J Pharm Sci 66:157-62|
|Kelleher Jr, Raymond J; Balu-Iyer, Sathy; Loyall, Jenni et al. (2015) Extracellular Vesicles Present in Human Ovarian Tumor Microenvironments Induce a Phosphatidylserine-Dependent Arrest in the T-cell Signaling Cascade. Cancer Immunol Res 3:1269-78|
|Fathallah, Anas M; Turner, Michael R; Mager, Donald E et al. (2015) Effects of hypertonic buffer composition on lymph node uptake and bioavailability of rituximab, after subcutaneous administration. Biopharm Drug Dispos 36:115-25|
|Fathallah, Anas M; Balu-Iyer, Sathy V (2015) Anatomical, physiological, and experimental factors affecting the bioavailability of sc-administered large biotherapeutics. J Pharm Sci 104:301-6|
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