GMP Manufacturing and IND-Enabling Studies of a Recombinant Hyperimmune Globulin Targeting SARS-CoV-2.

Conventionally, hyperimmune globulin drugs manufactured from pooled immunoglobulins from vaccinated or convalescent donors have been used in treating infections where no treatment is available. This is especially important where multi-epitope neutralization is required to prevent the development of immune-evading viral mutants that can emerge upon treatment with monoclonal antibodies. Using microfluidics, flow sorting, and a targeted integration cell line, a first-in-class recombinant hyperimmune globulin therapeutic against SARS-CoV-2 (GIGA-2050) was generated. Using processes similar to conventional monoclonal antibody manufacturing, GIGA-2050, comprising 12,500 antibodies, was scaled-up for clinical manufacturing and multiple development/tox lots were assessed for consistency. Antibody sequence diversity, cell growth, productivity, and product quality were assessed across different manufacturing sites and production scales. GIGA-2050 was purified and tested for good laboratory procedures (GLP) toxicology, pharmacokinetics, and in vivo efficacy against natural SARS-CoV-2 infection in mice. The GIGA-2050 master cell bank was highly stable, producing material at consistent yield and product quality up to >70 generations. Good manufacturing practices (GMP) and development batches of GIGA-2050 showed consistent product quality, impurity clearance, potency, and protection in an in vivo efficacy model. Nonhuman primate toxicology and pharmacokinetics studies suggest that GIGA-2050 is safe and has a half-life similar to other recombinant human IgG1 antibodies. These results supported a successful investigational new drug application for GIGA-2050. This study demonstrates that a new class of drugs, recombinant hyperimmune globulins, can be manufactured consistently at the clinical scale and presents a new approach to treating infectious diseases that targets multiple epitopes of a virus.

Generation of recombinant hyperimmune globulins from diverse B-cell repertoires.

Plasma-derived polyclonal antibody therapeutics, such as intravenous immunoglobulin, have multiple drawbacks, including low potency, impurities, insufficient supply and batch-to-batch variation. Here we describe a microfluidics and molecular genomics strategy for capturing diverse mammalian antibody repertoires to create recombinant multivalent hyperimmune globulins. Our method generates of diverse mixtures of thousands of recombinant antibodies, enriched for specificity and activity against therapeutic targets. Each hyperimmune globulin product comprised thousands to tens of thousands of antibodies derived from convalescent or vaccinated human donors or from immunized mice. Using this approach, we generated hyperimmune globulins with potent neutralizing activity against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in under 3 months, Fc-engineered hyperimmune globulins specific for Zika virus that lacked antibody-dependent enhancement of disease, and hyperimmune globulins specific for lung pathogens present in patients with primary immune deficiency. To address the limitations of rabbit-derived anti-thymocyte globulin, we generated a recombinant human version and demonstrated its efficacy in mice against graft-versus-host disease.

Latent, Immunosuppressive Nature of Poly(lactic-co-glycolic acid) Microparticles.

Use of biomaterials to spatiotemporally control the activation of immune cells is at the forefront of biomedical engineering research. As more biomaterial strategies are employed for immunomodulation, understanding the immunogenicity of biodegradable materials and their byproducts is paramount in tailoring systems for immune activation or suppression. Poly(D,L-lactic-co-glycolic acid) (PLGA), one of the most commonly studied polymers in tissue engineering and drug delivery, has been previously described on one hand as an immune adjuvant, and on the other as a nonactivating material. In this study, the effect of PLGA microparticles (MPs) on the maturation status of murine bone marrow-derived dendritic cells (DCs), the primary initiators of adaptive immunity, was investigated to decipher the immunomodulatory properties of this biomaterial. Treatment of bone marrow-derived DCs from C57BL/6 mice with PLGA MPs led to a time dependent decrease in the maturation level of these cells, as quantified by decreased expression of the positive stimulatory molecules MHCII, CD80, and CD86 as well as the ability to resist maturation following challenge with lipopolysaccharide (LPS). Moreover, this immunosuppression was dependent on the molecular weight of the PLGA used to fabricate the MPs, as higher molecular weight polymers required longer incubation to produce comparable dampening of maturation molecules. These phenomena were correlated to an increase in lactic acid both intracellularly and extracellularly during DC/PLGA MP coculture, which is postulated to be the primary agent behind the observed immune inhibition. This hypothesis is supported by our results demonstrating that resistance to LPS stimulation may be due to the ability of PLGA MP-derived lactic acid to inhibit the phosphorylation of TAK1 and therefore prevent NF-κB activation. This work is significant as it begins to elucidate how PLGA, a prominent biomaterial with broad applications ranging from tissue engineering to pharmaceutics, could modulate the local immune environment and offers insight on engineering PLGA to exploit its evolving immunogenicity.