Development of mRNA manufacturing for vaccines and therapeutics: mRNA platform requirements and development of a scalable production process to support early phase clinical trials

Abstract

The remarkable success of SARS CoV-2 mRNA-based vaccines and the ensuing interest in mRNA vaccines and therapeutics have highlighted the need for a scalable clinical-enabling manufacturing process to produce such products, and robust analytical methods to demonstrate safety, potency, and purity. To date, production processes have either not been disclosed or are bench-scale in nature and cannot be readily adapted to clinical and commercial scale production. To address these needs, we have advanced an aqueous-based scalable process that is readily adaptable to GMP-compliant manufacturing, and developed the required analytical methods for product characterization, quality control release, and stability testing. We also have demonstrated the products produced at manufacturing scale under such approaches display good potency and protection in relevant animal models with mRNA products encoding both vaccine immunogens and antibodies. Finally, we discuss continued challenges in raw material identification, sourcing and supply, and the cold chain requirements for mRNA therapeutic and vaccine products. While ultimate solutions have yet to be elucidated, we discuss approaches that can be taken that are aligned with regulatory guidance.

Fig 1

Plasmid map encoding an example vaccine immunogen for mRNA expression.

Fig 2

Scalable mRNA production process flow diagram and in-process testing.

Fig 3

Influenza HA-specific human antibody in serum following IV administration of the mixture of the heavy and light chain mRNA in LNPs. A, Dose response in wild-type BALB/C mice with CH65 mRNA in optimized Acuitas LNP (study 1). B, Dose response in wild-type BALB/C mice with CH65 mRNA in optimized Acuitas LNP (study 2). C, Dose response in wild-type BALB/C mice with Ab700364 mRNA in optimized Acuitas LNP. D, Dose response in non–human primates (rhesus) with Ab700364 mRNA in optimized Acuitas LNP.

Fig 4

Pre-treatment with Ab700364 mRNA-LNP protects mice from lethal challenge with X-31 influenza virus (1e6 FFU; mouse adapted A/Aichi/2/1968) 24 hours later.

Fig 5

Binding and neutralizing antibody responses elicited by mRNA-LNP immunization of heterozygous DH270 broadly neutralizing antibody precursor mice. A, Serum IgG binding titer to the HIV-1 envelope trimer (left) that matches the vaccine or a related HIV-1 gp120 subunit of envelope (right). Arrows indicate timepoints of immunizations. Group mean and standard error are shown. Binding titer is shown as area under the log transformed curve (log AUC). B, Serum neutralizing antibody titer against variants of the CH848.10.17 pseudovirus. DT indicates the virus engineered to bind to the HIV-1 bnAb precursor of the DH270 antibody lineage. N332T indicates the knockout mutant version of the CH848.10.17 virus, which lacks recognition by the DH270 lineage. MuLV indicates the murine leukemia virus used as a negative control virus.