January 10, 2023 PAO-11-022-CL-06
Taking a concerted quality-by-design (QbD) approach to the development and manufacturing of RNA means producing research-use-only (RUO) materials while keeping the end goal of clinical-grade production in mind. This can be achieved by adopting manufacturing operations that will ultimately be compatible with large-scale production. Along with this QbD approach and the expertise of veterans in the sector, one of Vernal Biosciences’ strengths is the ability to produce high-purity mRNA and lipid nanoparticles (LNPs) with the shortest turnaround time in the industry partnered with established platform technologies and robust processes. Additionally, the quality metrics established for small-scale production are maintained through large-scale production, ensuring proper product quality approval and consistency from drug discovery research all the way through clinical and commercial manufacturing.
At Vernal Biosciences, our unique QbD approach is reflected in the different project types and product grades produced by the company. Through our custom RUO products and services, Vernal provides turnkey solutions to support clients’ early research and discovery needs for mRNA and LNP testing in cell and animal studies.
For clients moving beyond early-stage R&D and RUO materials, Vernal Biosciences offers mRNA and LNP–mRNA made under GMP-Principle and GMP. Products made under the GMP-Principle are typically suitable for IND-enabling GLP tox studies, are produced using processes that mirror those used for RUO products, and are directly representative of the processes scaled for GMP products, even though not typically made in a GMP clean room. On the other hand, full GMP products are intended for first-in-human use and are produced in full compliance with GMP requirements and accompanied by comprehensive documentation and a GMP data package. GMP and GMP-Principle products are produced under oversight of manufacturing quality that is based on phase-appropriate quality systems and risk-management approaches.
A similar approach is applied with respect to the generation of LNP-formulated RNA products. At the RUO level, Vernal currently generates RNA drug substances encapsulated in LNPs for use in toxicology and other preclinical studies. Notably, RUO-grade mRNA can be generated through in vitro transcription (IVT) at a relatively large scale in terms of laboratory quantities: as much as 500 mg. Vernal anticipates offering GMP mRNA and LNP formulation services in 2023 and expects to further expand operations with a commercial-ready sterile fill/finish offering at a second CDMO site in 2024.
Vernal Biosciences’ platform processes for mRNA and LNP–mRNA manufacturing leverage a consistent set of processes and reagents that enable plug-and-play, turnkey solutions. Customers provide the sequence information and the scale needed, while Vernal rapidly and reliably produces RUO materials. Concurrently, RUO design will be generated with efficient scale-up to GMP processes that mirror those used for RUO. This end-to-end process design eliminates many of the tech transfer and proof-of-concept challenges faced when changing CDMO partners as the life cycle of drug development advances. Confidence in our platform processes and manufacturing expertise is based on our experience in manufacturing hundreds of batches of RNA and LNP formulations.
The establishment of platform processes at the RUO stage begins with codon sequence optimization to enhance protein expression. This process factors in accumulated knowledge, evidence, and studies on the effects of different DNA template elements on IVT and translation efficiency. This enables the establishment of critical quality attributes (CQAs), such as the characteristics of the pilot RNA batches generated via IVT and the type and level of certain product-related impurities, which can be determined using capillary electrophoresis (CE). After the subsequent capping reaction (for which Vernal Biosciences uses enzymes rather than other proprietary capping agents) and purification, CE is repeated to confirm the purity of the final capped mRNA product. For special projects that involve other types of RNA, such as structured or circular RNA, additional CQAs will be established and analytical methods will be developed, tested, and performed for every production run.
Determination of CQAs at the research-grade product level establishes a baseline target for product quality and RNA integrity. Once that is achieved at the drug discovery stage or for RUO materials, a quality target is established, which becomes the initial goal during scale-up. Additional CQAs are layered on to support the quality target product profile (QTPP) for each specific product.
At the RUO stage, it is possible to use the same or similar platform processes for different RNA projects, as these products are typically produced at small scale for RUO. However, differences in RNA sequences, including length, GC (guanine–cytosine) content, and other factors, can have significant impacts on process efficiency and ultimately on manufacturing costs and timelines. As a result, process development and optimization become critical to adapting the platform processes used for RUO into efficient, scaled-up processes suitable for GMP-Principle and GMP products.
Process optimization should be a focus as early in the project timeline as possible. At Vernal Biosciences, the first step is to screen the RNA sequence to verify that it does not contain motifs that might present issues. However, understanding about how different constructs will behave during IVT is still evolving. When odd behavior is observed, Vernal develops hypotheses regarding the cause of the behavior, such as the presence of repetitive sequences or DNA–RNA associations.
Once a hypothesis has been established, a series of small-scale trial runs is performed to determine which modifications improve the productivity or product-related purity profile, which can enrich our existing knowledge base and enable better prediction of the construct’s behavior for future projects. Additionally, if a product must be shipped from one facility to another, the logistics of storage, as well as the freezing and thawing process, must also undergo evaluation.
Vernal’s platform processes are designed from the start both to require little to no modifications to produce RUO materials and to transition seamlessly, with some modifications, into GMP manufacturing. In most cases, the types of adaptations required as a process advances to GMP can be anticipated on the basis of the information gathered during the RUO phase, such as transitioning to a larger bioreactor, extending the reaction time to increase productivity and yield, and shortening the reaction time to avoid overwhelming the chromatography column.
For many CDMOs, projects are brought in at the later development stages, with feasibility work completed and important information generated elsewhere. As a result, processes are not necessarily designed to fit the CDMO’s production platforms (if platforms are available), leading to the need for extensive adaptation through an elaborate technology transfer process. At Vernal Biosciences, our end-to-end capabilities span early- and late-stage development, as well as activities from production of working cell bank, plasmid DNA, and RNA drug substance to LNP formulation and filling into vials, which allows a high level of communication between the research and GMP operations groups.
Despite extensive optimization efforts, some changes in process performance can be expected during scale-up. When developing RNA drug substance and final product (LNP–mRNA) manufacturing processes, it is crucial to know which parameters will be impacted by scale and to plan accordingly.
Scale-up can be achieved in two ways: increasing bioreactor volumes (using a bigger reactor and more raw materials) or improving productivity. A more productive IVT reaction yields a higher quantity of RNA material per unit volume. Increasing productivity is a focus for Vernal's RNA Science team, while increasing scale by moving to bigger bioreactors is an emphasis for later-stage products. Once a process at a very small scale has been optimized with respect to productivity and has been demonstrated to work with most constructs, it is ready to be scaled up in stages from 1–2 mg up to 50 mg and larger.
Vernal is developing and qualifying a toolbox of testing methods. This includes assays that are not applied at the research level, because the relevant impurities are known to change at large scale and thus are only tested upon the initiation of process development, engineering, and GMP runs. They also include methods for the detection of impurities for special projects, such as tests for the presence of double-stranded RNA.
The concerted QbD approach that drives Vernal Biosciences’ operations meets the needs of therapeutic developers for reliable and high-quality RNA supply. With our end-to-end service offering from cell banking and plasmid manufacturing capabilities to mRNA and LNP formulation, customers only need to partner with a single CDMO across the entire mRNA value chain for the life cycle of drug development. Vernal’s reliable platform processes, state-of-the-art equipment, and expertise in process development enable seamless scale-up, fast tracking your drug development by ensuring timely and stable supply of high-quality mRNA-based drug products. Vernal is one of the few CDMOs with manufacturing slots available for new projects, as demand for CDMO services in the mRNA technology sector surges to unprecedented levels and mRNA developers struggle to find manufacturing partners with sufficient available capacity.
Grant Henderson is responsible for process scale-up of pDNA, mRNA, and LNP–mRNA and is the interim head of quality control. In addition to leading manufacturing sciences, Grant has been instrumental in facility design, process architecture, and leading the implementation of Vernal’s quality management system. Grant has over 10 years of process engineering experience in small and large molecules at Lonza Biologics and Mylan Technologies, with past responsibilities ranging from process development to management of regulatory filings.