Manufacturing Archives - The Antibody Society

Join us on April 7th for our next webinar, Precision Execution of Bispecifics at Scale from Design to Delivery!

March 28, 2022 by The Antibody Society

Thursday April 7, 2022 11am ET / 5pm CET
Speaker: Dr. Lisa Prendergast, Associate Director of Expression System Sciences in Licensing at Lonza

Registration for our next webinar, “Precision Execution of Bispecifics at Scale from Design to Delivery“, is now open!

Novel therapeutic modalities such as bispecific antibodies are increasingly being explored as more effective alternatives to monoclonal antibodies for a range of diseases. Therapeutics such as bispecifics, can have a combinatorial effect by targeting two antigens, resulting in treatments with enhanced utility, higher efficacy, fewer side effects and less resistance compared to mAbs.

Generating a bispecific antibody, which is correctly and stably paired, is a major production concern. Many solutions require significant changes to native antibody structure, which increases antibody complexity and forces adaptation of downstream processes. While a various platforms have been developed to mitigate Heavy-Light chain (HC-LC) mispairing, there are many other rate limiting steps for efficiently expressing these molecules in a CHO system. bYlok® technology is a design engineering approach that stabilise the interaction between the HC and LC, essentially removing the mispairing problem whilst retaining a more natural antibody structure.

This presentation will introduce you to a mechanistic review of the bispecific pipeline to demonstrate how a various tools and technologies can enable you execute bispecifics. Case studies will be presented to show how the bYlok® technology can be used to stabilise and select for novel bispecifics from a panel of parental immunotherapeutic mAbs. Our data demonstrates that correct heterodimerisation can be achieved consistently and how standard downstream purification processes can be used during production.

Register here!

Molecular Biology Can Improve Antibody Drug Developability

March 16, 2020 by Janice Reichert

Contributed by Nick Hutchinson, FUJIFILM Diosynth Biotechnologies

The discovery and development of antibody therapeutics often adheres to a series of stages starting with target identification and progressing through lead generation, lead optimization, then testing in preclinical and clinical studies. Molecular biologists engineer antibodies during lead generation and optimization to improve a range of characteristics, including antibody specificity and potency, or to reduce immunogenicity and the rate of elimination from the body (1).

Next-generation antibody biopharmaceuticals include bispecifics, glyco-engineered antibodies and antibody-fusion proteins with complex architectures. While drug development scientists may use antibody engineering techniques to generate candidates with very desirable or improved functional properties, at the same time, these can alter the biochemical, biophysical and in vivo properties of the antibody candidate, which can be detrimental to the overall target product profile (2). Engineering antibodies to improve their functional properties is frequently performed without consideration for the subsequent developability, including manufacturability, of the molecule. These issues are then often identified at a relatively late stage in the discovery process, after substantial resources have been invested in the molecule and, therefore, can have a real financial impact on drug development companies that may be being kept alive by funding from investors.

Ideally, antibody therapeutics should be capable of being manufactured with high productivity and at high quality with low protein heterogeneity. From a developability perspective, it is preferable if they express to high titer from the mammalian cell expression system and are stable during production storage and delivery (1). Some antibody candidates can exhibit a propensity to partially unfold, revealing hydrophobic patches that are more normally buried inside the molecule. Once revealed, the patches can interact with one another, leading to aggregation. Other liabilities that reduce developability include low solubility, unstable amino acids, clipping and antibody fragmentation (1). These can be sufficiently severe that projects can be cancelled due to poor toxicology data and concerns around whether the candidate can be safely administered to patients during clinical trials.

One solution, advocated by investigators from Roche (2), is to assess developability during antibody drug discovery. Their workflow incorporates two separate assessments, the first following the initial candidate screening and selection and the second following humanization and re-engineering, but before the selection of the clinical lead. During the first phase of the assessment, complementarity-determining regions are analysed in silico for potential liabilities such as degradation sites. This can be followed by studies on stressed samples, with samples incubated at elevated temperatures for two weeks. Stable candidates can progress to the next stage or drug development scientists can use humanization and protein re-engineering to remove the identified liabilities. The second phase, which follows humanization, again employs in silico tools but evaluates the whole humanized molecule and assesses potential hotpots where post-translational modification, charge variations or degradation might occur. Researchers then perform a second stress test for the most likely or detrimental liabilities. During this phase, they can include tests for self-interaction and aggregation, such as apparent hydrophobicity by hydrophobic interaction chromatography, thermal stability by dynamic light scattering (DLS), protein-protein self-interaction by DLS and viscosity at high concentration by DLS with latex beads (2).

Other groups have gone further, and not only select for candidates with properties that limit manufacturing and storage risks, but also apply molecular engineering techniques in order to improve manufacturability proactively. For example, in 2019, a team from AstraZeneca described manufacturing challenges they encountered during downstream purification of an antibody that was undergoing liquid-liquid phase separation (3). This in turn resulted in the need for longer mixing times that can be damaging for proteins, yield losses, increases in pressure during processing and misleading analytical results from in-process samples. The team attempted to resolve the problem by optimize the bioprocessing conditions, but there were still substantial limitations to large-scale manufacturing. To fix the problem, they used in silico homology modelling and charged-patch analysis to identify problematic residues, and this ultimately lead them to substitute charged residues with those with a neutral or opposite charge. Their research showed that these substitutions minimized electrostatic interactions and allowed them to engineer a variant that maintained antigen-binding affinity, but eliminated the liquid-liquid phase separation behaviour.

The molecular engineering of therapeutic antibodies is allowing development of candidates with ever improved functional properties. However, researchers should consider, where possible, the impact of this engineering on the biochemical and biophysical characteristics of the molecule, which can have a negative effect on the developability of lead candidates. Incorporating screens for developability during drug discovery workflow can help eliminate candidates with liabilities that will prevent them from being successful drugs. The more sophisticated developers of antibody therapeutics are cleverly applying molecular biological techniques to improve the stability and manufacturability of their monoclonal antibody leads.

(1) Chiu, M.L. & Gilliland, G.L. (2016) Engineering antibody therapeutics. Current Opinions in Structural Biology, 38: 163-173.

(2) Jarasch, A., Koll, H., Regula, J.T., Bader, M., Papadimitriou, A. & Kettenberger, H. (2015) Developability assessment during the selection of novel therapeutic antibodies. Journal of Pharmaceutical Sciences, 104:1885-1898.

(3) Du, Q., Damschroder, M., Pabst, T.M. Hunter, A.K., Wang, W.K. & Luo, H. (2019) Process optimization and protein engineering mitigated manufacturing challenges of a monoclonal antibody with liquid-liquid phase separation issues by disrupting inter-molecule electrostatic interaction. MAbs, 11 (4): 789-802.

The Antibody Society is an authoritative source of information about antibody therapeutics development. We are pleased to provide original posts and news summaries on our homepage, as well as semi-monthly summaries of recent news to our members. Archived news from 2019 can be found in the Web Resources section of the Society’s website.

Feeding drug development programs with sufficient antibody

November 1, 2019 by The Antibody Society

Author: Nick Hutchinson, Fujifilm Diosynth Biotechnologies

The demand for antibody and antibody-related therapeutics continues to increase. [1] The United States Food and Drug Administration has approved ~ 100 antibody therapeutics for a wide range of treatments. Nearly 600 antibody drugs are in clinical trials, [1] with ~75 of these in pivotal Phase 2 or Phase 3 studies.

Small or even virtual companies are developing many of these molecules. Technical teams working within these organizations must understand the activities needed to successfully commercialize the drugs. One critical activity is establishment of production strategies capable of supplying the material requirements of pre-clinical development, toxicology studies, clinical trials and then, if successful, market demand.

Patients cannot benefit from life-saving medicines if the drug’s launch is delayed due to lack of the material required for each phase of development. Furthermore, companies that miss clinical milestones suffer from delayed investments, thus reducing the opportunity to reach the clinic in a timely manner and capture market share, which lowers future revenues.

Many start-up biotech firms have a laser-like focus on the pre-clinical development of their antibody candidates, but sooner or later they must consider a manufacturing strategy that enables pre-clinical or clinical programs to stay on track.

Is manufacturability an obstacle to development?

One question drug developers should consider is the extent to which the manufacturability of the candidate is likely to be problematic and jeopardise material supply. Many of the standard, full-length antibodies have well-understood properties and are relatively easy to manufacture, allowing timely delivery to the clinic. However, there is an increasing number of modalities within this product class, [2] e.g., bispecifics, Fc-fusions and antigen-binding fragments, which may present additional production challenges. These can include challenges such as low expression from cell lines suitable for use in manufacturing, poor stability during purification processes or the need for non-standard analytical methods.

One company I spoke to, for example, knew that they needed to increase the productivity of their cell cultures from below 0.5 g/L to greater than 3 g/L in order for the product to be commercially viable. Another company developing a monoclonal antibody explained that they needed a titer of ~ 10 g/L to ensure production efficiency was sufficiently high to allow them to be price competitive. A third company found that the isoelectric point of their Fc-fusion molecule was relatively low and they needed a tailored purification process for their product.

Companies developing standard IgG1, IgG2 or IgG4 products can leverage manufacturing platforms. [3] These allow production of different monoclonal antibodies with the required quality specifications and at high productivity with little process development. They offer a significant time- and cost-saving over the alternative, i.e, developing new processes for each new candidate. Companies with a pipeline of products may choose to invest in their own manufacturing platform, but, for many early-stage biotech companies it makes little sense to spend investors’ cash on production assets when there is considerable uncertainty around the likely success of a program. For this reason, many will outsource process development and manufacturing to a contract development and manufacturing organization (CDMO), many of whom will have their own established platform processes.

Early material supplies of antibody candidates

Cell line development scientists can generate stable, clonal cell banks derived from a production-ready host cell line in as little as 10 weeks following transfection. Cell cultures with transfectant pools can produce tens to hundreds of grams of material in as little as eight weeks following transfection. Scientists developing antibody therapeutics can use this antibody for their pre-clinical activities and initial formulation development experiments. In our experience, even at the pre-clinical stage, the drug development process can consume substantial amounts of material. Accurately determining material requirements at this stage will help ensure sufficient antibody is available.

Preclinical material supply might be met with bench-scale bioreactors, but we have worked on programs where the material requirements were sufficiently large that a 200-L mammalian cell culture run was needed, even though the cell line gave a high titer. This clearly demonstrated the utility of having a platform process because no additional process development on either the bioreactor conditions or the purification steps was needed. Expert developers of cell lines know that their host cell line will grow to high cell density under their platform conditions, and will select clones that combine high productivity with the desired product quality profile using high-throughput screening technologies.

Process development scientists operating platform processes typically allocate time, which would previously have been dedicated to manufacturing development, to the refinement of operating parameters and studies of manufacturing robustness that increase the likelihood of that full-scale production lots will be successfully released.

Supplying Toxicology and Early Clinical Material

Pilot-scale batches allow companies to predict large-scale manufacturing performance and refine scale-dependant process parameters. Companies often use material from the pilot-scale batch for toxicology work, stability studies and for generating reference standard, against which the first batch for clinical use can be released. It generally takes 6 – 8 months to reach this stage from the start of cell line development, yielding hundreds of grams of antibody, if not more.

For many companies, the demand for clinical-grade drug, manufactured to current Good Manufacturing Practices (GMP), can be met using bioreactors no larger in volume than 2000-L. The initial batch can be released within 12-14 months from the start of cell line development. Each batch can supply between 1 to 10 kilograms of antibody.

Modern, high-throughput manufacturing facilities provide enormous amounts of capacity such that with a robust, high-titer cell line no further scale-up may be required and firms can commercialize their product within the same facility they used for clinical lots. Others elect to scale-up still further to large-scale stainless steel manufacturing facilities, especially if the market demand is high and the overall process productivity is modest. More recently, firms are considering going to market with manufacturing processes that utilize smaller bioreactors operated in a continuous, perfusion mode. We believe such processes can yield over 15 kg of antibody from a 500-L bioreactor over a 4-week period. Deciding which approach to adopt is never easy because of uncertainties around factors such as dose requirements, overall market demand and competitive pressures. Experienced CDMOs will support customers through this decision-making process and will be able to provide invaluable advice.

In conclusion, many small biotech companies with new antibody drug assets can mitigate risks to drug development and commercialization timelines by thoroughly understanding the material supply requirements for preclinical, toxicology and clinical studies. Once they know this, they can determine how the need can be met by manufacturing organizations during process development and GMP production operations as part as an over-arching strategy for product commercialization.

[1] Kaplon H, Reichert JM. Antibodies to watch in 2019. MAbs. 2019;11(2):219-238. doi: 10.1080/19420862.2018.1556465.

[2] Scott M, Clark N. Next generation antibody therapeutics: Antibody fragments, dual-targeting strategies, and beyond… . European Pharmaceutical Review. 2009.

[3] Shukla AA, Wolfe LS, Mostafa SS, Norman C. Evolving trends in mAb production processes. Bioengineering & Translational Medicine. 2017;] 2(1): 58–69. doi: 10.1002/btm2.10061