With over 30 years in biomanufacturing and projects completed for approximately 150 clients, a track record of assisting in over 50 successful IND filings, and flexible capacity, GBI is often the CDMO of choice for antibody-based projects. The company supports clients with end-to-end capabilities, starting with research cell banks and continuing through manufacturing, including aseptic fill and finish and stability studies for monoclonal antibodies (mAbs), even for complex biologics — helping clients simplify the development process and reduce both costs and project timelines.

Three Decades of Biologics Development and Manufacturing Experience

Over the three decades that GBI has been operating as a contract development and manufacturing organization (CDMO), the company has completed over 500 projects for more than 150 clients, including assisting in the filing of over 50 investigational new drug (IND) applications in the United States, Europe, Canada, Asia, Australia, and elsewhere. Those projects have largely involved recombinant proteins, monoclonal antibodies (mAbs), conjugated antibodies, and next-generation antibody-based products.

With such a long history, GBI has amassed a tremendous depth of knowledge, capabilities, and efficiencies in biologics process development and manufacturing, particularly across the range of IND-enabling activities. We provide end-to-end, integrated services from cell line development (via our strategic partners) through early- to late-stage clinical production, and de-risking processes to assure a high degree of confidence that they can be readily scaled from the lab to commercial GMP production.

The process starts with the research cell bank (RCB) from a mammalian cell line provided by the client, which is tested (mycoplasma, sterility, and virus) and used to generate a fully characterized and GMP-compliant master cell bank (MCB). Process development of the upstream cell culture and downstream chromatographic purification steps follows with the goal of generating material for preclinical (e.g., stability, toxicity) and eventually early-stage clinical studies. This work is supported by in-house analytical method development and qualification activities, which ensures timeliness, efficiencies, and smart costing. Generally, development-scale processes are performed in 5-L bioreactors, but GBI can scale processes both up and down as needed. For bioconjugates, projects may also involve further manipulation of the mAbs to achieve the desired linkages to specific payloads.

During these development efforts, extensive documentation is established to support the filing of INDs and ultimately biologics license applications (BLAs). These documentation packages are reviewed and approved by GBI’s internal quality and validation personnel and our clients before moving into IND/BLA activities. In addition, our manufacturing spaces are maintained according to the ISO 14644 standards for cleanroom capabilities, and extensive environmental monitoring records are included in the data packages. 

Effective Supply Chain Management

The COVID-19 pandemic created significant disruptions across the entire biopharma supply chain. Although GBI is a smaller CDMO and doesn’t have the clout of larger CDMOs, we have a well-evaluated sourcing strategy and are very selective about procurement, particularly for specialty materials and items.

That strategy is based on a foundation of early and ongoing engagement with suppliers. We tend to use a platform approach, and, where possible, we use the same materials and consumables across multiple projects and platforms to strengthen our positions with suppliers. We also hold essential items in inventory to ensure business continuity. For commonly used goods that normally would not be of concern but for which supply became an issue during the pandemic, our ongoing strong relationships with suppliers meant that they were aware of our needs and the scale and scope of our projects, thereby allowing us to avoid long delays and wait times.

GBI also provides significant flexibility –– whenever feasible and required –– to adjust production schedules to accommodate changes in the supply chain. In addition, our deep understanding of mAbs and recombinant proteins makes it possible to quickly identify suitable, readily available substitutes when specialized materials have long lead times, while established processes enable rapid evaluation and qualification of those alternatives. For all these reasons, GBI has been able to obtain the materials needed when we needed them and thus deliver as promised to our clients.

Aspects of IND-Enabling Activities^2–6

Through three decades of experience, GBI recognizes the technical considerations and IND-enabling requirements associated with developing and manufacturing recombinant proteins, antibodies, and other complex biological molecules using the RCB from proof-of-concept and preclinical studies through to subsequent early-stage and late-stage clinical trials. These considerations include ensuring from the earliest stage that any process developed is scalable, compliant, and economical for large-scale cGMP manufacturing, as well as that it produces a product that meets quality and regulatory requirements relative to safety, purity, potency, identity, and overall product quality through rigorous characterization (See Table 1). ^2–6

To meet these requirements, both methods and processes must be developed, as well as qualified and/or validated, in a phase-appropriate manner, during preclinical, early-stage clinical, and late-stage clinical product development.   To this end, GBI has leveraged past experiences and through quality by design (QbD) and design of experiments (DOE) to:

• Establish cell culture expansion, production, and culture harvest clarification platforms for any given RCB cell line.
• Develop robust mAb purification process to achieve the required product yield, purity, and quality specifications.
• Our internal Protein Characterization and Quality Control teams have developed a wide range of protocols / standard operating procedures (SOPs) for comprehensively characterizing mAbs and other biologics (Table 1). These methods are qualified and validated and thus suitable for use in GMP clinical and commercial manufacturing.

Ensuring the removal of challenging impurities, such as host-cell proteins, is one example, as is effective viral clearance using virus inactivation and filtration methods. Prior experience with many types of mAbs, fusion proteins, and other recombinant proteins facilitates the development of effective unit operations. Close collaboration with external partners ensures confident validation of viral clearance.

Cell Bank Creation

Bulk drug substance development starts with creating an RCB (usually provided by our client) and generating a GMP master cell bank (MCB). The generation of a GMP working cell bank (WCB) from the MCB is optional, particularly for early-phase clinical studies, and can be created at GBI at the client’s discretion. If possible, one should avoid using bovine serum albumin (BSA) when creating the RCB and MCB. The FDA has concerns that using BSA can introduce adventitious agents into the product that could later affect patient safety. If BSA must be used, it should be sourced from known BSE-/TSE-free countries, such as the United States and New Zealand, and needs a certificate of origin with a BSE-/TSE-free statement.

Following the generation of the MCB, it must be fully characterized by a contract testing organization (CTO) according to the FDA points to consider for GMP manufacturing, which include adventitious agents, microbial, retroviruses, and parvoviruses, as well as other requirements.

Viral Clearance Studies

For biologic products produced using mammalian cells, viral clearance studies are required to show that the manufacturing process can clear viruses that may have been introduced into the manufacturing process. Global regulatory agencies require a manufacturing process to have at least two dedicated orthogonal viral clearance steps to be considered acceptable.

The amount of potential virus in the product and the required level of clearance required (logs of reduction) is dependent on several factors, such as the number of virus-like particles detected in the bulk bioreactor harvest, the expected maximum clinical dose, and the incorporation of an acceptable viral clearance safety margin for the product. For viral clearance studies, purification process intermediates from a bulk drug substance batch are pulled, spiked with a virus, and then purified using qualified downscale process models. The in-process samples are shipped to a CTO for actual virus clearance studies and the determination of the number of logs of viral reduction across each step. For early-stage clinical studies, analysis of two model viruses, such as MMV or PPV (non-enveloped) and XMuLV (enveloped), performed in duplicate is sufficient.

Product Stability Studies

The final drug substance formulation must be chosen during the initial stages of the purification process development of the drug substance. For stability studies of antibodies, we apply our knowledge gained on numerous past projects and commercial products to suggest to clients two to four potential buffer solutions that work well. Such formulations include excipients/additives that are protective against stress conditions, such as elevated temperatures and freeze-thaw stability if the product and/or reference standard are stored frozen. Typically, limited (a few months) stability studies with early development material enables the selection of the optimal buffer for use in full studies with highly purified material for clinical studies.

Other IND activities include:

• Reference standard creation for product release and stability testing
• Assay tech transfer/verification from the client, method development, and qualification of the assays to test the GMP material for use in early Phase human clinical trials
• Stability studies of drug substance and drug product and reference standard via ICH guidelines
• Assessment of impurity profiles, such as residual host cell proteins, leached protein A, DNA, endotoxins, and other contaminants.

Bioconjugates have Additional Requirements¹

For bioconjugates, it is necessary not only to develop a process for production of the mAb but to ensure that the antibody possesses all the necessary attributes that will enable efficient and successful production of the desired conjugated product. Ideally, the mAb is generated in the buffer that will be required to perform the conjugation step, thereby eliminating the need for buffer exchange.

In certain cases, however, where clinical studies require administration of the antibody alone (for pre-dosing) before treatment with the bioconjugate, a different project strategy is required, as it is necessary to produce enough of the antibody at the required concentration and buffer formulation for the initial direct infusion into the patient, which is followed by production of the bioconjugate product for subsequent infusion into the patient.

GBI can support antibody–drug conjugate (ADC) and other bioconjugate projects from the RCB through to antibody manufacturing and production of the conjugated product.¹

Time Is of the Essence

In addition to process economics, scalability, and compliance, time is a critical component of any mAb or recombinant protein project. Drug developers must reach the clinic as quickly as possible in order to reach the market ahead of their competitors. They rely on CDMOs to help them achieve accelerated development timelines.

Clients come to GBI because they recognize the value of our 30+ years of experience and have seen that — with our deep knowledge of mAb and recombinant protein process development and manufacturing — we are able to move quickly. We help them transition from research-grade to fully qualified chemicals and critical reagents that can be used in a GMP environment. We can rapidly generate adequately (1–2 columns) purified material for initial preclinical studies (for animal PK/PD, ADME (absorption, distribution, metabolism, and excretion), etc.) while simultaneously developing cost-effective, robust, and scalable upstream and downstream processes to produce clinical trial materials with the right critical quality attributes. For downstream purification, we accelerate development by leveraging platforms designed specifically for monoclonal antibody production.

In addition, at GBI we make it possible for client projects to go straight from the confirmation run (three upstream batches in 5-L bioreactors followed by one purification process) to GMP production, because we spend significant time de-risking processes during development. Although there is no formal validation at this stage, the critical quality attributes of the product are evaluated to ensure that the process is under control. While GBI recommends performing an engineering run (and a technical run in some cases), it is ultimately the client’s decision on whether to bypass such a manufacturing run on the basis of the information generated on the product quality during the small-scale runs in the development lab.

Foregoing an engineering run saves time, because each run takes approximately four to five weeks for upstream processing and another three weeks for downstream purification and drug substance testing. It also saves significant amount of money, because engineering runs are usually performed at the same scale as the GMP run and at nearly similar price tag. On the other hand, an engineering run, if performed, can clearly demonstrate process performance and confirm that risks have been properly mitigated and controlled prior to the GMP run. In addition, the material produced from an engineering run can be released to create drug product for usage in toxicology animal safety studies and viral clearance (if the manufacturing is performed on the same equipment and scale as the GMP run). Many small and emerging biopharma clients cannot afford an engineering run, while others prefer to perform a technical or confirmation run and an engineering run in addition to the required GMP run. It is all about risk tolerance (based upon process development data), cost, and project timeline.

A typical project timeline from RCB tech transfer through to GMP manufacturing to generate the bulk drug substance (BDS) material for early-phase clinical trials for a mAb at GBI is approximately six (6) to seven (7) months and includes:

• Approximately three (3) to four (4) months: upstream/downstream tech transfer/process development, conformance run, and protein characterization
• GMP MCB creation from the RCB takes about one (1) month at GBI, followed by 2–3 months for characterization at a CTO. This activity is usually performed in parallel with the process development activities above.
• Approximately 3 months: GMP manufacturing of the BDS, aseptic fill/finish, and vialed drug product (VDP) release testing. Also, it should be noted that it takes about 2–3 months for the viral clearance studies to be performed by a CTO following the completion of the GMP BDS manufacturing.
• If an engineering run is performed prior to the GMP manufacturing run, the project timeline is approximately nine (9) to ten (10) months.

The Importance of Fill/Finish

Fill/finish is a critical activity because it is the last step in the production process before the drug product reaches the patient. Control of sterility is essential and, because most mAbs and other recombinant proteins are degraded under terminal sterilization conditions, aseptic processing is typically necessary. Automated systems help reduce the risk of human error and contamination.

As part of our end-to-end services, GBI provides fill/finish services, typically at vial counts of 2,000 or less and for various vial sizes (and occasionally cartridges) in an ISO 5 space with full media qualification. Our current system is a semi-automated fill, but we are in the process of installing a fully automated system and will have the capability for automated filling and sealing of up to 5,000 vials per shift — with up to two shifts per day — starting in October 2022. The new system is suitable for pre-sterilized nested vials (2R to 50R), syringes (0.5 mL to 50 mL), or cartridges (1 mL to 20 mL) with up to 10 units per minute at fill accuracies of. ± 1.0% from 0.5mL – 3.0 mL fill volumes and ± 0.5% from 3.0 mL – 50 mL fill volumes. It includes real-time, non-destructive, in-process weight checks, cameras for visual inspection, active particulate monitoring, vacuum stoppering, and container purging with inert gas. The system is currently configured for 2R and 10R vials and 1-mL syringes.

The Advantages of Fully Qualified Cold-Chain Storage

Many of the newest biologics candidates in development today, including next-generation antibody products, are unstable at room temperature and require storage and shipment under refrigerated or frozen conditions. Access to sufficient storage capacity, while not typically considered part of process development, is essential to ensure as projects move to later development stages.

 Given that regulatory authorities expect to see evidence of temperature-controlled storage capabilities in multiple locations, reliable cold-chain infrastructure is essential for any biologics CDMO.

GBI, based on its years of experience in recombinant protein and mAb process development and manufacturing, takes a holistic approach to the activities involved in biologics development. Therefore, we are currently investing in significant additional fully qualified cold-chain storage capacity, both onsite and at qualified offsite vendors, not only for bulk drug substance and formulated product storage but also for cell banking.

End-to-End Support

With a long legacy in the business and the completion of projects for approximately 150 clients, a track record of over 50 successful INDs, and flexible capacity, GBI is among the strongest CDMO providers supporting antibody-based and other complex biologics projects. To this end, we are recognized for our ability to quickly initiate projects and advance them rapidly. Unlike large CDMOs, which often have backlogs of two to three years or longer, lead times at GBI can be as low as a few months or less in some cases.

As importantly, GBI supports clients with end-to-end capabilities, starting with the transfer of the RCBs from the client all the way through the process development and manufacturing phases, even for complex biologics, such as bioconjugates, bispecific antibodies, Fc-fusion proteins, cytokines, enzymes, and many more. We have the capabilities in place to ensure the development of robust and scalable processes that produce high-quality products with the required critical quality attributes. Our development and manufacturing strategies and technology platforms enable rapid implementation of both IND- and BLA-enabling activities. As a result, we help our clients simplify the development process, lower costs, and reduce project timelines, ultimately helping get high-quality and innovative therapies into the hands of patients.

Table 1. Analytical methods performed by GBI (and CTO) for GMP BDS and VDP release; product (BDS, VDP and RS) stability; reference standard (RS) evaluation; and product comparability assessment.

References

1. Sesay, M. “Theranostic Manufacturing Solutions.” Pharma’s Almanac. 29 Aug. 2022
2. ICHQ7: Good Manufacturing Practice Guidance for Active Pharmaceutical Ingredients. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. Sep. 2016.
3. ICHQ8: Pharmaceutical Development. The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use. Jun. 2017.
4. ICH Q9: Quality Risk Management. The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use. Nov. 2005.
5. ICH Q10: Pharmaceutical Quality System. The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use. Jun. 2008.
6. ICH Q11: Development and Manufacture of Drug Substance. The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use. Nov. 2012.