"Regulatory Guidance Documents Provide Cell Banks With A Defined Set Of Testing" - Subhasis Banerjee

1. The pandemic proved to be a significant game changer in the biopharma segment yet there were certain pitfalls that are still prevalent in this segment.

The COVID-19 pandemic saw vaccine discoveries and manufacturing within a very short duration and the emergency use authorization being facilitated by the regualtors in a short time period. One of the best outcome of the vaccine development during pandemics was the emergence of mRNA as a vaccine modality. Although mRNA had approved therapeutics for gene therapy but the first-time vaccine was developed using the mRNA technology. Probably during the pandemic one challenge faced was the supply chain management.

2. Is there a vital need for regulation in the biopharma segment? What are the key learnings from the pandemic for a revived regulatory landscape?

Regulatory authorities play a crucial role in guiding biopharmaceutical manufacturers, ensuring the development and production of biologics are safe and effective. Adhering to regulatory guidance, creating solid manufacturing quality standards, and adopting sound process design are all critical components of assuring viral safety and sterility of the drug subtance.

Regulatory guidance addresses the expectations surrounding biomanufacturing processes, aiming to prevent contamination and establishing techniques for detecting and eradicating viral and bioburden/viral contamination.

Additionally, as essential variables in viral safety, the advice requires risk evaluations for cell lines and raw materials of both recombinant and animal origin. In the downstream purification phase, which encompasses all operations following the production bioreactor, regulatory expectations heavily influence viral safety decisions. The focus here is primarily on reducing the presence of endogenous and adventitious viruses to ensure the drug's safety.

In summary, regulatory guidance plays a pivotal role in shaping the measures and practices implemented by biopharmaceutical manufacturers to ensure viral safety throughout the production process. Compliance with these guidelines is vital to maintain the safety and efficacy of biologics.

The Covid-19 outbreak awoke the pharmaceutical manufacturing industry to the significance of a flexible and adjustable regulatory system that can promptly address emerging public health crises. Nevertheless, the industry successfully met the challenge and accomplished the remarkable feat of developing the first Covid-19 vaccine within a mere seven months of initiating clinical trials. This astounding achievement stands in stark contrast to the pre-pandemic era, where the average time to bring a biotherapeutic treatment to market was nine years and four months, with the quickest approval time on record being four years for a mumps vaccine during the 1960s.

The pandemic has presented valuable lessons that can contribute to revitalising the regulatory landscape. These include:

a) Streamlined regulatory processes - The Covid-19 pandemic has provided evidence that regulatory procedures can be accelerated without compromising safety and efficacy standards. Regulatory agencies have proactively facilitated the expedited development and approval of Covid-19 treatments and vaccines through the implementation of streamlined review processes and emergency use authorizations.

b) Collaborative approaches - The Covid-19 pandemic has emphasised the importance of collaboration among regulators, industry stakeholders, and other relevant parties. This collaborative approach enables the acceleration of the development and approval of new treatments while facilitating enhanced sharing of critical data and information.

b) Increased utilisation of real-world data - The pandemic has underscored the significance of incorporating real-world data into both drug development and the decision-making processes of regulatory authorities. Real-world data plays a vital role in providing insights into the real-world safety and effectiveness of treatments, thereby contributing valuable information for regulatory decision-making.

c) Focus on patient-centered outcomes - The Covid-19 pandemic has emphasised the need to embrace a patient-centered approach in the realm of drug development by entailing enhanced participation of patients and patient groups in the drug development process, alongside an increased emphasis on patient-centric outcomes during clinical trials.

In brief, the pandemic has underlined the need for a more adaptable and responsive regulatory landscape capable of supporting patient requirements and promptly addressing emerging health emergencies.

3. Can you share with us a holistic overview of viral safety? Why is viral safety important in Biomanufacturing?

Viral safety refers to the set of measures and practices implemented in the biopharmaceutical and biologics industry to prevent the presence of viral contaminants in drugs, vaccines, and other biological products. It involves a series of rigorous steps and precautions taken during the entire manufacturing process to ensure the absence or effective control of viruses. The goal of viral safety is to minimize the risk of viral contamination and subsequent harm to patients receiving these medications or treatments. This includes strategies such as sourcing high-quality raw materials, implementing strict facility design and environmental controls, employing validated virus removal or inactivation methods, conducting thorough testing and analysis of the final product, and adhering to regulatory guidelines and standards. By implementing robust viral safety practices, the biopharma industry aims to deliver safe and effective biopharmaceutical products to patients. Viruses present a substantial threat to the safety and effectiveness of various products.

The contamination of a biological product by a virus can have severe consequences, including potential harm to patients and rendering the product inefficient or unsafe for its intended use.

At the heart of biopharmaceutical and biologics production lies the paramount importance of viral safety, which is upheld by the well-established principles of "prevent, detect, and remove" to safeguard the well-being of patients. To guarantee the safety of drugs, a comprehensive assessment is conducted to eliminate or effectively manage viral contamination at every stage of the manufacturing process for pharmaceuticals using animal cell lines.

A comprehensive strategy is employed to ensure viral safety throughout the life cycle of biological products. This approach involves multiple components, such as careful selection and assessment of raw material suppliers, meticulous design of production facilities, implementation of stringent environmental controls, and rigorous testing and approval of the final product. By addressing each of these elements, a strong and efficient viral safety plan can be developed and implemented, effectively minimizing the potential for viral contamination at every stage of the product's journey.

Viral safety holds immense significance within the realm of biomanufacturing because it has the potential to have a significant impact on both patient safety and product efficacy. The presence of viral contamination can have detrimental effects across various aspects, including raw materials, cell culture techniques, bioreactor contamination, and downstream processing. Consequently, it becomes imperative for biotech companies to establish stringent viral safety procedures.

The assurance of viral safety in biomanufacturing is vital not only to safeguard patient health but also to prevent the dissemination of infectious diseases. Additionally, compliance with viral safety regulations is a mandatory requirement in many countries. Manufacturers who fail to comply with these standards may face serious legal and financial consequences. Furthermore, viral contamination can inflict reputational damage and result in significant financial losses due to product recalls, lawsuits, and regulatory fines. As a result, maintaining robust viral safety protocols is paramount for biotech companies to uphold patient well-being, adhere to regulatory requirements, and protect their own reputation and financial stability.

4. How can testing for the presence of viruses and other adventitious agents in cell banks, raw materials, and process intermediates prevent such outbreaks?

TESTING

Initiating biomanufacturing with a cell bank that has been extensively screened is the foundation to ensuring viral safety. A one-time rigorous testing of the master cell bank

(MCB) is required as this bank is the starting point for production. The working cell bank (WCB) is derived from the MCB and needs limited testing, with a focus on detecting adventitious agents the cells may have been exposed to during the banking process. Testing the end-of-production (EOP) cells at the limit of in vitro cell age (LIVCA) completes the cell bank testing package for a licensed product. This one-time testing may detect low-level contaminants that were not detected during testing of the MCB and WCB such as latent viruses or viruses introduced during production. Cell Line Characterization Testing Requirements for Well-Characterized Rodent (e.g., CHO) Master and Working Cell Banks and End-of-Production/Cells at the Limit of In Vitro Cell Age Used for Production involves testing for identity, sterility, mycoplasma, mycobacteria, general virus purity expressed retrovirus & also confirmation of the absence of specific viruses

In-Process Testing. In addition to cell banks and raw materials, key process intermediates should be tested for adventitious viruses. Low levels of virus, not detected in cell or raw materials testing, may amplify in a bioreactor containing susceptible production cells. Adventitious virus can also be introduced during manufacturing. Furthermore, production cells may harbor latent viruses that are amplified as cells are expanded. Accordingly, bulk harvests should be tested for both microbial and viral contaminants. The in vitro adventitious virus assay is used to detect general viral contaminants and real time PCR assays for relevant contaminants such as MMV are also used.

From a raw material perspective the strategies adopted are:

RAW MATERIALS

Point-of-origin mitigation reduces risk by selecting the lowest risk raw materials wherever possible. This includes:

· Selecting reputable suppliers with robust quality systems

· Eliminating animal origin (AO) components

· Using chemically defined media components where possible

· Using pretreated or recombinant components when chemically defined is not an option

· Minimizing plant-based components

One big advantage of point-of-origin mitigation is that viral risks are reduced before the raw material arrives at your facility, reducing the introduction of potential exogenous contaminants to the manufacturing plant.

Raw Materials of Animal Origin

Frequently the first step taken by manufacturers is to eliminate the use of AO components such as bovine serum and porcine trypsin. Best practice by manufacturers is to eliminate AO components and design the process with chemically defined (CD) cell culture media (CCM). Plant-based components significantly reduce risk associated with AO components, however, still carry some risk. When AO components cannot be replaced by CD or plant-based components, there are a few mitigation strategies.

a. Selective sourcing - This involves choosing suppliers who take measures to ensure safer raw materials. Suppliers accomplish this by using controlled animal herds or animals from certain geographies where there are no known instances of the problems associated with the species. For example, New Zealand sourced serum minimizes risk of bovine transmissible spongiform encephalopathy (BSE) transmission. For human plasma derived raw materials, prescreening plasma donors reduces the risk of latent or endogenous viral contamination.

b. Pretreatment - Pretreatment (such as gamma irradiation) is performed by some suppliers of the AO components. Risk is mitigated by inactivation of any potential viral load that may be in the material.

c. Recombinant supplements - Many AO raw materials (such as serum) contain beneficial components, such as growth factors or cell stabilizers in a complex mixture with other proteins, enzymes, and amino acids that may impact the effectiveness of the beneficial component. To mitigate the risk of viral contamination from these AO materials, some suppliers provide recombinant supplements (rSupplements); examples include insulin, insulin like growth factors (long R3 IGF), albumin, transferrin, trypsins, and lysozyme.

5. How can the implementation of technologies to remove or inactivate viruses and execute clearance studies help in demonstrating process safety?

The implementation of technologies designed to remove or inactivate viruses, along with the execution of clearance studies, plays a significant role in demonstrating process safety at every stage.

The ramifications of viral contamination extend beyond regulatory guidance and drug safety when it comes to upstream processing. For instance, the guidance provided by the United States Food and Drug Administration (FDA) pertains to viral safety considerations for biological products, encompassing vaccines and blood products. At present, there are no existing guidance documents that prescribe the adoption of viral clearance technologies specifically for upstream cell culture process materials. Nevertheless, companies that have integrated clearance technologies such as high-temperature short-time (HTST) treatment or virus filtration into their cell culture media have not reported any instances of contamination.

The validation requirements for assessing clearance capability vary depending on the stage of clinical development, as outlined in the EMEA CPMP BWP 268/95 (1996) guidelines. In the European Union, prior to phase I, clearance studies are conducted using two types of viruses. One is an enveloped virus like murine leukaemia virus (MuLV), which serves as a model for endogenous retrovirus particles. The other is a small, non-enveloped virus, typically a parvovirus such as minute virus of mice (MVM).Using worst-case parameters, two distinct and independent phases are analysed.

The USFDA requires testing to include at least murine retrovirus, with the mention that studies about parvovirus are considered useful but not mandatory. The implementation of virus removal/inactivation technologies and execution of clearance studies demonstrate the commitment to process safety. They provide scientific evidence and data that support the effectiveness of the manufacturing process in removing or inactivating viruses, thereby assuring the safety of the final biopharmaceutical product.

6. What kind of regulatory guidance both domestically and globally can be implemented to ensure viral safety?

Regulatory authorities offer guidelines to biopharmaceutical companies to ensure the safe and effective research and production of biopharmaceuticals. The establishment of viral safety is built upon a foundation of regulatory guidance, robust manufacturing quality systems, and sound process design. Regulatory guidance outlines the necessary criteria for biomanufacturing processes, aiming to prevent the introduction of adventitious viruses and providing protocols for detecting and eliminating viral contamination.

Moreover, regulatory guidance for viral safety also necessitates conducting risk assessments for cell lines and raw materials derived from recombinant or animal sources. Regulatory expectations play a key impact in determining viral safety judgements during the downstream purification phase (all procedures following the production bioreactor). These decisions are largely concerned with reducing the amounts of both endogenous and adventitious viruses to assure the safety of the medicine being manufactured.

When it comes to upstream processing, the impact of viral contamination extends beyond regulatory guidance and drug safety considerations. Companies have used clearing methods like high-temperature short-time (HTST) treatment or viral filtration of cell culture media.

According to the EMEA CPMP BWP 268/95 (1996) guidance paper, the validation requirements for clearing capability vary depending on the clinical development stage. Prior to phase I clinical trials in the European Union, clearance studies are carried out using two different viruses: an enveloped virus such as murine leukaemia virus (MuLV), which serves as a model for endogenous retrovirus particles, and a small, non-enveloped virus such as minute virus of mice (MVM). Using worst-case parameters, two distinct and independent phases are analysed.

Prior to submitting a licence application during the late stage of clinical development, clearance studies with a range of viruses are conducted across multiple process steps. These studies cover a range of factors, including assessing the effectiveness of critical steps, examining column sanitization, and evaluating the performance of both new and aged resin. When evaluating clearance in chromatography steps, it is crucial to not only measure the extent of virus removal but also understand the distribution of the virus. This involves determining whether the virus is detected in the product eluate, the flow-through and wash fractions, or if it has become bound to the column.

Virus removal filters with small-pore sizes play a critical role in the production processes of monoclonal antibodies and recombinant proteins. These filters are essential for achieving a significant level of clearance for both endogenous and adventitious viruses. The effectiveness of virus removal across the filter is typically evaluated during both early and late-phase clinical studies.

7. How can companies work on designing a viral clearance study with an accurate scale-down model to prevent outbreaks in the long run?

To apply viral clearance results to the full-scale manufacturing process, it is essential to design a viral clearance study using a precise scale-down model. Keeping in sync worst-case parameters is crucial during the design phase of the viral clearance study. A comprehensive understanding of all operational aspects of virus clearance filtration is crucial for developing a robust and cost-effective process. When conducting an economic analysis of virus filtration operations, it is important to take a holistic approach by incorporating all costs associated with set-up, processing, product recovery, and post-use integrity testing.

To validate the scale-down model, it is necessary to define acceptance criteria and apply them to the spiked runs to ensure authenticity Also, before commencing the clearance studies, pre-studies should be conducted to ensure that the product does not interfere with virus assays and that the virus spike will not undermine the credibility of the scale-down model. By meticulously designing and executing these studies, the results obtained from viral clearance studies can successfully demonstrate the manufacturing process's ability to contribute to the viral safety of the product.

8. Can you elaborate more on biosafety testing?

Maintaining the absence of adventitious viruses is of utmost importance in ensuring the safety of biopharmaceuticals for patients. A crucial aspect of any effective viral safety strategy is conducting thorough testing on production cell lines, raw materials, and bulk harvest materials to confirm the absence of adventitious viruses. Implementing a thorough testing strategy considerably decreases the chance of contamination, which, while uncommon, can have far-reaching ramifications and severe implications for the biopharmaceutical company.

Adopting a comprehensive, multi-faceted approach that includes the entire process is required for a strong viral safety strategy.

a) Testing cell banks: Establishing viral safety in biomanufacturing begins with the utilization of a thoroughly screened cell bank, which serves as the fundamental basis. Comprehensive testing procedures are conducted to confirm the identity and purity of master, working, and end-of-production cells. These assays, which are indicated in regulatory guidelines like ICH Q5A1, are critical in guaranteeing viral safety during the manufacturing process.

b) Novel Testing Methods: Regulatory guidance documents provide cell banks with a defined set of testing. Nonetheless, technological advances in testing have emerged, and regulatory authorities have demonstrated receptivity to recommendations for applying these new procedures.

c) In-Process Testing: It is critical to test important process intermediates for the presence of adventitious viruses in addition to testing cell banks and raw materials. This is significant because, even if the virus is not found during cell or raw material testing, it has the potential to multiply in a bioreactor containing sensitive production cells, resulting in higher viral levels.

d) Assay validation: Assays employed within a GMP (Good Manufacturing Practice) environment must undergo validation, although the extent of validation may vary depending on the product development phase. During the early phases, a fit-for-purpose and straightforward validation approach is sufficient. However, as the product progresses toward late-phase development, comprehensive validation becomes necessary. This involves a thorough understanding of assay performance and the analytical profile of the product.

e) Method Suitability and Product-Specific Qualification: Suitability testing is required for culture-based assays, such as those for sterility, bioburden, mycoplasma, and mycobacterium contamination, necessitate suitability testing to ensure that the cell bank or product intermediate matrix does not impede or disrupt the detection of infectious microorganisms. This testing procedure involves the addition of low levels of a control organism to the sample matrix, followed by incubation and subsequent confirmation of detection.