Feliza Mirasol is the science editor for 

Feliza Mirasol

Finding a right-fit partner for biologics drug development has become increasingly important, especially as hundreds of new biotherapeutics—cell therapies, gene therapies, bispecific antibodies, antibody drug conjugates (ADCs), vaccines, etc.—move through a burgeoning biologics pipeline. But what criteria, skills, experience make for a good manufacturing partner? Just as important, what is the evaluation process by which potential partners are screened?

To start with, what are biologic drug developers looking for in a contract development and manufacturing organization (CDMO) or a contract manufacturing organization (CMO), or other service provider? Jean-Christophe Hyvert, chief commercial officer at Lonza, notes that Lonza, for example, is positioned to work with many biotech companies of various sizes. He points out that emerging and small biotech companies make up approximately 80% of the total drug development pipeline today and are a key segment for CDMO companies. About 50% of Lonza’s partners, for example, are represented by emerging, small biotech companies and virtual companies.

“This particular biopharma segment is looking for a CDMO that can address their specific needs; not only free capacity but also critically importantly: experience with fulfilling regulatory requirements, procurement power, legal frameworks, and speed, without added risk. These small companies also require a well-established partnership offering and flexible funding milestones that add value at every development stage,” Hyvert states.

For biologic drug developers partnering with a CDMO or CMO, it is critical that the CDMO/CMO provide services that meet developers’ needs as well as have the capacity to manufacture the desired pipeline, says a company official at Samsung Biologics. With rising biologics demand, the Samsung official says, the company is seeing drug developers’ in-house capability hitting a limit, ultimately resulting in them outsourcing services to meet these demands.

When choosing the right outsourcing partner, biologic drug developers look for well-trained employees, well maintained facilities, and trustworthy communication with quality and data integrity, the Samsung official says.

Amid the ongoing work to bring new biotherapeutics to market is the added challenge of bringing new vaccines to market to combat the global COVID-19 pandemic. “The global pandemic has created supply constraints and long lead times for many products used in the biopharma sector; everything from gloves and other PPE [personal protective equipment] to resins and single-use disposals as well as primary packaging components have been impacted,” says Randy J. Maddux, chief operating officer, iBio.

Maddux points out that the pandemic also emphasized the gaps that exist in available fill/finish capacity. “And, as a result, we’ve seen a number of players make investments to bring more capacity on-line. That said, indications so far are that the biopharma sector has done a good job in planning for aseptic fill/finish of the new vaccines and reallocating and reprioritizing capacity where needed to meet current demand,” he says. He also cautions that the situation could easily change as the rate of vaccine administration ramps up and/or further disruptions in the supply of fill/finish components occur.

“For us, there was no big difference before and after the pandemic in regards to the technological aspect of the fill/finish process,” interjects the Samsung Biologics official. The most challenging aspect came from the supply of primary packaging materials, the official notes. Even before the pandemic, the utilization rate of CDMO companies continued to increase to meet ongoing biologics demand and supply balancing, but the COVID-19 pandemic added unanticipated demand in a very short period of time.

Hanns-Christian Mahler, head drug product services, Lonza, adds that sterile fill/finish facilities are also not available in abundance, and the capacity of existing sterile facilities is often quite well utilized. One should also not forget that there are also many other medicines to be supplied, not only COVID-19 vaccines, he emphasizes. “Hence, there is, from my perspective, still a significant need to have more sterile manufacturing capacity globally.”

Mahler observes that there are many factors to consider for long-term manufacturing supply agreements for a biotherapeutic project. The first key question that a biologic drug developer and prospective manufacturing partner may need to ask is whether the available sterile facility is suitable from a technical perspective:

Is the equipment that is required available and implemented?

Is the facility able to handle the drug (e.g., from any environmental, health, and safety perspectives?)

Does the facility have the relevant quality certifications?

Is there sufficient capacity available, or can it be made available in due course to meet the supply-demand?

In addition, are there sufficient experts available, or can they be hired in due course?

“Apart from these factors, regulatory expertise is becoming of crucial importance, especially in the context of the novel and/or accelerated pathways. As the diverse biopharma landscape changes, the methods we use for developing and manufacturing drugs, increasing control, and streamlining operations through automation become necessary in the future of manufacturing,” adds Hyvert.

Furthermore, service providers need to constantly monitor industry trends and be in tune with clients’ needs, developing technologies, and digitalized solutions, says the Samsung Biologics official. “Process intensification technologies, such as N-1 perfusion and non-stop centrifugation, are reflective of latest industry trends, and implementing these would make a CDMO an attractive partner,” the official states.

In terms of industry advice that can help maintain a long-term partnership between contract manufacturing service providers and drug developers, data integrity and transparency should be the top priority, says the Samsung Biologics official. “It is critical that a service provider maintain close communication with clients to achieve this. For example, Samsung Biologics provides real-time remote client access to our quality document viewing and approval system, allowing for faster release of product batches, and agile response in case any issues occur,” the official states.

Maddux concurs that frequent, open communication and a spirit of collaboration and teamwork are keys to any successful long-term partnership. “This takes the form of establishing trust between key stakeholders, often to the point where there is a personal relationship of mutual respect. Establishing a well-written MSA [master services agreement] that contemplates likely challenges and things that may go awry is important, but it is virtually impossible to cover every situation.The ability to work together in the gray areas between the black and white as written into the contract is the ‘gold standard’ for successful long-term partnerships,” he states.

New challenges have brought on accelerated approval pathways such as fast track and priority review, adds Hyvert. “We are witnessing an increased pressure to quickly deliver therapies for the patients who need them the most, which puts pressure on process development and manufacturing capacity. The COVID-19 pandemic has increased the emphasis on speed to market, disrupting supply chains, the supply of raw materials, and access to quality capacity, which causes delays in clinical trials,” he says.

“Forming a strong partnership is definitely the key to creating a transparent and open relationship based on trust and flexibility to solve customer issues, such as changes in capacity and timelines as well as technical challenges,” Hyvert adds.

Feliza Mirasol is the science editor for Pharmaceutical Technology

When referring to this article, please cite it as F. Mirasol, “Selecting the Right-Fit Partner for Biotherapeutic Development,” 

Articles

Open communication and transparency coupled with technical expertise foster strong long-term manufacturing partnerships.

Selecting the Right-Fit Partner for Biotherapeutic Development

Biologic drug products are typically formulated into a liquid or lyophilized powder form for the fill/finish step during biomanufacturing. As the much-anticipated COVID-19 vaccines move through the pipeline, and some are already in use under emergency authorization, manufacturers will need to optimize vaccine formulation and establish robust fill/finish operations.

BioPharm International's February 2021 issue.

In general, biomanufacturers face challenges in the fill/finish step when dealing with biologics that have been formulated into either a liquid form or a lyophilized powder. One main challenge is understanding the product’s characteristics and behavior under different circumstances, including what parameters may be necessary to lyophilize the product, for instance, says Dhaval Patel, senior manager, Manufacturing Science & Technology, Catalent. It is also important to understand the inspection requirements for the product because there could be different criteria for liquid vs. lyophilized drug products, he adds.

The difference in formulation may also require different approaches to fill/finish. For instance, Patel notes that different sizes of filters and membranes for sterile filtration may be required. “For a manufacturing partner, the biggest challenge is to build a catalogue of capabilities that cover different customer and product needs, and to be able to incorporate realistic lead times associated with having to source any new or additional equipment/components needed for manufacturing,” he says.

Christy Eatmon, senior scientist, pharma services, at Thermo Fisher Scientific says that, sometimes, liquid biologic products have stability challenges that can be overcome by formulating the product as a lyophilized biologic. “Lyophilization may be necessary to decrease prohibitive storage temperature requirements, allowing for shipment and storage in areas of the world where refrigeration isn’t as easily accessed. Lyophilization also extends the shelf-life of the biologic and can protect a labile molecule from degradation in an aqueous environment,” she says.

Eatmon does note that lyophilized and liquid biologic drug product vials are both filled in a similar manner, but the different formulations do pose different processing challenges. “The hold times during compounding of a lyophilized product are typically shorter than those of a liquid product and affect the production timeline and planning that must be done in advance of the API addition,” she explains.

A major difference regarding these two types of formulations for biologic drug products, Eatmon points out, is the varying fulfillment times for each project. For instance, liquid products require less time for development and, thus, have shorter lead times. On the other hand, she emphasizes, the lead time for lyophilized products must incorporate the freeze-drying cycle and characterization of that cycle. “Characterization is important because the parameters of that cycle affect the production of a high-integrity cake, and producing a cake without collapse, melt-back, or shrinkage requires additional development,” she explains.

In both cases, Eatmon continues, it is necessary to understand the stability of the formulation, but for lyophilized products “we need to develop the cycle through calorimetric measurement, define critical process parameters, and optimize the cycle,” she says. “We also must do characterization of the lyophilized product and complete the stability profile work.”

“Lyophilized products require more preparation in choosing the right excipients, bulking agents, and cryoprotectants as well as the cycle development,” Eatmon adds.

Fill/finish for vaccines requires a similar approach to biologics, Patel notes. In addition, the nature of the incoming vaccine drug substance will determine what equipment, filters, and other components are needed for formulation. “From a fill/finish perspective, vaccines and typical biologics require either a thaw, pool, and filtration process of the final product; or a thaw, pool, dilution with buffer, and then filtration of the final product. The configuration of the vial or syringe components, together with any additional packaging requirements, will determine what labeling or packaging of the vaccine or biologic is necessary,” he states.

It is also important to note that some of the COVID-19 vaccines are multidose and require the use of an evaluated preservative, includes Eatmon. For example, messenger RNA (mRNA) vaccines use nanoparticle technology to enhance stability, as opposed to the aqueous-soluble molecules that are typical of standard biologics. Furthermore, with recombinant protein vaccines, the use of an adjuvant could be needed in order to stimulate immune response. There are also unique differences between live vaccines and attenuated or inactivated vaccines, Eatmon notes.

“These differences require considerations in terms of facility classification and engineering controls as live viruses must be separated from other types of vaccines,” Eatmon says.

At the end of the day, COVID-19 vaccines are no more challenging than any other biologics from a fill/finish perspective, assures Patel. Where the real issue sets in, however, is in the management of time when the vaccines are out of controlled storage. This time management issue poses an additional challenge because of the requirement to freeze the filled product within a certain amount of time, he observes.

“Ensuring operations are managed in a timely manner means all the necessary resources for the process must be staged and be ready to perform manufacturing activities as soon as product moves to the next stage, minimizing the time out of storage,” Patel emphasizes.

“The challenge posed by the COVID-19 vaccines at the fill/finish stage of manufacturing stems from the fact that these candidates are dispersions,” adds Eatmon, who explains that the dispersion factor makes the vaccines sensitive to shear stress because they are a lipid nanoparticle rather than a solution.

“CDMOs/CMOs [contract development and manufacturing organizations/contract manufacturing organizations] must account for the different types of COVID-19 vaccines,” Eatmon states. “For some of the mRNA-based vaccines, once the drug substance has been manufactured, it must be frozen to maintain stability. The temperature-sensitive liposomes typically require additional monitoring during processing to ensure that filtration pressures are not exceeded and that temperature excursions do not occur,” she explains.

Eatmon further explains that facility capacity and suite segregation must be considered, noting that these vaccines must also be filled almost immediately after the end of the compounding process.

“For this type of drug product manufacturing, you want to make sure your CDMO/CMO has end-to-end experience and is knowledgeable in starting from drug substance production. A skilled CDMO/CMO will have the experience to know how to handle specific vaccine challenges that increase substantially as these products become more complex,” Eatmon adds. For example, it is strategically beneficial for a CDMO/CMO to understand that facility design is integral to efficient manufacturing, not only due to rapid hold times, but also due to the need for segregated suites for live viruses and compounding areas that require organic solvents, she says.

The use of particular excipients also plays a factor for ensuring vaccine stability as well as bioavailability 

, but determining which excipients to use may itself be a challenge. Some excipients used to enhance the stability of a vaccine, such as polysorbate, for example, are often foamy, Eatmon points out. As a result, the manufacturer or CDMO/CMO must pay close attention to foaming during liquid formulation filling and must reduce the rate of vial filling to accommodate excipients that foam, she notes.

Other excipients can also be adhesive, Eatmon explains, meaning that they cling to the product contact surfaces, such as filter membranes and disposable tubing. “Excipients such as these can dilute the concentration in the formulation, so we must compare component compatibility prior to use in fill/finish,” she states.

“In some cases, the need for an adjuvant could pose significant challenges to the process as a proper recirculation loop needs to be included as part of the line and can impact the overall filling strategy,” she adds.

Patel, meanwhile, explains that, for vaccines, the API itself can be considered the most conducive component. “All vaccines are based on a different platform; some are based on antigen and some of the recent COVID-19 vaccines are based on mRNA. Other than the API, excipients sometimes include: antibiotics, to prevent contamination by bacteria; adjuvants that help stimulate a stronger immune response; and stabilizers, to keep the vaccine potent during transportation and storage,” he notes, further explaining that the types of API used all help to ensure the product’s stability, and that each type plays a different role while in storage.

As fill/finish operations are predominantly outsourced to CDMOs/CMOs, these organizations are well suited to handle fill/finish of COVID-19 vaccines as they start to hit the market. Catalent is an example of a manufacturing partner that is well positioned to deliver on both scale-up and meeting demand, Patel notes. He says that additional capacity can be created by effective management and by expediting expansions.

“The supply of excipients and drug substance is obviously critical to the scale-up of drug product manufacturing, but the procurement of components used in manufacturing, such as vials, stoppers, seals, filters, labels, cartons, and other consumables is also important,” Patel says. He emphasizes that creating partnerships between suppliers can help alleviate some of these challenges as well as streamline manufacturing efficiencies to meet demand and timelines.

“Additionally,” he continues, “storage can become a challenge for vaccines without sufficient warehouse space, especially where specific storage conditions are necessary.” Normal production of a typical biologic, in contrast, does not require storage of both empty and filled components in such large quantities, which makes it much easier to manage. The situation with COVID-19 vaccine production, however, is slightly different because of the extremely high number of doses needing to be manufactured. “This constraint can be rectified by utilizing a third-party storage partner,” Patel asserts.

Eatmon points out that one of the biggest challenges for CDMOs/CMOs, even before the COVID-19 vaccines and therapies entered clinical trials, is capacity. “At Thermo Fisher, we have continued to invest in our facilities and build new lines. We are currently expanding sites across North America, APAC [Asia Pacific], and Europe to add development and CGMP [current good manufacturing practice] commercial production lines to support a range of capabilities, including live virus, aseptic liquid, and lyophilized vial filling,” she says. Equally important, she adds, is maintaining robust quality standards.

When referring to this article, please cite it as F. Mirasol, “Meeting Fill/Finish Challenges for COVID-19 Vaccines,” 

CDMOs address the unique challenges of liquid and lyophilized forms as well as preparing for the large capacity needed for COVID-19 vaccines.

Meeting Fill/Finish Challenges for COVID-19 Vaccines

Drug substance testing is an integral component in the manufacturing strategy for a biologic drug. Industry standard biologics (monoclonal antibodies [mAbs]) have, by now, well integrated drug substance testing-based control strategies to ensure that process parameters fall in-line and for the sake of product quality. However, the emergence of newer and more complex biologic modalities (e.g., cell therapies, gene therapies, protein fragments, and other constructs) challenges well-used testing methods.

The question is whether standard analytical methods for biologic drug substance testing can meet the requirements for quality assessment of these newer modalities. And if not, what innovations or adaptations are needed to address these analytical needs?

According to FDA’s industry guidance for mAb production, the antibody structure, integrity, specificity, and potency of a potential mAb therapeutic must first be precisely and thoroughly characterized before human studies can be conducted (1).

To characterize the structural integrity of the mAb, analytical methods such as sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing (IEF), high-performance liquid chromatography (HPLC), and mass spectrometry (MS) should be used, or other appropriate physicochemical methods, to show that the mAb, once purified, has not been fragmented, has not aggregated, or has otherwise not been modified as a result of the separation and purification process. FDA guidance also recommends that side-by-side comparisons should be conducted between each production lot and the in-house reference standard.

To test for the specificity of the mAb, direct binding assays should be used. The assays should show that the mAb binds to the specific target antigen for which it is intended (both positive and negative controls should be included here). FDA’s guidance also explains that “the protein, glycoprotein, glycolipid, or other molecule bearing the reactive epitope” must be biochemically defined. The antigenic epitope must also be determined. Fine specificity studies using inhibition or other techniques should also be conducted, when possible, to characterize the antibody specificity. Once antibody specificity is determined, antibody binding activity must then be quantified through affinity, avidity, or immunoreactivity assays, or combinations of these assays.

Potency assays are also important for characterizing the mAb product, monitoring consistency from lot to lot, and ensuring product stability. FDA’s guidance suggests using binding assays, serological assays, 

 functional assays, or animal model activity, to assess potency. A purified unmodified mAb must be fully characterized before it can enter human studies, with the mAb’s structural integrity, specificity, and potency described in the product’s investigational new drug (IND) filing (1).

With the evolution of biotherapeutic modalities from the traditional mAb format, however, drug substance analytical testing needs improved sensitivity. In addition, analytical methods used for small-molecule (i.e., chemical) drugs—such as solid phase extraction, gas chromatography, liquid chromatography, and/or mass spectrometry—are not the best suited for biologic drugs. For small-molecule drugs, these analytic methods remove biological matrix elements from the sample solution, leaving the chemical drug behind for subsequent analysis. Used for biologic drug analysis, however, the methods would remove the biologic drug itself from the sample solution. Testing of biologic drug sample for preclinical and clinical specimens would require specific binding techniques, such as immunological methods that quantify a desired biological target in the presence of a biological matrix (2).

There have been emerging analytical technologies, however, that allow for more sensitive scrutiny and more specific physiochemical detail. In the early development stages, more in-depth, orthogonal biochemical information can be gained from a target molecule to provide better understanding of its attributes. Having this in-depth information also allows for the

assessment of intrinsic product- or process-related impurities that could impact product safety in early clinical trials. The analysis of biological (i.e., protein) drugs can be done through methods such as HPLC, ultra-high performance liquid chromatography (UHPLC), gel electrophoresis, isoelectric focusing, gene sequencing, various other forms of mass spectrometry, amino acid analysis, carbohydrate analysis, peptide mapping, and capillary electrophoresis, among others (2).

Building test methods for measuring drug substance performance and quality of a new biologic modality can be guided by the appropriate regulatory authority, but harmonized standards can be most helpful, as these standards reflect a consensus of best practices among the major global regulatory authorities. The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) provides such a set of standards.

ICH Q6 (3) is especially useful as it gives guidance on establishing specifications for drug substance testing for new chemical entities (as well as drug product testing). Recommended test and acceptance criteria guidelines follow a particular format:

Description—gives a qualitative statement describing the state (e.g., solid, liquid) and color of a new drug substance, and should any of these characteristics change while in storage, the change should be investigated and dealt with.

Identification—ideally, this testing should allow for discrimination between compounds of closely related structures that are likely to be present, and identification testing should be specific to the new drug substance. Use of two chromatographic procedures, in which separation is based on different principles or a combination of tests are used in a single procedure, is acceptable.

Assay—this requires that a specific, stability-indicating procedure be included to determine the content of a new drug substance.

Impurities—this category includes both organic and inorganic impurities and residual solvents.

Additional testing recommended for new biologic modalities can include the following, where appropriate (3):

Physicochemical properties—these properties include pH of an aqueous solution, melting point/melting range, and refractive index, and their measurements can be taken using methods such as capillary melting point and Abbé refractometry. Testing of physicochemical properties should be determined by the physical nature of the new drug substance and its intended use.

Water content—testing for water content is important when the new drug substance is known to be hygroscopic or degraded by moisture, or when it is knows that the drug substance is a stoichiometric hydrate.

Inorganic impurities—it is important to include tests and acceptance criteria for inorganic impurities (e.g., catalysts) during development, and the inclusion of such tests should be based on knowledge of the manufacturing process.

Microbial limits—it is possible that there may be a need to specify the total count of organisms (i.e., aerobic microorganisms, yeasts, molds, etc.) and the absence of specific objectionable bacteria (e.g., 

)—to be determined using pharmacopeial procedures. The type of microbial testing used and acceptance criteria for microbial limits should be based on several factors: the nature of the drug substance, the method of manufacture, and the intended use of the drug product.

Thus, establishing appropriate testing methods and acceptance criteria will help illuminate where the need is greatest for more specific and/or more sensitively tuned analytical methods.

Guidance for Industry, Points to Consider in the Manufacture and Testing of Monoclonal Antibody Products for Human Use

 (Rockville, MD, February 1997).
2. H. Shintani, “Development of Test Method for Pharmaceutical and BioPharmaceutical Products,” 

Specifications: Test Procedures and Acceptance Criteria for New Drug Substances And New Drug Products: Chemical Substances


Vol. 45, No. 1
January 2021
Pages: 44–45

When referring to this article, please cite it as F. Mirasol, “Meeting Specificity Needs for Biologic Drug Substance Testing,” 

Traditional biologic-based testing methods may need an upgrade to properly test newer therapeutic modalities.

Meeting Specificity Needs for Biologic Drug Substance Testing

The European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) kept a robust pace of marketing authorization application (MAA) reviews in 2020, with 96 total new marketing authorization recommendations as of 11 Dec. 2020 (1), 45% higher than in 2019, when the committee recommended 66 new MAAs for authorization (2).

New non-orphan medicines accounted for the majority of the positive recommendations, with 38 MAAs recommended for marketing authorization by the CHMP. New orphan medicine and generics/hybrids/informed consent MAAs were next, with 24 and 22 positive recommendations, respectively. Twelve biosimilar MAAs were recommended for authorization.

Of particular note was Orchard Therapeutics’ gene therapy, Libmeldy (autologous CD34+ cell-enriched population that contains hematopoietic stem and progenitor cells transduced ex vivo using a lentiviral vector encoding the human arylsulfatase A gene). The therapy is intended to treat metachromatic leukodystrophy (MLD), for which there is currently no cure. MLD is a rare inherited metabolic disease that affects the nervous system and causes progressive loss of motor function and cognitive ability and, ultimately, death (3). If authorized, Libmeldy will be the first treatment approved for MLD in Europe.

Other notable CHMP recommendations include Givlaari (givosiran, Alnylam Pharmaceuticals), Rybelsus (semaglutide, Novo Nordisk), and Zolgensma (onasemnogene abeparvovec, AveXis/Novartis). Givlaari would be the first treatment for the rare genetic disorder, acute hepatic porphyria, in adults and adolescents aged 12 years and older. Givosiran received approval in the United States from the US Food and Drug Administration (FDA) in November 2019 under the Givlaari brand name (4). Rybelsus would be the first oral glucagon-like peptide-1 receptor agonist for type 2 diabetes; the active ingredient, semaglutide was first approved in the US as a subcutaneous injection in December 2017 under the brand name Ozempic (5) and was later approved as a an oral tablet under the brand name Rybelsus in September 2019 (6).

Meanwhile, Zolgensma is a gene therapy for the treatment of spinal muscular atrophy. In the US, onasemnogene abeparvovec-xioi was approved under the Zolgensma brand name by the FDA in May 2019 (7).

In addition, the committee recommended granting a conditional marketing authorization for Retsevmo (selpercatinib) for the treatment of cancers displaying a rearranged during transfection (RET) gene fusion, including RET-fusion positive non-small cell lung cancer, RET-fusion positive thyroid cancer, and RET-mutant medullary-thyroid cancer (1). The committee also recommended granting a marketing authorization under exceptional circumstances for Lumoxiti (moxetumomab pasudotox) for the treatment of relapsed or refractory hairy cell leukaemia (1).

Meanwhile, EMA’s work on COVID-19 vaccine evaluations continues. In January, the European Commission (EC) granted conditional marketing authorization to Moderna’s COVID-19 vaccine (8), following a positive recommendation by EMA, based on positive Phase III clinical trial data that showed over 90% efficacy in participants at risk of severe COVID-19 and a 94% reduction in the number of symptomatic COVID-19 cases (9).

Also in January, EMA received an application for conditional marketing authorization from AstraZeneca and the University of Oxford for their COVID-19 vaccine in development (10). EMA has stated that the assessment of the AstraZeneca/Oxford vaccine will run on an accelerated timeline, with the possibility that an opinion coulde be issued by 29 January.

Pfizer and BioNTech’s COVID-19 vaccine, Comirnaty, was the first to be granted conditional marketing authorization by the EC in December 2020 (11).

Meeting Highlights from the Committee for Medicinal Products for Human Use (CHMP) 7-10 December 2020

Meeting Highlights from the Committee for Medicinal Products for Human Use (CHMP) 9-12 December 2019

Meeting Highlights from the Committee for Medicinal Products for Human Use (CHMP) 12-15 October 2020

, 16 Oct. 2020.
4. FDA, “FDA Approves First Treatment for Inherited Rare Disease,” Press Release, 20 Nov. 2019.
5. FDA, “

, 20 Sept. 2019.
7. FDA, “FDA Approves Innovative Gene Therapy To Treat Pediatric Patients with Spinal Muscular Atrophy, a Rare Disease and Leading Genetic Cause of Infant Mortality,” Press Release, 24 May 2019.
8. Moderna, “European Commission Authorizes COVID-19 Vaccine Moderna in Europe,” Press Release, 6 Jan. 2021.
9. EMA, “EMA Recommends COVID-19 Vaccine Moderna for Authorisation in the EU,” Press Release, 6 Jan. 2021
10. EMA, “EMA Receives Application for Conditional Marketing Authorisation of COVID-19 Vaccine AstraZeneca,” Press Release, 12 Jan. 2021.
11. EMA, “EMA Recommends First COVID-19 Vaccine for Authorisation in the EU,” Press Release, 21 Dec. 2020.


Vol. 33, No. 1
January 2021
Pages: 18–20

When referring to this article, please cite it as F. Mirasol, “EMA Marketing Authorization Recommendations Rise in 2020,” 

The number of recommendations for European marketing authorization of human medicines saw significant increase in 2020 over the previous year.

EMA Marketing Authorization Recommendations Rise in 2020

The importance of adventitious agent testing, a routine aspect of biopharmaceutical production, cannot be overlooked as it is a critical component in ensuring the purity and quality of biological product from the start. The growing complexity of newer biologic modalities, however, requires more highly sensitive testing methods and poses challenges to current analytical methods.

Generally speaking, adventitious agents are the microorganisms (bacteria, fungi, protozoa, mycoplasma, viruses, etc.) that may be introduced into the product during the normal course of the biomanufacturing process. They can be introduced through product processing or through process material used for production.

“These contaminants are living organisms that can adversely affect manufacturing efficiency, product quality but more importantly pose a threat to patient safety,” notes Marian L. McKee, PhD, vice-president, Biosafety, Eurofins BioPharma Product Testing.

Typically, endogenous agents are differentiated from adventitious agents as they are integrated pathogens of the production system, says Horst Ruppach, scientific and portfolio director, Global Biologics, Charles River. The Chinese hamster ovary (CHO) production cell line, for example, contains retrovirus-like particles that are typically regarded as endogenously.

“As biologics are produced to treat patients, it is highly important to ensure pathogens are not co-purified with the product,” Ruppach states, adding that “even though a pathogen might be harmless for healthy people, it can seriously affect patients. It is, therefore, essential to detect and eliminate pathogens, ideally at an early stage of the product development.”

Contamination of the manufacturing process can also have significant business and medicine supply consequences. “Facilities must be closed and fully sanitized and a deep route cause investigation is required. The supply of urgent medicine is probably impacted. It takes a minimum of six months and can go much beyond to get back to production,” Ruppach adds, emphasizing some of the consequences that can result from adventitious agents.

To date, many guidelines and compendial methods recommend different approaches to screen for and identify pathogens in biopharmaceuticals, Ruppach states. “General screening methods for viruses include inoculation of manufacturing test articles into susceptible animal systems and/or indicator cell lines to amplify outgrowth of adventitious contaminants. The infection is detected via symptoms, including death or the production of virus-specific antibodies in animals, changes of cell-line phenotypes, including cell disruption, or detection of virus-specific components in the supernatant of the inoculated cell lines,” Ruppach adds.

Single polymerase chain reaction (PCR) or multiplex PCR are frequently used to screen for suspected specific contaminants. While in-vivo and in-vitro methods detect infectious viruses, molecular biology-based methods detect viral genomes that include both infectious and non-infectious viruses, which cannot be differentiated, Ruppach points out. “The combination of a cell-based assay with PCR readout combines the benefit of both methods and is, for instance, applied when screening adeno-associated virus (AAV) preparations for replication-competent viruses. In any case, the choice of methods must be adapted to the test item and the characteristics of the test item can affect the assay sensitivity significantly,” he says. “For instance, test items can be toxic for animals or cell lines and must be pre-diluted to bypass the toxicity, and there is a risk that low contaminant concentrations are diluted out before analysis. That said, low contamination levels can be difficult to detect, which can be a specific risk for recombinant products on cell lines. Minimal viral contaminants can be introduced via media into the fermentation process, and minimal amounts of viruses can amplify to high levels during fermentation with all the aforementioned consequences.”

Traditionally, and in accordance with regulatory guidance, an orthogonal approach to detecting the presence of adventitious agents has been taken, McKee states. The analytical methods used include in-vitro and/or in-vivo culture as well as molecular methods for detection. “In-vitro culture under permissive conditions for the suspected adventitious agents, taking into consideration the environmental conditions of the manufacturing space, is the long standing or ‘old school’ method used for detection of many adventitious contaminants. The benefit of in-vitro culture-based methods is that they will detect a broad range of agents. In the case of the IVAA [in-vitro adventitious agent] method for virus detection, various endpoints (for example, hemagglutination and hemadsorption of various species of red blood cells) are used to widen the range of detected viruses even further,” says McKee.

McKee notes that in the last decade, PCR-based methods have taken hold in the industry as a more specific and sensitive means for detecting adventitious agents. “As new viruses are found to contaminate raw materials, specific PCR-based test methods can easily and rapidly be deployed for use. A good example is the advent of PCR methods against the minute virus of mice (MVM), which came on the scene after a contamination event in the mid-90s. Next generation sequencing (NGS) is also taking off as a method for detection of contaminants in bioprocessing,” she states.

NGS technologies or other disruptive multiplex technologies are increasinglyconsidered for testing or replacing the standard methods and the in-vivo assays specifically, says Ruppach, who sees that these new technologies offer many benefits. “Different from PCR or multiplex PCR, NGS can also detect unknown viruses. In fact, NGS can detect any pathogen in a sample—bacteria, mycoplasma, and viruses—and makes it a multi-attribute method. Instead of applying many different methods, one method can be used. Like all nucleic acid-based detection methods, NGS can typically not differentiate infectious from non-infectious pathogens, but approaches such as whole transcriptomic analysis have been developed to circumnavigate this downside. Detection of pathogen-specific mRNA in cell substrates is a clear indicator of active replicating virus,” Ruppach explains.

Ruppach goes on to say that, while NGS is being progressively considered for pathogen testing in the biopharmaceutical industry, there is an emerging need for methods that attempt to offer the benefits of shorter turnaround times, small sample volume, and low equipment requirements to address specific challenges inherent to next generation biologics.

Early detection of adventitious agents is also important and can benefit the bioprocessing cycle. Early detection of an adventitious agent contamination helps contain the event, for one, McKee says. If the working cell bank or a raw material is found to be contaminated during release testing, for example, it is much less costly to deal with the contamination at that early point, rather than missing detection of that same contaminant and not finding it until after a full bioreactor run has been initiated. “Raw materials, cell, virus or plasmid stocks, and other reagents used in biomanufacturing should all be tested and confirmed free of adventitious agents prior to use in a bioprocessing cycle,” McKee recommends.

As there are multiple points throughout the bioprocessing cycle where sampling for adventitious agent testing occurs, early detection can save bigger headaches further down the line. “Ultimately, it comes down to mitigating the risk to a very costly and time intensive manufacturing process,” McKee adds.

Ideally, Ruppach says, the pathogen risk should be addressed in the product development phase and before stepping into the clinic. “Even though many regulations require pathogen safety testing for clinical material, it is reasonable to address the pathogen risk much earlier. For instance, extended pathogen testing is required for master cell banks (MCB—starting material for cell line-based production systems). However, it would be reasonable to screen any pre-bank or the parental cell bank before MCB preparation by using the most sensitive methods with the widest breadth of detection,” he states. 

NGS approaches have these attributes, Ruppach continues, and when applied at early stages they perfectly mitigate the risk for all subsequent steps. NGS significantly reduces the risk that any contaminant is found later in the production cycle, which Ruppach says can save many resources and time. “The same is true for animal- or human-derived raw materials, such as extracts of human platelets in cell therapy products used in the production process,” he adds.

Furthermore, detecting any contaminant in the raw material before it comes into contact with the product is mandatory. Early detection minimizes the risk for the product and avoids subsequent measures to clear the virus from the product, Ruppach says.

With complex biologic modalities, it is necessary to have analytical methods with higher sensitivity for detecting adventitious agents. As McKee points out, sensitivity is important in adventitious agent testing for several reasons. “The burden of the contamination may be quite low early in infection or very high later in the event. As discussed previously, the earlier an adventitious agent contamination is detected, the better. The ability to detect <10 microorganism is important in mitigating the risk by early detection of low-level contaminants,” she says.

Ruppach adds that sensitivity is highly important; however, he points out, one method is not equally sensitive to all potential pathogens. NGS comes closest, he says. Some animal-based assays, however, can be very sensitive for specific contaminants, such as embryonated chicken eggs for Influenza viruses. “These aspects must be considered when selecting testing methods which should be based on a risk assessment,” Ruppach states.

“For some biotherapeutics like viral gene vectors or CAR-T cells [chimeric antigen receptor T cells], the available sample volumes for testing can be limited. The smaller the test sample volume, the more important it is to have a highly sensitive method,” he further explains.

In addition, autologous cell therapy product cannot wait weeks for testing results. “Rapid testing methods must replace established long-lasting assays such as in-vivo and in-vitro test methods, and industry has developed rapid sterility and mycoplasma assays reducing turnaround times from weeks to a few days without impacting the sensitivity,” Ruppach says.

As the modality of therapeutic biological molecules grows increasingly complex, the manufacturing processes for these therapies also evolve. The needs for adventitious agent testing must also respond and change, says McKee.

“The complexity of therapeutics is also driving technology. Viral vectors for gene therapy are not going through the same downstream purification processes that traditional biologics such as monoclonal antibodies do. The viral clearance gained by downstream processing of protein biologics is not an option for cell and gene therapies. Both the need for increased sensitivity and a compressed time to result are becoming more important, especially in the field of autologous cell therapies and regenerative medicine,” McKee explains.

“With personalized medicine and small batch manufacturing, as we see for some rare disease gene therapy clinical trials, the sample volumes available for testing is also becoming smaller. A technology solution that can leverage a small sample to gain high volume information on contamination in a short period of time will be a game-changer in the field,” she adds.

The need for rapid testing assays is also driven by the limited stability of some products or the need to release final products quickly, Ruppach says. In some cases, as in the autologous cell therapy field, the patient cannot wait weeks for testing results before receiving treatment, he points out. “While rapid sterility and mycoplasma methods are available, there is still a need for rapid virus screening methods. PCR based testing is rapid but typically target known viruses or known virus groups. NGS approaches, however, have the potential to detect any contaminant and unknown variants but cannot yet be regarded as rapid, except where one is willing to compromise with respect to the sensitivity,” he further explains.

Ruppach notes that rapid testing requirements can also be met by application of onsite, easy-to-use, and robust assays/kits, rather than shipping material to contract research organizations for testing. “Here is still space for development, even though some of the rapid assays are set up for onsite applications,” he says.

Moreover, there is a trend away from “off-the-shelf” assays to customized assays, Ruppach observes. “Biopharmaceutical products are more and more optimized for specific applications (cell therapy, AAV serotypes, etc.) that require individual adaption of adventitious virus testing methods. For instance, the assay to screen for replication competent AAVs in AAV vector products requires a sensitive cell line capable of supporting amplification of a potential replication competent virus. Not all wild type serotypes grow up on the same cell line and it requires implementation of serotype-specific suitable cell lines in the assay. Ideally, this is addressed by building platform assays which can be adapted to the specific needs of a specific product type,” he explains.

New production methods, such as continuous manufacturing processes where material from the fermenter moves through to fill/finish continuously, require continuous online testing, Ruppach also notes. Continuous online testing is best achieved by automated sampling and testing using devices installed at critical positions of the process flow and that provide results within hours, maximally.


Vol. 33, No. 11
November 2020
Pages: 44–47

When referring to this article, please cite it as F. Mirasol, “Complex Modalities Require More Sensitive Adventitious Agent Testing,” 

Early detection and more sensitive methods of detecting adventitious agents are becoming increasingly critical in bioprocessing.

Intricate Modalities Need More Perceptive Adventitious Agent Testing

With an increasing number of gene therapy candidates expected to move through the clinical trial pipeline and toward commercialization, the need for innovative process development to bring these potential new products to commercial scale is a focus in the biopharmaceutical industry. Among the bioprocessing steps seeing forward movement is the cell culture for producing adenovirus-associated virus (AAV) vectors for gene therapy, which has largely depended on less efficient methods of cell culture but is moving to more modern methods.

Currently, many methods used for AAV production still involve adherent cell culture, meaning that cells are grown on a solid surface, such as flasks or multi-layered cell culture dishes or roller bottles. These traditional systems are generally difficult to scale-up and are associated with a high propensity of mishandling risks, which are the result of increased processing time due to the manipulation of large numbers of culture vessels, notes Alengo Nyamay’Antu, PhD, scientific communication specialist at Polyplus-transfection, a France-based biotechnology company specializing in gene and cell therapy, biologics manufacturing, and life-science research. Some direct consequences of following these traditional cell culture methods during manufacturing scale-up are compromised reproducibility and space limitation problems, Nyamay’Antu says.

To achieve larger production volumes for AAV vectors, scale out rather than scale up has been typically employed, says Jerry Keybl, Head of Cell & Gene Therapy Manufacturing, MilliporeSigma. Scaling out uses specialized equipment that increases the surface area of the flask so that a greater number of cells can attach.

“Typically HEK293 cells are grown in undefined media, such as DMEM [Dulbecco’s modified eagle medium] that contain fetal bovine serum. Unfortunately, the manual handling of such culture formats increases contamination risk and is extremely costly and labor intensive,” Keybl states.

Going from small-scale to commercial-scale production presents several challenges. For example, scale up requires a significantly large number of vessels, which results in an increase in the number of incubators and space needed to house them, says Susan D’Costa, senior director, Technical Program Design, Commercial Operations, Viral Vector Services, Thermo Fisher Scientific. In addition, scale-up requires an increase in the resources needed to manipulate the cell culture vessels. The risk to asepsis is also higher because of the number of manipulations needed, D’Costa asserts.

Scaling to commercial-level production runs into technical difficulties as well, such as adjusting the process for large-scale production without impacting production yield and reproducibility, Nyamay’Antu points out

An alternative to scaling out of traditional cell culture methods, such as flasks, is the use of bioreactors. Bioreactors are becoming more frequently used, even for small batches of vector product, observes Jorge Blanco, director of operations at VIVEbiotech, a Spain-based biotechnology company. Bioreactors simplify the production process, increase reproducibility, and reduce costs associated with footprint and labor, Blanco notes.

Because traditional cell culture methods operate within two dimensional (2D) systems that can be only a few cm2 or multi-layered stacked cell factories, they present poor scalability, Blanco confirms. For reaching the required commercial yields, therefore, multiples of 2D cell factories are required. “This makes these systems far less operational,” Blanco states. “A very high number of multi-layered cell factories are required to reach the yields that are easily harvested from single 3D adherent bioreactors. Additionally, these 2D cell factories require high manual handling, thus lowering reproducibility significantly.”

The fact that many cells are adherent, meaning they have to be attached to a substrate in order to grow, significantly limits scaling up, Ulrich Kettling, PhD, chief business officer, CEVEC Pharmaceuticals, further explains. “When it is not possible to use larger dishes to provide larger surfaces, the only option is to scale out.”

Keybl attributes scaling challenges to the fact that the flasks are limited by surface area, and the only way to increase production is to add more flasks and incubators to the process. “Up to hundreds of flasks and incubators may be utilized at one time to meet the demands for a commercial product. Subsequently, the increase in resources to handle and process the flasks are proportionately increased as well,” he states.

The move toward modern cell culture methods and techniques would mitigate the challenges and limits inherent totraditional methods when scaling for commercial production.

Two major trends of alternative culture systems that address scalability and reproducibility are fixed-bed cell culture systems that increase adherent cell seeding density and volumetric productivity and suspension cell culture systems that provide the needed flexibility to adapt a production scale to meet large-scale production demands. “We are clearly seeing that alternative systems are taking over, and already at small scale, as viral vector manufacturers are increasingly anticipating what their process should already look like at small scale to facilitate transition to large-scale manufacturing,” Nyamay’Antu says.

“When it comes to AAV manufacturing, there is a clear preference for suspension cell-based systems, directly inspired by the success of this approach for commercial-scale manufacturing of recombinant proteins and antibodies produced in mammalian cells,” observes Nyamay’Antu. For instance, suspension cell systems improve batch-to-batch reproducibility during scale up by eliminating varying cell culture parameters (e.g., serum, cell seeding density, etc.) and by simplifying downstream AAV purification.

“In addition to improved reproducibility, with suspension cell systems it is possible to further increase AAV production yields with the right set of tools: cell lines that can be grown at higher density, optimized set of plasmids, the transfection reagent, and the synthetic medium used to support AAV production,” Nyamay’Antu adds.

“Some processes are beginning to use a fixed-bed bioreactor, but these processes still require the use of serum, introducing adventitious agents and consistency challenges,” Keybl chimes in.

VIVEbiotech, meanwhile, uses the adherent production system for cell culturing a different type of vector: lentiviral vectors. The company uses fixed-bed bioreactors, however. “Today, scaling up is feasible given the availability of intermediate scales in the market, which allow manufacture from early stages to commercial. It is achievable to get up to 1200 liters of harvest from fixed-bed bioreactors,” Blanco says. “Additionally, different providers for fixed-bed bioreactors are already on the market, de-risking the chance of running out of them or of increasing cost of consumables.”

The smallest bioreactor sizes are adequate for process development, Blanco also notes. These small bioreactors can easily perform fine-tuning runs without investing high sums of resources, he adds.

“Regarding downstream processing (DSP), fixed-bed-based manufacturing turns into simpler DSP processes, as once the viral vectors are bulk harvested, DSP processing requires fewer steps than for suspension systems,” Blanco explains.

Each technology has strengths and weaknesses, Blanco further enumerates. It is well known, for instance, that viral proteins are cytotoxic for producing cells regardless of the manufacturing technology used. However, there are some additional facts that increase the stress to which the cells are exposed, he highlights. “In stirred-tank reactors, producer cells are exposed to mechanical forces that may result in a higher cell lysis during the growth within the bioreactor. Any stressing factors may directly impact functionality, and thus performance of the resulting viral product,” Blanco states.

“Adherent viral vector production systems do also present some aspects that need to be addressed. The growth of producer cells in absence of animal-origin components, such as fetal bovine serum, is more challenging than in suspension systems. VIVEbiotech’s R&D department is able to produce vectors in the absence of serum in 2D productions, and tech transfer to reactors is currently ongoing with the aim of offering serum-free 3D productions in the near future,” continues Blanco.

“Last but not least, the industry is moving towards continuous bioprocessing. The ‘go continuous’ tendency is especially challenging in viral vector manufacturing because, as mentioned, viral vectors affect the viability of producer cells due to the toxicity of virus-producing proteins. This is why cell cultures, and thus, harvesting time, cannot be lengthened as wished,” Blanco adds.

Suspension bioreactors are the format of choice as commercial production platforms for biotherapeutics. “Suspension bioreactors in volumes up to tens of thousands of liters and stable producer cell lines have been used in industry for decades now, for manufacturing of recombinant proteins and monoclonal antibodies (mAbs),” Kettling states. “And this way of manufacturing is now becoming available for gene therapy vectors as well, including innovations in stable producer cell lines combined with high cell density-processes such as perfusion.”

Gene therapy commercial production can benefit by taking a lesson from the mAb production world. “Scaling up cell expansion by growing cells in suspension culture in controlled bioreactors is certainly the wave of the future and where the industry is moving to,” says Keybl. “Suspension methods are scalable, less labor intensive than scaling out adherent production, and can utilize chemically defined media, which is a huge benefit to downstream purification/patient risk.At MilliporeSigma, we have a number of production platforms in development to accelerate adoption. These processes are in development across the industry and I believe will power gene therapy manufacturing in the future.”

“Adherent cell culture can be scaled up into micro- and macro-carrier-based reactors,” adds D’Costa. “However, the better alternative is to adapt adherent cells into suspension cells grown in large scale bioreactors in serum-free, chemically defined media. Transient transfection of large-scale reactors is still limited to 200–500-L scale, so currently the process needs to use multiple 200–500-L reactors that are harvested at the same time. While traditional purification methods utilizing cesium chloride/iodixanol density gradients for enrichment of AAV full particles are currently used in commercial production, more scalable and process-validatable methods include purification through chromatography media (capture and polishing),” D’Costa explains.

Regardless of the method for cell culturing viral vectors, however, there are two viral-vector production modes: transient transfection and stable producer cell lines, Blanco points out. Although each production mode has its own pros and cons, there is a general trend leaning toward stable producer cell lines. The cost associated with plasmids used for transient transfection is very high, for example, which increases the final price of the product considerably, Blanco explains. Stable producer cell lines, however, allow dispensing with these DNA molecules, which thus makes scaling-up much smoother and translates to a decrease in expenses and an increase in reproducibility. “The generation of stable producer cell lines is a long and challenging process that requires the involvement of significant material and personnel resources,” he says.

Modernizing the cell culture methods and techniques for vector production, whether AAV or lentiviral, also poses its own challenges. The biggest challenges for a company like VIVEbiotech, which has already spent more than 30 months fine-tuning the manufacturing process, include improving the performance of the final product (i.e., the ratio of empty to active infectious particles) so that the lentivectors are more functional and increasing recovery, Blanco states.

In terms of performance, however, there are increasingly more transfection enhancers bringing promising results, Blanco adds. “As for the recovery after DSP processing, it is usually around 30% when using adherent culture systems. This means there is still considerable room for improvement, so VIVEbiotech´s development professionals are working tirelessly on this, already achieving recoveries of 40%.”

Transient transfection has particularly been a challenging area when scaling to commercial production, Kettling affirms. Issues with reproducibility and robustness of the transfection steps, as well as the significant costs for GMP-grade plasmids, require solutions, Kettling observes.

The adaptation of the cell line to the suspension process is another major challenge on the path toward modernization, says Keybl. “Typically, adherent cells need to be carefully adapted into different types of cell culture media (preferably serum- and animal-component-free) and selected for good growth and viral vector productivity. This can mean several years of R&D development time in order to choose the right cell line and medium combination that will give the optimal results,” he states. “Commercially available cell lines are coming to market and can reduce this burden for innovators.”

Meanwhile, bridging the data obtained with traditional methods, including non-clinical toxicology and early clinical data, to conform to newer commercial-grade processes presents a significant challenge for those that want to change over to modern methods, D’Costa points out. “It is also important to consider the additional development time it takes to change the upstream production and downstream purification process and refine the assays, which is needed to build out tools for cell adaptation,” she says.

“When aiming to switch from traditional adherent to suspension cell systems, there are several parameters that need to be considered,” includes Nyamay’Antu. “I would not consider them as challenges that need to be overcome, but more as part of protocol optimization. As for all new set-ups, it requires delving into the literature, relying on the technical support of suppliers, and timescales. Some of these questions include whether to adapt the cells to suspension or to buy a commercially available suspension cell line; which synthetic medium should cells be grown in, and whether it is the same during the production phase as well as which transfection reagent will reach highest production yield in these suspension cells. These are all valid questions when moving on to suspension cell systems, and during the upscale process additional questions rise when choosing the set-up for large scale culture (bioreactor),” Nyamay’Antu emphasizes.

Innovations in cell culture materials ease transition

To ease the transition from older cell culture methods to more modern means requires a number of breakthrough innovations. Recent innovations in materials, such as media/supplements that support high density cell culture, transfection reagents that support high productivity, and single-use bioreactors that are scalable, have made the shift from older methods to modern methods easier, says D’Costa.

Particularly important is the development of producer cell lines to meet the high industrial demands on the production processes: stable producer cell lines offer reliable and consistent quality combined with sufficient yields in standardized processes and equipment, Kettling points out. Several labs and innovative biotech companies are working on providing solutions, including Cevec, which recently launched a new producer cell-line technology (ELEVECTA) in April 2020 (1). The ELEVECTA technology enables large-scale manufacturing of AAV vectors using fully stable producer cell lines and can be implemented in bioprocess development and large-scale GMP manufacturing facilities that use standard suspension bioreactor equipment.

“Thankfully, suppliers have been working hard to support the transition of AAV manufacturing in suspension cell culture systems. We can see that companies that develop synthetic cell culture medium, supplements, and also plasmid DNA now offer tailored tools specifically for AAV production,” Nyamay’Antu (Polyplus) chimes in. Polyplus-transfection, for example, has been aware that viral manufacturers needed a transfection reagent specifically developed for large-scale transfection to improve scalability, productivity, and flexibility of AAV manufacturing in suspension cells. The company developed a chemical-based and animal-free transfection reagent (FectoVIR-AAV) that addresses current limits of transfection for AAV manufacturing in suspension cells.

“These limits include scalability, flexibility and, last but not least, productivity as transfection, whether at small or large scale, is dependent on the efficiency of the delivery molecule,” Nyamay’Antu says. “FectoVIR-AAV improves AAV production yield in suspension cells up to 10-fold in functional titer yields compared to [other reagents]. The increased production yield is reproducible at different scales for the production of several AAV serotypes as confirmed by viral manufacturers who took part in the beta-testing.”

On the supplements and reagents front, VIVEbiotech is working to introduce some new items to its production process, such as a transfection agent. “Given that animal-origin reagents need to be avoided in medicines to be applied in humans, the standard benzonase has been removed from the production process and replaced by an animal-origin-free endonuclease, with really good results. [We] are also working hard trying to move to serum-free media for producer-cell-culturing,” Blanco states.

1. CEVEC, “Cevec Announces the Launch of the ELEVECTA Platform—the Stable Producer Cell Line Technology for AAV Gene Therapy Vectors,” Press Release, April 28, 2020.


Vol. 44, No. 10
October 2020
Pages: 28–33

When referring to this article, please cite it as F. Mirasol, “Modernizing Bioprocessing for Gene Therapy Viral Vectors,” 

The manufacture of gene therapy vectors is shifting to more modern technologies.