Advancing OSD: Continuous Production Considerations and Dose-Level Authentication

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Jill Wechsler is Pharmaceutical Technology's Washington Editor, jillwechsler7@gmail.com.

As expected, Congress reauthorized four key user fee programs last week, as part of a must-pass measure to fund the federal government for another two months. The Continuing Resolution (CR) signed on Sept. 30, 2022 averted a federal government shutdown by extending the Oct. 1, deadline for approving a federal spending plan for fiscal year 2023 to Dec. 16, 2022—after the mid-term elections in hopes that this will enable the legislators to reach a viable budget compromise.

The CR reauthorizes fees for drugs (Prescription Drug User Fee Amendments [PDUFA]), generic drugs (Generic Drug User Fee Amendments [GDUFA]), biosimilars (Biosimilar User Fee Amendments [BsUFA]), and medical devices (Medical Device User Fee Amendments [MDUFA]) for the next five years, 2023–2028. In confirming FDA’s authority to collect fees from manufacturers, the agency avoids having to notify thousands of fee-supported staffers of looming layoffs. That prospect already had eroded agency morale and undermined efforts to recruit and hire needed staffers, as FDA struggled for months to maintain and expand its professional workforce during the added hardships imposed by the pandemic and in a very competitive labor market.

Medical product user fees generate some $2 billion in agency revenues, approximately 40% of FDA’s non-tobacco budget. While Congressional leaders on both sides of the aisle support this program to bolster key agency operations and innovations, the broader political debate over escalating government spending generated concerns about new fee-supported initiatives that extend the agency’s authority.

Even so, FDA officials, manufacturers, and research advocates gave a loud sigh of relief following the Congressional action. Commissioner Robert Califf praised the user fee reauthorization measure, while thanking agency staffers for their diligence in engaging in this “prolonged, demanding and, at times, frustrating process.” He noted that the bill avoids “a devastating impact” on FDA’s ability to carry out its “independent and transparent review of medical products.”

Califf added that FDA is committed to working with Congress to enact additional policy changes to benefit public health, but for now, is moving fast to implement multiple new fee-supported policies and programs. Similarly, Patrizia Cavazzoni, director of the Center for Drug Evaluation and Research (CDER), praised the new fee programs for supporting CDER’s commitment to monitoring the safety of marketed products, protecting patients in clinical trials, and facilitating review of treatments for life-threatening diseases.

In an effort to make up for lost time in meeting tight deadlines for implementing new PDUFA-backed initiatives, FDA quickly posted a new webpage outlining criteria for manufacturers to participate in the new 

Split Real Time Application Review (STAR) program

 to accelerate patient access to critical therapies. The pilot aims to shorten the review time for efficacy supplements to approved drugs and biologics through earlier review of certain submissions before 

. FDA also provided information on a new Rare Disease Endpoint Advancement (RDEA) 

pilot to develop novel efficacy endpoints for critical treatments

. Still to come are multiple new policies described in the 

Enhancements in GDUFA III aim to reduce the number of assessment cycles for generics, support the development and approval of complex generics, and help manufacturers resolve quality issues more quickly. First off the line are new draft guidance documents on assigning review goal dates based on a 

manufacturing facility’s readiness for inspection

assessment of APIs to speed application review

. There’s new guidance on expediting development of 

And for biosimilars, BsUFA III priorities involve expediting the review of certain supplements and launching a new regulatory science program to advance biosimilars and interchangeable products, already posted in a 

outlining new pilots to improve the efficiency of biosimilar development and for interchangeable products. Further program revisions are listed out in the 

The “skinny” user fee reauthorization dropped multiple high-profile proposals for revising how FDA regulates 

 diagnostics, dietary supplements, and cosmetics, as well as the agency’s accelerated drug approval program and the regulation of artificial intelligence medical devices. Advocates for developing critical new antibiotics back the PASTEUR Act to establish a new funding mechanism to support the development and proper utilization of drugs to fight resistant diseases. There is bi-partisan support for this “subscription” model for new cures, but its estimated cost of $11 billion over 10 years makes it a hard sell.

In past user fee reauthorization campaigns, a deadline to prevent fee expiration encouraged legislators to slip numerous pet proposals into this must-pass legislation. All parties recognized that this year would be much trickier, with a sharply divided Congress heading into mid-term elections and unwilling to agree on much in the policy arena. The short-term budget agreement avoids a government shutdown and funding crisis at FDA, but it dims prospects for enacting controversial or complex new measures.

Articles

FDA keeps its user fees but fails to gain important reforms.

FDA User Fees Reauthorized

Editor of Pharmaceutical Technology Europe

Feliza Mirasol is the science editor for 

In this exclusive Drug Digest video interview, Felicity Thomas and Feliza Mirasol, 

editors, interview experts in solid dosage development and manufacturing. Alex Trombley, oral solid dosage (OSD) process specialist/business development manager of Syntegon, runs through the benefits of continuous OSD production and key considerations for containment and operator safety, while Ali Rajabi-Siahboomi, vice president and chief innovation officer, and Gary Pond, global lead, authentication, both of Colorcon, highlight the importance of authentication at the dose level.

 is Syntegon’s Business Development Manager where he is focused on technical support, customer trials, and market development for Huttlin products in North. Alex is experienced in early phase formulation development, process identification, scale-up, and technology transfer and has worked extensively with continuous manufacturing, high shear granulation, fluid bed granulation, tableting, and coating.

 is the vice president and chief innovation officer at Colorcon, based at the Global Headquarter, USA. Rajabi-Siahboomi has held various academic positions in Nottingham and Liverpool JM Universities in the UK before joining Colorcon as technical director, responsible for Europe, the Middle East, and Africa in 2000. His main research interests are solid dosage form pharmaceutics, pharmaceutical technology with emphasis on oral drug delivery systems, solubility enhancement to improve bioavailbility, and consistency of drugs and bioequivalence formulations. He has published more than 300 articles, book chapters, abstracts, and patents and obtained his B.Pharm. and PhD in pharmacy from the University of Nottingham (UK).

 is the global lead authentication for Colorcon and is responsible for leading the overall strategy, business planning, and operational execution for Colorcon’s on-dose authentication business. Pond has more than 25 years of experience in product management, marketing, operations, and digital transformation, and he is an established leader in on-dose authentication. Prior to Colorcon, Pond held marketing and operational leadership roles at Sanofi, Merck & Co, Abraxis Bioscience, and IQVIA.

This episode of Drug Digest is sponsored by:

Drug Digest is a tech talk video series with the 

 editors, who interview industry experts to discuss the emerging opportunities, obstacles, and advances in the pharmaceutical and biopharmaceutical industry for the research, development, formulation, analysis, upstream and downstream processing, manufacturing, supply chain, and packaging of drug products.

Automating pharma and biopharma processes

Videos

Pharmaceutical Technology editors interview oral solid dosage development experts from Syntegon and Colorcon, with discussions centered on continuous OSD production, containment safety, and authentication at the dose level.

Drug Digest: Advancing OSD: Continuous Production Considerations and Dose-Level Authentication

Grant Playter is the Assistant Editor for 

Cleanroom monitoring is an industry that some reports estimate will be valued at as much as $7.1 billion by 2028 (1). In spite of that massive projected value proposition, however, many questions remain regarding the current (and future) state of the industry. How are recent advances affecting the field? What upcoming changes should we be aware of? Is the industry stable or in flux?

To learn more about the current state of cleanroom monitoring, recent advances in the field, and potential upcoming changes that might impact the industry, 

 spoke with the Alex McDaniel, Environmental Monitoring Program manager, Element; Joe Mundell, chief research officer, Sonicu; and Stephen Tierney, president, XiltriX North America.

When taken together their perspectives provide insight not only into the current state of cleanroom monitoring, but also into changes that may be cresting over the horizon. Topics of discussion include the current state of cleanroom monitoring, recent advances in the industry, upcoming changes, and more.

: Broadly speaking, can you share your thoughts on the current state of cleanroom monitoring? Would you say it is in flux, or a relative state of stability?

: Over the course of the past six years, it has been apparent the current state of cleanroom monitoring is always seemingly in flux. As the industry works to align the methodology, frequency, and validation of a formal environmental monitoring (EM) program, many applicable guidance documents and standards are undergoing revision. This includes 

] General Chapter <797> (2), which is (hopefully) nearing the finish line of its long overdue revision. An increased frequency of surface sampling within the cleanroom suite is anticipated in the 

 <797> revision, in addition to changing the organism identification requirements to be more pragmatic to delivering patient care.

In the current good manufacturing practices sector, the EU Annex 1 revision will emphasize the increasing need for a contamination control strategy, whereas the current version lacks specificity on this. A more consistent and patient-focused approach to EM will be embraced by the industry, as the Annex 1 revisions will impact cleanroom monitoring, especially as it relates to an enhanced focus on conducting a risk assessment of the activities within the facility.

: Cleanroom technology is rapidly evolving as more healthcare and life science customers migrate to the cloud and demand mobile-first solutions that are always on and can be accessed from anywhere. Moreover, clients are looking for monitoring solutions that both integrate with and serve as a multiplier for their BMS/BAS [building management system/building automation system] systems.

: Can you discuss some of the most recent advances in cleanroom monitoring? What makes these technologies fundamentally different from those that came before?

: Some of the recent advances in cleanroom monitoring would be continuous particle counting and measurements, such as volatile organic compounds (VOCs), becoming more and more ‘the norm’. Technologies never fundamentally change because it’s evolution, not revolution. Legislation and regulation would not be able to keep up if it were the latter.

[Increasingly] sensors [are being seen] in a single system. For example, analog magnehelic differential pressure sensors can now be digitally integrated into an [environmental monitoring system] alongside a room’s conditions and particle counters, as well as the equipment stored inside.

: Rapid microbiology has garnered a great deal of interest, yet it remains an unknown quantity and certainly does not look to unseat conventional microbiological testing methods in the near future. The turnaround time for traditional incubation of viable media is its primary pain point, as it takes a minimum of (roughly) a week to 10 days, depending on duration of media dual incubation conditions. This does not include the time microbial identification and reporting takes. Rapid test methods allow for quicker batch release and insight into the state of microbial control, as firms can receive insight into potential growth of bioburden much sooner (some within minutes or hours).

Fundamentally, the validation process for this is not necessarily as straightforward as traditional methods. Guidance documents like 

 <1223> Alternative Microbiological Methods (3) are a good starting point to consult when considering validation of this system. The data comparison is not ‘apples to apples’, as the rapid method employs the use of technologies like ATP [adenosine triphosphate] bioluminescence and viability staining to detect the presence of viable organisms. Rapid forms can cover a wide range of assays, from bioburden of raw materials to sterility confirmation, water monitoring, and active air sampling. However, it is important to ensure that rapid methods are of equal or better quality than traditional testing.

: Has there been any recent changes in what customers want in their environmental monitoring systems? If so, how has the industry changed to accommodate it?

: Data security is continuously becoming more stringent every year. Since the pandemic, life science facilities have been in greater need of remote accessibility; to have full insight into everything going on in a facility, no matter where the staff are located. [Facilities’ operators] want their electronic management systems more integrated with other critical systems like LIMS [laboratory information management system], building management systems, electronic lab notebooks, batch records, asset management, [and so on].

: Along with automation, clients are asking for trended data from their monitoring projects. While trending is a wide-ranging regulatory requirement, it is currently performed via a very manual process. To produce better reports that feature trended data as a standard inclusion, [Element implements and uses] LIMS.

Compressed gas testing is also more frequently requested in the industry. Including secondary points, such line drops within the building that are not routinely monitored, can provide a holistic diagnosis of how the entire system is performing versus a fragmented approach of selecting only certain locations. [It is expected that there will be a] significant increase in this [request] moving forward, especially in terms of validating a previously installed system.

Within the next several years, the momentum will likely swing towards systems that can provide continuous and automated sample collection during a production run. Some processes are still performed in a very manual way and require a great deal of human intervention, from differential pressure monitoring, temperature, and humidity data, or non-viables. Some manufacturers of monitoring devices are also developing viable particle counting units to provide real-time data of colony forming unit (cfu) counts with the use of laser technology similarly used for non-viable particle count testing.

: As the EU GMP Annex 1 revisions edge closer to publication, what changes, if any, will this make to environmental monitoring specifically? If we’re anticipating significant change, what future-proofing (if any) are you seeing in customer orders?

: There is an increased onus on manufacturers to implement and document a contamination control strategy and a vigorous risk assessment within the pharmaceutical quality system. Manufacturers may need to completely overhaul their program to include additional sampling locations if a formal monitoring program was not previously established, or the original program was not updated to reflect current processes or was based upon previous facility designs. An increase in EM performance qualifications conducted on existing cleanroom areas to align with an updated and more modern approach to the documented risk assessment [is expected].

Given the push to take a comprehensive look at processes to identify failure points and consequences of those failures in the upcoming Annex 1, using the failure mode and effects analysis (FMEA) tool has worked out well for clients looking to future-proof their risk assessments.

: Do you have any final thoughts on the topic that you can share with our readers?

: [A] greater attention from larger healthcare systems to include air pressure differential and humidity as well as O2, CO2, and VOCs [is being witnessed]. Infection control experts are driving the conversation as part of their risk management focus while construction firms are being consulted on both new build and retrofit projects to work collaboratively on these projects. [Additionally, a] significant demand relative to pre-COVID [is being seen] and [this is] expected to continue accelerating.

: [From personal experience, it is apparent that] critical gaps within an operation may not be identified until it is too late. Downtime can be eliminated, back-end costs reduced, and production lines will stay in operation if those within the industry tasked with maintaining compliance to these standards establish documented protocols in partnership with a subject matter expert (SME) and team of microbiologists.

As professionals, [there is] a responsibility to seek out continual education, as well as educate others in the industry. Establishing a partnership with a collaborative organization with a consultative team invested in teaching others is vital to staying on top of these dynamic requirements—and that is only the beginning. Selecting a firm that has a robust scope of service offerings and quality procedures that can look at processes, provide a gap analysis, establish methods to help mitigate contamination control before it becomes problematic, and even assist in validating a cleaning and disinfection program is a gamechanger when the FDA walks through the door.

USP, General Chapter <797>, “Pharmaceutical Compounding—Sterile Preparations,” 

USP, General Chapter <1223>, “Alternative Microbiological Methods,” 

Grant Playter is the Assistant Editor at Pharmaceutical Technology.

Recent technological advancements may have put cleanroom monitoring into a state of flux.

Environmental Monitoring Advances

Cynthia A. Challener is a contributing editor to Pharmaceutical Technology.

Viral vectors must be free of contaminants, such as adventitious viruses introduced via raw materials and helper viruses introduced purposefully to stimulate expression of the desired viral product. Viral clearance used with incoming raw materials and, where possible, viral-vector products combined with testing is essential. Because conventional viral clearance methods used for protein biologics may degrade or destroy viral vectors, assessment of the potential risk for contamination and the implementation of prevention and control strategies are essential.

The most common source of viral contamination is usually traced back to animal-derived raw materials, such as certain cell-culture media (e.g., serum) and trypsin, according to Artur Padzik, adeno-associated virus (AAV) production manager at Biovian, a contract development and manufacturing organization (CDMO). Non-animal-derived raw materials can be an issue as well, particularly glucose if a chemically defined medium is used. A risk-based approach to process development combined with extensive testing of raw materials (and often the application of virus removal steps at raw material entry points), in-process materials, and final products is essential to ensuring the safety of viral vectors.

Similar to other biologics but challenging

The requirements for adventitious agent testing for viral vectors overall are consistent with those performed for other biological therapeutic products. As with other biologics, too, selection of appropriate testing methods is guided by the need to mitigate the risk of viral contamination taking into account the materials and processes used.

“Viral vectors are biologics, and as with all biologics, the concern around adventitious agents must be addressed with a thorough risk assessment that [considers] control and probability of contamination. The principals from the three-pronged complementary core strategy (material selection, testing, and clearance assessment) to prevent and minimize adventitious agents can and should be applied to viral vector manufacturing processes and products,” says Audrey Chang, executive director, Rightsource and Biologics at Charles River.

Direct adoption of strategies used for recombinant proteins and monoclonal antibodies may not be possible, however, Chang adds, due to biological differences between viral vectors and large protein molecules. Indeed, it may be necessary to modify standard assays or use alternative methods because viral vectors are viruses themselves and could interfere with virus detection methods, notes Leyla Diaz, a technical consultant in the Technical and Scientific Solutions unit of MilliporeSigma.

Specifically, adventitious agent detection can be challenging if cell-based assays are being used in combination with live-virus vaccines, replication-competent gene therapy vectors, or vectors exhibiting the cytopathic effect (CPE), Padzik observes. This issue arises largely because human cell lines are used for cell-based assays, and human cells are susceptible to human viruses. Lytic viruses such as adenoviral products, for example, will infect human and primate-based cells and can cause invalid assays. Robert Schrock, director of bioassay services at Lonza Houston, adds that even if adenovirus is only conditionally replicating and does not replicate, cellular toxicity may occur.

In these cases, neutralization of interfering and abundant product viruses is required, says Padzik. There are three approaches that can be taken, according to Schrock. One is to block antibodies specific to the virus product to “soak up” the product as much as possible without interfering with the detection of other adventitious viruses. Alternatively, the sample can be diluted so as to avoid overwhelming the detection cells. Often these two approaches are used in combination. The third option is to pull the test sample from an uninfected parallel satellite culture that is split off the bioreactor just prior to transduction with the virus bank. “For oncolytic vectors, FDA guidance mentions the use of #3 as acceptable. The first two have limitations, such as with test #2, where the value of the test can rapidly decline due to sample dilution,” Schrock comments.

In general, the key is to select the appropriate test method for a given product. For example, Sophia Nguyen, director and head of quality control at Lonza Houston, points to the selection of cell lines for infectivity assays as being important. “Viruses differ in their ability to infect host cell types.” For the endpoint assay used to determine whether a host cell is infected with a virus, a monolayer culture is preferable to a semi-adherent or suspension culture. With the former, CPE and hemadsorption (HAd) can be visualized by microscopy, making the analysis relevant both to viral detection and subsequent viral identification.

The plethora of potentially contaminating sources arising from the complexity of the viral-vector production process favors a holistic scheme for adventitious agent testing, according to Padzik. In this approach, both general and species-specific assays are used.

Adventitious virus detection assays, explains Nguyen, mostly fall into three testing categories: cell-culture-based infectivity assays, targeted nucleic acid-based amplification, and antibody production tests. Both in vitro cell-culture detection methods and in vivo assays are employed. No universal method is available to detect all adventitious agents, and therefore various complementary methods must be used. “There is a clear tendency, however, to move away from assays that require animal models toward assays with higher sensitivity, specificity, and rapid turnover, such as polymerase chain reaction (PCR),” Padzik remarks.

In vitro cell-based detection methods are typically broad-spectrum and intended to detect viruses that are able to replicate in cell lines—a human diploid cell line, a non-human primate cell line, and a cell line of the same species as the one used to produce the vector, Diaz observes. In vivo, animal-based detection methods are also broad-spectrum and intended to detect viruses that replicate in animal models—typically mice and embryonated eggs, but also other animal species based on specific risks associated with the product being tested.

With these non-specific 14- and 28-day adventitious agent tests, CPE or haemagglutination and HAd values serve as the readouts. The obvious limitation, notes Padzik, is the difficulty in detecting adventitious viruses that do not cause CPE. The limits of detection for these assays can also be an issue. Padzik says a partial remedy, but with limited sensitivity, is the use of transmission electron microscopy (TEM) to detect, for example, retroviruses. XC plaque, S+L focus assays, co-cultivation assays, or fluorescent product enhanced reverse transcriptase (FPERT) testing are also commonly used to detect retroviruses.

Molecular methods such as PCR tests are used to detect specific viruses that are either not detectable by other methods or that are emerging as particular biosafety concerns, according to Diaz. Known contaminating entities, including porcine and bovine viruses, minute virus of mice, vesivirus, rhabdovirus, polyomavirus SV40, and arboviruses for various animal and insect cells are addressed with PCR-based specific assays, Padzik says. PCR-based methods that can detect virus families rather than specific viruses are also being employed. They are also used to detect mycoplasma, spiroplasma, mycobacterium species, and mice DNA sequences, according to Nguyen.

Nguyen stresses that each method exhibits a different level of sensitivity, and the testing requirements and sample preparation protocols differ as well. It is imperative, therefore, to select the appropriate test for each vector product.

Adventitious agent testing of raw materials should be proportional to the risk posed by the raw materials, and the testing methods chosen based on such an assessment, states Horst Ruppach, executive director, scientific and portfolio global biologics for Charles River.

The most common methods of adventitious agent testing for raw materials are cell-culture-based assays using specific indicator cell lines, with Vero cells preferable because they can detect viruses from all sources, according to Nguyen. The added risk for introducing animal viruses posed by animal-derived components requires the use of sensitive cell-based assays that can detect replicating infectious viruses, Ruppach adds.

PCR-based methods are also used depending on the raw material and turnaround requirements. It is important to recognize, though, Ruppach stresses, that while using molecular methods can be advantageous due to their speed, they do not discern between a nucleic acid positive signal and an actively replicating virus.

Viral vectors produced to modify cells for the production of ex vivo cell therapies have some additional raw material concerns with respect to adventitious agents. Human serum albumin (HSA), a commonly used excipient for cell therapies, is a high-risk material with respect to virus and prion transmission, but there is no practical assay for direct prion testing, according to Ruppach. “Here, special emphasis must be placed on HSA donor screening and the manufacturing process in order to mitigate the risk of virus and prion transmission,” he says.

In addition, Ruppach notes that for gene-modified cell therapies, the viral vector is considered a critical raw material, and the same three-pronged complementary core strategy involving material selection, testing, and clearance assessment should be applied to mitigate the introduction of adventitious agents into the final cell therapy product.

Allogeneic, off-the-shelf cell therapies in which the cells used to produce ex vivo-modified cell products are derived from multiple human donors are worth a special mention, according to Diaz. They require a carefully derived risk-mitigation strategy, because each donor contributes a separate, individual virus risk to the product. “Upfront donor screening plays a large role in the development of a strategy that can mitigate the risk of virus contamination of these cell-based therapeutic products,” she states. In addition to normally performed adventitious agent product testing, it may be necessary to also perform additional virus testing to address potential risks associated with a specific set of donors or even a specific geography.

While traditional in vivo and in vitro methods for adventitious agent testing of viral vectors are sufficient to ensure the production of safe and effective products, they do suffer from some limitations, including sensitivity, the time required to perform the assays, throughput, and the detection of unknown contaminants, according to Padzik.

“Delivery times of adventitious virus test results have always been a serious challenge regardless of the method used, with some of them taking four to five weeks, and up to a few months with full analysis and documentation,” Padzik observes. For some gene therapy products that have a short shelf life, Diaz notes that these lengthy periods can be prohibitive. This concern is particularly relevant for autologous gene-modified cell therapies that must be administered to patients shortly after production. Molecular methods are being used to fill this gap, in particular PCR-based methods are being fine-tuned or developed to fill this need.

“The growing scope of required assays is creating continuous pressure, especially on early-stage clinical projects where results from the first human clinical studies are pivotal in securing the funding for full clinical medicine development,” Padzik adds.

“A partial solution could be a new pan-microbial microarray comprising 29,455 sixty-mer oligonucleotide probes for screening on a single chip vertebrate viruses, bacteria, fungi, and parasites,” Padzik comments. He cautions, though, that PCR-based methods are not able to help with the recognition of undefined adventitious agents and they suffer from noticeable instances of false positive cases.

Sample volume is another concern, particularly for viral vectors used in gene-therapy products. “Depending on the scale of vector production, adventitious virus testing can take up a significant amount of volume that could be otherwise used for patient dosing,” Diaz explains. This issue is of particular concern in early stages of product development before a production scale-up strategy has been implemented.

Nguyen reiterates that the different methods used for adventitious agent testing have different sensitivities for the detection of different contaminants and limitations. “These methods are intended to complement each other to provide a greater understanding of the detection of adventitious agents. In addition, the methods also have specific pharmacopeial and regulatory requirements/guidelines, such as sampling size. As always, these requirements must be considered when establishing a testing strategy,” she contends.

Tried-and-true test methods such as in vivo and in vitro virus assays and mycoplasma culture and microbiology culture assays have been used to demonstrate the biosafety of biologics for decades and can be applied in viral-vector manufacturing for certain steps such as cell-line and viral-seed-stock characterization, Ruppach emphasizes. During the past few years, adds Nguyen, understanding and methodologies have evolved significantly for adventitious agent testing, and Lonza believes this trend will continue to accelerate.

Given the limitations of existing methods and the advances being made in molecular-based methods, Ruppach expects the eventually the industry will switch to molecular test methods and rapid alternatives such mycoplasma PCR and rapid microbiological testing.

NGS-based assays are attractive for a number of reasons. The biopharma industry is focusing on using the full potential of NGS for adventitious testing requirements due to its low turnaround time in particular, according to Nguyen. The other main reason NGS is attractive is its ability to detect unknown contaminants, says Padzik. NGS can also be used to detect low-level known virus DNA/RNA sequences, according to Schrock. Identification will, of course, still require a comprehensive library of known and potential viral genomic sequences, and verification will be necessary by comparing results to those obtained using established methods.

In addition to these technical benefits, rapid NGS development has the potential to reduce costs and increase accessibility. “These advantages are driving significant interest and the urgency within the industry to validate this technique so that it can be swiftly implemented and applied for routine use,” Padzik remarks. The Advanced Virus Detection Technology Interest Group (AVDTIG) is an industry-based organization facilitating the exchange of experiences with the development of NGS-based assays to accelerate the introduction of practical solutions.

For Ruppach, one of the main challenges to effective viral-vector adventitious agent testing today is the resistance to new analytical methods. “There are several barriers to the adoption of new techniques such as NGS, including fear of regulatory delays, the risk associated with changing platforms, the resources (financial, personnel, time) needed, the tendency within the biopharma industry to be more focused on the short-term and less on the long-term, and the hesitancy to share information and desire to protect company trade secrets,” he explains.

“While all are valid reasons, it is essential to develop and share data that will support progress in the NGS field,” Ruppach says. He points specifically to the need for reference standards that will allow sharing of data obtained during development, comparability studies, validation and re-validation, technical transfer and assay trending, and ultimately the design of appropriate bridging studies that will enable translation to commercial application.

“Switching to rapid methods for adventitious agent testing must be done carefully, taking into consideration the fact that viral-vector manufacturing processes offer limited viral clearance steps,” states Ruppach. “Certainly, new alternatives such as NGS have applicability for viral assessment,” he adds. Padzik is hopeful as well. “The requests for using unbiased NGS are significantly increasing, especially in vaccine development. The current COVID-19 pandemic accelerated this transition even further,” he comments.

Ruppach also observes that a revision to International Council for Harmonisation (ICH) Q5A Quality of Biotechnological Products: Viral Safety Evaluation of Biotechnology Products Derived from Cell Lines of Human or Animal Origin is currently in the works and expected to include updated guidance to reflect updated scientific knowledge and advances in analytical technologies for new modalities, including viral vectors. For Padzik, the changing regulatory landscape and pressure to reduce animal testing are important drivers for NGS adoption, along with the apparent increasing acceptance of NGS-based assays in vaccines and other products where contaminating virus detection by the classical test is difficult and vaccine release is time-sensitive. “It is possible to envision gradual supplementation and, ultimately, the replacement of in vivo and other nucleic-acid technologies by NGS,” he concludes.

Taking a holistic view is the best strategy

“For most virus-based vaccines and viral vectors, the removal of contaminating viruses is not feasible, so the prevention and detection of virus contamination become more critical in a virus risk mitigation strategy,” emphasizes Diaz.

Although the principles used for adventitious agent testing of monoclonal antibodies (mAbs) apply to viral vectors, it is certainly not a “plug-and-play situation”, according to Chang. She stresses that a holistic view of the product, manufacturing, and ultimate use of the viral vector must be taken into account when performing risk assessments and establishing risk-control strategies.

For instance, the batch size for viral vectors is different from that for mAbs, with only a small number of doses produced per batch. In addition, some aspects of viral-vector manufacturing, such as the level of empty capsid production and consequent impact to the patient, are not fully understood. “Furthermore,” says Chang, “it is not possible to introduce robust viral removal/inactivation steps that exist with antibody manufacturing. Therefore, closer characterization of the starting raw materials, including biological characterization that assesses adventitious agents thoroughly, is prudent.”

Diaz agrees that an effective adventitious agent testing strategy starts with an appropriate risk assessment that evaluates all possible sources of virus contamination, including cell banks, virus seeds, plasmids, media, and other substances used in production. The risk assessment should also include identification of any steps in the manufacturing process (upstream and downstream) where virus contamination could be introduced.

“Evaluating the manufacturing components and processes for their contribution to the virus contamination risk allows for a multi-pronged approach that includes appropriate sourcing of materials, the selection of relevant virus detection methods for the risks identified, and the potential removal of contaminants associated with specific viruses in downstream processes,” Diaz summarizes.

There are several key aspects of any strategy for adventitious agent testing, according to Nguyen. Appropriate testing regimens must be included that monitor the possible introduction of adventitious agents. These methods must be suitably sensitive or use indicator cell lines or animal models in which a specific viral entity is known to replicate. The potential for matrix interference must be avoided; spiking of the test sample matrix with a positive control virus enables assessment of potential interference and the limit of detection of the method. “As a general rule of thumb,” she says, “the assays should be sufficiently developed with the appropriate set of predetermined system suitability and acceptance criteria, including relevant positive and negative controls, and fully established before validation.”

Cynthia A. Challener, PhD, is a contributing editor to 

Production of viral vectors requires a holistic view of the product, including its manufacturing process and its ultimate end use.

Testing for Adventitious Agents in Viral Vector Production

Cue Biopharma, a clinical-stage biopharmaceutical company focused on injectable biologics designed to selectively target tumor-specific T cells directly within a patient’s body, announced on Oct. 4, 2022 that FDA has granted Fast Track designation to CUE-101 for the treatment of patients with human papilloma virus (HPV16+) recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) as a monotherapy and in combination with KEYTRUDA (pembrolizumab).

Fast Track is a process designed to facilitate the development and expedite the review of drug candidates to treat serious conditions and fulfill an unmet medical need. Therapeutic candidates with Fast Track designation may be eligible for accelerated approval and priority review if supported by clinical data.

CUE-101 is currently being evaluated in a Phase Ib trial as a monotherapy for the treatment of second line and beyond patients with HPV16+ R/M HNSCC and as a first-line treatment in a Phase I dose escalation and expansion trial in combination with pembrolizumab for the same patient population.

“We are very pleased to have received Fast Track designation from the FDA for CUE-101. This designation not only underscores the large unmet need for patients with R/M head and neck cancer who currently rely on available non-targeted therapies, but also highlights the potential of CUE-101 to provide a significant clinical benefit,” said Matteo Levisetti, senior vice-president, clinical development of Cue Biopharma, in a company press release. “To date in its Phase Ib clinical trials, CUE-101 has demonstrated a favorable tolerability profile and single-agent anti-tumor activity in monotherapy as well as encouraging anti-tumor clinical activity in combination with pembrolizumab, supporting the potential to improve overall survival for these patients. We look forward to providing periodic updates and remain committed to advancing the development of CUE-101 to provide patients with a potentially more effective and better tolerated treatment option. We anticipate initiating a registrational trial for CUE-101 monotherapy by mid-2023.”

FDA has granted Fast Track designation for CUE-101, a treatment of recurrent/metastatic head and neck squamous cell carcinoma. 

FDA Grants Fast Track Designation to Cue Biopharma

Pfizer announced on Oct. 3, 2022 that it has completed its acquisition of Biohaven Pharmaceuticals, the maker of NURTEC ODT (rimegepant), a migraine therapy approved for both acute treatment and prevention of episodic migraine in adults.

The acquisition adds a calcitonin gene-related peptide (CGRP) portfolio to Pfizer, including rimegepant, zavegepant, and a portfolio of pre-clinical CGRP assets. Pfizer has acquired all outstanding shares of Biohaven not already owned by Pfizer for $149.50 per share, for a total cost of approximately $11.6 billion. Biohaven is now a wholly-owned subsidiary of Pfizer.

Immediately prior to the closing of the acquisition Biohaven completed the spin-off of a new Biohaven company that retained the company’s non-CGRP development stage pipeline compounds, Kv7 ion channel activators, glutamate modulation, myostatin inhibition platforms, preclinical product candidates, and certain corporate infrastructure assets excluded from the Pfizer acquisition. Pfizer owns approximately 3% of the new Biohaven company.

"We are proud to build on Pfizer’s legacy of delivering breakthrough medicines for patients living with complex pain disorders,” said Aamir Malik, executive vice-president, chief business innovation officer, Pfizer, in a company press release. “The success of NURTEC ODT coupled with Biohaven’s CGRP pipeline will strengthen Pfizer’s innovative Internal Medicine pipeline through 2030, and beyond. Combined with Pfizer’s global reach, this acquisition increases our potential to bring new treatment options to patients with migraine – a disease which affects over 1 billion people worldwide.”

Pfizer has completed its acquisition of Biohaven Pharmaceuticals for approximately $11.6 billion.

Pfizer Completes Acquisition of Biohaven Pharmaceuticals

Meg Rivers is the former senior editor for 


Drug delivery has grown in leaps and bounds in recent decades, including growth in administration methods, therapeutic formulation, and delivery systems. David Bunka, chief technical officer, Aptamer Group, joins Meg Rivers, senior editor, for a deep dive into Optimers (optimized aptamers). Bunka discusses some of the key differences between Optimer drug conjugates and antibody-drug conjugates (ADCs), such as their properties, how they are created, and potential immune responses. He also shares how Optimers can target malignant cells without prior knowledge of specific biomarkers, the scalability capabilities of Optimers due to their chemistry/being synthetically manufactured, and what long-term safety could look like.

David Bunka, chief technical officer and co-founder of Aptamer Group

, holds a PhD in molecular biology and has spent nearly 20 years developing nucleic acid aptamers against a wide variety of targets including small molecules (i.e., antibiotics, food contaminants, chemotherapeutics), disease-associated proteins, several cancer-associated cell-lines, viruses, and tissue biopsies. This work has been facilitated using high-throughput, automated aptamer selection methods. Bunka has built up an established international reputation in the field and has authored several peer-reviewed research articles, invited review articles, and a book chapter on aptamer-based therapeutics. He has also given many guest seminars covering aptamer-based applications at top universities and international conferences.

 presents the Drug Solutions podcast, where the editors will chat with industry experts from across the pharmaceutical and biopharmaceutical supply chain. Join us as experts share insights into your biggest questions—from the technologies, to strategies, to regulations related to the development and manufacture of drug products.

Podcasts

An expert from Aptamer Group reveals the potential of Optimers (a type of aptamer) in the realm of drug delivery, including its targeting capabilities, scalability, and key differences between Optimers and antibody-drug conjugates. 

Drug Solutions Podcast: Drug Delivery Systems: Optimer’s Therapeutic Targeting and Scaling Capabilities vs. ADCs

While the debate between stainless steel and single-use systems (SUS) will continue to rage for the foreseeable future, most would agree that there is a time and place for either approach. Naturally, however, this raises the question: when is it ideal to utilize an SUS approach? What advantages does it confer? How are they being used in the current manufacturing environment?

spoke with SUS experts Nick Johnson, director of Product Management, Biopharma, CPC, Wolfgang Walcher, chief commercial officer, Single Use Support; and Helene Pora, vice-president, Technical Communication & Regulatory Strategy, Pall, to get their perspective on the current benefits of single-use systems.

Can you share your thoughts, broadly speaking, on the merits of single-use systems, consumables, etc., in manufacturing? Is there any aspect that you feel is under or over-emphasized in this discussion?

 Think about the flexibility single-use systems allowed during the pandemic. Manufacturers urgently reallocated new therapy and other capacities to commercial vaccine production. The capability to quickly switch from one kind of production to another is a huge benefit that SUS affords in everyday practice. Single-use technologies (SUT) definitely contribute to speed and efficiency by allowing multiple products to be produced in one manufacturing suite with relative ease.

SUT’s flexibility and sterility also has made it simpler to ‘fail fast’ in clinical trials, too, compared to traditional stainless steel. The impact on bioprocessing from early-stage development through commercial manufacture has been an industry game changer.

 SUS offer a level of flexibility, scalability, and cleanliness that is near impossible to achieve with glass and stainless-steel counterparts. Lines can be repurposed more easily, and there is no need for cleaning and cleaning validation. This saves a great deal of time and money while making the process safer for operators. SUS can also reduce the time to build a plant and lower overall capital expenses. And from an environmental perspective, there is a lower carbon footprint, less water, and less chemicals despite higher solid plastic waste.

Unfortunately, the amount of solid waste is frequently overstated compared to the benefits. In 2020, ISPE released a review showing that SUS is responsible for .01% of all global plastic waste, which is largely driven by consumers. This does not mean that the industry does not see the use of plastic as a problem—we are actively investing in recyclability and overall process impacts—however, it does not deserve the level of criticism it gets.

: Single-use systems are trending for a reason:

They help to improve safety, cost-efficiency, and sustainability in comparison with the use of durable stainless-steel manufacturing facilities.

With single-use assemblies, bioprocess containers, and other sterile consumables operators can transfer liquids in closed systems and as customized options.

They are adaptable to changing requirements of system setups.

Usually, the systems are designed to minimize manual interventions, thus preventing human errors which can result in quarantined or even rejected batches.

The most under-emphasized aspect is probably sustainability. Different life-cycle assessment studies have proven that single-use systems can be more sustainable than stainless-steel solutions (1). However, there is still room for improvement, and we’ll drive innovation to further improve sustainability in the pharmaceutical industry.

What are the costs of using single-use systems, consumables, etc.? What factors should be considered when deciding whether or not to employ them?

 There are different factors that come into play to influence costs of single-use systems because of the wide range of consumables on the market, which offers a wide span of prices.

The answer is strongly dependent on the application/use of single use systems. For example, in API primary packaging the alternative to single use systems is shipping hundreds of kilograms of cryo-vessels worth millions of dollars and causing tons of CO2 [carbon dioxide] emissions; alternatively, SUS, like bags, are low at cost, easy to store, and safe to ship.

For other applications, [such as] sampling or bioprocess containers, it is a question of flexibility, and people forget that stainless-steel multi-use vessels require a high amount of resources—producing, repairing and maintenance, cooling, etc. 

: Ease of use, flexibility, reliable sterility, production efficiency—these are all factors to be considered. Thanks to SUT, it’s economically feasible to manufacture therapies for diseases that affect small patient populations that have the kinds of numbers that might not justify an investment in a traditional stainless-steel operation.

Modular, purpose-built SUS can be optimized for specific processes so they’re ready when needed. The production suite can be changed over quickly to accommodate the next process. There’s no downtime between production runs because SUS don’t require cleaning or equipment requalification in between batches. The ability of SUS to eliminate the risk of cross-contamination between processes is significant. All of this contributes to more streamlined operations.

Also, SUT is the most cost-effective way for manufacturers to make a wide range of drugs from vaccines, to mAbs [monoclonal antibodies], to cell and gene therapies.

SUS are priced more affordably than traditional equipment. However, SUS require bags and connectors that will generate consumable costs over the life of each process. The cost of consumables and security of supply is very important to consider. Working with trusted suppliers that have taken steps to secure sourcing is paramount in today’s market.

It is, of course, important to consider batch size and the number of batches that will be needed per year. With size constraints usually hovering around 2000 L, any high-volume drug would require a parallel processing approach. And whether the plant will be multi-product or single product is also critical.

Though it can be argued that the ability to changeover is only valuable if it is needed, it is always a smart investment. Having the flexibility, even in a single product environment, is a good backup if anything were to go wrong (e.g., clinical failure) along the way to commercialization.

What trends have you seen occurring as it pertains to single-use manufacturing? Do you anticipate them continuing for the foreseeable future, or is the end in sight?

If you looked back a decade ago, the discussion was still, ‘will this work?’ We are so far past that now, and SUS have helped to enable an era of innovation in this industry that is unmatched. We see a diverse range of modalities, which continues to grow, and a move towards more efficacious or even curative products.

The technologies needed to support the continuous high growth projections in the industry will rely on SUS in many cases. As we’ve seen through the pandemic, SUS not only enable innovation, but they allow for the type of rapid response needed for vaccines. Undoubtedly, the COVID-19 vaccines would not have been introduced and produced so quickly without SUS.

The growth may not be as high as we have seen throughout the last two years of the pandemic, but it will continue. A new product mix with an emphasis on biologicals and smaller indications will keep that demand growing over time. We also cannot ignore that SUS will be the backbone of existing processes (pending the patient population), creating sustainable demand in those areas.

Additionally, the scope of SUS use is continuing to expand, with more critical applications than ever before like formulation and final filling.

SUS will play a vital role in pharmaceutical and biopharmaceutical manufacturing and supply chain in future. The more personal medicines and low volume high potency medication (e.g., gene therapeutics, mRNA [messenger RNA], small interfering RNA, etc.) is progressing, the more important single use system will be. Challenges [such as] recycling of single-use systems will be solved in the near future and [will], therefore, significantly improve the environmental sustainability and CO2 footprints of systems used.

: Most new and upgraded contract development and manufacturing organizations, contract manufacturing organizations, and biopharma companies are incorporating single-use bioprocessing equipment. That’s the way the industry has been moving and will continue to go.

From a big-picture standpoint, it might take five to seven years from groundbreaking to a qualified facility using stainless steel. In contrast, a SUS-based facility might require two to three years. Then, after a facility is operational, SUS allow biomanufacturers to process multiple drugs simultaneously in one space or make rapid equipment changeovers between production runs without compromising sterility. That push for efficiency and modularity within and across sites is a driver.

There’s strong interest in standardizing SUT, which begins with components purchased from SUS equipment suppliers. The same equipment, standard operating procedures, and a shared supply chain create efficiency. SUS components also will need to work in automated equipment as the industry moves away from reliance on operators toward automatic processes.

Are there any unique use cases for single-use consumables, systems, etc. that you have experienced in the industry?

: The SUS component industry is catching up a bit to create solutions specifically for small-bore tubing in small-volume work—applications [such as] sampling, seed train expansion, analytical processing, buffer/media transfers, and early cell-culture processes involving shaker flasks and rocker tables.

A growing number of companies are now engaged in small-volume (< 10 L) aseptic processes, such as early-stage drug development. You’ll also see very small volumes in cell therapy, for example, where cell availability is limited or media is expensive, and in the development of small-batch autologous therapies.

In the past, making reliable sterile connections in these smaller aseptic processes was typically handled using biosafety cabinets or tube welding. But biosafety cabinets can only handle a limited number of processes at one time. Tube welding is labor intensive, and the equipment is expensive—easily $15,000 or more per welder—and takes up valuable cleanroom space. Small companies with limited resources may not have the capital to purchase tube welders.

Until recently, tube welding was the only option for creating sterile closed systems at small volumes. Now there are single-use aseptic micro-connectors designed to sterilely connect small-bore tubing, so that’s new to the industry. Aseptic connections with new micro connectors can be completed in three steps and up to four times faster than an operator using tube welding, which can require a dozen steps or more to get a successful weld.

Also, in our line of work—connection technologies—there’s never been a genderless connector that can both connect and disconnect tubing using one product in bioprocessing until this past spring. Users appreciate genderless products because they’re more convenient. They eliminate mating complexity, reduce inventory requirements, simplify system design and reduce operator error. That genderless convenience factor was taken up a notch by creating a product that connects and disconnects aseptically without the need for ancillary equipment.

: Initially the use of SUS was focused on providing a solution for media and buffer preparation and handling. Over the last decade, we can now leverage the benefit of SUS throughout the process and even into the final filling applications. The use here is very functional—we only use exactly what we need, which is another part of how we keep the volume of waste minimized.

: There is a broad application of SUS established, so you will find all (even exotic) applications of SUS in the industry.

While the broader effects of the COVID-19 pandemic have lessened in public discourse, the supply chain interruptions it brought on remain a concern. Can you discuss the impact this has had on manufacturing? How would a mass return to the just-in-time (JIT) delivery model shift the current landscape?

The industry wasn’t prepared for such a supply chain challenge. The shortages have jeopardized business continuity of major manufacturing sites apart from COVID-19.

The shortage of SUS has therefore made biopharmaceutical manufacturers reflect on their relationship with suppliers. It has shown that it is crucial to have reliable partners, to plan ahead, and to establish reliable forecasts. Suppliers can react accordingly by building stock and procuring it early. Manufacturers and suppliers need a common understanding and common standards across the industry with respect to equipment and consumable design, as this enhances delivery speed.

A JIT delivery model in the pharmaceutical industry needs suppliers who rethink supplier relationships by offering solutions [such as] supplier agnostic solutions for flexibility or various business continuity measures to allow fast delivery times.

From a supplier perspective, it has driven us to significantly increase our manufacturing footprint and take deeper steps internally to secure our supply chain. Just about a year ago, Danaher announced an investment of $1.5 billion into the Cytiva and Pall lines of business (2). Over $300 million of that has been dedicated to strengthening the SUS line of business. Even as we start to realize some of the benefits of these investments, we remain committed to honing an agile approach to business processes standardization in parallel with our daily activities.

There will be a tradeoff for every approach. JIT will be largely dependent on the capability of biomanufacturers to produce accurate forecasts. While this can be achieved to a certain level with commercial products, it will remain very difficult for clinical manufacturing. Therefore, JIT delivery will be a combination of demand and how much some form of standardization is achieved, together with improved forecasting practices. It will still take some time to reach that level after the pandemic. The goal is really to more reliable and reproducible lead times, regardless of the model.

: From a supply-chain perspective, there’s no question that COVID-19 has disrupted everything from obtaining raw materials used to create components to the ability to ship sterilized equipment in a timely way. This isn’t exclusive to SUS, but it’s had an impact throughout the supply chain.

Supply-chain considerations are especially important when selecting suppliers of single-use assemblies. That’s because no supplier of single-use assemblies manufactures all of the products used in that assembly. For example, the manufacturer of a single-use mixer bag probably sourced the aseptic connectors, tubing, tubing clamps, T or Y connectors, filter capsules, etc., from other companies. Each of those component suppliers has a supply chain that may comprise sub-component suppliers, external assemblers, raw material suppliers, contract manufacturers, and so on. You can see that the SUS supply chain is multi-tiered and complex; the ability of the SUS manufacturer to supply product is 100% dependent upon the robustness of the entire supply chain.

Enhancing sustainability in the pharma industry

Experts outline the benefits of single-use consumables relative to traditional approaches.