Closed-System Connections in Monoclonal Antibodies R&D for Cancer
Todd Andrews,
Bioprocessing Global Sales & Business Development Manager
CPC

Monoclonal antibodies (mAb) is projected to exhibit profitable growth in the biotech industry of up to USD 138.6 billion by 2024. As a major class of emerging therapeutics for several human diseases, the surging incidence of cancer is the key contributing factor for the growth of the mAbs vertical, particular in Asia Pacific due to increasing government support in the region.

This article discusses the role closed-system connections play in eliminating contamination during R & D of cell culture applications such as mAb.


World Health Organization reveals that the number of patients diagnosed with cancer is expected to see a global spike by over 70% in the next two decades. Specifically in India, this spike will result in a 25% increase in new cases by 2020, of which breast, lung and cervix cancers are the most prevalent causes of fatality. With greater government support from the region, the rising incidence of cancer as well as a variety of chronic diseases drove a steady demand in Asia Pacific for monoclonal antibodies - a biological therapy used to restore the immune systems of patients by targeting affected areas to destroy diseased cells. According to a recent study by Transparency Market Research, the global monoclonal antibodies therapeutics market is projected to worth over USD 245.8 billion by 2024, a huge growth from USD 86.7 billion in 2015. In order to effectively capture a share of this thriving market, researchers must attain quality findings to develop monoclonal antibodies in the most cost-efficient ways.

However, researchers are constantly facing two critical forms of contamination during their daily lab tests which hinder their pursuit for quality findings: biological contamination and cross-contamination. Biological contamination includes competitive organisms such as bacteria, fungi and yeasts that are inadvertently introduced into cell culture processes. These organisms utilize culture nutrients, produce unwanted proteins and limit growth or destroy the intended cell culture. Most biological contaminations result in rapid growth and observable culture changes that indicate a culture must be discarded. However, slow growing contaminations can be subtle and may only become apparent when unwanted proteins are detected. In either case, biological contaminations are costly both in wasted time and materials.

Cross-contamination occurs when protein residues from cell culture and processing equipment is reused without proper sanitation. These residual proteins might inhibit proper cell growth or, if they are structurally and chemically similar to the target protein, they pass through purification with the target protein and yield inconsistent results. The systems and connectors used in R&D and process development of cell culture applications play a critical role in determining the efficacy of systems adopted to protect against both biological and crosscontamination.

Creating the Optimum Research Environment

welders or open systems using luer fittings are commonly used. However, they do not necessarily have the flexibility required of today's research environment to allow onthe- fly changes during cell culture, even more so now with the rising demand for monoclonal antibodies therapeutics.

Tube welders may work well for some R&D scale applications, but are expensive to purchase and maintain, and typically takes longer time to install. Additionally, they do not work with silicone tubing, and may experience difficulties operating in tight spaces. Breakthrough in sterile connections have made singleuse connectors designed for smallscale connections a great alternative to tube welders. They offer a robust construction, ensuring repeatable and reliable performance in the 1/8" to 1/4" ID connection range with no additional hardware required. For instance, the genderless AseptiQuik® S is designed to offer a lightweight, cost-effective option for sterile connections which can withstand pressures in high vibration applications, giving an edge over tube welders that will rupture under the same conditions.

Male-to-female connections like luer fittings and quick connects require more part numbers both at the component level and the finished good level. On the other hand, genderless connections simplify the supply chain ordering process and ensure that a connection can always be made at the user site. Issues of receiving single-use systems with incompatible types of connections (i.e. both have a male connector) can be eliminated with the use of a genderless connector. Moreover, connectors with multiple terminations such as 1/8", 1/4" and 3/8" hose barbs, 3/4" sanitary and MPC quick connect insert are useful for adapting tubing sizes, connecting securely to filters and adapting quick connects to sterile connections. For instance, by using genderless connectors, several ports on a bioreactor can be used interchangeably for medium feed sampling or harvests. Additional sterile connections can be added to a bioreactor at any time through the addition of a manifold with several genderless connectors. Furthermore, sterile connectors allow connection to be done even in nuke corners, a flexibility that tube welders do not offer.

Considerations in Implementing Genderless Single-use Connections

While genderless interchangeability is a significant advantage, it is not the only feature to consider. Process engineers need to ensure that the connector has an overall functionality to deliver a reliable, repeatable and secure connection. Important connector attributes to consider are:
  • Ease of use - Connectors should be as intuitive to use as possible with aminimal number of actuation steps. The more actuation steps required in a connection, the higher the risk of operator error. Simpler is better.
  • Robustness - Connectors need to be able to withstand intended use as well as unintended abuse. One of the issues common with some connectors is the inability to withstand sideloading. Side-loading is difficult to avoid when dealing with tube and bag assemblies, so the connector you choose needs to be able to handle situations that are less than perfect.
  • Secondary equipment -, Connectors should not require additional equipment (such as tri-clover clamps, fixtures or assembly aids) to ensure a solid connection. If additional equipment is needed, this may indicate that the connector on its own is not as robust as you need. Another concern is that operators can fail to use components not integral to the connector, and these usage errors could make the connector non-functional.
  • Seal design - The seal design is your last line of defense against leaking or microbial ingress into the connector, so it is important to understand what is providing the final seal within the connector. When evaluating connectors, you will want to look inside each option to see the seal design and how it functions. A great seal design ensures the seal will stay in place throughout the actuation steps and that the connector will withstand side-load and tensile forces.
Single-use in Final Fill Operation

The rising demand of targeted therapies for human diseases indicates a need for a cleaner and more efficient method for transferring monoclonal antibodies. Traditionally, three-way valve assemblies were added to fill and drain ports to facilitate SIP operations, but the design of these valve assemblies makes it difficult to validate cleaning procedures. Replacing them with singleuse tube sets and connectors can eliminate cleaning validation and maintenance by simplifying connections to mobile stainless steel transfer tanks which are designed to transfer product from formulation suites to storage areas and ultimately to filling suites.

Single-use tubing assemblies can either be attached to the mobile tanks prior to equipment sterilization with single-use SIP connectors, or steamed separately, just prior to fluid transfer. For vessel outlet, combining a number of single-use components into the transfer line can create a robust system to ensure product safety. Next, a sterile connector is used to attach the transfer line to a separate portion of the transfer line that has already been steamed onto the filling machine with a single-use SIP connector. Finally a quick disconnect coupling validated as an aseptic disconnect enables the processor to confidently make an aseptic disconnection of the transfer line from the storage vessel when the process is completed.

Conclusion

As the cell culture industry for monoclonal antibodies continues to grow and mature, opportunities are vast but competition will also to stiffen. Biopharmaceutical companies will need to continually innovate and explore new options to gain a sustainable edge over others. Sterile connectors may seem like a trivial component in the elaborate research process of biological therapy for cancer, but the implementation of the right connectors can help establish critical links for achieving desired results accurately, timely, and cost-efficiently, all while continuing to exceed growing industry demands.

Contact: www.abipr.com