In this podcast, we spoke with Emanuel Krobath, Biopurification Specialist and Chiara Pacini, Bioprocess Specialist both with Pall Corporation about gene therapy process development including challenges and resources that are available for support.  

I began the discussion by asking Emanuel and Chiara to tell listeners a little bit more about their jobs and how they support gene therapy developers on the bench. Emanuel started by saying that as a bioprocess product specialist, he performs customer bench case studies at the customer site, specifically for the downstream process including vaccines, recombinant proteins, monoclonal antibodies and gene therapy products. He shared that the customers he works with are usually in preclinical or Phase I studies and he supports them from clarification to the final sterilizing grade filtration. This scale up, optimization, and technical support is offered free of charge to help customers succeed in their process development. He said that he also finds new technologies and ideas for the Pall R&D team during these visits.

Chiara shared that she supports customers from bench scale studies through the manufacturing process on downstream starting from  clarification to sterile filtration. She spends most of her time traveling to her customers’ laboratories or manufacturing sites to provide general support, conduct optimization studies and technical support training to find the best practice or membrane selection for their process.

I then asked if they could share what are the most common questions that they get from their customers. Emanuel said that what size filter do they need for a specific product and what is the best material to use is one of the most common. Chiara said that for her it is how to intensify a process or make it more robust for clarification, TFF, chromatography, and membrane filtration.

We also talked about a series of videos on Pall’s website and how these were created to help translational academics who work in gene therapy. Emanuel explained that they wanted to support academia specifically in their scale up and small-scale process development, because often in academia, the user will take the first filter that is available at their site. It is important that they understand and have the support to select the correct filter for their product, so that the process is optimized at manufacturing scale. Chiara agreed that the videos were designed to show we can support the development process not just for manufacturing scale, but also for initial bench scale studies. This and the initial optimization study that Pall performs with the customer ensures scalability to large scale processes and identifies the critical process parameters needed to reach high yield and product productivity.

Next, we discussed what they like most about the work that they do. Chiara described how being a bioprocess specialist gives her the opportunity to meet the people in both large and small companies who are working on these therapeutics. She enjoys supporting the development of different molecules and gene therapies and is always updated on the latest techniques used for gene and cell therapy. Emanuel said that he enjoys traveling, which is important because visiting customers in person is a big part of his job. He added that it never gets boring since he is supporting customers as they deal with very diverse processes and challenging problems. His favorite part of the job is that basically they are doing scientific work at the frontline, and he saw this to an even larger extent during the COVID pandemic as they were involved in nearly every vaccine process development.

I followed up by asking which projects that they were most proud of. Emanuel said that with the exponential growth of plasmid DNA demand, as it is either used as a template for mRNA vaccines or the molecular function for DNA vaccines, the upstream and downstream processes have not been optimized. Now, a couple of very eager Pall scientists, including Emanuel, are optimizing the plasmid DNA process map, particularly the clarification, as this seems to be the most challenging.

Since Pall and Cytiva are two sister companies under the Danaher umbrella, the goal for this project is to provide a complete process map for the upstream and downstream solely using Pall and Cytiva products.

Chiara agreed that they are focused on the plasmid platform due to the COVID pandemic. Last year she worked with an Italian customer to develop a COVID vaccine with plasmid DNA to mRNA in a liposome carrier in the clinical stage. She also worked with Pall colleagues and other companies under the Danaher portfolio, Precision Nanosystems and Cytiva, on a global project.

I then asked about what they saw as the most difficult aspects of process development, purification, and downstream processing of viral vectors. Chiara said that she feels the most challenging part is to achieve high virus titer and active particles. For example, she said that they work on the AAV viral vector process and it is very robust and established compared to the lentiviral process which is still very challenging due to stability and therefore you have to manage pressure, temperature and shear stress. Over the last 2-3 years the trend is moving to pDNA and mRNA.

I closed the podcast by asking if they had anything else that they would like to add for listeners. Emanuel said that filtration is not something redundant and should be carefully thought through, because perhaps the product becomes a game changer along the line. Studies done during academia studies could save a lot of money and time during the process development.

Chiara added that she joined Pall to make a contribution to the development of gene therapies and she has worked on covid vaccines, cancer therapy and personalized medicines. She sees that personalized gene therapies for cancer treatments are a huge target for academia and the emerging cell therapy work.

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