From The Editor | October 30, 2023

A Sneak Peek At REGENXBIO On Cell & Gene: The Podcast


By Erin Harris, Editor-In-Chief, Cell & Gene
Follow Me On Twitter @ErinHarris_1

Sneak Peak

To date, I’ve written recap or highlight articles about Cell & Gene: The Podcast episodes that have already aired and are available anywhere you get your podcasts. Here, I thought I’d give you a sneak peek at a forthcoming episode with REGENXBIO’s CEO, President, and Director, Ken Mills.

Ken and I discussed a whole range of topics including his take on where AAV is headed into the next handful of years and what the improvements could mean for both CGT companies and the patient population. Here’s a look at part of our conversation; be sure to subscribe to Cell & Gene: The Podcast so you’ll have the entire episode when it airs.

Exciting Results for Duchenne Muscular Dystrophy

At the time of our recording, Annual International Congress of the World Muscle Society had just wrapped, and at the event, REGENXBIO announced additional interim safety data and initial efficacy data from the Phase I/II Affinity Duchenne trial of RGX-202 for the treatment of Duchenne Muscular Dystrophy (Duchenne). I asked Ken about the data REGENXBIO shared at the event. Here’s part of his response.

“Scientific work for us started about two or three years ago. And this is the first-ever efficacy data that we’ve been able to show. The first two boys have received our treatment, which is called RGX-202. We were really pleased to report early signs of improvement with respect to how the drug is working and some early evidence clinically that there’s the potential for us to change the trajectory of disease for these young boys. There’s context here: this year, in fact, just a few months ago, was the first-ever approval of an AAV gene therapy product for Duchenne boys, and we’re really pleased about that as well, because it was something that we had hoped for. When we announced our program, we thought that AAV as a gene therapy modality was the right class of medicines to provide treatment options for boys with Duchenne, and we wanted to get involved in that. But there were some people ahead of us and some of their data influenced our thinking. I think what has happened in the last couple of months, and even including our readouts, is that treatments have become available on an access basis to more boys and families. The FDA has made it known that there’s a pathway for approval for these types of treatments.”


Scalability with consistent yield and product purity are critically important factors for gene therapy manufacturing, but they aren’t easily achieved. I asked Ken for his perspective. Here’s part of what he shared with me.

“When I got involved in gene therapy and was involved in the formation of REGENX, there wasn’t much of a field when it came to industry. There were a few outposts in some large companies that were doing some work; Genzyme comes to mind, for instance, at that moment in time.

But most of what I consider to be translational research or drug development work was happening in academic settings. And therefore, the production was happening in academic settings as well. I have a degree in chemistry, and I've worked in biotech labs in different forms, including in process, development, and purification. It’s very different when you have to pour your own gels and manage and create your own tools than when you could have an industrial setting where you can take advantage of innovations in technology. And that’s a big difference in scale. So, the first step, what I'm alluding to here, is that we needed to get out from under the kind of academic tools and into state-of-the-art for basic biotech to begin with. When you're already getting reasonable material that is being accepted for investigational new drug applications to begin with, the other thing you need to be careful of is you don’t want to make a lot of changes. Because as soon as you start to make changes, you may receive advice from regulators to go back and re-run studies or start over. And I've seen that affect how things have been executed in the early stage.

My discussion with Ken is informative. You will want to tune into the entire episode when it airs. For more information on the future of viral vectors, tune in to our recent Cell & Gene Live, Stability To Scalability: The Future Of Viral Vector Therapies. Ken’s colleague, REGENXBIO’s COO, Curran Simpson and Candel Therapeutics’ VP, Head of Process & Analytical Development, Dave Maheu, and I spent an hour discussing on accelerating scale for viral vector production.