What the Field of Cell and Gene Therapy Needs Most in the Current Moment

This is the seventh part of a transcript of a Special Report with Deborah Phippard, PhD, and Renier Brentjens, MD, PhD. For the sixth part, click here.

The past 25 years, from 2000 to 2025, have been an unprecedented and rapid period of development of the field of cell and gene therapy. To get a perspective on how far we've come, and how far we have yet to go, CGTLive® reached out to Deborah Phippard, PhD, the chief scientific officer of Precision for Medicine, and Renier Brentjens, MD, PhD, the chair of the department of medicine and the deputy director at Roswell Park Comprehensive Cancer Center, to hold a Special Report discussion on the topic entitled: "Quarter Century Update: What’s Holding up Progress in Development? Where Have We Seen the Most?"

In this transcript of the seventh episode, Phippard shared her thoughts with Brentjens on what the field of cell and gene therapy needs most right now. She highlighted the importance of big wins, pointing to examples like mainstream papers such as The New York Times covering gene therapy research breakthroughs or the huge advance in sickle cell disease treatment provided by the FDA's approval of 2 new gene therapies in 2023. She emphasized that these wins can help galvanize researchers working on cell or gene therapy programs for other diseases by showing them what is possible. Phippard also discussed the specific potential of gene therapy to treat the underlying cause of genetic disease subtypes, and noted how the field is moving towards precision treatments in this regard.

CGTLive: If you could deliver one message to the broader healthcare community about what this field needs most right now, what would it be?

Deborah Phippard, PhD: I was going to say, the big wins always help, right? Whenever I see an article pop up in the mainstream papers like The New York Times, where they suddenly get all excited about dosing in Huntington disease because it's an intractable disease, it has a horrible outcome, it happens to adults, and there's a lot of emotion around it—you see a very successful clinical trial in a disease like that and everybody gets very excited. It was the same when we spoke earlier about sickle cell disease—there's been no real therapies, and suddenly there's a big jump. I think things like that very much help the field because you can see what's possible.

I think a lot about rare disease versus less rare disease versus common disease, and I would love to see CAR-T therapies work in solid tumors. There's all sorts of challenges to get that to work. I think there's still a lot of research that has to happen before you're going to see something that works very well in hematological malignancy move to a solid tumor, but there's so much unmet need there that people will keep working on that.

I think people don't necessarily think about the fact that rare disease as an aggregate is actually the most common disease. There are just so many diseases that sit under that umbrella and there's a lot of patient organizations really advocating for their particular disease. You can't do anything about most of those diseases except gene therapy. They're just fundamental mutations where you need to give a protein back or turn off a defective protein. To me, not working on those diseases would be such a shame because you can have massive impact. I'm probably getting a little off topic here, because it comes back to cost. Because you can fix something, you still have the question, is it financially feasible to do it? I think yes, eventually, I think we're going to get to being able to do those types of things. There's still so much we have to do. We're going to be here in 25 years time, Renier and I will be at the end of our careers, sitting here gray-haired, thinking, "Oh my god, 25 years ago, we thought we would be further ahead!"

To me, I see a lot of promise in really getting into the precision medicine side of it. So what do I mean by that? Cardiovascular disease is the biggest killer still, globally. Companies like Tenaya Therapeutics are looking down at what drives specific cardiomyopathies. There's underlying gene mutations that cause that. They're thinking about gene therapy that really affects those cardiomyopathies and potentially cures those diseases. Remember, with gene therapy, you're not looking at controlling symptoms, you're looking at potential cures. That's a real different mindset when you might think about dealing with cardiomyopathies. There's a big paradigm shift in my mind that if you truly understand what's driving the disease, you don't just say, "Oh, it's heart disease"—that is a massive pleiotropic disorder, where we can keep chipping away at that. So I feel that where we're going to see incremental improvement is in really understanding what's driving a disease. I mean, we've been doing this for cancer for years. We say "breast cancer", but anybody who works in the field knows there's all these different molecular drivers that sit behind that and we've got different therapeutic regimes depending on what that driver is. I sort of feel cell and gene is in that same space. We're in that personalized medicine space. And it's not easy, it does come down to rare subsets, but there is so much promise that the field is just excited about what we can do.

This transcript has been edited for clarity.