Future Predictions for the Field of Cell and Gene Therapy

This is the eighth part of a transcript of a Special Report with Deborah Phippard, PhD, and Renier Brentjens, MD, PhD. For the seventh 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 eighth episode, Brentjens and Phippard discussed their thoughts on what the future holds for the field of cell and gene therapy. Brentjens compared the situation to trying to predict smartphones in the age of flip phones—the specifics of that large leap in technology seen in a relatively short number of years was not easily forseeable at the time. Although, he did highlight that the one-time treatment nature of many cell and gene therapies will likely revolutionize treatment in oncology, which currently consists largely of lengthy chemo regimens. Phippard concurred, and predicted that chimeric antigen receptor T-cell (CAR-T) therapy will likely move into earlier and earlier lines of treatment in the future.

CGTLive: What do you think the future holds for the field of cell and gene therapy?

Renier Brentjens, MD, PhD: I'm a medical oncologist, so I'll focus on the cancer. I told Rick O'Reilly, who is one of the fathers of bone marrow transplant, at some point that I saw it as my personal mission to get rid of allogeneic bone marrow transplant. He laughed at the time... The cell therapies that we have today versus the cell therapies that we will have in 10 years, will be the same as, in my opinion, looking at a flip phone versus looking at a smartphone because I think it's incredibly difficult to to predict where this field of cell therapy is going to be 10 years from now, which is exciting. Our smartphones are no longer phones, they're basically Walkmans, phones, computers, and what have you. I do think that the ceiling is incredibly high for engineered cell therapies in general. As we get to know more and more about whether it's cancer or some inheritable disease that we're trying to treat, we'll become increasingly more elegant about how we how we use these technologies. That's my first prediction.

The second prediction, or at least impact, that I could foresee (and this is also true for the sickle cells, etc) is this type of therapy is designed to be one and done. The number of patients with cancer or with other genetic disorders who get chronic therapies just to keep people alive, that go on for years, whether it's sickle cell with the number of admissions with crises or cancer patients who can go through 4 or 5 or 6 years of damaging and difficult chemotherapies. I think the paradigm that we have with cell therapies will definitely change what these patients go through. The opportunity, once you're diagnosed, to get a single infusion and then be done—if we look at acute lymphoblastic leukemia, for example, in adults, treatment regimens would be written out for 2 and a half years—2 and a half years of receiving nonspecific toxic drugs until you're finished. The number of patients I've had over the years that just after a year and a half or 2 years have said, "You know what, I'm in remission, I'll play the odds"— that's going to be, hopefully, a thing of the past.

Deborah Phippard, PhD: That's a great point, right? Because it's like the checkpoint inhibitors. You used to have to fail every therapy before they would consider a checkpoint inhibitor, and they steadily move up to first line therapy. I feel the same way about the CARs. You've got a certain type of disease, why would you have to go through and fail years chemotherapy, take all of those side effects and damage? So I do think we'll see cell therapies move up the line for treatment, but again, it's cost and access. So all these things have to be worked out in parallel. That's what's so exciting about our field because all those different things are getting worked on.

Renier Brentjens, MD, PhD: Yeah, and keep in mind, if you talk about the last 25 years and the next 25 years, as much as we may not feel it because it's over an extended period of time, the last 25 years brought antibodies, brought small molecule inhibitors, brought checkpoint inhibitors, and brought CAR T-cells. That's not bad.

Deborah Phippard, PhD: And don't forget gene therapy, and better ADTs—

Renier Brentjens, MD, PhD: Exactly. So when you then ask, what is going to happen in the next 25 years—I don't think anybody 25 years ago would have been able to list— you know the concept of small molecule inhibitors was born out of Gleevec, but I wasn't involved in the field, and no one on the clinical side had even guesstimated—I mean, the only thing we could wrap our heads around back then was because rituximab was just FDA approved when I was doing my fellowship training. So I think it's very good to try to project, but I think my flip phone and smartphone analogy probably holds. It's going to be extremely interesting what happens in the next 25 years. But I would bet that Deb and I, even if we put our heads together, might get 1 out of 5 right.

Deborah Phippard, PhD: Yeah, if we're lucky.

Renier Brentjens, MD, PhD: If we're lucky.

This transcript has been edited for clarity.