Bringing Solid Tumors into the Cell Therapy Space

While hematologic malignancies continued to dominate discussions at the 2023 Tandem Meetings |Transplantation & Cellular Therapy Meetings of ASTCT and CIBMTR, held in Orlando, Florida, February 15-19, 2023, solid tumors found their space in the meeting too, with the first ever solid tumor cell therapy session chaired by Alison Betof Warner, MD, PhD, medical oncologist and assistant attending physician, Memorial Sloan Kettering Cancer Center.

CGTLive sat down with Warner to learn more about the growing prevalence of cell therapies investigated for solid tumors, and the opportunities and challenges that may arise with the shift. She discussed how the field is embracing strategies such as tumor-infiltrating (TIL) therapies, T-cell receptor (TCR) therapies, bispecific antibodies, next-generation chimeric antigen receptor (CAR) T-cell therapies, and combination therapies, and also overviewed some standout talks from the session.

CGTLive: Can you talk about the solid tumor session?

Alison Betof Warner, MD, PhD: I was the chair of the session, which was the first time that this meeting has had a session on solid tumor cell therapy, which is really exciting. This group has obviously focused for a long time on hematologic malignancies. And what we're seeing is that cell therapy is coming for solid tumors, it's probably going to be approved in at least 1 malignancy this year. ASTCT really recognized the need to have transplant doctors and cell therapy doctors learn more about solid tumors. Last year, they had asked me to chair a session really introducing solid tumor cell therapy to this group, and it was great, exceptionally well attended, people were really excited about it.

Personally, I talked a lot about TIL therapy in melanoma, which is sort of the up-and-coming therapy that will probably be approved in 2023. For melanoma, what we've seen is that patients may have a great response to checkpoint blockade, but if they are a non-responder to checkpoint blockade for melanoma, there are very few treatment options,andmedian overall survival is usually measured in short months for those patients. Over the last year or 2, we've seen really impressive data for TIL, suggesting that there's about a 31% response rate. The patients who do respond tend to have very durable responses, with about 40% of them still responding 2 years later to a 1-time treatment. So, for patients with melanoma that have progressed on checkpoint blockade, this is really the only option for a durable treatment strategy. And that's what we're really excited about. We've seen quite a bit of evolution in TIL over the last year, and a lot of data have emerged for lifileucel, for which a biologic license application is being completed.

Did any presentations stand out to you?

Dr. Brian Van Tine from Washington Universitytalked about sarcoma cellular therapy and the data there is impressive. Sarcoma has been a disease that traditionally doesn’t respond to chemotherapy, radiation, classic immunotherapy,or checkpoint blockade. Dr. Van Tine has participated in a number of trials of cellular therapy. But there's some really impressive data in several types of sarcoma, and a registrational trial going on right nowwithpotential approval in the next couple of years. I think that's a disease that we never thought would be immune responsive, and so that’s really exciting and there’s more data to come.

How do you think the cell therapy is trending in solid tumors?

Just the fact that you have solid tumor medical oncologists at this meeting shows that this field is blowing up. I couldn’t fit all the therapies in clinical trials now into my presentation. If we think about where we came from 3 years ago, when you could count on both hands, the number of cell therapy trials there were actively enrolling patients for solid tumors, the growth of this field is so fun to be a part of. Another thingwe're seeing issolid tumors really moving away from traditional CARs and moving more towards TIL, TCR therapies, and bispecificsin melanoma and many other solid tumors. I think we will also start to see some hybrid of those technologies and I think that’s where the future of this field lies. Right now,we're at the very tip of the iceberg and there's a lot to come.

For a long time, we thought that cell therapy was going to be a hematologic malignancy thing. With the scientific advances in the last couple of years, I think it's very clear that solid tumor cell therapy is here to stay and is going to get approved soon. When we think about the numbers of patients with solid tumor versus hematologic malignancies, realistically, we're going to start treating a lot more patients with solid tumors. One of the important things that we've been trying to stress is the integration of solid tumor doctors into care, andnot just plugging solid tumor patients into the traditional heme cell therapy model, because they have different problems and complications. That's one of the really nice things that can come out of a meeting like this, when we all sit down and talk about issues treating these patients and planning ahead to treat these patients because they're coming. And we all need to be ready for it.

Transcript edited for clarity.

REFERENCE

Warner AB. TIL therapy for Melanoma: We've reached the tip of the iceberg. Presented at: 2023 Tandem Meetings, February 15-19, 2022.