Buffalo, N.Y. (WBEN) - WBEN sat down with Dr. Brian Betts, a cancer physician, Professor of Oncology and Vice Chair of Strategic Initiatives for Transplant & Cellular Therapy at Roswell Park Comprehensive Cancer Center for a discussion on the advancements in cell therapy for cancer patients.
Dr. Betts breaks down the different subtypes of one type of cell therapy: stem cell transplant, also known as bone marrow transplant.
"The most traditional is stem cell transplant, and there's two different sources. I could transplant you with your own cells, that'd be autologous, or use someone else's, that's allogeneic.
We have different reasons for doing either one of those. For an autologous transplant, think of it as a way to give high-dose chemotherapy, and then rescue you with your cells. That way, you don't have a long period of low white blood cell count, low platelets, anemia, that type of thing. So typically, if someone has a autologous transplant, they're in and out of the hospital within about two to three weeks and we're moving that to outpatient by the way, so that's in and of itself is exciting.
For an allogeneic, using someone else's stem cell, that's usually an indication for something like acute leukemias, some types of lymphoma, also bone marrow failure syndromes like aplastic anemia and with that, patients are in the hospital for about three to four weeks, a little bit longer."
But the main discussions at Roswell Park recently has been the newer forms of cancer therapy: engineered cell therapy.
"That's kind of the newer thing that we've been talking a lot about with CAR-T cells, CAR, meaning chimeric antigen receptor. We will take your white blood cells and then engineer them to have a new receptor to go directly after the target cell and in many cases, it's a cancer cell. The reason why that's important is because our immune systems for a T-cell, to go after a tumor like it normally should, we call that an immune surveillance, it needs some help.
So antigen-presenting cells have to gobble up stuff, and then present it to a T-cell for it to do its job. Cancer cells, sometimes take advantage of that process and make it less efficient, so T-cells ignore them altogether. By making these engineered white blood cells or CAR T-cells, they can directly bypass the antigen-presenting cell, and then kill the target cell directly."
In addition, gene engineering of stem cells, used to treat sickle cell anemia, is being discussed in cancer treatment as well, and treatments of it have been recently FDA approved.
In recent years, Dr. Betts says there has been dramatic improvements to side effects of stem cell transplant, particularly in Graft Versus Host Disease (GVHD). According to the National Institutes of Health, GVHD is a systemic disorder that occurs when the graft's immune cells recognize the host as foreign and attack the recipient's body cells. “Graft” refers to transplanted, or donated tissue, and “host” refers to the tissues of the recipient.
"About two years ago, risk [of GVHD] was around 40 to 60%, so kind of high. About 20 to 30% of patients could die of that. Now, there's an approach where we give cyclophosphamide after the stem cells go in, a type of chemotherapy. We've reduced that risk from 40 to 60% to less than 10% and the risk of dying [of GVHD] is less than 5%, a dramatic improvement there, that's pretty exciting," said Dr. Betts.
Another exciting newer development according to Dr. Betts: accessibility to CAR T-cells.
"FDA approval-wise, we have CAR-T cells for different types of lymphoma and myeloma. We're working in the lab to go after solid tumors now. Probably one of the exciting things there that's unique to Roswell Park is the use of armored CAR T-cells, coming out of the Brentjens lab where you can actually have a CAR-T cell that brings its own cytokine and that actually helps the CAR T-cells persist longer in the body to go after the tumor more efficiently. So a lot of exciting work is happening there."
And new CAR-T cell approaches.
"We're not just going after large-cell lymphomas and myeloma, but bringing it out to acute leukemias, different solid tumors. Part of the thing that is facilitating that work is using novel binders, we're going towards using camelid. So alpacas, camels and llamas as a way to make the CAR T-cells and sharks as well."
These new developments are bringing great excitement and hope to cancer patients, who are oftentimes Googling certain therapy results that direct them to research from several years ago, like risks of stem cell transplant, that are scarier than what the reality of the risk is today.
"There's almost a sense of relief from patients," said Dr. Betts. "And also, I think they're excited and having access to therapies that we've never had before, taking their own white blood cells and then engineering them to go after cancer. That's pretty neat."
According to Dr. Betts, the armored CAR T-cells for small cell carcinoma are coming "very soon" and better CARs to go after some of the current indications like lymphoma and newer ones like acute myeloid leukemia.
"Those are kind of the things that are happening right now and then as you know, we have things that are phased over the next three to four years. But we truly are making Roswell Park a destination for cell therapy, and it really is a hub for cell and gene therapy."