What Prostate Cancer Research Is Showing Promise?
What Prostate Cancer Research Is Showing Promise? from Patient Empowerment Network on Vimeo.
What areas of prostate cancer research are showing promise? Expert Dr. Sumit Subudhi explains ongoing research and shares an overview of prostate cancer treatment classes in development.
Dr. Sumit Subudhi is an Associate Professor in the Department of Genitourinary Medical Oncology, Division of Cancer Medicine at The University of Texas MD Anderson Cancer Center. Learn more about Dr. Subudhi.
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I’d like to begin with an update on prostate cancer research. Would you walk us through the newer classes of treatments that are showing promise?
Yeah, in clinical trials, there are classes of drugs known as androgen receptor degraders. And so, the androgen receptor is a protein that basically is the mouth of the prostate cancer. That’s how I like to describe it. And it actually allows testosterone, which is the food, to be eaten by the mouth, and it actually helps the cancer grow.
And what these drugs do is they actually degrade or break down the mouth of the cancer. And, therefore, it starves the cancer to death, and that’s actually the concept. And they seem to be showing some exciting activity in clinical trials, especially in those patients who are resistant to the second-generation hormonal drug that you may have heard of already, such as enzalutamide (Xtandi), apalutamide (Erleada), and darolutamide (Nubeqa). So, I think is something that we’re looking forward to seeing more data on.
Another class of drugs are antibody drug conjugates or ADCs.
And these are what I think of as heat-seeking missiles. So, one part of the drug actually recognizes the cancer, and the other part of the drug actually has a payload that sort of releases a bomb or sort of like chemotherapy-type agent right where the cancer’s located and kills the cancer in that way. And we’re seeing some great clinical activity in prostate cancer with this class of drugs.
And then the final one is bispecifics, and in particular T-cell bispecifics. So, T cells are part of the immune system that actually help kill the cancer.
And, unfortunately, prostate cancer, like some other cancers like pancreatic and glioblastoma, have few T cells inside it. And, therefore, a lot of the immunotherapies that many people have heard about, such as ipilimumab (Yervoy) and pembrolizumab (Keytruda), they’re not very responsive in patients with prostate cancer. And it’s because there’s few T cells in prostate cancer.
What the T-cell bispecifics do is they actually have one part of the drug that actually recognizes the cancer and the other part that recognizes T-cells. So, like a bulldozer, it brings T cells right into the prostate cancer and helps kill the cancer that way.
Now there are some inhibitors as well. Is that correct?
Yeah. So, the immune checkpoint inhibitors have been around for a while. And, basically, in combination, they seem to be more effective in prostate cancer. But when given alone as monotherapy, they’re less effective.
Are these treatments specifically for patients with advanced prostate cancer?
All of them are actually in trials in patients with advanced prostate cancer. And I define advanced prostate cancer as either having metastatic disease, meaning the cancer has spread to other parts of the body outside of the prostate.
Examples include lymph node, the bone, the lung, the liver. But there are so few trials in patients with locally advanced prostate cancer. What I mean by that is they have high-grade prostate cancer, but it’s local, or it’s just in regional lymph nodes. And some of these classes of drugs are being evaluated in that setting as well.
Let’s shift to talk about your research. What are you excited about right now?
So, my research focuses on immune checkpoint therapies, which are the inhibitors that you were referring to and understanding how to make them work better in prostate cancer.
And we’re finding out that in prostate cancer there’s about 20 to 25 percent of patients that appear to respond to this type of treatment. But these are patients that don’t have a lot of bone metastases. And these immune checkpoint inhibitors are given in combination. So, they’re not given alone. They’re given with either a combination of anti-CD34 and anti-PD-1 or some other form of that.