Transcription:
The Latest Advances in Cancer Immunotherapy

Bill Klaproth (Host): Immunotherapy has become an important part in the fight against certain types of cancer, and new types of immune treatments are being studied and will soon impact how doctors treat cancer in the future. So, what is cancer immunotherapy and how is it changing the face of cancer treatment? Here to talk with us today, is Dr. Kunle Odunsi of Roswell Park Comprehensive Cancer Center. Dr. Odunsi, thanks for your time. Can you start by explaining to us, what is cancer immunotherapy?

Dr. Kunle Odunsi (Guest): Cancer immunotherapy is an approach where we use the immune system to treat cancer. Basically, the immune system is able to recognize and attack bad things in the body. That’s how the immune system is designed. If you have a flu infection, for example, it is your immune system that helps to get rid of the flu virus, but the immune system struggles when it comes to cancer and over the past twenty years or so, especially, we have now developed a deep understanding of how the immune system interacts with cancer cells and how can we then leverage that information and use it in the treatment of patients? Immunotherapy is essentially a new approach that is highly personalized, whereby your immune system is turned against cancer cells in order to provide long-term remission for patients.

Bill: So this is employing the body’s immune system to work against the cancer?

Dr. Odunsi: Yes, so the body’s immune system – the immune system is a powerful system in the body, and that’s how we have survived over the years. When I say, “we,” I mean the humans have survived because of our ability to fight off infection -- whether they are bacteria or viruses, but cancer cells essentially are normal cells of the body that have gone bad. They’ve gone essentially abnormal, and so the question is, “How do you turn the immune system against these abnormal cells?”

There are different ways of doing this, and the ones that are most promising are the use of what are called vaccines. I think everyone is familiar with how we use vaccines to treat infections, or prevent infectious disease. Just like you are getting a flu shot, the flu shot revs up the immune system so when the flu virus comes, the immune system is able to attack and destroy the virus. That’s one approach, can we make a cancer vaccine?

A second approach is an approach that has become very important over the last few years, and in fact, several types of cancer are showing excellent response to this new approach. This is the use of what are called checkpoint inhibitors. Let me explain. Checkpoint inhibitors are simply drugs that are designed to unleash the immune system because normally the immune system has certain checkpoints that prevent the immune system from just going on without control. What checkpoint inhibitors are is to take off the breaks from the immune system and allow the immune system to be unleashed and attack and destroy cancer cells. That is the second type of immunotherapy that has become very useful for many cancer types, and the FDA has approved this type of therapy for many cancer types in the last two to three years – and we will talk about that later.

The final type of immunotherapy that I want to talk about is called adoptive T-cell therapy. Essentially, the major cells of the immune system that are the foot soldiers of the immune system, that destroy and kill cancer cells are called T-Cells. What we do with adoptive T-cell therapy is to take a patient’s own blood and re-engineer T-cells from the patient’s own blood and turn them into cancer-fighting immune cells. This re-engineering takes place in a special facility, and then we then grew up these new cancer- fighting cells into billions and billions of cells, and we give this back to the patient, and that is called adoptive T-cell therapy. This therapy is very strong, very potent. It will too cause regression of even large, established tumors. We’ve seen very promising results, especially liquid tumors, or cancers of the blood, but also some solid tumors, cancers affecting organs such as breast, ovary, gastrointestinal, and so on.

Bill: This is very encouraging. Those three, again, basically, cancer vaccines, number two, checkpoint inhibitors, and number three, adoptive T-cell therapy. Does immunotherapy work for everyone when you use one of these three forms?

Dr. Odunsi: Unfortunately, immunotherapy does not work for everyone, however, based on the standing of how the immune system works against cancer – again, we have a deep understanding now – it is entirely foreseeable that one combination of immunotherapy approaches might work for everyone. There’s active investigation asking questions about when it works, how does it work, when it doesn't work, why not? We are uncovering and discovering some of the mechanisms by which cancer cells escaped from immune attack and based on those understanding of those mechanisms; we are beginning to design strategies to counteract the cancer’s mechanisms of escaping from an immune attack. It’s almost like playing a chess game where you’re always mapping out counter-strategies in order to defeat your opponent.

Bill: Always trying to stay one step ahead basically.

Dr. Odunsi: Absolutely, you’re trying to stay one step ahead and what we are finding is that some patients respond to one form of immunotherapy and not the other type. Sometimes when you now combine the immunotherapy approaches – two of them together or when you combine one form of immunotherapy with conventional therapy such as chemo or radiation, you get better results. There are a lot of clinical trials that are going on at Roswell Park, and in some other institutions, trying to understand how best to deploy immunotherapy approaches and some of the results are really very, very promising.

Bill: So, Dr. Odunsi, when you talk about immunotherapy as a vaccine, is this something that we eventually will take before getting cancer, or is immunotherapy only used after somebody does develop cancer?

Dr. Odunsi: That is a good question, and at Roswell Park, we have developed vaccines to prevent relapse of cancer. We call that secondary prevention. Someone has cancer, gets diagnosed, gets treated, they go into remission, there’s always the fear that the cancer will come back and that’s why it’s cancer. In order to minimize the risk of relapse is we have ongoing clinical trials where we utilize vaccines to minimize the risk of relapse, or at least prolong remission rates. That is secondary prevention.

Your question is also about primary prevention, can we prevent it in the first place -- almost like how you try to prevent the flu virus, or smallpox, or any of those immunization strategies. There’s ongoing work in this area. There’s still a lot of work to be done, but I envision that in the future this is going to be potentially possible.

Bill: This is amazing, and the last question, what is the long-term outlook for patients that have had immunotherapy?

Dr. Odunsi: That is a great question as well. When you respond to immunotherapy, the responses are usually deep – I call them deep responses. Many times, they are long-lasting, durable, and deep. What we are finding out is there are specific aspects of the immune system that allow for deep, long-lasting immune responses. At Roswell Park, we are – based on the understanding – we are developing strategies to try and make sure when you are treated either with a vaccination or adoptive T-cell therapy, the responses are long-lasting durable, sustained, so even when the cancer cells begin to come back, the immune system is already primed, ready to go on the attack. Those studies are ongoing at Roswell Park.

Bill: Very promising, and very encouraging. Dr. Odunsi, thanks for your time today, speaking with us about immunotherapy. For more information, visit RoswellPark.org, that’s RoswellPark.org. You’re listening to Roswell Cancer Talk with Roswell Park Comprehensive Cancer Center. I’m Bill Klaproth, thanks for listening.