Thanks David. Thank you very much for having me. It is really a pleasure and also an honor to be here. What I will try to talk about today is, I will give you within the next ten to twelve minutes just the background about vaccines. This is one of the new areas in therapy development, especially ovarian cancer. I think the title of my talk is Phase I, II, III trials. Unfortunately we don't have lots of Phase I, II and none III. Probably we have one or two trials that are going on in ovarian cancer vaccine currently in the country. What I will try to do is to show you the development of the field and I'm going to also tell you what is the essence of vaccine so you will know. You'll have a background of why we're developing vaccine and on what basis. And then I will tell you about a couple of trials, at least the one that we are doing at the National Cancer Institute. I am going to re-emphasize again what Mike just said, and he stole it from me by the way, so you just remember that.

Cancer is a genetic disease and the reason I am saying this is because, as Mike eloquently showed you, without knowing the cause we cannot develop a therapy. I am going to give you now a very specific and obvious example of what we mean by that. This is a very nice model of how cancer develops. This is actually probably one of the most developed models in cancer, which is colon cancer. Unfortunately we do not have one now for ovarian cancer, but hopefully we will have one very soon. This tells you that for the development of colon cancer from the normal cell to become cancer and then metastasize it needs really to accumulate multiple genetic changes along the way. To go from one stage to another, to another and finally to become cancer and metastasize. Well that is very important because that would give us, as a matter of fact, some specific areas in molecules to be able to target because these now are characteristics of each cell. So when we have the cancer, the cancer has all those in it that normal cells don't have. So we can develop therapies that will target those and spare the normal cells and hence decrease the side effects and give more efficient therapies.

These are some of those that Mike talked about. These are the oncogenes, tumor suppressor genes, and mutation susceptibility genes. So the more we know about those the more we can develop effective therapies and the more we can target multiple steps of the cancer development. One of those therapies is vaccine. So what we know about ovarian cancer, and again Mike had showed you the laundry list for this. Now there are some of those molecules that we have already identified, and multiple labs have identified, and we know that they contribute to the development of ovarian cancer, or ovarian cancer will acquire them as part of their phenotype or as part of the way it looks. Some of those are P53, Her-2-neu. So we know that there are some changes in the ovarian cancer that do not exist in the normal cells. Now how can we intelligently develop some therapies to them like vaccine?

Now for a long time we have known that the immune systems and the tumors they do interact and they interact very closely. Not only do they come close to each other but the immune system, and this is one of the immune cells, and this is one of the T-cells, it comes very close to the tumor cell. It recognizes something wrong on the tumor cell, which is different than our normal cells, because it doesn't do this with our normal cells. What happens is that the T-cell gets very activated and secretes certain materials that we call cytokines and it literally digs a hole into the tumor cell and completely abolishes it. So the tumor cell is gone. That tells us that the immune system really has a tremendous amount of potential to utilize and boost and teach to be able to attack or fight cancer. Well how does this happen? Why would the immune system be like this, why would a T-cell like that, which is the immune cell, recognize something on the tumor?

Well we know that this is the immune cell, this is the tumor cell. We know that there are what we call pieces of proteins or when the protein is chopped up into pieces we have what we call peptides. These pieces of proteins are called antigens and they are presented on tumor cells. The immune cell can recognize those as abnormal, get activated and kill the tumor cell. Where do they come from? Actually they come from the proteins inside the tumor cell. Now Mike told you about the proteins and how important they are, and these abnormal proteins are now the abnormal proteins that come out of the abnormal gene like the P53, Her-2-neu, etc., etc. So all these proteins are inside the tumor cell, what happens to them is they get chopped up, they get presented on a plate, which we a call MHC plate, we don't have to go through this, but then they get presented on the cell surface. So anything inside our tumor cells, or inside our normal cells for that matter, come and presents itself on the cell surface. This is where the immune cell can come and recognize that there is something abnormal in the tumor. And when it recognizes that there is something abnormal it gets excited, it releases its weapon and it kills that cell.

So in our normal cells those are normal because they come from normal proteins. When the immune cell comes in contact with one of normal cell, not the tumor cell, it would say, "Oh, this is one of us, we'll leave it alone." However, if it recognizes that this is something abnormal, which is something that is foreign, then it releases its weapon and kills that cell.

What we know now is that there are abnormal proteins in the tumor cells, and this is the list that Mike showed you and I showed you at the beginning, at least of some of what we know about ovarian cancer. The more we know the more we can develop things to attack them. Okay. So if one of those is mutated, which is abnormal, altered, then one of those small pieces that comes out of the protein, if this is a protein, like say this is P53 protein for example, there is a change in that P53 protein in one of the blocks that compose the P53. Then one of those small pieces is abnormal, then this is going to be represented on the cell surface of the tumor and the immune system is going to get excited and maybe it kills that cell. Well, because this is abnormal, so that might happen. So the question is great. You're telling us you know that ovarian cancer has multiple of those abnormal ones. And that the immune system is going to recognize it and kill it. Why the hell did I have tumor? Or developing tumors?

Because, the tumor is intelligent. This is exactly where vaccine comes from, to break that intelligence, to go through the essence of the escape of that tumor. One of the reasons, as a matter of fact, and this is a very active area of research, that tumors escape the immune system, or that the immune system cannot do anything for the tumor, is because for the immune system or for the immune cell, which is this one, to get activated and release those weapons, it needs to have two signals to it. One that comes from that antigen, or that small piece that I showed to you, but the other one comes from another molecule that should be on the cell that it attacks. "Okay, here I am, see me, kill me, and this is the weapon." Well, tumors don't have that. I mean, the tumor is not stupid enough to say, "Okay come here, look I have something abnormal and I'm going to give you the weapon, just go ahead and kill me." Because otherwise we wouldn't have tumors, and the human race wouldn't have tumors.

But what happens is that the immune cell comes and recognizes that there is something abnormal. It gets that first single and then it can't do anything. Why? Because it doesn't have the weapon. Just like, the tumor laughs at it. So, the immune cell goes away. Now there are cells in the body that are called professional antigen presenting cells. We don't have to go through those in detail. What I want to tell you is that those cells that are present in our blood, and in our skin, and in our guts, etc. they have the capability of presenting those abnormal antigens and they have that second molecule on their surface. So they can basically generate a good immune response. So, when an immune cell comes in close contact with them it recognizes that thing on it, so it gets the first signal and then it also gets the second signal from here and now it is activated. Now it is fully loaded with a weapon. It's ready to go. It can kill if it sees this again some other place.

So we have a normal cell, we have a tumor cell, we have those abnormal antigens in it now on the cell surface, we can identify the antigen. If we identify this antigen, give it to the person in the proper context, in the vaccine, which is what is the vaccine now. Give it that antigen in the proper context, then on those cells, then this immune cell would get the first signal, get the second signal, then when it goes to the tumor, it doesn't need to have the second signal anymore because is it already loaded with weapons, so it could kill the tumor. This is exactly where vaccine comes from. We identify that abnormality, we give it to the immune system in the proper fashion so we can load the immune system with the weapon to be able to go to the tumor and get rid of it. While it cannot do it itself because the tumor doesn't give it the appropriate weapons.

How can we deliver it? We can identify those. We can put it under the skin, because under the skin we have those. Or, we can give it directly to the blood because in the blood we have those. So there are many ways of delivering the vaccines. The more this field grows the more you are going to be hearing about it. At least I wanted to let you know about those issues so you will know when you think of clinical trials, or you compare clinical trials. Or, you ask questions. So that's the purpose.

Vaccines. Now we know that we have identified tumor antigens. Some of the tumor antigens are listed here. Some of them are derived from the abnormalities that the tumor has like the P53, like the Her-2-neu, like the CEA or Mach-1. These are antigens that we know are present in ovarian cancer and we know that we can develop therapy vaccines against them.

I'm going to concentrate on one of them, which is the P53. Because this is what we have clinical trials for. P53 is mutated in lots of tumors, including ovarian cancer and in maybe 30 percent or sometimes 50 percent of ovarian cancer. If the P53 is mutated and this is ovarian cancer, one of those things on the surface is abnormal, then we could utilize that and we can give this as a vaccine in the proper context so that this immune cell could get activated, stimulated and be loaded with the weapon. That would be the purpose. So we have a clinical trial that targets P53 in ovarian cancer at NCI. This is one of the very few vaccine trials for ovarian cancer, as a matter of fact.

The clinical trial that we have is a Phase II randomized study. The patients that we are targeting are patients with low burden disease. That means they have no evidence of disease after therapy. Or they have marker disease only, which is Ca-125. The patients usually get vaccinated four times with the P53. What we do is, when the patient comes, we look at the tumor that was originally extracted and see whether the patient has abnormal P53 in the tumor. If the patient has abnormal P53 then the patient would be a candidate for the study. The study is randomized. We are comparing two different ways of how to administer the vaccine-whether in the blood or under the skin.

So for eligibility the patient should have adenocarcinoma of the ovary. The patient should have Stage actually Stage III, not IV. Stage III/IV or recurrent that are currently NED or with marker disease only. The tumor should have positive P53 expression which is over expression, abnormal P53 and then have good performance status.

Why are we doing this study? One reason is to see whether we can generate an immune response against an abnormality that is present in ovarian cancer, which is the P53. We want, in the first place, to see if we can get the immune system in women that have ovarian cancer, and the ovarian cancer has a P53, to generate an immune response, immune cells that could attack the tumor. So that is one of the main purposes at this stage. So we can get the first step and then build on it. We wanted to see whether the immune response could affect the Ca-125 level and we wanted to compare between different approaches of giving the antigen.

We started the therapy and actually this is it. We have another one for breast cancer. I put the wrong slide up but it doesn't matter. Just to give you an idea. We, so far in the very few patients that we started treating, we've seen we can generate a very specific immune response against the P53. So in principle, as a proof of principle, we have found that after we vaccinate the women it generates very specific lymphocytes or very specific immune cells to attack the abnormality in the tumor.

Soon we will have another study, hopefully in the next month or so. It's been now amended for approval where we are going to be treating not only NED patients but also advanced disease patients--stage IV, recurrent, or progressive disease with the same antigen but in a different way of vaccination.

For referrals, I always get asked about referrals, and you have the 1-800-4-CANCER number, this is at least the referral for ovarian cancer at NCI, vaccines at NCI.

There is one other ovarian cancer vaccine. It's not specifically similar to what I showed you. It's a little bit different. It's more antibody related and I think Carol will talk about this, which is Ovarex vaccine, which is present in other institutions. Basically these are the vaccines for ovarian cancer that are present. Thank you very much.

David Mutch: Next we will have Dr. Jeff Boyd and Dr. Carolyn Muller. Dr. Boyd is from Memorial Sloan-Kettering. Dr. Muller is from The University of Texas in South Dallas. They will be talking about targeted molecular therapy. Then we will have a break around 10:30 after the panel discussion and then we will have some case presentations on quality of life and there will be lunch out here around noon. A buffet style lunch.

Audience: Is P53 specific to these cell lines?

Samir Khleif: Yes. The P53 is changed and it is changed only in the cancer cell. Now not all patients have the P53 change. There are probably 50 that don't have it. But when they have it, it is specific to the cancer cells.

Audience: Did you say that P53 is presents in bracket II?

Samir Khleif: No I did not. P53 is a sporadic mutation. This is actually a very important question. P53 happens whether bracket II is there or no bracket II is there. I just want to make sure that you know that these vaccines are being developed not against genetically inherited mutations, but again against the mutations that occur. Why? Because the inherited mutations, like bracket I and bracket II, are present in every single cell in the body. Well this is not the purpose for the vaccine because we want to generate it against the cancer only.

Audience: I have a question about the risks of the vaccine?

Samir Khleif: This is actually a wonderful question. The vaccine itself--we've treated now not for ovarian cancer but for hundreds of other cancer patients--the risk from the vaccine itself is almost minimal. I mean it doesn't exist. At least for the short term that we followed our patients. The only risk is basically a local reaction maybe that would happen if you give it just like any other vaccine, some mild fever or something. But from the vaccine itself there is none.

Audience: You said there are four shots in the vaccine? Would that be like a flu shot? You get those every year?

Samir Khleif: No. On the trial the shots are every month. We give them every three to four weeks, and then it depends on the patient's response if we continue. In other words, if the patient has a decrease in the Ca-125. Okay, no progression of disease we will just continue, I think we go up to a year. We are getting up to a year, but it is every month.

Audience: Is that only at the NCI? Nowhere else?

Samir Khleif: Correct. It is actually GOG that is sponsoring the trial and they will refer patients but they will refer them to NCI. So if there is a GOG sponsored institution, they refer the patient directly to NCI. We have to do it at NCI because the way we prepare the vaccine is pretty complicated, and it cannot be done elsewhere.

Audience: How long has the vaccine been used?

Samir Khleif: How long has it been used? You mean the study, how long has it been opened? Maybe for about six months.

Audience: Can you get the vaccine along with chemo?

Samir Khleif: No. As with any other protocol or investigation therapy the investigational therapy cannot be given with any other treatment because, one, you need to determine whether it works or not. And second, you need to determine the side effects, whether they are coming from here or from there.