Adam Yanke, M.D., an orthopedic surgeon at Rush University Medical Center in Chicago, talks about a new experimental stem cell therapy that is supposed to help patients who suffer from osteoarthritis.
Interview conducted by Ivanhoe Broadcast News in August 2016.
Let’s first talk about this treatment and its use before in eye surgery. Can you talk about that?
Dr. Yanke: Yes, originally it had most of its data with cataract surgeries and also with wounds or burns in other words. It’s been shown with other tissues that it has the ability to increase healing potential and give you better quality tissue. With both cataracts or with burn victims, it’s actually been very helpful for healing those types of wounds.
Now explain how it works and what it is.
Dr. Yanke: The treatment that we offer specifically is an amniotic membrane product that also has amniotic fluid in it. It has the constituents of amniotic fluid and the cells themselves. Between the two of those they’re a potent anti-inflammatory and they also have growth factors that help promote healing or healthy growth of tissue in certain settings.
Why apply it to osteoarthritis?
Dr. Yanke: Mainly because of the track record that we’ve seen in other parts of the body and other connective tissues. These are where it’s been used before as other connective tissues which are not standard organs like you would think of like the liver or the heart. We’ve talked about the skin and the eye, so this is just another organ as a joint that we’re trying to treat by trying to decrease inflammation in the tissue.
Explain osteoarthritis too, what is that?
Dr. Yanke: Arthritis is a spectrum that involves the loss of cartilage inside the knee. Cartilage is the lining of the joint and it’s like the rubber on the tires. As you start to lose the rubber in your tire the rim hits the road. That’s what happens when you have bone on bone arthritis and you’ve lost all the cartilage in your knee. What we’re looking at specifically are patients that have some element of arthritis but they haven’t gotten to the point of having bone on bone arthritis so they’re not quite at the stage where they would be a candidate for a knee replacement yet, but they’re also too far along for any surgical treatment short of that. This leaves them in a grey zone with regards to current surgical treatments.
In using this amniotic fluid what does it do exactly?
Dr. Yanke: The point that I think is really important to keep clear is that it may or may not have an effect on growing healthy tissue back; that’s the part that we just don’t know yet. What we think that it does have is a higher likelihood of being able to decrease inflammation in the joint which is the primary source of pain in the joint. If it has any other secondary benefit with regards to tissue growth, then we view that as an added bonus and not the primary goal of the study. The primary goal is to try to show that it’s an adequate method of decreasing inflammation in the joint.
When it goes in, it decreases the inflammation because the term you used you said like a rubber tire then it hits the road, is that still going on?
Dr. Yanke: You can certainly still have some of that go on. The amazing thing is that those patients that have that happening don’t always have pain. The correlation of how bad the arthritis is actually rarely correlates with how much pain an individual is in. We see some people with very early level arthritis that have a significant amount of pain and some people have terrible arthritis and actually didn’t even know they had it. They came in for some other reason. The idea is that we’re just trying to either slowdown that process or at least make the whole process not painful so the patients don’t notice it any more.
We don’t know yet if this would actually stave off a knee replacement?
Dr. Yanke: It’s too soon but that’s the whole idea. Not because his or her arthritis is gone but because it doesn’t bother them like it used to. If you’re going to have a knee replacement the best time to do it is when you know that that’s going to last you for the rest of your life and then you know you won’t have to have any other surgery.
The amniotic fluid in the cell, what is it about that that’s just so healing?
Dr. Yanke: There are probably two main aspects and it has to do with the growth factors that are in the amniotic fluid. Those growth factors have the ability to decrease inflammation and decrease the negative response that happens when you get scar formation. Imagine if you get cut in your skin, when your skin heals, it will seal back over but usually it has a visible scar because it didn’t form normal tissue. It didn’t put hair back and it doesn’t have sweat glands back in it. The whole idea is that these growth factors decrease negative inflammation and promote healthy healing if it’s going to be possible. That’s the whole hope here. The other component is the cellular aspect. The amniotic stem cells probably have more ability to be a potent anti-inflammatory than the cells of an adult because they lose that ability as they age. Just like a person ages, cells actually age too. Amniotic fluid cells are essentially very young or almost embryonic cells but it’s not to be confused with embryonic stem cells that would be a separate category. Hyaluronic acid is another component that is also in currently used injections. The difference here is the size of the molecule is much larger which tends to correlate with an increased anti-inflammatory effect.
With this I guess is still in the study phase and how many, are you still enrolling people in that?
Dr. Yanke: We’re still enrolling now. This is a Phase II trial; Phase I has been completed and they have shown that it’s been safe. What we’re doing now is looking for efficacy. We still are currently enrolling and what we’ll do is follow patients for a year after the injection to show that it is effective compared to known existing treatments, which is part of the study as well as a placebo treatment, which is a negative control.
What are the existing treatments?
Dr. Yanke: The existing treatment that is in the study is hyaluronic acid and that’s a molecule that’s normally found in the knee; it’s just that the injection is a large volume of that molecule. It’s often referred to as HA for short or people commonly refer to it as gel injections or rooster comb injections. That molecule is also an anti-inflammatory but it’s also a lubricant and there are different sizes of the same molecule. In a regular knee or a knee that has arthritis, the smaller version of the molecule is present which actually can promote inflammation. The HA injections which is one of the treatment arms and what is commonly available now, ranges from medium to high molecular weight. In amniotic fluid there’s a very large form with multiple molecules stuck together which we think is even more of a potent anti-inflammatory based on lab studies.
How does the two compare so far?
Dr. Yanke: That’s what we’re trying to find out now. We don’t have enough data to know strictly what the actual answer is yet, but by the end of the study that’s what we’ll have.
Let’s talk about Linda and her case. What was the deal with her?
Dr. Yanke: Linda had knee arthritis, and again, it was not bone on bone; it was an earlier stage. She would not have been a candidate for a knee replacement because her disease wasn’t advanced enough. But she had advanced beyond having simple arthroscopic or debridement type surgery so she was in a little bit of a middle ground. The pain and inflammation that she had was limiting her in her daily activities as well as the things that she liked to do outside of that. She had tried the standard treatments that exist. She had a hyaluronic acid as well as steroid injections and they haven’t given her sustained relief. I discussed with her that we could try enrolling in this trial to see if she could have a benefit or not understanding that we wouldn’t know which group she would end up in, in the beginning. In the end, she was doing very well and had a great response to it.
It seems like because it was both of her knees that hurt, but she only did it in one, which is a great way to compare.
Dr. Yanke: Yeah, exactly. It just so happens that she’s interested in having it done in her other knee now because of the response that she had in the knee that we did it in. Obviously that’s what we’re hoping, that everybody is going to have a response to the trial injection.
It seems like depending on one of the applications that this could broaden beyond that once the results come out from the study and find how this works.
Dr. Yanke: It’s definitely true and there are different forms that it can be applied. There’s the fluid which is the injection that we use for a study like this. There’s also a strict membrane that’s literally a sheet of tissue, it’s almost like wet tissue paper that can be laid in to defects; that’s actually how they use it in the skin and in the cornea, it’s a little bit different method of application. We’re actually doing now an animal study where we’re using that in animals that have cartilage defects to see if we can actually grow cartilage back in that setting.
Are there any side effects with this?
Dr. Yanke: That’s a very important question, especially when you’re talking about donated tissue which is essentially what this is. To make sure that we decrease the risks of that, the donors are screened and we make sure that they don’t have any known transmittable diseases, obviously if they did they would not be included in the donor group. Then on top if it, the amniotic cells actually are semi immune-privileged. That means that the body actually doesn’t recognize them as foreign because there are no receptors on the cells for the body to do that. That’s all the theory part of it which makes sense and why we’ve gotten to this point. But then the evidence is that the Phase I trial has had no side effects and we have not run into a side effect in our trial either. I think that that’s the key and so far there have been no known side effects. They would really be just the side effects of an injection which could be risk for infection or local pain in that area but luckily that’s very rare and uncommon.
END OF INTERVIEW
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