Baptist Health Miami Neuroscience Institute invites Dr. Roy A. Bakay to discuss emerging developments in functional neurosurgery and restorative therapies for neurological disorders.
Um, so interest of time will get started. So, um, today is the first, uh, Roy Baquet. Uh, functional, um, lectureship and Roy Baquet was uh. A neurosurgeon um who started practice back in the early 70s, went to um Emory University in Atlanta after a fellowship, and then with two neurologists started. Uh, the first human work in DBS, deep brain stimulation. Um, spent about 28 years there and then in 2000 he moved to Rush University in Chicago. And continue the same uh practice was well regarded in Um, in the field of movement disorders around the world, Phil Starr, who's coming in December, uh, did a fellowship with Roy and found it one of the most relaxing and stimulating, uh, parts of his career because he had time to do some other things and think and observe and wasn't taking tons of calls, so. Uh, Roy died of stomach cancer after a long battle, but he worked um up until one month prior to his death. And um his partner at the time was a nurse, and she helped him out quite a bit, but he was determined to keep making a difference in people's lives, so. Uh, that was very respectable. Um, Russ, um, is a neurosurgeon, and he was trained at Loma Linda in Southern California and went to Utah for his residency, correct Russ? Was Bill Caldwell chairman then? Who was was it um oh yeah, Ron Applebaum, yeah, spine surgeon and Peter Harbor was a tumor. He did everything, yeah. He was a Renaissance man, I guess. So, um, anyway, uh, then really the transformative thing was Russ went to NIH for a fellowship with Ed Oldfield. And Ed Oldfield was a Kentucky born neurosurgeon who was the head of neurosurgical services at NIH. And had a very big interest in pituitary tumors, spinal vascular malformations, and hemangioblastomas. And Russ was there as a fellow, and then stayed there on faculty, and then became the chair of NH um neurosciences Services, and stayed there until 2012 when he went to go to Ohio State. As um a chairman of neurosurgery at Ohio State, uh, Ed was big on convection enhanced delivery, improving the technique, uh, development of some of the catheters. Um, Russ met a, a, a scientist by the name of Chris Bankkowitz, who worked actually at UCSF for a number of years, subsequently left to join Russ at Ohio State. And um Uh, two of them worked really hard on, um, convection enhanced delivery, and I won't spoil the show, but something that's gonna be um a biological product for Parkinson's disease treatment in the next 18 months, maybe 18 months? Yeah. Yeah. Now, uh, Russ is one of maybe 1.5 handfuls of true clinician scientists. He has Almost $80 million in NIH research funding. So, when he was at NIH every patient that came into the hospital was part of a clinical trial. And the work that Russ is gonna present today, he was the principal investigator on this study. Uh, the funding was $13.5 million for the study because patient care costs a lot of money, especially when you're looking at safety. Um, apart from that, Russ is, uh, about the same kind of golfer as me. We're not very good, but we have a lot of fun when we do golf and um I'm really, he's become. A good friend over the years. He was president of the Congress of Neurological Surgeons, uh, in the past, uh, which is a big honor. He's highly regarded as uh a cool-headed. Um, thought leader in, uh, neurosurgery and so we're delighted that he was able to come down for a really short visit. So Russ, thank you very much. So thanks, Mike. Mike's a dear friend and uh it's so impressive to see what's going on down here and we're talking about this last I really believe that more and more, um, the types of things that you're doing with industry and in academics will really drive what we do, particularly in neurosurgery, we're moving more and more to a model, um, where we're uh doing more clinical trial work and things like as you'll see today. Uh, through centers of with clinical excellence and um high volume. And um it's great to see Ro, who's a fellow of mine from how many years ago, a few years ago. Um, nevertheless, um, it's great to be down here among friends. So I'm gonna talk about uh direct convected delivery for nervous system gene therapy. I'm gonna show three examples and we'll talk about that trial Mike uh was describing. In gene therapy, just so we're all on the same page, cause a lot if you're not doing gene therapy. Um, it's critical to kind of know the basics of what we're talking about, and what we're doing is using viral vectors that are non-pathologic, we're placing the gene or the genetic material in for the gene of interest. Viral vectors obviously are great getting into cells. They get into the cells, they deliver that gene, it goes into the nucleus, and it creates a permanent um treatment, meaning once that genes in there for as far as we know, we follow these out in nonhuman primates for over two decades, there's still um expression of the gene that you want to put into the cells. So it's important to kind of know the history to understand why we are where we're at. This is not a new idea. In 1968, Rogers showed that you could use viruses as carriers to insert uh genetic material into cells. In fact, they added uh foreign genes to uh Lenihan's uh human cells to correct the deficit within that cell, on that same year, uh, seamuler. Went on in an they tried it experimentally in trials very early on in the 70s, um looking for argininase deficiency that didn't work, but nevertheless, the ideas were there. They tried to treat beta thalassemia and mice and were successful in mice but failed in two patients. Um, in the late 70s, early 80s, uh David Baltimore and his group began looking at retroviruses uh for gene therapy and published that work, um which they're very well known for. Steve Rosenberg, which I had the opportunity to work with for over a decade, Rolls knows him as well, uh started really using retroviral mediated gene therapy for till cells for cancer, for melanoma and renal cell carcinoma with some degree of success. Um, uh, Blaze, Anderson, and Culver, uh. Probably they thought they had some success with gene therapy and children's uh SID uh syndrome or SID uh disorder. Uh turned out that that didn't really pan out and French Anderson had a, a much more of a checkered past around that time as well. Uh, Jim Wilson, the Jesse Gelsinger uh case where they were treated orine uh transcarbamalace was a disaster. That patient was treated and died shortly thereafter from an overwhelming uh immune response. To adenoviruss. And so that really changed the field in the sense that it caused a real pause for almost a decade, from clinical trial work. Um, nevertheless, people then moved into other virus like lentivirus, as we, you know, we talked about that earlier today, and um they started to engineer uh lymphocytes and adoptive T cells for cancer, uh using genetic therapies, CAR T cells, you know, ultimately. Now you're all very familiar with the FDA approved its first gene therapy, and they moved on to AV or adeno associated viruses, and those are now the most characterized, um, because everybody wanted to get away from the adeno and lentivirus because of HIV, the connotation or the, the idea that it was the virus associated with HIV, um, even though it has, it would have no pathologic effect in the scenarios we'd use it, um, kind of went by the wayside. Um, lentivviral therapy was used in, uh, children though, uh, in the mid 2000s, um, and, uh, seemed to halt disease. CAR T cells, as I mentioned before, came on. The FDA approved, uh, seven gene therapy platforms for treatment in 2017, expected it to continue to grow. Uh, at our, our shop in Nationwide Children's, or children's hospitals, they had a spinal muscle atrophy, of vexis, um. Uh, was approved, uh, for had FDA approval in 2019, and now that's the way uh spinal meral atrophy is treated. Saint Jude's is used, uh, SID, um, for in infants as late as 2019 as well. ADC, which also some work in for replacement for that. Um, that is probably gonna go to registration. The FDA gave it clearance two weeks ago, so that'll be the first, um, uh, gene therapy that's gonna be registered by the FDA, um, here that's gonna come up and we'll talk a little bit about that. The FDA anticipates 10 to 20 new applications per year for gene therapy. Um, starting next year. So it's really, it's moving. There's a whole bunch of issues that we have to overcome and better understand regulatable genes, non-viral vectors, because viruses still cause immune responses. Uh, how do we produce better vectors, um, how do we do personalized therapy for these ultra rares, and um, how do we have vectors that are targeted to specific cells? We can do a lot of that through promoters and things like that, and how do we improve uh delivery? And how are we going to control the cost at the end of the day? So if you look at nervous system gene therapy trials, um, these are growing at an exponential rate. If you take that graph out to 2023, there's over 90 clinical trials, um, so we're really seeing this steep end of this curve. Um, it's growing, um, across the country and around the world. If you look at the gene therapy trials, now the FDA in phase one really requires us not just for safety, but they want us to look at efficacy. And if you look at gene therapy trials, 80% of those first in human trials have met, um. Uh, efficacy endpoints, striking, um, to see something that effective, um, for any of these diseases as you see, um, here, but it really goes to the core of why gene therapy can be transformative because it's actually targeting the problem, um, as it exists at the genetic, um, the genomic level. There's really 3 routes when we're talking about nervous system gene therapy, 3 routes of delivery. Systemic is the first one. it has widespread delivery cause you're giving it into an artery or a vein. It's advantages, it's the least invasive of all of them, and you can have potentially have systemic impact. The limitations are the blood brain barrier, um, these are large, um, uh, the compounds or or viral vectors. Um, they don't cross the blood-brain barrier. Um, they can be non-targeted and covered, so you have off-target effects, and you can't redose, or you can have, uh, because of the immune response, um, and even some patients, as you know, there's 2 patients in the 3 now, in the SMA trial that was approved that have died from overwhelming, um, uh, uh, autoimmune or immune responses. Not only that, one thing that goes by the wayside is you're diluting vector in 7 L of blood, and so we are pushing titers high enough so we can get biological effect by directly applying them to cells and ally. Imagine if you deliver in 7 L of blood and then the first pass effect with the liver removes all of it after one pass. Intrathecal intraventricular has the ability to have widespread nervous system, um, distribution. It's minimally invasive and you get, you have the potential for widespread spread nervous system impact. The uh blood dependable barrier can be in, in some disorders can be problematic. It's non-targeted in coverage, um, so you can have off-target effects, and then the immune response that I just told you about with SMA we didn't expect it. Um, we thought there was some shielding, but it turns out there's not. Um, you get exposure. Uh, nevertheless, the volume is only about 150 cc, so not 7 L, so you don't get as much dilutional effect. And what I'll talk about today is the direct interparal infusion. Distribution for this is limited. It's only to the profuse site, uh, maybe and beyond, as I'll explain a little bit more. It's targeted. You can selectively manipulate neuronal circuits and treat regions, bypasses the blood brain barrier. However, it's the most invasive, you have to directly profuse regions and requires significant infrastructure. You have to have an intra-MR and you have to be able to tie that intra-MR up uh for a day. The routes of delivery, when you look at inter uh interparal or convective delivery compared to others, when we wrote this, this was 2020, about just under half of the studies were interparable. Now, for the reasons we'll get into, over 60% of them are interparchimal. We see the intravenous declining, intramuscular is declining, cerebrospinal fluid is coming up a bit, um, and multiple um routes of delivery are, are rapidly vanishing. So it's really Uh, interparinal is the majority driver of how we give gene therapy today. So I want to talk a little bit about convected delivery cause this will inform why the uh we are doing what we're doing with the gene therapy uh protocols and some of the mistakes we made um along the way is, as Mike mentioned, Ed Ophel is a mentor of mine. He really, along with two bioengineers, Paul Morris and Bob Dedrick, uh, really developed a gene, I mean, a convective, uh, drug delivery. And what they found was, if you look at that met that circled in the red, there's a lot of edema around it, but it doesn't cause permanent effects and it rarely. Unless that edema gets too bad, causes any functional effects. But what they found was that there's large and small molecules that are moving out to that adenomous region at a very fast rate. And so you could, the idea came that they could push molecules through large regions of brain in a short period of time, and that's because it wasn't diffusion related, you could push those molecules, small and large molecules out at the same pace. It's an extracellular infusion process. So as edema got. Expanded the extracellular spaces, they can move molecules through there, and what they found it was simply just a small hydrostatic pressure gradient that drove those molecules through in a uniform way. And that uniformity of small and large molecules moving out at the same pace becomes important when we begin to images, and I'll come back to that in a second. It bypasses the blood brain barrier. These are some of the unique features, as I mentioned before. This is a non-human primate where we're putting a cannula into the brain stem and fussing in that area. So molecules that don't cross the blood brain barrier are ideal for this therapy or this drug delivery technique because they remain sequestered on the abdominal side. Those that cross the blood brain barrier, they just go, uh, like, um, BCNU and things like chemotherapeutics like that just leak right back out into the systemic circulation. You can get uniform distribution. This is quantitative autoadiography, spinal uh pig spinal cord, you see the dark area where the um autoadiogram demonstrating distribution. So you can put high concentrations of drug into localized uh areas, several magnitudes of order above, uh, that's what's necessary for biologic effect. Distribution is reliable, not so much for tumors, but other, all the other disorders where the Uh, tissue architecture is the same, and for a volume of fusion, you get a, a distribution, um, uh, in the tissues in a highly reliable relationship. And what that, uh, relationship is, it's inversely proportional to the interstitial space available for the distribution of the infusing. So the tighter, the broader or the wider the um cells are spaced out, and the extracellular space or interstitial space is bigger, it takes more filling so it doesn't travel as far. So in the brain and spinal cord that ratio is about 5:1. And what that means is for every milliliter of tissue or infuse that you infuse, there's 5 mL of tissue covered in the brain stem where the fibers are very tightly compacted, that ratio is anywhere from 6:1 to 10 to 1 because it can spread farther. It doesn't need to fill those bigger extracellular spaces. That's really critical for the trial work that will show up here in just a little bit, because the FDA now requires us to estimate what we're gonna need to infuse to cover those structures. We can cover uh clinically relevant volumes. Mouse rat, nonhuman primate rhesus in human, every virtually every disorder in the neurologic diseases has been cured at the mouse and rat level because you can cover those regions. The study a number of years ago in animals and neurology, 1250 trials and and rodents showed efficacy in stroke, and not one of those ever went through to um to reach um FDA approval. Uh, when you look even at the non-human primate to human. That's a magnitude order of 13 times smaller than humans. So a lot of what we do in non-human primate, we can't extrapolate uh to human. So we have a lot to learn as we're doing infusions, and we did learn a lot. We've made a lot of mistakes, you know, in our estimations of what we could do in human that I'll come to in a second. The delivery is targeted. These are uh coinfusions of imaging tracers that you see in white. We can, we can treat the brain stem. Uh, we can treat the spinal cord and peripheral nerves. We can and we can see, as you can see in the brain, some some of the most eloquent areas in the nervous system, uh, safely and successfully. We can target this, um, we can do this, we don't, we use frameless stereotaxis, uh, because we use an intraopMR and we have a high degree of resolution. Uh, we can do it with less than 2 millimeters of air, so we could put these into very small nuclear structures with a high degree of precision. Uh, this is work that Chris uh Bawits did, that worked with New Mike for a number of years and Adrian Kells. They published this in 2009, and the idea was when they were beginning to get into uh vector transport and gene therapy, uh, and up until that point, we struggled with it. We worked with the University of Florida, it is a powerhouse in AAV uh understanding, and this was back uh Mike Chen in '99 through 2000. It never worked and we never published anything about it. Um. The reason was, was that we, we at the time we didn't know that viral vectors were clumping. We couldn't distribute them consistently. So it went for a long pause. Chris and Adrian start to look at this with better vector preps, and so they infused down there in the left hand column, the thalamus of this nonhuman primate with AAV2, and what they saw in for expression of GDNF, and what they found is that through thalamic cortical transmission or transport. They were getting widespread um uptake and uh production of GDF in the cortex. So this created a whole new paradigm. It allowed for the focal targeted uh or targeted uh profusion of structures that would allow for widespread distribution throughout circuits. So one idea would be the substantial ventral tegmental areas, and I'll come back to that, some, you know, potentially ideal targets for Parkinson's or up or downstream targets. Nevertheless antrograde retrograde transport. You could do very small infusions and have profound effects. We didn't know that up until that time. Now these vectors have all been characterized. You see Ino associates the best, plenty, um, those are the best characterized, and then you can change the uh cellular tropism by changing the promoter, so you can target specifically astrocytes, neurons, um. Uh, uh, in myelin, if you want to, um, just by changing your promoter, and then the transport, um, you by the different stereotypes, particularly of the AAV you can go antegrade, retrograde, keep it in the same place without any intrograde or retrograde transport. So now you can target certain structures within the brain and drive gene therapy throughout in a in a way that you want or what in a way that's most conducive. They mentioned before AV is the most common vector. For interparriyal, um, use, 91% of those trials employ the AAV um virus, so this is really what we'll focus on. And then you can see the different serotypes and the directions that they go. So AV2, which is the most employed, and we use that, um, you'll see all the trials I'll present today are AV2, but we've used 5 and 9, and you can see that they're antigrade or bidirectional. We can also go retrograde. With some of the other um vectors that we're beginning to use now. We also use real-time imaging. So what we do is we place a small, we just use gadolinium off the shelf, it's a small molecule, but because convection uses bulk flow or small hydrostatic pressure gradient, we confuse these with large viral vectors or large proteins, um, and we can accurately track them. So I'll show you an example. This is years ago we started infusing, uh, Diffuse pontine gliomas in kids, and we're using IL 13 pseudomonas exotoxin, we're infusing with gadolinium. This is one of the first uh children we did, and you can see this in this axial MR. You can see we can see the distribution. But we were beginning to learn a lot. You see that area in the top left quadrant where the cortical spinal uh fibers are coming out of the screen. We were easily able to perfuse the more axial oriented fibers, but because they cross at a 90 degree angle, we realized that there wouldn't be perfect perfusion throughout that structure. So now we had to take into mind using the anatomy, the DTI images, all of that has impact on where this the drugs will distribute, including viral vectors. Went on and Mark Richardson, who, you know, Mike knows obviously well, Chris, and our group at the uh NIH Phil Star as well, the one on to show that not only could you predict where the vector was going, you could also predict where transgenic expression would occur at the site of infusion. We couldn't tell retrograde or antegrade, but we can use other bio biologic markers uh to determine that, and I'll come to that in just a second. So here's a clinic, we have 11 clinical trials right now at OSU, um, with gene therapy, uh, Parkinson's disease, AEDC deficiency and ultra rare, multi-system atrophy, Alzheimer's, Huntington's disease, that's a unicure trial, uh, melinic glioma, we have several, uh, there, we're bringing on, uh. ALS and um Uh, ALS and, uh, epilepsy are coming on in the next frontal temporal dementia all in the next 4 months. Um, we'll start trials on those. So I'm just gonna talk about 3 of them, cause these are the 3 earliest trials that, uh, we did. Some of these spanned into the NIH uh where Chris and I started a Parkinson's disease trial. One of those Parkinson's disease trials, the GDNF is regenerative, the ADC is symptomatic. Um, so the regeneratives for early stage, the symptomatics for late stage, and then the ADC deficiency, where we're just replacing the ADC enzyme defect, um, and that's something that's the easiest thing to do, and you can see we're, you know, we can make a lot of progress in ultra rares. There's the targets and there's the imaging, gadolinium is the imaging agent we use each time. So I'm gonna talk about the ADC trial first. Um, and so Chris and his group other at UCSF found that there's an AADC deficiency, and what ADC does is it converts levodopa to dopamine. If you look at the striatum of Parkinson's disease patients, they have propound uh reduction of dopamine and ADC. Levels in those patients. In fact, it's reduced to about 90% compared to age matched control. So they lack the ability to convert levodopa, the oral form of medication into dopamine, and this probably explains why they have those rapid cycling on-off effects where they're diskinetic, going to bradykinesia. Those, uh, the dosing required to do, to keep symptomatic relief goes higher and those, those fluctuations becoming more and more frequent throughout the day. And so here's this, what this does is the ADC converts as I mentioned before, the levodopa to dopamine, and here you see the differences. And, and you can look at non-human primates, they have the same loss that normal, uh, that they, that, that Parkinson's patients do compared to normal uh controls. And so, uh, Chris and that group really got the idea that that was, you know, creating a lot of problems, the on-off effects and things like that. So the idea would be, if you look over the course of a Parkinson's disease patient, and this occurs over 3 to 5 years after diagnosis and medical treatment. Early on, they require infrequent levodopa dosing. They have good periods where they're on very few dyskinesias and the off time is compressed. As they move through the moderate and advanced stages, those, um, the levodopa dosing increases um dramatically. The on off times fluctuate more frequently, dyskinesias increase and off-time increases as well. The on or good time uh diminishes, and so the idea was What if we could take and infuse the AADC, restore that enzyme deficiency, get them back to converting the levodopa to dopamine in a consistent way. We could reverse. Those symptoms. So this is a study done at UCSF OSU, UPMC and Emory, and what we're doing at the time, and this was, this is a little out of sequence from the regenerative. Uh, we learned a lot from the first regenerative trial that we'll come back to. We knew that we weren't treating enough for the butaneen. So what, what we did in this second trial was increase the dosing from 450 microliters per butanen all the way up to 1800 in the 4 dose cohort. Since this was phase one, this was determined the safety and feasibility. We were looking at secondary objectives like looking at increased uh ADC activity through fluor DOA PET, obviously monitoring clinical impact and seeing if we could reduce the levodopa requirements in that. Um, we used the transfrontal approach and that becomes important where we're coming from on top through multiple stab, uh, little incisions and infusing. Here's an example of that, and just the three different views were coming from above. You see there in the coronal, uh, axial, uh, coronal plane there again, and you can see in the axial plane, you can see where we're doing two deposits on each side, and you can see there's a little bit of leak back and the as the vessels come up from inferior to superior, they create uh perivascular spaces that are low resistance flows, so there tends to be a cranial caudal distribution that's low resistant, that becomes important just a bit. So we thought is like is, remember, we're doubling the doses or the, the amount of infusion, you can see from cohort one to cohort two to cohort three, the amount of the butane is do um increases significantly from 21 to 42%. Nevertheless, 42% isn't spectacular at the end of the day. But not only did we see that increase in infusion with increasing volume, we did actually see biologic and clinical impact. So the ADC deficiency is uh seen by an increase in fluorodopa pet. Sequentially went up with the increasing coverage of the butanen from 13% to 80%. The uh levodopa dosing requirements dropped from 14% to 42% with that increase, that doubling of, of increase in coverage. So we were now walking away from a paradigm where, where the FDA initially was looking at, well, you just need to treat the amount of viral vectors you're giving, that should be uh based on the uh body mass um or the body surface area of an individual like the dose um medications. And now this really became about how can we cover the. The structure within the brain because that's the actual dosing. For covering 100%, it's very different than covering 50%. And so here's what clinical results showed, uh, just briefly, you see the baseline um group on the left, and you see that the on time after at 12 months increased nearly doubled, the um off times decreased in half, dyskinesias virtually vanished cause these the levodopa dosing decreased, and um so what uh that was able to show is that we're able to Really do what we set out to do, and that was take it back from a late stage disease symptomatically, bring it back to an early stage uh disease and um Nevertheless, so that, so that was a company Chris started called Voyager, that was bought by Nurocrine. In that process of going into the phase 3 final trial, Nuriran changed the manufacturing setup. The FDA did not require them to go back that completely different way of making the vector, same vector, but a different way of making it. That trial got stopped because when they started to infuse that vector, it started to put holes into the butanen where they were um confusing. So that trial was stopped. It never got resurrected. In fact, we probably will resurrect it. But we've got to go back because the results were pretty were um dramatic. They've been published um uh several times or as they, as we migrated through that study. And so it's a great, it was a very good treatment for severe um Parkinson's disease. What we also learned, as I mentioned before, is that the trials that have failed in the past, seragen, uh, nurturin, that they're only covering 10% or less of the putamen. As you increase more, you started to see better clinical impact. Each putamen is about 4250, um. Uh, microliters or 4.5 mL of tissue that you have to cover. And if you get up into the 60 to 80% range, um, then you can really start to have dramatic impact. So it really emphasizes that we have to cover these structures, and there's a real neurosurgical, uh, technical piece to that, and we had to figure out from going from that trans frontal, how can we get more coverage. So I went back to the non-human primates, this work we did with Chris at the time. And look, can we come posteriorly, just down the long axis of the putamen. And then instead of keeping fixed uh infusion areas, move that down the putamen, take advantage of those low flow perivascular spaces that are going from ventral to caudal, and start to do more with that. So the idea, this is just a schematic here, and this is what happened in the non-human primate. So when we did transfrontal and non-human primate. There's about 40% coverage. When we came from behind and advanced the catheter from back to forward, you can see by changing position and rate, we can actually perfuse about 80% of that butaneen uh successfully and contour the infusion rather than just have the kind of dots of infusion. So that's, and so the clinical trials reverted to that as we move forward. And here you see an example of that in in a human, and now you can see we can get much, much better coverage than when we're doing those transfrontal uh infusions, and anywhere from 60 to 80% coverage now in humans, and this is what we apply when we're trying to uh perfuse the uh butanen. So at the time, and prior to the ADC trial around the same time, Chris and I started a trial when I was at the NIH is for regenerative therapy. So in 1993, Frank Collins, uh, really had a, a great discovery. He was using GDF or glial cell derived neurotrophic factor, and he was rescuing midbrain dopaminergic neurons. So the natural consequence of that was that would be great if we could just rescue midbrain dopaminergic neurons and substantial Parkinson's disease patients. Steve Gill took the protein GDNF, started infusing it chronically in Parkinson's patients published a landmark paper in 2003 in Nature Medicine where they saw uh very uh dramatic results. And this is Steve's, I think it's his second patient. This is pre GDNF implanted a catheter, continually pumped GDNF. Into the patient And um had pretty significant results and more than just this patient. So there's a great deal of enthusiasm around this at the time. A second here, I'll get to the infusion part. So this trial went on to, uh, from phase one to phase two, launched to multiple sites and failed miserably. And so we weren't part of that trial cause we were advocating for imaging agent. We wanted to see where this is going, no one was really tracking it. And so when we Medtronics, who had the catheter and everything else, allowed me, Paul Morris, and Ed Oldfield to look at all the data. 70% of the catheters were placed in the wrong place. Sites that had never done this before were just dropping catheters. They wanted to participate in a first in human trial or near first in human trial, and it failed miserably. It killed the trial, uh, Parkinson family groups advocates, uh, were beside themselves with it. And nevertheless, it wasn't an ideal strategy because you had to chronically infuse. So gene therapy was emerging, you could see at the time that AV GDNF study that was published by in PNES by Chris and Adrian, really showed that you could target one place permanent delivery or permanent treatment, and have widespread effect. So the idea was, and Chris did this in nonhuman primates at first, infused um. Uh, the putamen, you could see that the uh striniral pathways, um, through antegrade transport with AV2 and GDNF, you could have rescue, uh, tyrosine hydroxylase neurons, um, throughout that entire system through that as mentioned before the antigrade transport fuse the butanen goes totantinagra, so people ask, well, why don't you just infuse the substantia nigra, you get it there. Unfortunately, the antigrade goes also to the uh hypothalamus and those animals becoming anorexic. So we could take it and move it back as a snaps, put in the butaneen, capture that for motor effect, post commissal motor effect, and pre-commosural uh cognitive effects as well, and then get the substantial rate to go as well. So it's just applying those biologics of the vectors. Uh, we can now begin to manipulate systems in a really sophisticated way. So the idea again, putting the deanen. Antigrade transport takes it to the substantial ***, but we don't have the hypothalamic uh anorexic effects. Did it in non MPTP monkeys saw a dramatic effect, uh reduced their symptoms in over half, and some of these animals are still alive over 20 years later and still having a sustained impact. So so in an animal model that this could work. So the idea was, and at this time, the FDA said, we're not gonna allow you to do this other than a severe Parkinson's patients. They later went back to moderate. We knew this trial is going to be a failure because that when symptoms start, 80% of substantial is gone. So how could we rescue anybody with severe, um, because there's no cells to rescue. Nevertheless, we were stuck with that. Um, they yielded, they gave us instead of unilateral, which they wanted, they allowed us to do it bilaterally. They made us keep a fixed volume dosing, uh, so we're at 450, and if you know that roughly it's the butanen's 10 times bigger, the best we could ever hope to is get half of that. Um, with the just that that ratio of 1 to 51 to 4 to 1 to 5, and we knew we were gonna get it. We used the transfrontal approach because we again this would start at the same time, the ADC. So we didn't have any idea about using a posterior approach. We looked at safety and feasibility. They did expand even at that time to a instead of a 3 by 3, it went by a 6 by 4. They want us to do 6 patients in each cohort to see if we could tease out any efficacy. We looked at fludopa pet. Um, we also looked at motor assessments and uh levodopa requirements. And so obviously not a great, uh, group of patients post the first three year results in that group in 2019, again transfrontal. We were only covering in that group of patients 22% of the butanen, and that goes perfectly to what we saw in the ADC transfrontal. So we were getting less than a quarter of the butaneen, most of it was leaking out of it. On fludopape, nevertheless, at 6 months and 18 months, we saw increased uptake of anywhere between 40 and 50%. So it was having some impact on those patients. Um, none of the patients got better, but they did remain stable for 3 years, and their average levodopa dosing remained stable as well. So it dramatically changed the course, the natural history of the disease, and I'll come back to that in a little bit. We just published the 5 year data, I think it's just out in pre-print, um. And movement disorders as well at 5 years, and we still see stable levodopa requirements and no progression of the disease across that cohort of patients. So we were surprised, quite frankly, that they did remain stable, suggesting nevertheless a few amount of cells, maintaining a few amount of cells can help. One of the patients passed away, was treated, uh, operated on, not at the NIH but somewhere else he had an ACDF. He got a pneumonia, aspiration pneumonia uh afterwards and died. So we uh obtained the post uh his brain afterwards we were able to do postmortem comparisons to his original infusions, and in fact, where we saw the infusions, we actually saw persistent GDNF production 3.5 years later. Confirming that what we see is what we get on those scans, and when we did quantitative auto radiography, those nonhuman primates, we had less than a 15% error, so less than a 2 millimeter er and distribution from what you see is what you get. So seeing sustained uh production also showed that that imaging uh was a a great uh surrogate for where we're gonna get transgenic expression within the brain. We also saw, you know, we just published this a couple years ago, that the long-term safety data um holds out through short and through long term with imaging um for using uh gene therapy within the brain and using coinfusion of gadolinium. So we decided, you know, when Chris moved over to OSU, we decided we wanted to go back and treat the patient population that this was really designed for early, and, and the idea there as well, if we can prevent that because these early stage patients can remain look normal for years and years if we can prevent progression, or if we could take moderates with, you know, additional cell reserve and restore um. Restore function to them and bring them back to an earlier state by infusing uh the AVGDNF. And we went from a transfrontal to a posterior approach so that we could cover more of that putamen, as you saw in that previous scan, that was an ADC infusion I showed before. We wanted to determine the safety of treatment, and we're using fluorodopa pet and looking at motor uh function as well as levodopa requirements. And so we ran that study um at OSU and we found that, and we, these are the mild and moderate cohorts, uh, we found that we could treat on average 63% of the putamen, so um um over tripling or nearly tripling what we saw in the initial GDF trial, and you can see the advantages of the posterior. Um, now what we're able to cover is significantly different than what we're able to do from the transfrontal and the severe patients. The mild cohort remained stable. Uh, the on-off periods of what we had hoped and expected, um, from that, um, but when we began to tease out in those 6 patients and Chris presented this, uh, stuff at the, uh, uh, this data at the Academy of Neurology last month, uh, showed him that now he had it out to 24 months, but we saw 2 of those patients got worse. One of them had a tyrosine hydroxy mutation. We don't know what the impact is. That patient continued to go off. Uh, uh, in progress in a, in an aggressive way, and then half of those patients got significantly better, returned to a near normal state at reduced doses of levodopa. The moderate cohort um got significantly better, um, in fact, almost in the uh in the on and off periods, uh, uh, reduced their symptomatology as as well as the requirements for Levodopa, and here you see, you know, through, um, Over time at 12 months, 18 months, and now we go out to 24, um, their on time increased significantly, their off time, uh, was reduced significantly in half, and their dyskinesias, uh, virtually uh dis disappeared as they were going, um, as they were coming along and reducing their levodopa dosing, and they began to appear just like mild uh Parkinson's disease patients. And they presented that, uh, data, um. At the uh both at the academy and when you compare the AVGDNF, that phase one B trial that we ran to the AVGDNF in the nonhuman primates, which really was uh dramatic, you could see that it actually it did better than that and you look at the CRG nurturing trial where they only covered 10% of the. Uh, putamen, you can see the difference there, and then you look at the natural history curve shown there in black, and so you see all the way out to 24 months. So a significant improvement in this small uh phase one first in human trial, uh, for the moderates and stability across the mild. And this just goes and shows and this, these patients dropped off, this is still early now, we have the 24 month data. The uh moderates dropped down to a motor score of about 10, and so did the milds um as well, and you compare it to the severe dis uh patients that we had just a quarter of the putamen covered, the low and the medium doses there, um, so very, very different scenario, better patient selection, better patient, better putaminal coverage. Uh, that trial is, we, that um was uh picked up by Bay. Bay is gonna run the phase two. Uh, phase 3 trial of Mike was alluding to that's gonna start here in the next few months. So I'm gonna talk last about an ultra rare where we're just replacing something. We're not trying to regenerate, we're not trying to change symptoms. Um, this is the easiest thing we can possibly do. You found a gene defect, you replace it in a target area, and these are the impact that can really happen. So we just published this data a couple of years ago. It's the ADC, which is aromatic amino acid decarboylate sufficiency. Uh, this is what called pediatric uh Parkinson's disease, so it's a counter to the symptom pathology problem that occurs. Um, in adults that have severe in, uh, severe disease and have the fluctuations, these are kids that just don't have this enzyme period. This is what they look at, look like. They have severe developmental delay, global hypotonia, she has to sit in a chair with support. They're nonverbal. The impact hits at about 10 months, so they never learn how to talk. They have involuntary limb movements, debilitating oculogytic crises, which you see here, their eyes roll back it's almost like they're seizing. These patients from diagnosis to death is average 6 years. These patients mostly die in the 1 or 2nd decade of life. The ones that go on are pegged and trached, and they have sophisticated uh healthcare, um, that get them through, um, because they obviously have no ability to aspirate, they have a brain stem um type death. I mentioned this ADC that's missing. So all the downstream conversion of ADC from L-DOPA to dopamine is gone, so you don't have dopamine. You don't have serotonin because it prevents the conversion of 5HTP into serotonin. You have upstream increases in 30 methyl dopa as well as 5 HTP. So now we have a biologic or marker or markers we can track to see if we're having a biologic effect, even if we can't see clinical effect. This is their PET scanning, so we can use PET scanning. They're completely devoid of dopamine, uh, fluor dopa uptake, uh, compared to normal controls on the top. And Chris and his group at the time when they're at UCSF looked at this using the AAV again confirming putting in the putamen, or in this case butamen, later fine tuned it to the substantial nigra and the VTA, but see, you could apply that AV2 and get antegrade transport across large regions. And so the idea was, why don't we put it into the substantial Igo and VTA into antegrade transport increase dopamine production throughout the brain. From a small target a few millimeters in size and the upper midbrain. And so started a two dose cohort, um, with increasing viral vector, uh, viral genomes in in 160 microliters. 160 microliters is more than adequate to cover, and remember, the brain stem has those tight fiber tracts and cell density, so you can distribute much further into these very small structures. And the idea was to put it into the stantia nigra and ventral tegmental areas to find safety, look for clinical effects, so this again, the efficacy piece of that, and look for fluoriddopa biologic changes for uh pet. And assess the feasibility, um, and accuracy using MR guided infusions as you see we're using in all of these cases. So this is a coronal MR as you can tell, T1 ventral tegmental area and substantia nigra, drawn out there place cannulas we now use a transfrontal approach because we're coming down the long axis and to perfuse those regions, and then we do real time imaging like we do in all those other cases. And you can see that we're covering significant amounts of substantial nigra and ventral tegmental areas. In fact, when you looked over that study, almost 100% of the substantial gra is covered and about 80% of the ventral tegmental areas. So really strong coverage, we can really test the efficacy of replacing that gene defect in that site. So we're looking at we're just replacing loss, real straightforward, simple kind of um idea for therapy. So what the other interesting thing is we're monitoring these patients is you can see. Baseline there, in the middle top, and then you well you see where we infuse, you can see baseline, we compare that to what the floor dopa pet shows three months later, a striking increase there. But what was also interesting is we were never, you can't confirm that we saw downstream impact or angrade impact in the team and the other areas we wanted to see, and in fact, at the 3 month uh fluid dopa pet, you see dramatic. Uh, increases in uptake of fluorodopa suggesting or um, that we are getting that antrograde effect from those two small variant infused areas. It's another biological way to look at it. Again, we could see in CSF when we looked at these at defined time points 36, and 12 months, you see that um dopamine is increasing significantly across all those patients and the 30 0 uh dopamine is decreasing. Um, in those patients as well, suggesting it's being converted, uh, from levodopa into dopamine. And so I think, uh, you know, we can look at all those biologics, uh, the biologic or biochemical studies, and, and, and obviously we're doing motor exams and things like that, but it's probably most striking to see what we can do when we can replace, you know, simple areas like this. This is that uh girl, um, you know, before infusion. This is her 5 weeks post infusion. She's now beginning to get trunk control. She has dyskinesias. We now know that dyskinesias are probably a really positive sign because they've never had dopamine. So dopamine receptors are hyper up regulated. So now they're starting to produce dopamine. This is a great sign. They're producing dopamine, they're hitting those receptors. She's starting to get dyskinetic, um, just as soon as 5 weeks after. We now see this as soon as 2 weeks after. This is her at 9 months, still dyskinetic, but she starts to have emotive expressions that these children never have emotion or can express emotion before. They have to wear ankle foot orthoses because they've never borne weight on their joints, so they need support for a long period of time, and she's, you know, obviously needing significant support to ambulate. Dyskinesia is a little bit better, um, uh, nevertheless progressing. This is her at 12 months. She's now has full trunk control, no dyskinesias, um, uh, there are subtle dyskinesias. I'm able to speak in 234 word sentences, and now at 24 months, and I forgot to put that in, she's now able to ambulate without, without, with no assistance, and now can talk in short sentences. Um, and so, but they've really been developmentally stalled, but the cells are still intact, the pathways are still intact. All we're doing is just replacing that defect. And now we're interested in can we go into deeper serotonergic areas like the rafa and things like that, potentially retreat, we've done this once, um, and look for more cognitive impact and things like that and get more aggressive. In fact, we're now almost doubling the infusion sizes. Um, the FDA allowed us to do that. This is her there and before. So you can see a dramatic impact in these patients. I think 70% of them went on to ambulate independently. As they get older, they don't seem to have as much of the reserve as these younger children that are 45, and 6. And now we're moving into treating um uh 2 and 3 year olds um in the next phase of this with the um with the FDA's approval. This is the this is the uh objective data. The ocullogya crises, which concerned the parents the most resolved in all the but one patient. Uh, within 3 months, uh, motor scores improved in all of the patients, as you can see, I think 70% that went on to ambulate independently. Dyskinesias, which I think are a positive sign early on. If, if they didn't have them, I'd be concerned. Those all resolved within 24 months, and you can see that most of them resolved by nearly 18 months. And so, they're not painful, um, and, uh, nevertheless, it's something we expect to see and we can see as early as 2 weeks. So I think, you know, now we can apply gene therapy interally. We can use targeted um areas and have global impact, just understanding the neuronal circuits. The MR guided delivery right now is important. We're trying to move away from that over the next several years, so it doesn't require intraoperative imaging, and we can get therapeutic coverage, things we needed to do in large, um large areas in small areas as well, and we can clearly have significant um impact across those three diseases I've shown. Those other diseases that were on that table, we're still learning about Alzheimer's, frontotemporal dimensions I said it's coming on. Um, so, nevertheless, I think there's a whole lot of opportunity moving forward to, uh, personalize this as well as treat an ultra rares and treat, uh, widespread uh disorders that really impact, like Alzheimer's, Parkinson's, and we're beginning to look at stroke recovery and things like that as well. So, thank you very much, and I'd be happy to take any questions. Um, I think the, uh, videos are the most dramatic thing you would want to see. Um, I saw those years ago with Paul Larson, for a while, the NIH would not allow the investigators to show videos at during talks because they thought it was too dramatic and would be, um, there'd be repercussions if the treatment eventually failed, but as you just heard, it is not, so. Um, questions, Justin? Fascinating. There is a rate of, I don't, I don't know what you would call it, infection, so that you deliver the virus and then on a postmortem or something are able to see what percentage of the cells actually got that vector inside of them. So that efficiency that you're talking about hasn't been done yet. It will be in time as these patients begin to pass away, so there's a number of patients have been treated with HD. We're still waiting on the results, your results uniture is uh published and presented. Um, eventually these patients will pass away. It's hard to get efficiency in postmortem at distant time points because you're really looking at the expression, and you don't know, it's hard to tell what originally was there, like you could in a nonhuman primates. I don't know if we'll ever get to that. We'll probably what we will be able to do the regional comparisons. And the reason I'm asking is because it seems like. You're getting great coverage and, and but then you're saying we need to get more of the butaneen or more of whatever structure it is. It seems like you're getting a large percentage of it and, and that it wouldn't make a difference whether you need to get like 100% of the actual visual coverage of it, you know. Yeah, so the, the lower coverage coincided with less impact. So the patients in that those trials have not passed away. Um, but we do know it really does linearly correlate with their clinical impact as well as their, uh, bio biochemical markers. In the ultra rare, they were just getting covered, so we could easily cover that amount of volume and then get and get impact. We're we're teasing out now is in that those that phase one B for the GDNF and things like that. Um, as well as ADC if we restart that covering that 80% of the putamen and really looking back at the historical pieces of those, but we can see that, uh, from that early data that really does matter how much you can cover. It's directly correlative to, you could call it dosing. So you dose half the butamen. In that ADC you got half the impact. So another weird question real quick, uh, has there been any, uh, look into selectively opening the blood brain barrier, uh, with focused ultrasound or something? Yeah. So we have hyphoon Li. I don't know if you guys have it. We use it for thalamotomies and stuff like that. LiFU's been used for Alzheimer's. But here's the thing that, you know, since the, the mid-seventies, Razan, Fenstermacher, and Patlack doing a lot of CSF studies, doing a lot of blood brain barri open and just studies. And what they found is that you get a drug in, it leaks back just as fast. So BCU, even though gliadel wafers makes no sense, it's just gonna leak right back because it can cross the blood brain barrier. There's no magic being on the other side of it that keeps it in. So the same thing occurs. Now saying that there's gonna be some percentage of uptake that's better than systemic when you open it. Um, the ability to target is hard. The other way to look at it is you're diluting it in 7 L of blood. So we're pushing to get therapeutic levels when we're putting it directly in, but then you take that those 160 microliters and you put it in. Take multiply times 10 and then you put it in 7 L of blood. It's almost there's nothing there, um, and, you know, so it's, it's super problematic that way, yeah, and immune immune response is another issue, um, yeah. Um, you mentioned that you're in the future, you mentioned that you're going to be looking at SMA patients like the, the high mortality young kids. What's gonna be your approach, uh, to where you would in, are you gonna use gene, um, that's been done that so our colleagues at Nationwide that our faculty or or children's hospitals did that. It's been FDA approved and it's had dramatic impact, but it's been done through CSF delivery. In that case, and they've had, so it got, it's already been um approved for that's widespread then. OK. It's just such a rare disease that you hear a lot about it. Um, but yeah, it's had a dramatic impact on those kids' life. The issue, go back to New York Times and stuff a couple years ago published is it cost, I think, 2.1 million. For child. Now it's life saving, yeah, it is life saving, and um nevertheless, it's 2.1 million and so what we're looking at, to be honest with you, is strategies partnering with our institution. To indemnify and then to drive the cost of these down into 100 to $100,000 which is reasonable for like these ultra rare. So this is why we kept it as a research trial, is to keep it out of the hands of that. It's just multiple infusions for those kids? You know, it's permanent that we can tell, one time dose and one time dosing, wow, that's amazing. Thank you. You know, one of the things um I thought was most traumatic for the moderate severe PD patients was The stabilization of dose and the reversal of the on off to the steady state. You, you wanna talk about that, how important that is for the patients? Yeah, and, and, you know, that that was gonna obviously gonna take some time to really see if it holds, cause now we're looking at regeneration in the GDNF. The ADC was dramatic and, you know, again, well, those patients that were first treated in the phase one will be continued to follow. GDNF, same thing, stability. We're learning a lot about what that means, are the cells just You know, is there any you know, how much is regeneration, how much is just supportive of the cell? We don't know that at the end of the day. But that, if we could, uh, that's bending the arc, hopefully, well, but we won't know for years. It's been in the arc of the natural history of the disease, returning them to a a moderate to a normal or near normal state where no one, if you're walking around, can tell you have Parkinson's disease, but it in those scenarios would have if it is truly regenerative, then, you know, hopefully we don't worry about it coming back. The ADC, um, where we're just replacing that enzyme, is that gonna be enough to keep their symptomatology at bay for 10 years or 20 years? That's the thing we don't know. We know, you know, in 5 or so years out, we can do that, but in 10 or 20 years, because these patients are living a long time now, we don't know if it will hold you. Another question from our radiologist, how much gadolinium are you infusing and are you diluting it? Yes. So we, the interesting part about that is for proteins and in smaller, so albumin, which is 60 0 70 kilodaltons unless we use 5 millimolar concentration in with a protein or therapeutic in the that size or smaller. For virus, we know it traffics a little bit differently when we infuse, so we use 1 to 2 millimolar, and we then know that it will, it, it will correlate with the transgenic expression and give us a smaller uh distribution volume, but a great question. Any other questions? I'm just thinking about something. I got distracted by that radiology question. Um, Oh, the frontotemporal dementia, uh, the cell, the von Economo cell was just discovered like 5 years ago, and, uh, Bruce Miller, who hopefully will eventually come, told me that he thought it was gonna become a surgical disease. And um, do you want to talk a little bit about that? So first patient went over there, uh, treated in Europe, thalamic infusion, so we're applying what Chris showed in that initial study to get, yep, and then. It gets down to the point where we, you know, we want to refuse the thalamus, you know, ideally you would target just the subnuclei of the thalamus that go to the frontal and temporal regions. Um, it got a little more complex than we thought, so we refused the t had excellent distribution, uh, in the thalamus bilaterally, and it's for progranulin. Um, it's an Aviato bio study, so it's out it's public information. Um, we'll do the first US one probably next month, I think it is, and then we got a couple lined up. But it's for progranulin and we'll see what happens cause we're getting and at least in that first patient great coverage. It was like clinical stabilization. Yeah, and, and, uh, imaging as well, and lack of imaging progress cause they progress so fast on imaging, that's probably the fastest biologic readout, but they're also doing cognitive stuff as well. Yeah, I think uh I wanna ask you a question, um. So do you think Chris will get the Nobel Prize if the phase 3 trial is positive? Uh, It'd be great, but you know how it is impossible to tell. I mean, because a lot of the, it's looking at it in a technical way, the techno it's, it's it's technical at some level because you can see each of these platforms is different. The the it's each of these companies, each of these researchers are are coming up with their different gene, but at the end of the day, the genes the gene, the vector is the vector, those are all been done by other groups. And then the technology is, you know, it's, that's 35 years of work. I mean, all the properties, Ed, Bob Dedrick, all of them hammered out for this, so yeah, yeah. Yeah, I remember, um, when I first came to UCSF we had a really bright, uh, Dan Lieberman, remember Dan Dan worked with that old field and he, yeah, and he was, you know, perfusing, um, dopamine at the time, and Dan and I submitted aEA grant, our academic center grant to perfuse. Herpes virus into the rat or into the cat brain, sorry for the cat lovers, but um to look at uh toxicity because we'd published information in Vancouver on the utility of the virus to eliminate U 87 in an immunocompetent rat, and then we and then Bill. The virologist um took the same herpes virus in 108th multiplicity of infection or 10 units, 108 units, and showed that after 6 weeks, there were no detectable remnants of uh herpes virus DNA in any of the cells around the injection site. So everybody was worried about the uh inflammatory viral effect of some of these mutated and safe non-replicating viruses. Of the herpes virus was replicative if you had proliferating cells. So if you needed that, you need that for a tumor and oncolytic effect, uh, but I won't mention the Nobel laureate's name, but we had a a few at Us if we got the the shortest refusal. On a yellow piece of paper typed out, this is the most ridiculous. Project I've ever heard of. And that was in those days, remember we were trying to infuse heparin to increase the distribution of the virus cause the virus is relatively big, but as you can see, adeno associated virus, which is a similar DNA virus to herpes, uh does quite well. Any other questions? Yes, Justin, one last one. Delivering the vector to cells outside of the target. Yeah, so. Yeah, and that's why the imaging age is important because then we can control the and that's why the FDA likes, there's a safety component. So we get safety out of it, we get distribution, we get the ability to paint the structure by moving and changing rates, uh, but it does provide us safety information and um by controlling the minimizing the amount outside of the structure. There have been um some Particularly in the unicures all public information, there's some T2 changes that last for several months. They've only resulted in headaches and things like that. Um, so they're thinking is there, is there some immune reaction to it that a transient period of time. So we're looking, some of these will require some immune suppression potentially afterwards. But, but even if there was no immune response, the overproduction, I guess, of that particular protein outside of that particular circuit, does that That's what we're trying to sort out. So a very big example to your point. A great question is, uh, the Unicure studies that using a microRNA to shut down the production of mutant Huntington, how much do we need to shut down? How much do we need to use? We don't know. I see. Yeah, thanks. In the condition like ALS that is so widespread, here you can target very specific size, but in ALS it's so spread. What is, what are you planning to do? what would we do? With ALS, yeah. So there's a number of companies looking at this currently, and a lot of them are doing it in a pragmatic way for FDA approval and beginning to look at use, treating the cervical spine for respiratory issues, and I think where that lands, where it goes, I we'll have to see, but it would be early stage, and it would be everybody's looking at the Cervical spine for diaphragmatic it's a. Yeah, so depending on familiar or whatever, they're looking at a whole, yeah, everybody's kind of chasing different stuff. What's the um uh degree of technical difficulty with the infusion surgically? I mean, I used to see my Uh, functional people doing it, um, I mean it's a 6 hour day, correct? Or longer for if you're doing 6 infusions, it's longer for you to cure. Is it, is it, so that's the issue. That's a big thing, and we, so we've had a couple of meetings, um, Ignite, we call them Ignite. This is from Clear Point because ClearPoint is the only technology approved because the big concern is that this will fail like the other, the GDF. If you get out the minute you get outside of a center that doesn't do it routinely, like any surgery, it fails. And I'll use, you know, Sandeep Kumar's, you know, the IL 13 pseudomono exotoxin, he's probably told you this, they did phase 3 trial, only phase 3 trial. In uh GBM with convection ever done. They've got 300 patients in 14 months, yeah. And what they found is if you take the 3rd highest enrolling site, remove it, we would be treating GBM that way. Cause their results were so different and so you ask yourself what happened. They had the fellows in the residents placed in the catheters, the attending member was in. And the infusions were terrible. They weren't even at target. That one site blew up the whole trial. You just take their data out. We have a different way of treating genes, you know, not a microphone wasn't even in the country and um and so yeah, that's how important the technical parts of it, and they weren't even using imaging agent either. So now what we can do is there's technology that, you know, through uh Maestro at Clear Point, they can quantify the structure, they can quantify in near real time the um the percentage covered, and now you can imagine you can use that, that coverage as a way to distinguish surgical ability, center ability, as well as efficacy, you know, what threshold you need to get efficacy so that, you know, now you'll have a whole corehort of patients with really defined, this is what's covered. Um, and so now the technology is moving and evolving very rapidly, but yeah, it's, so we're grappling with this. How do you qualify a site at this point that gets up and running? How, you know, do you do it like you do endovascular, you know, you come, you see some the procedure done at a site, 3 of them, then, then you go back and then 3 people get proctored and then it probably unfolds into, does it unfold into functional, doesn't unfold in tumor cause The tumor in this has been probably the biggest driver for it, but don't you think you need some certification program here. But it's gonna probably have to come from industry. What's that girl with this young girl he showed me that's yeah, the, the girl that um you saw with the enzyme deficiency, Paul Larson, I think, and Nalan Gupta, Nolan did her treatment and the first words she said to her mother were I love you. So that was pretty traumatic anyway, Russ. Fantastic talk. The biologic future is here, um, soon to be coming, I think in the next 18 months, both for movement disorders and epilepsy as well, so very exciting time to be in neuroscience. Thank you very much. Good.
