# Understanding Treatments and Care Management of Mucopolysaccharidosis (MPS) in Children

00:50:29

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[00:00:00] Dr Christina Lampe: And hello to all the attendees and also to Roberto. We have today the last, but not least, webinar of the series 6 of Spot the Early Signs and Symptoms of MPS. And we had two very nice webinars before. So first, successfully identifying MPS symptoms, which was done by Barbara Burton from Chicago. And myself, when we presented case reports to show the heterogeneity of MPSs. We had a second webinar on Monday with Roberto Giugliani and Julie Eisengart from Minnesota talking about early diagnosis of MPS, understanding the diagnostic journey. And probably you asked yourself why you should diagnose these patients so early. And the answer is quite easy. There are many treatments available. There are a lot of research at the moment. And there are some clinical trials ongoing, many clinical trials ongoing. And this will be presented by Professor Roberto Giugliani now. He is full professor of genetics, postgraduate program in genetics and molecular biology, Federal University of Rio Grande do Sul, Medical Genetics Service Hospital, the Clinics de Porto Alegre, DASA Genomics Casa dos Raros, Brazil. I'm sorry for my bad pronunciation, Roberto. Just a few housekeeping notes as usual. And now I can, let me see whether I can click the slides. Yeah, as usual, we have some housekeeping slides. And please note that you don't make any screenshots or reproduce any of the slides. We will have around 50 minutes to hear Professor Giugliani's presentation and we'll have a question and answer via text at the end of the presentation. So please submit as much as possible questions at the end of the question panel. And if you would like to see this webinar again, there's also a recorded webinar available. And with this, I hand over to you, Roberto, and happy to listen to your talk.

[00:02:40] Prof. Roberto Giugliani: Thank you, Christina. Thank you for the kind introduction. It's a pleasure to be here and to have you as a moderator. And thank you for the invitation to present on treatments for mucopolysaccharidosis. Here are my disclosures. These slides are moving a little bit slowly, but you managed to have them present. So glycosaminoglycans is the substance that is stored in the mucopolysaccharidosis. They are an important component of the connective tissue. So they are everywhere. They are in the bone, they are in the viscera, in the viscera, they are in the heart, in the knees, in the central nervous system. So a disease that affects the glycosaminoglycans is necessarily a multisystemic disorder. And the glycosaminoglycans are synthesized continuously and also need to be degraded to avoid that they are stored. When the degradation process has some interruption, we have the storage. There are at least 12 enzymes involved in the degradation of that. Any of these enzymes that is missing, is deficient, we have storage. This process takes place on the lysosome. So the mucopolysaccharides, the glycosaminoglycans are synthesized. They have their functions in the body and when it's time of degradation take it to the lysosome where the degradation process occurs. So mucopolysaccharidoses are lysosomal diseases because the lysosomal degradation is impaired. There are many, as I told, 12 enzymes at least are known to degrade the GAG. So there are at least 12 mucopolysaccharidoses. This is a list of these mucopolysaccharidoses and they are based on the different enzyme that is involved. And of course, a different gene is involved because each gene codifies each enzyme. So the next one. So the disease mechanism in MPS is that we have genetic mutations on the gene that codifies the enzyme. So we have a deficient enzyme activity in consequence and impaired degradation of glycosaminoglycans leading to GAG storage, storage of these glycosaminoglycans in lysosomes and also in tissues and organs. And so at the end, clinical manifestations of mucopolysaccharidosis. Let's talk about therapies. So, what therapies we have approved for mucopolysaccharidosis? In the 80s of last century, it was proposed that the hematopoietic stem cell transplantation can be a therapy for this disease. And, in fact, it became the standard of care for the severe form of MPS- I or Hurler syndrome. It was already studied in MPS- VI and MPS- VII with reasonably good results, so it's also an option for these conditions. And there are some reports, I would say controversial results, in MPS- II and MPS- IVa. It's not an option for MPS- III, the more neurodegenerative condition. It has not been extensively tested in other MPSs. It is also not an option for this attenuated form of MPS- I because we have another option for these patients. And this came with the introduction of intravenous enzyme replacement therapy in early this century. The first one asked for MPS- I, then MPS- VI, then MPS- II, then MPS- IVa, and the most recent is MPS- VII. So, I told that there are 12 types of MPS. In just five, we have enzyme replacement therapy available. But this, at least in Brazil, accounts for 85% of the patients with MPS are one of these five types. So, we say the majority of patients have an enzyme replacement therapy available. Well, so this intravenous enzyme replacement therapy, where we provide also weak amount of the enzyme that is missing, the enzyme goes to the circulation, has uptake to the cells, and then degrades the glycosaminoglycans. And this is important to... there is a decrease in the levels of the glycosaminoglycans in the urine. But this is not a clinical marker, but what happens also in the clinical point of view is you have this reduction of the visceromegaly, the liver becomes smaller, the spleen becomes smaller, improvement in respiration, so less respiratory infections, better respiration, better sleep pattern. There is improvement in joint mobility. Also, the heart muscle becomes better with the enzyme replacement therapy. They are some of the benefits of this enzyme replacement therapy. You see on the left, bottom left, the urinary GAGs declined. You see in the center, the bottom center, the liver volume declining. And you see in the bottom right, the 12- minute walk test, an endurance test that is improving patients that receive enzyme replacement therapy. So there are many benefits, but there are problems that still persist. One is not available for all MPS types. So, for instance, MPS- III, A, B, C, or D, we do not have this possibility. The heart valve seems to not respond to enzyme replacement therapy. They keep deteriorating as the corneal clouding also does not respond. The bone dysplasia has minor benefits. It is largely not improving with the enzyme replacement therapy. And an important problem is the cognitive decline that continues because these enzymes, they are provided intravenously, and they do not cross the blood- brain barrier. So there are other options that have been explored, especially some small molecules like genistein, because it's proven that it decreases the levels of synthesis of GAGs in in vitro studies, in animal studies. But when it was tested in humans, it was observed that there is no improvement because the idea is to use for the forms that have neurocognitive decline as the MPS- III, Sanfilippo, because this molecule can bypass the blood- brain barrier and could reduce the GAGs there. But the clinical trial showed that there were no benefits of the use of genistein, and so it's not an option, a recommended option today. Another molecule this is in development is Odiparcil. Odiparcil is able to clear the substrate, not to reduce synthesis, but to clear, and especially Dermatosulfate. And you see here in this picture of the cornea of the mouse, you see that in the figure in the left, you see a normal cornea. The figure in the center, you see a cornea of MPS VI mice affected. And the figure in the right, you see MPS VI mice treated with this Odiparcil with improvement in the cornea. So this is an option that is in development, this kind of therapy. Another possibility is that we observed that the aortic root is dilated in patients with MPS, especially MPS IVa and MPS VI. And if you use an antihypertensive like Losartan, you may improve this parameter. And this has been tested in patients with MPS IVa and MPS VI, with interesting results still in clinical development. More recently, it was tested as pentosan polysulfate. It's a molecule that is able to decrease inflammation and decrease also the levels of GAGs. It was reported on a trial on MPS I. These are inflammatory markers that decrease the figure in the left. You see the inflammatory markers decreasing with the use of pentosan polysulfate. It also decreases the GAGs and the pain associated to problems in the joint. So it's interesting. It's also been tested in MPS VI. It may be a possibility. But I would say that the main problem, or one of the main, is that these intravenous administrated enzyme replacement therapies do not cross the blood- brain barrier. So they do not reach the brain. And many of the MPS have CNS manifestations. So we tried, well, how to get into the CNS. So one thing we tried to do is a physical approach, is to bypass the blood- brain barrier by infusing the enzyme in the CSF space. So we tried this, and this patient has an attenuated form of MPS I. No neurocognitive decline, but had the meningeal, had the cord compression due to meningeal infiltration. So we tried to use this in this patient some years ago. We did monthly intrathecal injections of laronidase, the enzyme that, the recombinant enzyme that is used to treat MPS I. And then we published the results, which were very encouraging regarding the improvement of this patient in terms of cord compression, improvement on respiratory parameters, and many other manifestations. And this opened the door for trials using this intrathecal approach to bypass the blood- brain barrier. One trial was for MPS II. You see in the left, you see that in the bottom, you see the bottom left, you see the decrease on the levels of GAGs in the CSF following the injections. These are injections, you see in the center, a few that are provided by a device in the lumbar region that has the cannula that goes to the CSF space. So these are MPS II, but it was also tried for MPS IIIA. It is on the right. But you see this figure showing that the decline, the cognitive decline continued despite the intrathecal injections. So both trials, MPS II and MPS IIIA, they failed. They did not meet the endpoints. So it was not an option. But it was a slightly different approach. The intracerebral ventricular enzyme replacement therapy, instead of providing the lumbar region, the CSF in the lumbar region, you provided the CSF but in the ventricular area. So this was tried for MPS II and is already approved in Japan for MPS II, this intracerebral ventricular enzyme replacement therapy. And this was also tried in MPS IIIB. And this is something that is now being reviewed by regulatory authorities. Possibly it will be approved for MPS IIIB, intracerebral ventricular injections. In the case of MPS II, it is every month. In the case of MPS IIIB, it is every two weeks. But you should agree with me that these are invasive procedures to have every two weeks an intracerebral ventricular injection, even if this is provided through a device. So there are start to develop different approach to reach the brain. And one is using the fusion proteins or Trojan horses. So there is a therapy that's provided intravenously and can bypass the blood- brain barrier. I'll show you how it can bypass. So our brain penetrating intravenous enzyme replacement therapy. So this is what is a fusion protein. A fusion protein is a protein that is one part of the protein as an antibody that binds to a receptor in the blood- brain barrier and take along another part of the molecule that has the enzyme that wants to be into the CSF space to degrade the glycosaminoglycans or to the brain but can go to the CNS. So this is a fusion protein for MPS II so there is an antibody against the transfering receptor in the blood- brain barrier and taking in the tail two molecules of iduronate sulfatase similar that can degrade the glycosaminoglycans in patients with MPS II. So this fusion protein, I'm showing the composition. So they can reach the tissues via mannose 6- phosphate receptors, the somatic tissues, or can reach the brain through the transferring receptor. And this is something that proves to be very, very useful. And I will show you about some results on this. So the levels in CSF, you can see in this figure that the baseline, the levels are quite high. All patients above 4, 000 in this figure. And when you administer this intravenous enzyme, it is able to decrease the levels of GAGs in the CSF, so proving that it is able to bypass the blood- brain barrier. And with continued injections every week, we have a very long- term decrease of these urinary GAGs. As you see, all patients below 4, 000. And 4, 000 is interesting because it's the level, maximum level, that patients with attenuated disease may show. So it's a kind of safe limit for having or not the neurocognitive defects. And what you see in terms of clinical parameters, you see that patients in the left, in the red part, you see that patients, if they are treated early, they have quite a good development, neurocognitive development. If they start treatment later the results are not so good which is consistent with what we know the pathogenic cascade is triggered, is difficult to stop it, to reverse it. So it is important to think in the need of treating patients early. This is another way to express the benefits of therapy. In green we see patients that show improvement in the domains of the cognitive development. And in blue, you see the patients reported as stable. And in orange, you see patients that were reported as worsening. So the vast majority of the patients are improved or became stable, which in a progressive disease is a very important achievement. This program I stored for MPS II, but now also developing for MPS I, and the same approach. The molecule is a little bit different, but takes in detail the enzyme that is needed for the degraded GAGs in the case of MPS I. And you see in the bottom area of this slide, you see that there is a decrease in the levels of GAGs when you use this enzyme in several areas. So it's a very important and very interesting way of decreasing GAGs in the CNS. You see also the reduction of GAGs. You see also in this MPS I, reduction of GAGs in the CSF after an injection, in the intravenous injection, and this was quite remarkable. We also observed, this is interesting because the enzyme is supposed to go to the CSF and it goes, because it decreases GAGs in the CSF but also decreases GAGs in the somatic tissues, and so it can be used both for treating the CNS disease and also the somatic component of the MPS. So you see the serum markers and the urine markers. You see that there is a decrease on the levels of glycosaminoglycans. Okay, so I showed two examples of these intravenous replacement therapies with fusion proteins. I showed examples that are being developed by JCR, but there are others, like the ones developed by Denali, and not only for MPS I and MPS II, but also for MPS IIIA and others that are in the pipeline. Now I will explain about another approach that is to take, instead of having these weekly infusions of enzymes, to have a way to provide to the individual a capsule where there are, inside this capsule, there are cells that are producing the enzyme, over- expressing the enzyme that we need for that patient. So the enzyme is in cells and can be a kind of pump of enzyme, and producing this enzyme can degrade many of these GAGs in the body. So this capsule is seeded in the omentum by a surgical procedure, very simple, and then the patient may last there for many months producing enzyme and avoiding the need of weekly infusions. This is a project in development by the company Sigilon and it's a quite interesting approach, but it's not an approved therapy. It was proposed by this company, Sigilon. So let's move now to gene therapy. It's another area that is a very huge development. So gene therapy, you see, may be in vivo. As you see on the left part of this figure, it is maybe tissue injection, directly in the tissue or in the circulation or maybe in the CSF, always transferring the gene we wish to transfer to the individual with vectors, usually viral vectors. So we use a viral vector, we displace the viral genes, we put the human genes, the therapeutic genes, inside the capsid of this virus and this virus, depending on the type of virus, goes to the liver, goes to the brain or goes to the eye, depending on the serotype of this virus. So it's a very practical way to transfer gene therapy. This may be in vivo, as I said, when you provide, by intra- circulation or the CSF, or inside or directly in the tissue or maybe ex- vivo. Ex- vivo is when you take cells from the individual and you manipulate the cells in the laboratory. You make the gene transfer in the laboratory and then you provide the cells back, the therapy that was already modified to the patient. So this is usually. There is a conditioning period, like bone marrow transplantation, but not so critical, but you condition the individual to receive this cell. So this is an approach, or in vivo, or ex vivo. So I will see some examples. And for instance, for the ex vivo gene therapy for MPS I development for many years in a site in Milan, you see the increase of the enzyme activity, a decrease in the GACs. So it's also very interesting. Take the cells of the patient, you modify the cells with a vector, you transfer to these cells the therapeutic gene, and then you put the cells back in the body. And then they spread to many, many organs and tissues. So this is very good results for MPS I. Also being tested for MPS II and MPS IIIa. And another kind of ex vivo gene therapy is this one proposed by the company Immunosoft. You take the B cells from the body, you transform these cells, you make the transfer of the gene to these cells, and you put back in the body. And this is something that these cells, these B cells, they last around four months. So every four months you have to do this process. But you do not use viral vectors, it's a non- viral vector, so there is no reaction of the body. There is also no need to make a conditioning. So it's a quite interesting approach. But it's not for the CNS because these cells, they stay in the peripheral circulation. But this is an approach that will start clinical development very, very soon. And now let's talk about this in vivo gene therapy. As I said, maybe direct application in the tissue, you see this needle that goes to the brain. And there in the brain are spotted some six areas, in fact there are 12 areas, but because they administer the vector in two levels on the same application, and then you can transfer this vector directly to the tissues. So this was attempted in MPS IIIA with some interesting results, but the program had faced some difficulties to move on. Another approach is in vivo administration, intravenous administration of a sorotype that is able to reach the CNS, and this was tried on MPS IIIA by the company Abeona, with some results interesting when the patient is treated early, not that interesting when the patient is treated late, and this is something that occurs in all these therapies. Now this program was transferred to ultragenics and it keeps being developed. It's a gene therapy for MPS IIIA. For MPS VI, that is a disease that has no cognitive involvement, no CNS involvement. So they transplanted a liver- directed gene therapy, so it's AAV8, it's a virus adeno- associated serotype 8. It goes to the liver, and in the liver it expresses the enzyme and makes a large quantity of enzyme that is distributed to the body and can degrade the glycosaminoglycans. So it's using the liver as a kind of distributor of enzyme to the body, which makes sense in this kind of MPS that has no CNS involvement. So this is in development in a center in Naples, Italy. And now I will show some slides of a trial. We are involved in Porto Alegre's intracisternal administration. So in the cisterna magna is a needle that goes to the cisterna magna, and from the cisterna magna there is a very ood bio- distribution to the CNS and also outside the CNS. And this seems to be a very interesting approach to gene therapy. And so this is AAV9 that goes to the cisterna magna, and you see that after this single injection of the vector, there is a decrease in the levels of glycosaminoglycans in the CSF. You see in light blue the low- dose cohort, in dark blue the medium- dose cohort, and in orange, very encouraging results, the high dose of the viral vector. So it seems to be a very good... And so this high dose was selected for the next step of this trial. That is the... And you see here that when you look at the results of... You see here that in regarding the, for instance, the expressive language, if you treat the patients when they are still within two standard deviations from the normal, you see that they go to the center of this figure. You see that the patients that are treated early and still within two standard deviations, they perform quite well, while the patients that are treated when they are already deterioration of more than two standard deviations from the mean, they do not have responded very well. Again, showing that's how important it is to treat early MPS patients. So there are some gene therapies in development for MPS I, the intracisternal injection that I showed you but for MPS I, the lentiviral vector which is the ex vivo and also some gene addition program. For MPS II they have the same intracisternal administration, we have a lentiviral ex vivo gene therapy and we also have a gene addition program. For Sanfilippo A, we have this study with lysogene, the directing brain tissue administration. Then they study this intravenous that was Abeona in Ultragenyx and the intracisternal administration with another company, Steve. And for MPS IIIB, there is a Abeona trial with intravenous injection. For MPS VI, the intravenous injection for the liver- directed gene therapy. So these are some of the gene therapies in development. There are more, but so it's an area that is growing very, very fast and very promising area. I will also mention the status of therapies. So what you have for it, this is in general, not only gene therapy. So what you have for MPS I, we have the the bone marrow transplantation for patients with severe form, but it is recommended before the age of two years, two years and a half, where it is still able to prevent further cognitive decline. So you should be careful about this age. We have intravenous enzyme replacement therapy for patients over two years, two years and a half, and or patients with the attenuated phenotype. And in development, you have these fusion proteins for MPS I. You have also the intrathecal, intracellular ventricular enzyme replacement therapy. Some small molecules are also being tested and also gene therapy and genetics. So MPS I has two approved therapies and in many therapies in development. Let's see the panorama for MPS II. Well, there are some cases reported with bone marrow transplantation, hematopoietic stem cell transplantation. I would say controversial results, some very good results. Other results were not encouraging. So I think still controversial. Maybe the timing of the procedure in case of MPS II should be earlier than for MPS I, maybe. We have intravenous enzyme replacement therapy, standard of care, and you have the intravenous fusion protein that is approved in Japan and in development in the rest of the world. Then you have intrathecal, intracellular ventricular enzyme replacement therapy. The intrathecal failed, but the intracellular ventricular was approved already, already approved in Japan. And you have the gene therapy in development for MPS II. Let's see for MPS III. MPS III is tough one, and it does not work the bone marrow transplantation. There is a fusion protein, intravenous fusion protein, in development with sites in the U. S. and by Denali and in Germany by JCR. We have the intrathecal gene therapy that failed, unfortunately. Small molecules also tried with genistein that failed. And gene therapy and gene addition in development. Let's see MPS IIIB. MPS IIIB had the bone marrow not work, and also intravenous enzyme replacement therapy was attempted, it did not work. We have in development the intracerebral ventricular, and also the gene therapy. For MPS IIIC and IIID we do not have any prospect very close, but for MPS IVA it was proposed to have the bone marrow transplantation, also still controversial. But the intravenous enzyme replacement therapy is approved and is a standard of care for this disease. Which we also have some, probably a clinical trial for gene therapy starting later this year. For MPS IIIB we do not have any trial, but I think that these patients may benefit from trials in GM1 gangliosidosis. That is also deficient of the beta- galactosidase enzyme, same as MPS IVB. So maybe they can use this therapy. For MPS VI, as I said before, the bone marrow transplantation is an option. We have the intravenous enzyme replacement therapy established, it's a standard of care. And we have the small molecules like the pentosan polysulfate being tested, and also the gene therapy on clinical trial. For MPS VII, we have the bone marrow transplantation already available, and it's something that is an option for these patients. But we have the intravenous enzyme replacement therapy that is the standard of care for this patient. Also gene therapy is in development for MPS VII. For MPS IX and MPS, we do not have any therapies in development or approved. So in summary, the MPSs include 12 different diseases, each one caused by the deficiency of a specific enzyme involved in the breakdown of glycosaminoglycans. In addition to hematopoietic stem cell transplantation prescribed for the severe form of MPS I, and intravenous enzyme replacement therapy available for 5 MPSs, several new therapeutic products are currently in development. These new strategies include small molecules, intrathecal or intracerebral ventricular ERT, ERT with fusion proteins, and gene therapy or gene addition approach. Independent of the type of therapy, early diagnosis will continue to be a major challenge to prevent disease burden and disease progression. And newborn screening should be considered for the MPS types which have effective therapies available. So this was my presentation. I have my last slide where you see my email, so I'd be happy to answer any questions you have. And a special thank you to the patients, to the team, and to the new Rare Disease Center that just opened in Porto Alegre. So I think now we have time for some questions. I will be very pleased to address them. And just reminding that I am talking on specific therapies, but these patients, they really need a very comprehensive management. And even the types that do not have a specific therapy available, a multidisciplinary approach and a comprehensive management plan will improve their quality of life. But I'm sure that Christina has much more information on this. So I will welcome your questions.

[00:39:35] Dr Christina Lampe: Thank you so much, Roberto, for this great and comprehensive overview. I mean, I was a little bit confused because we have so many different treatment options and clinical trials ongoing at the moment, which shows how much research is ongoing in this field. And my question to you, because I know you are principal investigator of many, many of these trials. What do you think is the most promising treatment for these diseases?

[00:40:07] Prof. Roberto Giugliani: Thank you, Christina, for the question. I think that in the short term, we have these fusion proteins, very final stage of development. So one was already approved in Japan and the other one in phase three. I think this is the ones that will come first. But these are weekly fusions that require the patient coming to the center or having a trauma infusion every week. And you have coming the gene therapy or genome addition, and I think that will be maybe the ultimate option for this treatment option because it's a single dose of treatment. And it seems that maybe the single dose may be able to provide a lifelong correction. But this is still – we still need to have some more data on this. At this moment, the results are encouraging. We have the MPS I and MPS II very close to approval. But the others are more less advanced development. But I think this will be the – there are many questions to have. Probably some patients will do better in the enzyme replacement therapy, others will do better in the gene therapy. So it's very good to have several treatment options because not all patients will fulfill the criteria for one or other therapy.

[00:41:58] Dr Christina Lampe: Well, what I think is – when you showed all the clinical trials, it showed how important it is to have an early diagnosis because, as you said, most patients have a cognitive decline at a certain point, and we need to start the treatment before we have an irreversible damage of the brain. Do you have newborn screening in Brazil for MPS?

[00:42:31] Prof. Roberto Giugliani: Yes and no. In fact, we have a very limited newborn screening currently in Brazil. That is the six disease, just six disease, very limited program. The good thing is that covers all the populations, a nationwide program. But three years ago, it was defined that it would expand and would include treatable lysosomal diseases. So we have the legislation to expand the program to include mucopolysaccharidoses, but we still did not implement this because this needs resources, personnel, and many equipments and centers, and this may take longer. But I think we will have it in some time.

[00:43:19] Dr Christina Lampe: We don't have in Germany any newborn screening for lysosomal diseases, unfortunately. I think this would be probably the best step to start an early treatment. So we are by now still, we need the earliest signs and symptoms of the disease, and a lot of physicians were really making a diagnosis as soon as possible. There's also the fetal enzyme replacement therapy. What do you think about it?

[00:43:52] Prof. Roberto Giugliani: Yes, it is a very exciting possibility, although it's limited, the possibility of starting intrauterine enzyme replacement therapy because it should be limited. It's a patient, a family that already had a case, and then there is a risk for another pregnancy with the same disease, and the family wants to carry on the pregnancy. But I think that this is an opportunity to introduce the therapy very early in the formation of the individual. I believe that the benefits will be great to have this enzyme very early, even before birth. And we see in the neonatally treated patients that they also perform much better than the patients that are treated later.

[00:44:50] Dr Christina Lampe: Are you a site for this treatment, for the fetal, or is it only in San Francisco, in the USA?

[00:44:58] Prof. Roberto Giugliani: As far as I know, it's only in San Francisco, but we have been referring patients, so it is something that is at this moment, I think, centralized in San Francisco, but there are many centers of recruiting patients around the world.

[00:45:20] Dr Christina Lampe: I have another question to the intrathecal versus the advanced ERT, the IV ERT. How can you explain that the IV enzyme replacement therapy is working better than the intrathecal? But what is the explanation behind that the studies with the intrathecal ERTs failed and it seems to work if you have the Trojan horse treatment?

[00:45:55] Prof. Roberto Giugliani: Yeah, I think that probably because when you infuse the enzyme in the cerebrospinal fluid, the ability of that enzyme to penetrate the tissue is limited. If you provide the intravenous and it is able to bypass the blood-brain barrier, it can have a much better distribution in the brain and I think this is something that the extent of dissemination of that enzyme in the central nervous system, much better when you have fusion pronating compared when you have a CSF administration. I think maybe it's not sure, but I think it's a reasonable explanation.

[00:46:47] Dr Christina Lampe: Yeah. I mean, beside the cognitive involvement, another major issue, at least this is what I hear from my patients, is the bone. So the skeletal deformities, the growth in particular. So are there any treatment ideas how to improve the bone deformities, the growth in our patients?

[00:47:14] Prof. Roberto Giugliani: Yes, this is a major problem, really the bone. The bone is not that well vascularized, so there is a difficulty for the enzyme to reach the bone. Even the bone marrow transplantation has very good results, but when we are talking about the skeletal displays, the results are not so good. So what I think that maybe some modifications to target the enzyme more to the bone. When you increase the doses, you see some effect, but sometimes increase the dose is not practical because one is much more expensive and the second patient may have more reactions to the treatment. And so this is an area that we still need to develop. What is being observed in these early results of the intrauteral studies is that, at least in animal models, you see that the bone is much better shaped when you treat the intrauteral. Since the early development is affected by the lack of the enzyme in storage of GAGs and maybe this early administration. So I would not say in terms of intrauteral because this will be very limited, but in terms of new native screening, if you have the possibility of detecting patients early and treating early, maybe the bone will be a better outcome.

[00:48:48] Dr Christina Lampe: Great. Thank you so much. I don't see any further questions. So I think what we really learned today is that it is a big area of research in MPSs that we have quite a lot of enzyme replacement therapy available at the moment. Not enough for all our patients, but there's a lot of clinical trials ongoing that will hopefully show an effect for our patients. We should not forget also the symptomatic treatments or the palliative care of our patients or to check all organ systems, to have regular checkups for all the organs that could be involved to also treat symptomatically with surgery, with medication, physiotherapy and so on. And in particular, in this chronic progressive diseases, the early diagnosis is the most important because then we can start the treatment, even if it's just in brackets symptomatic as soon as possible. And with this, I leave you the last word, Roberto. Thank you so much for being here. You're really one of the most experienced people in the world in this topic. And this is why I'm very honored that I could have this talk to you today. Thank you very much, Roberto.

[00:50:12] Prof. Roberto Giugliani: Thank you very much. It was a pleasure to participate and to have you as a chairperson was very nice. Thank you, Christina. Thank you, everyone who attended.