Adolfo García-Sastre, PhD, describes how his team took an “omics” approach to identifying drugs that may be likely candidates for repurposing in treating SARS-CoV-2. A team from Mount Sinai and University of California at San Francisco took the set of all drugs that are approved for use in humans and cross-referenced their effectiveness against the host factors present in SARS-CoV-2. As a result of this process, Dr. García-Sastre and his colleagues found that plitidepisin was an inhibitor of eEF1A, a host factor involved in SARS-CoV-2 replication in every known variant. The team then studied the effect of plitidepsin on SARS-CoV-2 in vitro and in vivo, and found it was an effective antiviral agent. The team also studied plitidepisin in combination with remdesivir, which was found to offer additional therapeutic benefits. Currently, plitidepsin is approved in Australia, but not in the United States, under the name Aplidin as a treatment for multiple myeloma. However, the data from the Mount Sinai research points to value of conducting phase 3 clinical trials with plitidepsin for SARS-CoV-2.
Hi. My name is Adolfo Garcia Sastri, and I'm a professor of the Department of Microbiology, Uh, as well as director of the Global Health and Imagine Pathogens Institute at the Action School of Medicine at Messina in New York on today. I wanna share with you some new results that we got in terms off searching novel therapies for the treatment, the potential treatment off of it. 19 caused by SARS. Cov too. On Dhere, the professors life. Just what I saw. It's a It's a cell that is infected with SARS Cough too. And you can see in red one of the proteins that is being expressed by the virus in red. The nucleus is in blue on the receptor off the virus is in. It's in green on. We use disaster. It is sustaining, uh, to look for virus infection and how much how many virus infected cells we have in the presence of different inhibitors, allowing us to determine that developed potency off different inhibitors. All right, so, um, they're gonna talk about potential therapies for South coffee, too. On DWI have already some a proof therapies. We know off rendez severe, which is an antiviral that inhibits the polymer rates of the virus and then inhibits are on the replication of the virus. Um, there are some other approved therapies for emergency use. Such is the plasma for convalescing individuals. They have neutralizing antibodies that have been infused into people on then inhibit ALS of our replication. Monochrome antibodies last like the ones off Regeneron off Lily. That's himself. So to be good for the treatment, um, on then, there are some other therapies that are not targeting the virus but are targeting the the symptoms of your disease like the anti inflammatory dexamethasone on also some of these. Like, for example, um, the use off anticoagulants. Now what? What? What my lab has been concentrated in collaboration with with all the people is trying to do look for new therapies by drug repurposing. Why? What is tracked? Repurposing and white track repurposing Well, drug repurposing consists in trying to use us antivirals, auras, therapies, drugs that are already using humans for another indications on the advantage that this this has is that distracts because they're used for another indications they have already known existing humans. They already known What is the bio distribution in humans. How much of the drug unit to using humans to achieve an impact? Andi. Therefore, if these strikes or one of these trucks will be able to inhibit the virus also, then it's more easy toe. Implement the studies in humans because we know already what are the doses that are tolerably humans and which those we need to treat with. Now many people are doing this type off approaches. Um, some of them are using just all the drugs that are known to be in humans and trying to look which ones off them inhibit viral replication. In our case, we have used Mawr predicted approach. We are not using all of the drugs that we know off that can be using humans, but we make predictions about which of these tracks are most likely to make an impact in virus replication on. I will tell a little bit how we do that in a second now, knowing these predictions that now we take these tracks that now we predicted make have an impact in viral replication we look with that's actually the case by looking whether the inhibit the virus first in tissue culture. Andi, if that's the case, Then we move into animal models and hopefully that's the case also into clinical studies now. So the question is, can we identified compounds that inhibit hose factors involved in sask of two replication? Um, unknown human drugs? So the idea here is that if we know what those factors are required for sask off to replication on if we know off any truck that issues right now in humans for an indication that can inhibit this particular host factor, then it's likely that this truck also makes an impact not for Onley, for the treatment that has been developed it, but also for inhibiting SERC sculpture replication. So having a devil activity now, how we determine what Haas factors are involved in viral replication. With that, it comes my collaborator Nevan Kragen on a big group at the U. S. C. S f that what they did very early on. As soon as the genome off the virus waas sequence, they took all the genes of the virus total of 29 genes. They express them individually as proteins inside human cells on they conducted immuno precipitation experiments and mass spectrometry e in order to identified Haas proteins that interact with viral proteins. With that, it came out with the map off what is called Interact um, in which we cannot see which house proteins they're, but a total of 332 protein protein interactions with in red, one of the proteins off Starsk off to on in Constellation, the house proteins that interact with. Now we make the prediction here that if the bar protein is interacting with this house factors, it is very likely that is using this host factors for his own benefit. And that's the reason why is interactive and therefore, if they're drugs, that may inhibit any of thes 332 horse factors. Perhaps some of these trucks may have an impact in viral replication. So from all these 332 protein protein interactions, 69 are trackable host factors, meaning their host factors for which is known drugs that can inhibit this particular host factor, Um, for determine destructs. We collaborate with Kevin and Brian the also at UCSF, where they look to all of these house proteins and then look in the literature what host factors, what drugs are able to inhibit this house factors on they come out with a number of drugs around in this case, 97 that we use now in the lab to test them for inhibition of our replication in my lap is creased to get with Rommel, Elena, Alyssa the ones that are doing these experiments. So how do we do these experiments? We actually collaborate also with the institute pastor, um in Paris, where we do also parallel experiments just to make sure that we get the same data. So we first put Vero cells in that our cells that replicate well, the virus into plate. Then we incubate the cells with the different drugs that are predicted to make an impact in by our replication of different solutions. And then we have the virus at on. We let it grow in these cells. We let it go from 48 hours, and if these trucks are not making an impact of our application, the virus will be able to infect all the cells off the tissue culture on. Then, when we're staying against the nuclear protein, then all the cells will be in fact. But if the drug is very good at inhibiting the replication, then no cell will be infected and they will not be standing with nuclear protein. So therefore, we can determine the concentration off the track that inhibits viral replication. Based on this assay on, uh, they say that this thing that in in the in Paris is looking to rne loads. It's very similar. And we are getting actually, in this, uh, results we were getting, um, comparative data. So whatever we saw that this inhibiting viral replication in New York was also song to inhibit viral replication in Paris. And this, obviously our experiments that I need to be done because with infectious viruses in BSL three now here I'm gonna show you what the other data with Brenda severe inhibitor that we know it's working that is, targeting of Allah and it proliferates on. Then you can see here is that as we increase, the concentration of friend is severe in this assay. Then we start to see inhibition this solid line inhibition of our replication with 1990 meaning a concentration in which we achieved 90% off inhibition offer out one micro Moloch on a selective index. That's the difference between inhibited off our replication and site of toxicity that is also attending in parallel in this broken line from the city. It doesn't seem to be toxic at these concentrations. Selectivity off Iraq. 26 million. Good is good. It does not kill the cells at a concentration that inhibit viral replication on it has an activity that is relatively good in the macro. Moeller, uh, level. But we actually we like to get drugs that are working at the nano Melor level. So even better, Um, if we use friend Ecevit not in Vero Cells but in human cells is a human cells that express the receptor. Read this adults actually works better. So it goes from a 1990 of 1.5 micro molar to 24 Nana Mola. Now we're talking about low levels off the track that disabled to inhibit viral replication, perhaps in human cells, the the this compound is less degraded and in Vero cells in monkey cells. And that's the reason why works best in human cells. But that's good news, right on Brenda's. If it actually is being used. I said treatment for coffee. 19. Now we have done this anti viral assay with many different compounds is example of decent velocities. Some work Santa work in total. Now, we have, um, two collaborations with other people. In addition to the people that I mentioned before, we have tested around 800 drugs. Out of that, we have been ableto prove good and evil activity of around 10% of these drugs on some of them. They have extremely potent antiviral active now amount the tracks that we found that they have more pertinent devil activity there translational inhibitors that target some factors that are involved in protein synthesis that we identify that they were able to interact with a viral proteins. These one example of one of these trucks is sort of Taif in that has been in the studies in face one and two for the treatment of cancer. So has been putting humans already is inhibiting one of these factors involved in protein synthesis. E Y f. Four A. On is able to hit it very well. Our replication in this solid line with any hitori concentration 90 off sub micro Mahler animal arranged, so it is very good range. Now it looks like there is some sort of toxicity, but actually what happened? Why it drops to 50% is because thes are dividing cells in the 48 hours a say in the absence off sort of caffeine, there is a double amount off cells. At the end, the present sort of life in the cells stopped dividing and therefore you get 50% of the cells with sense will not kill. I just stopped inability to divide. So we don't think that this may be a major concern with respect. To cite a toxicity, toxicity on in fact, is known from this face one and two clinical price. What is the toxicity of distract in here? But the ones that were working even better than typing are translational inhibitors. Attack it. Another hose factor involved in translation also known to interact with one of the viral proteins in this case now is E F one A. We first found turn it in for, um has an ability to inhibit the virus. I see. 90 off, uh, 10 Anna Moeller so very close to Anna Moeller range very good inhibition of our replication. But there is another compound. That tag is the same factor that is actually already approved for one off the treatments in humans, which is treatment of multiple myeloma in Australia, That is called pretty depths in. Or a pleading which is the trade name off the off. This compound, which inhibits of our place even better than turn it in, has the same target. Even better antenna thing, Not the level off. Nana Melor. So very good Potency. Very low concentration for inhibiting viral replication. This is in Vero is six this monkey cells, Uh, in addition to Vero cells, we also now have tested in human cells human cells containing a C two as well as in primary cells, which are, uh, stem cells that human stem cells that are gravity into numa site. And then it gives us a very potent inhibition. 10. Anna Moeller inhibits infection in these cells when the city requires 10 times higher Concentration 100 Nana Moloch on in Vero cells um up leading are pretty. Dobson is much better within icy 90 off nano Moloch range compared to the macro Mahlum, it rates off rendez severe, But that's not fair because it's a monkey. Cells in human cells from the civil works better with I C 19 around 29 a mullah, but it's still a pretty, you know, Pretty lapsing has 1990 that is more potent Sub nano Moloch in order to inhibit replication of the virus without much side of toxicity. And we know that is, if we, um at this truck after Val infection were still inhibit viral replication, meaning that is inhibited, uh, the step in viral replication that is after entry. Which makes sense, we think division of protein, viral protein synthesis, having any eating habits. Better that I anticipate. Now we know that picking up steam Busy wife to a one A on, uh, this the This is how it looks like this truck on Interestingly, because he has been used for the treatment off cancer, these compounds cancer may acquire resistance to be inhibited by this factor. And this is acquired by mutation in this factor. Uh, this 8399 V mutation that makes now this fact are not able toe find pretty Dobson. And that's the way how conscious has can escape inhibition by plenty deficit. Now what? What we have done is we have introduced into cells this mutation in the way of one day and then we look where the pretty Dobson is still able to him it on. We were super well, we were actually happy to see that if you make this mutation that prevents binding off as the single point mutation in the south that prevents binding a pretty reps into this factor prevents the ability off pretty lips into inhibit viral replication. This doesn't happen with Brenda City, which doesn't target this fact. So that demonstrates that this compound is inhibiting viral replication by binding to wave 18 If you have a way one day that does not buy this compound, then it's not able to inhibit viral replication. So we determine what factory it is way next look, whether is also able toe work with friend decibel because we think that if this implementation of the use off this compounding humans, it will be used together with friend Ecevit which is already approved on. Uh, if we combine rendez vous with Jepsen, we still get good inhibition. In fact, we get some additive effects. So in the presence of from the Rendez Seville, you need a little bit less off a pleading in order to be able to make an impact on the other way around. Well, the finally does it working, driven for that we have used a mouse model to mouse models. Actually, the first one because the virus ask off to does not infect well mice. Because the receptor 82 has not been able to be used by the spike. The mouth receptor can use the human receptor, but not the mouth. One way how you can make him out susceptible to infection with, um, Sask off to is by previously, um, putting intron initially in adenovirus vector that express human Is it true? What it does is just genetically put inside the cells off the lank off this mouth, the ability to express now humanity, too. Now, because the cells off the land off this mouth that has been 25 days before with this gene therapy vector express humanity to now, this might become susceptible for infection with us coffee, too. Now what we have done is we, in fact, this minds with us coming to three days later, we look to the presence of the virus in the land. How much is replicating on that? We lift demise in the untreated are we traded with pretty deep. Sonora pleaded one make per kick. Only one single does or 10.3 per kicks three doses or with three doses of friend s a bit 50 mics per kick. We infect them with SARS cov to we harvest the lungs and they three and then we determine vital Titus. So in the absence of treatment, the virus grows too high. Titans between 10 to 3. 25 in the presence of friendly severe. Now you get the reduction in violent Titus, but you get an even better reduction viral. Try this in the business off pretty deep center operating if the single does were mixed per kick or three doses at 30.3 mics per kick. In which case we don't see any virus in the lungs that they three So very good inhibition in an animal model. The second animal model that we use also mice, but instead off sensitizing with another expressing human institute. These are transgenic mice that express a C two under the control of a karate aside receptor promoter and then expressed a C to not only in lungs but also in some of the tissues. This one's replicate really very well. Sask off to to tie this around into the seventh. Now, when we repeat the same experiment, 0.3 mics per kick. In this, mice were treated with a plane or lapsing versus render severe. Then we have again very nice inhibition of our replication with friends. Easily give us a the same effect the 0.3 mics per kick. That's when they said give us a 50 mics per kicks. You require less pity deficit in order to get the same impact as friend recipes on and we look to the length of these animals in the animals that are not treated. There is high levels of inflammation that are being here observed higher magnification. But in the mindset a tree with pity dips in. We see very little levels of inflammation. We're Endesa. Will we see a little bit of inflammation? Not as much as without treatment, but we see even better lack of inflammation in my secretary with pretty depths in more close to what happens with uninfected mice. Um so in summary, what I've seen is that this ask of to interact on provides professional therapeutic targets for drug repurposing and for that we have found Pretty Jepsen an inhibitory. Why one A that has Putin's ask of two anti viral activity both in vitro And this animal models on the pretty Dobson has been now used for conducting phase 12 clinical trials in humans for the treatment of Cavite 19. I don't have to data with me because they have not yet released. But it seems that they also promising on this, uh, will lead hopefully to phase three efficacy clinical trial in humans to actually proof that this, uh, makes an impact in Covent 19 disease. I guess we're not, um, acknowledge all the funding agencies Andi consortiums that have been including philanthropy that have been funded my lab for research on covet 19 as well as my team off people that have bean conducting studies with coffee. 19 since the beginning off the pandemic. Thanks a lot for for listen