Reinventing Lipid Nanoparticles - Dr. John Lewis

Talking Biotech Podcast - Dr. Kevin Folta

[00:00:00] Kevin Folta: Hey

everybody, and welcome to this Week's Talking Biotech podcast by Col Collabora. A while ago, probably in the early nineties, I remember the talk of liposomes empirical bubbles of lipids that had the potential to fuse with a cell membrane, because that's a lipid bilayer. and allow transit of specific payloads into a cell.

So whether you were trying to deliver a drug or some other kind of compound, or perhaps dna, which maybe could transform or transfect cells. This was a really interesting way to try to do this, and there was some successes along the way in that process, but how do you make this even. And define very precise formulations of lipids into particular size.

Sphericals nanoparticles that now had the potential to do the same kind of job. And we saw this in the Covid 19 vaccine. So mRNA encoding the SARS COV two spike protein was encapsulated inside lipid nanoparticles, and these were delivered into the muscle, the deltoid muscle, in order to confer immunity to the SARS Cov.

Virus or at least partial immunity. Right? This worked very well because the lipid nanoparticle could fuse with the muscle cell and then inside open up and deliver the mRNA of the spike protein. The mRNA encoding the antigen of question and allow the cellular machinery to translate that protein using the ribosomes of the cell to make the protein and to induce an antigen.

but it hasn't stopped there. More innovations in the area of lipid nanoparticles have allowed for a broader range of applications, some which we've talked about here on the podcast. But today we're going to focus strictly on the innovations of the lipid nanoparticle itself and how new innovations are allowing it to be more effective and deliver different kinds of payloads, namely pharmaceuticals that could have a role in different processes down.

So we're speaking with Dr. John Lewis. He's the founder and c e O of Antos Pharmaceuticals. So welcome to the podcast, Dr. 

[00:02:13] John Lewis: Lewis. Oh, hi Kevin. It's a pleasure to 

[00:02:15] Kevin Folta: be here. I mentioned in the introduction that we are really in need of novel ways to deliver the newest therapies and lipid nanoparticles are an outstanding vehicle for this, and it's not new technology.

Most people learned about it during Covid 19. So can you give us a little more background on where this all. 

[00:02:33] John Lewis: Yeah, Kevin, it's actually quite the story. So research on on novel lipids began in in Canada, in Vancouver, in the lab of Peter Cuis, a friend of ours who was really interested in the, the way lipids partition on on the outside of a cell.

And and when he started studying the behavior, he realized he could use certain lipids to be able to actually gain access to cells and therefore deliver things like nucleic acids, such as RNA and dna n And so in the ni it was what the 1990s when he first sort of showed this was possible. And then through a number of collaborations with c.

One of the big companies that really started this field was a company called Alnylam out of Boston. And, and he, the Alnylam and Peter worked together for many years to optimize and create better lipids for this platform. Which led to really this breakthrough first clinical trial for an l LMP based therapy in 2012 that eventually became the first LMP approved drug in 2018 which is called on Patro.

And this is to treat a rare disease called h a TTR Amyloid. 

[00:03:39] Kevin Folta: Yeah, I've heard of this one. This was actually really the predecessor of using a nucleic acid that was coded in a lipid nanoparticle. And people are surprised to hear that. Cause I think it was always the Covid 19 

[00:03:50] John Lewis: injection. Yeah. So I think there were, you know, it was decades of sort of background work, trying to figure out what lipids made sense you know, how they behaved in the human body and sort of what kinds of therapies could be.

so that the technology had had come to a point, you know, in, in 2020 when the pandemic hit, that it was just primed to be able to rapidly adapt and, and be used to create two successful covid vaccines. 

[00:04:15] Kevin Folta: Well, very good. Can, can you give us a basic breakdown of what a lipid nanoparticle is and why are lipids the good delivery system compared to, say, other biological 

[00:04:26] John Lewis: molecule?

Yeah, that's a great question. So, so obviously, you know, we have billions of cells in our body. We've evolved over millions of years to reject or to, to avoid having foreign agents inject their you know, genetic material in our cells. So, so really, you know, there are a lot of defense mechanisms and, and so there are only really a couple of very good ways to deliver DNA or RNA into cells for therapy.

And LMPs obviously have emerged as a major. Viruses evolved for millions of years to be able to inject their DNA material in cells. But again, you know, once, once you see, you know, once your body, your immune system sees a virus it, it recognizes and doesn't let it come back in. And, and so this is why lipid nanoparticles are really compelling because they basically mimic what a cell looks like.

They're made of the same lipids that a cell is made of. And so so they can pretty much get in into your blood. And get to cells and not be recognized as foreign. And then they're taken up by a, a very established mechanism. We call it endocytosis which is basically a mechanism to pull in different material in the blood and either take it into the cell or, or process it.

And and there are very specific kinds of lipids that are incorporated in, in lipid nanoparticles that basically change their shape once they get into this endo zone compartment. And, and allow, basically break up a hole in the endosome and allow some of the, you know, RNA or DNA to get into the cell and have its therapeutic.

[00:05:53] Kevin Folta: Yeah, maybe we're kind of jumped the gun a little bit for listeners who may not understand. Sure. What's happening with the chemistry of a nanoparticle, a lipid nanoparticle is that this is kind of a small sphere that'll form in solution that we can put some sort of a payload inside. Right? So this is a, a very, and about how big.

[00:06:13] John Lewis: Yeah, so they can vary in size, but typically they're between, they're in the nanometer range, so these are, you know, a hundred times smaller than a millimeter and, and, and thousands of times smaller than an inch. You know not visible to the naked eye. Yeah. 

[00:06:28] Kevin Folta: So these are small little bubbles basically of, of, of a lipid with some sort of payload inside that confuse with the membrane of a cell and then be brought inside and then dump whatever the payload is inside.

Do I have that right? That's correct. Okay. Just so that I get everybody on the same page. So what are some of the advantages of this kind of system, other than the immunogenicity that you mentioned? With, especially with regards to delivery of nucleic acid. . 

[00:06:58] John Lewis: Yeah. So the, the real benefit is in the fact that it, it is basically a platform technology.

We've, you know, we've, we've sequenced the human genome in the 1990s, and in the meantime we've developed these really incredible tools. To be able to either turn genes on, turn genes off, or even edit genes where in the case where there's a mutation that causes a deadly disease. And so the key for genetic medicines that are made with LMP and other delivery systems is to be able to deliver the correct gene.

or the correct enzyme into cells that'll, that'll actually cure that disease. And so lipid nano particles have been just a spectacularly successful platform because, as I said, they mimic what a cell looks like. They don't look foreign in the body, and they're able to uh, enter the cell through this established pathway for taking out material and then deliver that lifesaving drug inside the cell.

[00:07:52] Kevin Folta: And there's a few examples of companies, especially some that we've had on the podcast that are using nanoparticles that are decorated with specific proteins that target them to discreet tissue, so prostate or cardiac tissue. Is this kind of the way that the field is rolling to target where nanoparticles can move throughout the body?

[00:08:14] John Lewis: Yeah. So we've seen with the development of LMP based vaccines that they excel, you know, really well when they're delivered locally. So in this case, in the muscle to make you know, a vaccine that, that can protect us from Covid 19. The first approved drug that's on Patro drug is one that's given intravenously iv.

And. And the majority of the LMP that are available today will go through the bloodstream and the majority of them will will actually be taken up by the liver. And because you know, a TTR amyloidosis a liver based disease, this is ideal and I think the, the holy grail, the next step of L N v LMP de development.

is in being able to hit organs outside the liver. Obviously there's many, you know, debilitating diseases you know, cystic fibrosis in the lungs, muscular dystrophy in the muscles that require delivery of a genetic medicine like an l p outside the liver. And I think this has been the real challenge for the LMP field and being able to target them to different tissues is one of the main mechanisms by which we think we might be able to.

[00:09:14] Kevin Folta: and sounds like a great idea. You know, it's an awesome delivery vehicle, but what are some of its limitations, either in terms of that targeting or how well they're tolerated by the body? 

[00:09:25] John Lewis: Yeah. So the way I see it, the, the way the current technology in for LMP is really two main limitations. And they're both really related to where they go in the body as, as you brought up.

So because of their formulation with these, these kinds of lipids that allow them to escape and deliver some of their genetic material. They have natural trophism or know, basically they get taken up by the liver. Now the liver is an organ in the body that typically is there to, to take in, you know, particles of this size.

And so so I guess the, the main initial limitation is their biodistribution, you know, where do they go in the body? And and about 85% of an LMP when you inject in the body goes to the liver. And I would say the other I would say challenge. Is in actually their mechanism of action. So the way they.

And in get into the cell is through these what we call ionizable lipids. So they're, they're fats basically that, that become charged, have a positive charge, and this actually creates a bit of a disruption in the cell to allow, you know, basically pokes a hole in it so they can get through. And the issue is, is when you have a high concentration of LMP in one place in the liver and they're poking holes, you're gonna see some toxic.

And so you know, being able to overcome both the, the concentration of the particles in one organ and then the toxicity associated with it I would say is the main challenge of, of expanding the application of l and p to every disease. 

[00:10:49] Kevin Folta: And we'll talk about that more on the other side of the break.

So we're speaking with Dr. John Lewis. He's a CEO of Antos Pharmaceuticals. This is the Talking Biotech podcast by Collabora. And we'll be back in just a. And now we're back on the Talking Biotech podcast by Collabora, and we're speaking with Dr. John Lewis. He's the c e O of Antos Pharmaceuticals, and we're talking about modern innovations of reinventing the nanoparticle, the lipid nanoparticle, so that.

It can serve more different diseases. And earlier we set the stage by talking about what LMP were some of their strengths, some of their limitations. And if you wanted to go back to the drawing board and really tweak this system, what could be done? 

[00:11:35] John Lewis: Yeah, that's a great question. I think, you know, if we look at the platforms available, so l n P is one of them, and the really, the huge strength of L N P is that it can be rapidly adapted.

You know, any gene, any rna can be put in it to address any disease. And it's a platform technology that we know very well. It can be re-dos so it can be given again and again. So if we don't hit the right dose the first time, we can continue to treat. And that's in contrast to, to the, the gene therapy approaches that we have now that use viruses.

But again, the limitations, as I mentioned, are, you know, where do they get taken up in the body, specifically the liver. And and then there, you know, there's toxicity issues when you give a high enough dose to treat some of these diseases we want. So I think, you know, I think the ideal delivery system would use an alternate mechanism of getting into cells.

And I say this because, you know, viruses have evolved over millions of years to be able to do an amazing job of being able to get into cells and deliver the genetic material, and except they can't be sed and l n P, you Do a great job of avoiding the immune system, but have these toxicity issues.

So I think, you know, the, the best case scenario is a, is a particle that combines the best aspects of both viral and non-viral approaches. To be able to go everywhere in the body, but yet also to be dosed multiple times. 

[00:12:51] Kevin Folta: Okay. That's pretty good stuff. So why do viral fusion proteins help this process?

[00:12:59] John Lewis: Yeah. So many of the viruses that we're familiar with you know, h i v flu. They all as a part of their infection, they make these viral fusion proteins that can very very elegantly engage with a target cell and and fuse with the outside of that cell to deliver their genetic material inside the cell to make more viruses.

Except for the, the viral fusion proteins of, of flu and h i v are gigantic proteins that would be extremely difficult to manufacture and actually would, you know, elicit or create their own immune response. So so Attos pharmaceuticals one of our scientific co-founders a virologist named Roy Duncan, some 30 years ago found discovered a novel virus that.

Alligators and birds, that makes a very, very tiny fusion protein. And he would got it really excited about it back then that if he incorporated into a lipid particle like an lmp, he could actually cause that particle to fuse directly into target cell without causing any toxicity issues.

[00:14:03] Kevin Folta: And when you say a target cell, is that really saying a cell that it covers or contains some sort of a ligand that confuse with that specific l n P signature from the viral domain? 

[00:14:16] John Lewis: Yeah, that's a great question. So many of the, the viruses like h, hiv, V and flu, they do have a specific protein on the surface, a target that they, they stick to.

What's really interesting about these fusion proteins that Dr. Duncan. Is that they, they use a purely mechanistic biophysical approach to fuse with cells. So so if you if you have this protein embedded into a lipid nano particle all they have to do is get close to any cell in the body and they'll catalyze a fusion reaction whereby the lipid data particle fuses with the target cell.

[00:14:50] Kevin Folta: Yeah, that's really cool. So if, if you're able to say, treat cystic fibrosis and get this into the, into the bronchial tubes or into if you're treating, you know, some injecting co sars, COV two r n a, you could do this in the muscle cells, but are there ways to get that target a little sharper, that targeting a little sharper by maybe having some way to target where that l and p would go with that?

Same 

[00:15:14] John Lewis: kind of, . Yeah, I mean that's, that's, that's essentially the, the main challenge we have in nanoparticle biology. And, and I think the way I love to look at it is is you can't target a tissue if you don't get there in the first place. So and, and I would say the real challenge with the current LMP technologies is that because the vast majority of it goes to the liver, there's just not enough getting to the lung.

There's not enough, you know, getting to the heart and other places where you want to have the treatment reach. So that our goal when we designed these sort of reimagined what an LMP can be, we created formulations that just go everywhere. and then we engineered in characteristics into the nanoparticle that made them selectively stick around in certain tissues, like muscle, like lung, like the eye, where they could deliver their, you know, their therapeutic payload.

[00:16:05] Kevin Folta: And is, is that therapeutic payload doing something that's transient or is it really a stable integrion? So if you're delivering RNA or dna, N especially DNA N I guess, is this something that you would just be looking for a temporary expression of a gene like in the SARS COV two vaccine? Or is this something where you are actually performing gene therapy by replacing a defective.

[00:16:29] John Lewis: Yeah, so the, the, this would really depend on the disease you're trying to treat. So, so you're exactly right. So for a vaccine, you want a very quick pulse of the antigen, so you can show the immune system what the danger is and it can mount an immune response. . But for diseases where we have, you know, defective production of proteins we need to replace that production.

We need, you know, we wanna deliver something that can express for very long periods of time, you know, ideally the entire life of the patient. And so with our, our proteolipid vehicle platform, we're able to interchangeably sort of package and deliver. Either RNA or dna N So, so there may be situations where you just wanna make the therapeutic for a couple weeks, and that way an RNA would make a lot of sense for that.

But there may be situations where you want long durability, you know, expressed for years or even tens of years. And in this case, you know, a stable dna, n a cargo would make a lot more sense. 

[00:17:19] Kevin Folta: Is there any evidence that shows that this can be a really long-term delivery vehicle, like, you know, can't actually induce those decades long deliveries?

[00:17:30] John Lewis: Yeah, so Antos hasn't been around long enough to do the decades experiments, but we certainly do have some very promising data pre-clinically in a number of different animal models, showing that when we deliver dna systemically, we're able to see expression well over a. And so this is, you know, similar expression I would say levels comparable to the current approved gene therapies, except now in a delivery system that's easy to manufacture, can be re dosed and can be used to package a wide variety of different cargos, including, you know, gene editing cargos.

[00:18:02] Kevin Folta: And I guess the thing that always comes back to is the safety question. And you mentioned, you know, some of the levels of potential toxicity and some of the issues that could happen at extremely high doses. But if you look on the internet, and especially around discussion of SARS COV two vaccine, There's all kinds of discussion about nanoparticles ending up in different places, like in the ovaries and, you know, leading to infertility and all this stuff.

How much do we know about localization beyond the liver and what do we know about relative safety? 

[00:18:34] John Lewis: Yeah, the safety question is a very important one. And, and for nanoparticles, a lot of thought and care has been putting in put into establishing the safety. And obviously we're, we're still doing clinical trials and we're.

trying to understand exactly the consequences. And I would say you know, it really depends on the disease you're treating. So, so obviously with the vaccine safety is, is really critical because you're treating a healthy population and it's a preventative measure. Obviously the, that that sort of risk benefit equation is different in a cancer patient is different in a.

You know, dying of a rare genetic disease. So I think, you know, as we better understand the safely safety implications of lipid data particles and, and lipid based particles we'll be able to, you know, make those decisions. For our platform, again, since we're using a different mechanism of action than the lmp, we've been able to sort of completely change the lipid composition of the formulation so that, you know, we're primarily using lipids that are already present in the human body.

So delivering more of those lipids has no consequence. And so, and so then, you know, the, the key questions of safety really depend upon what you're delivering. So is the gene you're deliver. , you know, does, is there a risk to, to make it in, in an organ that you wouldn't expect it or, or can you build in safety switches?

So that doesn't happen. And 

[00:19:50] Kevin Folta: I guess that really leads into my next question because. You're, you're basically making the vehicle to do the delivery of a drug that would be approved or be tested in clinical trials. So how does that work from a regulatory standpoint? Do you have a separate regulatory loop for the nanoparticle delivered version of a drug, or is it the nanoparticles themselves?

How does that work? . 

[00:20:14] John Lewis: Yeah, that's a great question. So, so, and it is really two, two separate questions in that the delivery vehicle for the most part will be identical, if not very similar between different medicines. And the cargo will, will be substantially different between medicines. And I think our goal as a company is to get you know, enough exposure and enough information on the safety of the delivery.

So that we can then go to the regulators and and then plug and play different cargoes for different diseases because I think, you know, the real exciting promise of genetic medicine is that with a safe, effective, reusable cargo that can go anywhere in the body, there's really no disease out of our reach, and it's just a matter of our creativity and coming up with cargoes that can cure those disease.

[00:20:59] Kevin Folta: And have these revised lipid nanoparticles with the viral protein fusion cassette. Are those currently being used or what's the approximate timeline to approval? 

[00:21:10] John Lewis: Yeah, so we so Antos during the pandemic developed a Covid 19 vaccine. It's very similar in concept to the RNA vaccines made by Pfizer and Moderna, except ours is made with dna.

And we made the decision to u use DNA N because DNA is super stable, right? You can pull DNA to dinosaur bones intact, you know, for instance. And so we thought this would solve the supply chain issues and, and and create you know, allow you countries that don't have access to these RNA vaccines to have access.

And we also have evidence that dna makes the antigen for longer. So we think we can create a booster, for instance, for covid that is much more durable. And so this vaccine is just sort of at the end stage of clinical phase two trials, and we're hoping to enter into phase three trials. Later this year we're also developing a wide variety of other therapies therapies for so for brain diseases, CNS diseases.

We have this really wonderful, productive collaboration relationship with Eli Lilly, where we're, we're hoping to develop, you know, some really groundbreaking new genetic therapies for, for CNS diseases. We have a great relationship with companies like BioMarin develop. You know, sort of breakthrough therapies for rare diseases.

And we also, we, you know, I have a keen interest in, in oncology and cancer and and so we have some really exciting, you know new therapies that we're developing for cancer as well. 

[00:22:28] Kevin Folta: Well, you mentioned all these collaborations, which really is the power of this technology, the b, the ability to put anybody's payload inside your vehicle.

And is there one that really sticks out to you as showing potential promise? 

[00:22:42] John Lewis: Yeah. One thing that's really personal for me is, is the treatment of cancer. My father-in-law passed away from metastatic kidney cancer almost two decades ago, and to be honest, I was appalled at the lack of, you know, options there were for treating metastatic cancers at that time.

So, so I'm really passionate about curing metastatic cancers. There's a really exciting approach an immune-based approach to cure cancer called CAR T therapy. And currently CAR T therapy is performed by taking the, the sort of the immune cells out of your body, programming them to, to recognize the cancer using a gene therapy and then putting them back in your body.

But what if we could, through a single injection, introduce the instructions to program your T-cells, you know, in your blood? I think that's a, that's a really exciting application of a technology that we already know works and could be adapted and make it much more available and much more applicable to different kinds of cancer.

So we're 

[00:23:39] Kevin Folta: really excited about that. , that's something I didn't know about because CAR T-cell therapy, we talk about it frequently on the podcast, but it always has that limitation of someone has to do this very expensive and challenging engineering step of, of T-cells. And so now if you can get lipid nano particles to find the T-cells and deliver a payload, now you're automatically programming them inside the body, which takes out that really tricky.

[00:24:06] John Lewis: Absolutely. Yeah. We think it would. Potential game changer in the future. 

[00:24:11] Kevin Folta: No, that's really exciting. So what is the timeline for approval of these kinds of technologies? . 

[00:24:17] John Lewis: Yeah. So it's, it's always a little longer than you'd hope but, but it, it, you know, it will come. I think, you know, for us, a, a huge clinical proof of concept was that our covid vaccine, you know, we know it's safe in people.

As a company. We've learned a lot about how to manufacture the platform safely to, to scale it know, to commercial scale. And I think, again, our goal is to, to adapt this, to become a plug and play platform. You know, one day we can have a cancer program, one day we can have an infectious disease program another day, a rare disease program.

And so we have about five programs internally that we're bringing forward to phase one studies, and we expect in the next two to three years to start multiple clinical programs. You know, obviously starting at phase one, but hopefully pre proceeding rapidly through your approval. If people 

[00:25:02] Kevin Folta: wanna learn more about Antos Pharmaceuticals, where would they look online or possibly on social?

[00:25:08] John Lewis: Sure. Yeah, absolutely. Well, I guess the best place to look is our website, www.antospharma.com. And we're also on LinkedIn, Twitter, and Facebook. 

[00:25:18] Kevin Folta: Oh, very nice. Well, thank you very much, Dr. John Lewis of Antos Pharmaceuticals. Thank you so much for informing us about the current state of innovation around lipid nanoparticles and something we've heard a lot of in the last few years and probably hear a bunch more in the future.

So thank you. Thanks, Kevin. Pleasure to be. And thank you for listening to this week's episode of Talking Biotech, again, one that gives us another ray of hope of new therapies that can be delivered via novel strategy. We've talked a lot about viral delivery. We've talked about lipid nanoparticle delivery now, and these types of therapies can be further honed to treat these rare problems, or maybe more common ones, but this really exciting technology that's coming to us fast and furious.

Thank you very much to our guests, so thank you very much for listening to The Talking Biotech podcast, and we'll talk to you again next.