WEBVTT - The First Pig to Human Kidney Transplant 0:00:15.356 --> 0:00:24.076 Pushkin. Rick Slayman is sixty two years old, lives in 0:00:24.116 --> 0:00:28.116 a suburb of Boston, works for the state Department of Transportation, 0:00:29.036 --> 0:00:32.436 and about five years ago he got a kidney transplant. 0:00:33.436 --> 0:00:37.996 Then last year his new kidney stopped working, his health declined. 0:00:38.436 --> 0:00:42.956 His prognosis was pretty bad, so earlier this year, he 0:00:42.996 --> 0:00:46.116 and his doctors decided that he would be the first 0:00:46.156 --> 0:00:48.676 person in the history of the world to get a 0:00:48.756 --> 0:00:54.196 kidney transplant from a genetically engineered pig. Surgeons did the 0:00:54.196 --> 0:00:58.836 transplant on March sixteenth, and two weeks later, Rix s 0:00:58.916 --> 0:01:02.276 Layman walked out of the hospital. It's still too soon 0:01:02.316 --> 0:01:04.796 to say how he'll do in the coming months, but 0:01:05.316 --> 0:01:14.476 as of this recording, he's doing well. I'm Jacob Boltstein 0:01:14.556 --> 0:01:16.756 and this is What's Your Problem, the show where I 0:01:16.836 --> 0:01:20.276 talk to people who are trying to make technological progress. 0:01:20.716 --> 0:01:25.276 My guest today is Mike Curtis. He's the CEO of Egenesis, 0:01:25.556 --> 0:01:29.716 the company that bred the genetically engineered pig that provided 0:01:29.716 --> 0:01:33.956 the kidney for Rick Slicker. Every year, thousands of people 0:01:34.156 --> 0:01:37.436 die waiting for an organ transplant that never comes. And 0:01:37.716 --> 0:01:42.676 so Mike's problem is this, is it possible to genetically 0:01:42.756 --> 0:01:48.996 engineer pigs to provide organs, kidneys, livers, hearts for people, 0:01:49.756 --> 0:01:52.236 and in the long run, is it possible to make 0:01:52.356 --> 0:01:56.596 pig organs that work even better than human organs for 0:01:56.876 --> 0:02:03.996 human transplant patients. So for a really long time, right, 0:02:04.076 --> 0:02:07.716 like hundreds of years, people have had this idea of 0:02:07.836 --> 0:02:14.396 transplanting organs or skin from animals to people, like where 0:02:14.436 --> 0:02:17.076 do you where do you date the beginning of this 0:02:17.196 --> 0:02:17.676 idea too? 0:02:18.356 --> 0:02:21.396 It was it was even pre dated human human transplants. 0:02:21.436 --> 0:02:24.476 So as soon as you know, physicians realize that organs 0:02:24.476 --> 0:02:27.356 can fail, I think the first instinct was can we 0:02:27.396 --> 0:02:30.036 get them from somewhere else? Right? And in the early 0:02:30.116 --> 0:02:33.996 days of that horribly right, no, no good success. So 0:02:34.156 --> 0:02:36.076 we kind of pre you know, date that to the 0:02:36.316 --> 0:02:38.836 dawn of modern medicine. And nothing worked. 0:02:39.036 --> 0:02:43.196 And nothing worked because basically the human immune system rejected 0:02:43.316 --> 0:02:44.076 the transplants. 0:02:44.236 --> 0:02:45.676 And that was before we even knew what that was. 0:02:45.716 --> 0:02:49.556 But right, yeah, And so to jump forward a very 0:02:49.596 --> 0:02:55.116 long way, it seems like Crisper, this ability to edit 0:02:55.556 --> 0:02:58.036 genes is sort of a key breakthrough. 0:02:58.516 --> 0:03:01.276 Is that the kind of key moment that enables this 0:03:01.356 --> 0:03:04.196 new era that seems to be beginning right now? 0:03:04.436 --> 0:03:08.956 Absolutely. There were some challenges in the cross species transplant 0:03:08.956 --> 0:03:12.276 that just unresolvable until the discovery of Crisper. So the 0:03:12.276 --> 0:03:15.116 one that we took on was in the nineties, it 0:03:15.156 --> 0:03:20.316 was discovered that poresign retroviruses that are indigenous in the genome, 0:03:20.356 --> 0:03:23.076 so they're kind of embedded in the pig genome, could 0:03:23.076 --> 0:03:25.316 infect human cells. And in the nineties, you know, we 0:03:25.316 --> 0:03:29.236 were coming out of the HIV epidemic, and we did 0:03:29.236 --> 0:03:31.956 not want to, you know, cause another problem. So we 0:03:31.956 --> 0:03:34.996 didn't want to have a cross species zoonotic event. So 0:03:35.276 --> 0:03:37.476 in many countries around the world they put a moratorium 0:03:37.636 --> 0:03:42.676 on cross species transplantation because of this risk of indigenous retroviruses. 0:03:42.756 --> 0:03:46.556 And so I just want to pause here because I 0:03:46.596 --> 0:03:50.636 didn't know about indogenous retroviruses until I started preparing for 0:03:50.676 --> 0:03:54.436 this interview, and it totally blew my mind that there 0:03:54.516 --> 0:03:58.836 is such a thing. Right, So, an indogenous retrovirus, as 0:03:58.876 --> 0:03:59.916 I understand. 0:03:59.556 --> 0:04:00.436 It is. 0:04:02.036 --> 0:04:05.396 Not like a disease that a that an animal has 0:04:05.396 --> 0:04:08.556 in this case, a poor sign. Indogenous retrovirus obviously is 0:04:08.556 --> 0:04:11.516 an indogen retrovirus in a pig, and it doesn't mean 0:04:11.516 --> 0:04:13.436 that the pig is sick It means that in the 0:04:13.516 --> 0:04:17.436 genome of every pig there is genetic code to code 0:04:17.476 --> 0:04:22.116 in that pig a retrovirus, right, And similarly, in humans 0:04:22.156 --> 0:04:25.796 there are other indogenous retroviruses. We have in our genome 0:04:26.196 --> 0:04:32.476 the code for retroviruses, that's right. Why why do mammals 0:04:32.516 --> 0:04:35.236 have the code for viruses in our genomes? 0:04:35.316 --> 0:04:38.396 Yeah? What's interesting because there are some functions that are 0:04:38.476 --> 0:04:42.596 ascribed to these indigenous retroviruses. So they kind of co evolved, 0:04:42.956 --> 0:04:45.836 you know, with pigs with people, and they pick up 0:04:45.836 --> 0:04:49.596 some function, right, And so we don't completely understand why 0:04:49.596 --> 0:04:54.516 they're there, but they're there and they pose a risk, right, 0:04:54.836 --> 0:04:59.196 an infectious disease risk to patients, especially when you think 0:04:59.196 --> 0:05:01.756 about patients who might be under immino suppression. 0:05:02.036 --> 0:05:04.036 And so, just to be clear, just I won't I 0:05:04.036 --> 0:05:05.796 don't want to be labor this, but it is really 0:05:05.836 --> 0:05:11.356 extraordinary coming to it new. The notion is a very 0:05:11.476 --> 0:05:15.276 very very long time ago, some pig in this case 0:05:15.316 --> 0:05:19.436 got infected with a virus and that virus made its 0:05:19.476 --> 0:05:22.916 way into the genome of essentially all the pigs living today, 0:05:24.316 --> 0:05:29.956 and that genetic code is not harmful to pigs, but 0:05:30.076 --> 0:05:33.556 there is a fear that if you took a pig kidney, say, 0:05:33.556 --> 0:05:35.756 and put it in a human being, the code for 0:05:35.836 --> 0:05:38.356 that virus, which is fine in pigs, might be harmful 0:05:38.356 --> 0:05:38.796 in people. 0:05:39.116 --> 0:05:42.356 Exactly. It's an unknown risk, ye. 0:05:42.796 --> 0:05:46.556 And so in the nineties, particularly as you said, in 0:05:46.596 --> 0:05:48.836 the context of the fear of HIV, people are thinking 0:05:48.876 --> 0:05:52.836 about doing could we transplant a pig kidney into a 0:05:52.916 --> 0:05:57.476 human and regulators essentially are saying, well, one reason you 0:05:57.516 --> 0:06:01.236 cannot do it is because of these endogenous retroviruses in 0:06:01.276 --> 0:06:02.436 the pigs DNA. 0:06:02.596 --> 0:06:05.676 Exactly, and we can't quantify the risk, and so we 0:06:05.716 --> 0:06:08.756 don't know what will happen, and we actually don't want 0:06:08.796 --> 0:06:10.676 to know. You need to come up with a way 0:06:10.676 --> 0:06:14.436 to mitigate the risk of retroviral transmission from the donor 0:06:14.476 --> 0:06:15.756 to the recipient. 0:06:15.396 --> 0:06:19.556 Okay, And so that's just like a red light, do 0:06:19.716 --> 0:06:23.156 not pass. Go stop doing this for a while. Once 0:06:23.196 --> 0:06:23.676 that happens. 0:06:23.716 --> 0:06:27.396 In the nineties, exactly, most of the people that were 0:06:27.436 --> 0:06:29.556 investing in the space stopped investing in the space. The 0:06:29.596 --> 0:06:32.836 progression towards clinic stopped. It really slowed the whole field 0:06:32.836 --> 0:06:34.796 down because no one knew exactly how to quantify the 0:06:34.876 --> 0:06:37.156 risk or then what to do about it. And so 0:06:37.236 --> 0:06:40.636 any pig genome you'll have between fifty and seventy copies 0:06:41.076 --> 0:06:44.316 of the retrovirus scattered throughout the genome. And so even 0:06:44.356 --> 0:06:46.956 if you wanted to go in and remove them, there 0:06:47.036 --> 0:06:49.356 was no technology available that would allow you to do that. 0:06:50.596 --> 0:06:53.316 And no one knew of a way to actually actively 0:06:53.356 --> 0:06:56.196 get rid of these viruses right until the discovery of Crisper. 0:06:56.836 --> 0:07:01.596 So Crisper comes along what ten issuars twelve years ago, 0:07:01.956 --> 0:07:07.636 and it's this incredible technology for editing a genome. Right, 0:07:10.636 --> 0:07:14.996 people think, oh, maybe we could solve that poresine and 0:07:15.116 --> 0:07:17.636 dogenous retrovirus problem using Crisper. 0:07:18.036 --> 0:07:19.996 Yeah, so this is what George Church kind of took 0:07:20.036 --> 0:07:22.396 up at Harvard was like, it kind of what would 0:07:22.356 --> 0:07:24.436 do we use chrispher for? And this this problem was 0:07:24.476 --> 0:07:26.436 out there and George took it on and said, well, 0:07:26.476 --> 0:07:29.156 let's see if you can inactivate all copies of the 0:07:29.156 --> 0:07:31.876 retroviruses in the pig geno. The beautiful part about Crisper 0:07:32.556 --> 0:07:35.076 is once you give it a sequence, right, it will 0:07:35.156 --> 0:07:38.636 edit all copies of that sequence in a given genome. Now, 0:07:38.676 --> 0:07:43.036 the worry was that you would then create basically Swiss 0:07:43.076 --> 0:07:45.156 cheese out of the genome. Right, you would create an 0:07:45.236 --> 0:07:48.076 unviable genome. There's too many edits, was the original thought. 0:07:48.476 --> 0:07:50.756 But George and the team at Harvard showed that no, 0:07:50.836 --> 0:07:54.516 you could actually inactivate all copies of the retrovirus and 0:07:54.596 --> 0:07:56.596 then produce a viable pig. 0:07:57.156 --> 0:07:59.196 Right, because I suppose the other question is like, even 0:07:59.236 --> 0:08:03.796 if you can cleanly make all the edits, do does 0:08:03.836 --> 0:08:07.676 the pig actually need this indogenous retrovirus for a reason 0:08:07.716 --> 0:08:08.996 we don't understand. 0:08:08.636 --> 0:08:10.516 Right, And we know it does if you if you 0:08:10.556 --> 0:08:12.516 completely knock it out or get rid of it, the 0:08:12.516 --> 0:08:16.156 pigs are not healthy. So we make a relatively subtle 0:08:16.236 --> 0:08:19.716 change to the viral genome that that prevents the virus 0:08:19.716 --> 0:08:22.636 from replicating. So with this edit, the virus can no 0:08:22.676 --> 0:08:24.156 longer replicate hot. 0:08:24.196 --> 0:08:27.676 But so you don't knock it. You don't entirely remove 0:08:27.756 --> 0:08:29.036 the sequence from the genome. 0:08:29.116 --> 0:08:29.716 You just. 0:08:31.356 --> 0:08:35.156 Edit the genome such that this virus, once it's expressed, 0:08:35.516 --> 0:08:36.396 cannot replicate. 0:08:36.596 --> 0:08:39.436 Right, So essentially inactivate those of Dodges viruses. 0:08:39.756 --> 0:08:42.116 And so this idea from George Churchill was one of 0:08:42.156 --> 0:08:46.396 the like giant names in genetics. Right famous scientists was 0:08:46.476 --> 0:08:49.196 that the origin of the company. 0:08:49.356 --> 0:08:53.076 So it came from from from George's lab and we 0:08:53.076 --> 0:08:59.356 we one of his postdocs started Egenesis by outlcensing the 0:08:59.396 --> 0:09:03.316 technology from Harvard. So the original idea was to start 0:09:03.316 --> 0:09:07.956 Egenesis with the idea of making animals that were retroviray 0:09:07.996 --> 0:09:11.876 inactivated and then also do the rest of the editing 0:09:12.156 --> 0:09:15.276 right that made the pigs more compatible with human recipient. 0:09:15.316 --> 0:09:17.396 So that's how we got into the field. And then 0:09:17.516 --> 0:09:21.956 from the from then we've built the additional editing to 0:09:21.996 --> 0:09:24.956 provide organs that are more compatible with first non human 0:09:24.956 --> 0:09:26.436 primates and then now with people. 0:09:26.796 --> 0:09:31.836 So you have inactivated the endogenous retrovirus in the pig. 0:09:32.316 --> 0:09:35.996 This is like step one, right, But at this point, 0:09:36.116 --> 0:09:41.116 if you tried to take that kidney, even though you've 0:09:41.116 --> 0:09:45.236 solved the retrovirus problem, it's still a pig kidney, right, 0:09:45.316 --> 0:09:47.516 and the human body would know that and would not 0:09:48.196 --> 0:09:51.276 accept it. So what do you have to do next? 0:09:51.436 --> 0:09:54.396 Sure, and so if you just took an unedited pig 0:09:54.476 --> 0:09:55.916 kidney and try to put it into a monkey or 0:09:55.956 --> 0:09:59.356 to a person, to be rejected within minutes. And that's 0:09:59.396 --> 0:10:02.996 primarily due to what we call hyperacute rejection, where the 0:10:03.116 --> 0:10:07.396 humans are recognizing the carbohydrate differences between pigs and humans. 0:10:07.396 --> 0:10:12.676 So carbohydrates are that coat all the cells, and humans 0:10:12.716 --> 0:10:16.236 have antibodies that can recognize those pig sugars. So what 0:10:16.276 --> 0:10:19.996 we do is we inactivate three genes responsible for those 0:10:20.036 --> 0:10:23.756 carbohydrate differences between pigs and humans. Once you do that, 0:10:23.796 --> 0:10:25.716 we create what we call the triple knockout. So we 0:10:25.836 --> 0:10:31.236 inactivate those genes, knocking out those carbohydrate differences and eliminating 0:10:31.956 --> 0:10:32.916 hypercute rejection. 0:10:34.156 --> 0:10:41.676 And when you create a pig with those particular carbohydrates eliminated, 0:10:42.756 --> 0:10:45.596 does it matter to the pig? Is the pig sicker? 0:10:45.636 --> 0:10:49.316 As a result, we haven't seen any impact on the 0:10:49.636 --> 0:10:52.356 health or longevity of a pig. So, for instance, we 0:10:52.436 --> 0:10:55.796 have several animals in our colony that are a couple 0:10:55.836 --> 0:10:58.836 of years old, and so we haven't seen any effects 0:10:58.876 --> 0:11:01.516 on the longevity of those animals. So no, we haven't 0:11:01.516 --> 0:11:02.396 seen any downside. 0:11:02.596 --> 0:11:07.316 Okay, so you've inactivated the endogenous retrovirus and now you've 0:11:07.356 --> 0:11:12.236 eliminated the carbo hydrates that are causing acute rejection. There's 0:11:12.316 --> 0:11:14.796 like one more set of changes you've got to make, right, 0:11:14.836 --> 0:11:15.196 That's right. 0:11:15.516 --> 0:11:17.636 So what the field has shown over the past forty years. 0:11:17.676 --> 0:11:21.156 Is that if you add human genes to the pig genome, 0:11:21.556 --> 0:11:25.036 you can help regulate different areas of incompatibility. So when 0:11:25.076 --> 0:11:28.516 we think about, for instance, coagulation, right, So the coagulation 0:11:28.636 --> 0:11:32.716 factors in the pig are not one percent compatible with humans, 0:11:33.076 --> 0:11:36.356 so we introduce human coagulation factors into the pig. 0:11:36.716 --> 0:11:39.356 Coagulation factors just what causes the blood. 0:11:39.036 --> 0:11:42.276 To clot basically or prevent the blood from clotting? Yeah, 0:11:42.316 --> 0:11:45.516 either way, both both corrections, yep, absolutely. And then we 0:11:45.556 --> 0:11:49.356 also add regulators of complement activation. The first kind of 0:11:49.396 --> 0:11:51.796 immune response that you're going to get to a graft 0:11:52.236 --> 0:11:55.476 in a transplant is what we call compliment activation, and 0:11:55.516 --> 0:11:58.316 that leads to loss of cells, right, and that leads 0:11:58.356 --> 0:12:02.036 to death of cells. But by introducing human complement regulators 0:12:02.276 --> 0:12:05.396 into the poor scine tissue, we can slow down or 0:12:05.476 --> 0:12:09.436 quiet that complement response. And then we add module later 0:12:09.636 --> 0:12:12.076 of what we call the innate and adaptive immune response. 0:12:12.636 --> 0:12:16.076 In total, we add in the animal that was used 0:12:16.116 --> 0:12:19.076 in mister Slamon's transplant, we introduced a total of seven 0:12:19.676 --> 0:12:23.076 regulatory human proteins. So if you add it together, it's 0:12:23.156 --> 0:12:27.716 fifty nine edits to inactivate the retroviruses three edits to 0:12:27.796 --> 0:12:32.476 improve the carbohydrate compatibility, and then seven edits to introduce 0:12:32.556 --> 0:12:35.356 human regulatory trans genes, for a total of sixty nine edits. 0:12:35.476 --> 0:12:38.836 So it's basically the first two categories are make it 0:12:38.916 --> 0:12:41.676 less like a pig, and then the third category is 0:12:41.876 --> 0:12:43.116 make it more like a person. 0:12:43.316 --> 0:12:44.796 Yeah, that's a good way to think about it. 0:12:44.916 --> 0:12:49.516 That's right, And I mean presumably at some margin you 0:12:49.636 --> 0:12:52.916 want to make it as little like a pig and 0:12:53.076 --> 0:12:56.396 as much like a person as possible. But the pig 0:12:56.436 --> 0:13:01.276 still has to live, to grow up and have a kidney. 0:13:00.996 --> 0:13:05.636 Right, absolutely, And we've produced animals with more trans genes 0:13:05.676 --> 0:13:08.916 without any issue. But you can imagine at some point, right, 0:13:09.156 --> 0:13:11.076 you'll reach a point where the pig no longer can 0:13:11.116 --> 0:13:14.516 tolerate whatever the editing you're doing. We're actually already impressed 0:13:14.876 --> 0:13:17.596 that we can produce healthy, viable pigs with this number 0:13:17.636 --> 0:13:20.876 of edits. If you go back ten fifteen years, nobody 0:13:20.916 --> 0:13:24.956 thought that you could viably do this. Even in activating 0:13:24.956 --> 0:13:27.476 fifty nine copies of the retrovirus. Many felt that that 0:13:27.596 --> 0:13:29.636 was too many and the genome wouldn't be able to 0:13:29.676 --> 0:13:32.196 handle it. We can tell you that it's not easy, 0:13:32.236 --> 0:13:34.676 and it's not trivial to do it. It took us 0:13:34.676 --> 0:13:36.916 a lot of time to figure out how to do it, 0:13:37.436 --> 0:13:39.636 but now we've shown it it is doable. 0:13:40.396 --> 0:13:42.916 I'm sure that it's not easy, but I don't know 0:13:43.076 --> 0:13:48.396 enough to understand, like what's hard about it? Like tell 0:13:48.436 --> 0:13:50.076 me a thing that you had to figure out. 0:13:50.236 --> 0:13:53.396 Sure, so when you do that much engineering to the genome, 0:13:53.436 --> 0:13:58.236 you can get aberrations in the genome that prevents you 0:13:58.276 --> 0:14:00.276 from making a pig. So one of the things that 0:14:00.316 --> 0:14:03.636 we do is we do what's called clonal selection. So 0:14:03.756 --> 0:14:08.396 we'll engineer thousands, tens of thousands of cells and then 0:14:08.516 --> 0:14:12.356 select genomes based on viability. So, for instance, to so 0:14:12.476 --> 0:14:15.356 produce our seventeen eighty four donor, we had to screen 0:14:15.436 --> 0:14:19.036 over four thousand clones to find clones that had the 0:14:19.076 --> 0:14:21.796 adequate quality of genome to then make pigs. 0:14:22.036 --> 0:14:25.076 Huh. So let's just let's just talk about that for 0:14:25.076 --> 0:14:29.036 a minute, like how that actually works, which is the 0:14:29.036 --> 0:14:32.916 more basic question of just how does the whole thing work? 0:14:32.996 --> 0:14:35.556 Like I get in a sort of abstracted space what 0:14:35.596 --> 0:14:40.396 you're doing, but like in whatever in a you know, 0:14:40.436 --> 0:14:42.756 in a cell, fundamentally there is a cell, right like, 0:14:42.756 --> 0:14:43.556 what are we starting with. 0:14:43.756 --> 0:14:46.476 So we'll take a sample of skin from an adult 0:14:46.796 --> 0:14:49.996 what we call wild type so unedited pig. Then culture 0:14:50.036 --> 0:14:52.796 those cells, make many cells, and then those are the 0:14:52.836 --> 0:14:54.476 cells that we're going to edit. So those are the 0:14:54.516 --> 0:14:57.196 cells that we take crisper. We make the fifty nine edits, 0:14:57.236 --> 0:14:59.156 we make the triple knockout, and we make the seven 0:14:59.236 --> 0:15:02.996 trans geens. In the case of the seventeen eighty four animal, 0:15:03.036 --> 0:15:05.356 we did that through three sequential routes. 0:15:05.396 --> 0:15:07.636 So just to be clear, the seventeen eighty four animal, 0:15:07.716 --> 0:15:10.436 this is like one particular pig, the pig that donated 0:15:10.476 --> 0:15:12.396 the kidney that is in a person right now. 0:15:12.476 --> 0:15:15.596 So that's the seventeen eighty four refers to the genetics. 0:15:15.876 --> 0:15:19.516 So we make many seventeen eighty four animals. So it's 0:15:19.556 --> 0:15:20.796 a particular. 0:15:20.716 --> 0:15:23.236 Edited genome, and it's the edited genome that you have 0:15:23.316 --> 0:15:23.956 described to me. 0:15:24.036 --> 0:15:26.636 Yeah, exactly, okay, right, So to make that animal, we 0:15:26.636 --> 0:15:29.156 actually went through three rounds of editing, right, So we 0:15:29.196 --> 0:15:33.436 would make the retroviolent activation make a pig, then take 0:15:33.476 --> 0:15:35.796 those cells, edit them to make the try add the 0:15:35.836 --> 0:15:38.436 truckle knockout, make a pig. Then we come back and 0:15:39.156 --> 0:15:40.476 add the seven trans sheats. 0:15:40.276 --> 0:15:43.956 So it's multiple generations. You're you are sort of adding 0:15:45.716 --> 0:15:49.276 changes genetic mutations over successive generations. 0:15:49.516 --> 0:15:54.916 Exactly why this allows us to select right. So there's 0:15:54.956 --> 0:15:59.676 there's two there's there's two restrictions the time. Because we're 0:15:59.676 --> 0:16:02.116 working with primary cells the time, you have to edit 0:16:02.156 --> 0:16:05.276 them before they what we call sinat. So at some 0:16:05.316 --> 0:16:08.236 point those cells stop dividing. You need to edit while 0:16:08.236 --> 0:16:10.636 the cells are still divide, so you have a limited 0:16:10.756 --> 0:16:13.236 number of days to do the editing, right, So we do. 0:16:13.516 --> 0:16:15.596 So this is why we were doing three rounds of editing, 0:16:15.796 --> 0:16:18.676 because we can get the retroviral in make a pig, 0:16:18.716 --> 0:16:20.356 we can get the triple knockout make a pig. We 0:16:20.396 --> 0:16:22.476 get the seven genes and make a pig. What's really 0:16:22.516 --> 0:16:25.036 important to that whole process is at the end of 0:16:25.076 --> 0:16:31.596 each editing round, we then screen individual cells for the genotype. Right, 0:16:31.636 --> 0:16:33.916 And this is where we'll go through and screen you know, 0:16:34.276 --> 0:16:37.276 up to four thousand cells to pick cells that look 0:16:37.716 --> 0:16:40.076 like they have a good morphology and a good phenotype 0:16:40.196 --> 0:16:42.876 for which we would then make a pig. So, once 0:16:42.876 --> 0:16:45.876 we do the editing, we then pick individual cells that 0:16:45.916 --> 0:16:49.236 we call clones, and then we grow those clones out, 0:16:49.396 --> 0:16:52.196 and now we have an edited porsone genome, but we 0:16:52.196 --> 0:16:53.116 still don't have a pig. 0:16:53.316 --> 0:16:56.556 So you basically have a whatever, a petri dish full 0:16:56.556 --> 0:17:01.636 of pig skin cells that have the genotype that you want, exactly, okay. 0:17:01.476 --> 0:17:02.836 And so now we need to make a pig. And 0:17:02.996 --> 0:17:05.036 the technology we use to turn a single cell into 0:17:05.076 --> 0:17:08.156 a pig, it's called a somatic cell nuclear transfer. It 0:17:08.236 --> 0:17:10.716 was similar to tchnology that was used to clone Dolly, 0:17:11.316 --> 0:17:13.996 where we take the nucleus of the edited cell and 0:17:14.156 --> 0:17:18.236 basically transfer it into the O site of a pig. 0:17:18.076 --> 0:17:21.476 An egg cell. And and so this is now a 0:17:21.716 --> 0:17:24.996 whatever thirty year old technology that they used to clone 0:17:24.996 --> 0:17:26.796 a sheep with in the nineties exactly. 0:17:27.516 --> 0:17:30.116 There's been some obviously improvements since then, but the core 0:17:30.276 --> 0:17:33.196 idea is essentially the same. And then we use that 0:17:33.236 --> 0:17:36.116 cloning technology to then make pigs. So we make an 0:17:36.116 --> 0:17:39.276 embryo and then we transfer that embryo into a surrogate 0:17:39.356 --> 0:17:42.716 sal and then that surrogate sal will carry the piglet 0:17:42.796 --> 0:17:43.396 to term. 0:17:44.116 --> 0:17:47.116 There's some ethical dimension to this, like like, what are 0:17:47.156 --> 0:17:48.796 the relevant ethical dimensions to you? 0:17:49.116 --> 0:17:51.956 Yeah, our focus is on preserving human health and saving 0:17:51.996 --> 0:17:54.916 patients who are dying on the transfer wait list, and 0:17:54.956 --> 0:17:58.676 we believe that this approach is justifiable with that goal 0:17:58.716 --> 0:18:01.476 in mind. So every day we show up, we focus 0:18:01.556 --> 0:18:03.836 on patients like mister Slayman. And so this is a 0:18:03.876 --> 0:18:06.436 means to an end. This is a means to producing 0:18:06.556 --> 0:18:09.476 organs that currently don't exist. It's to save paces who 0:18:09.476 --> 0:18:12.316 are imminately dying, but they are. It's a very bleak 0:18:12.356 --> 0:18:14.596 outlook for some of these folks, right, And so we 0:18:14.716 --> 0:18:17.036 view that the work that we're doing for engineering the 0:18:17.036 --> 0:18:20.596 persa and genome and producing compatible organs all about, you know, 0:18:20.676 --> 0:18:23.756 realizing that mission of helping these patients, and we believe 0:18:23.756 --> 0:18:28.196 that that puts us on a very firm ethical route. 0:18:29.916 --> 0:18:32.476 Still to come on the show, how pig hearts might 0:18:32.596 --> 0:18:46.596 help human babies. How many pigs with this genetic sequence 0:18:46.636 --> 0:18:46.996 are there? 0:18:47.036 --> 0:18:49.756 You have about fifty or so animals that are at 0:18:49.796 --> 0:18:50.476 different ages. 0:18:50.796 --> 0:18:53.636 So, like, do you have a farm somewhere? 0:18:54.076 --> 0:18:56.676 So we do. We have two farms we have and 0:18:56.796 --> 0:18:59.356 they are both out in the Midwest. One is a 0:18:59.396 --> 0:19:01.556 research more of a research farm. It's a two hundred 0:19:01.596 --> 0:19:05.036 acre farm where we institute biosecurity. So one of the 0:19:05.116 --> 0:19:07.716 keys here is to produce animals that are free of 0:19:07.836 --> 0:19:11.356 pathogens that could put harm to either the organs post 0:19:11.356 --> 0:19:15.156 transplant or the patient or the recipients. So that farm 0:19:15.196 --> 0:19:18.036 produces relatively clean animals. But then we have what we 0:19:18.076 --> 0:19:22.676 call a clinical grade or designated pathogen free facility where 0:19:22.716 --> 0:19:24.756 the animals are growing inside what we call a barrier. 0:19:25.516 --> 0:19:28.676 So there we control feed, water, everything that comes in 0:19:28.716 --> 0:19:31.556 to try to keep pathogens out. So we're actively managing 0:19:31.876 --> 0:19:35.436 the environment that those animals are raised in. And on 0:19:35.516 --> 0:19:39.516 top of all of that, we're doing very robust path 0:19:39.676 --> 0:19:44.516 consistent pathogen testing, so we're constantly monitoring all the animals 0:19:44.556 --> 0:19:46.956 for any potential pathogens or disease. 0:19:47.276 --> 0:19:50.756 Right, I mean presumably some kind of like jumping the 0:19:50.836 --> 0:19:53.876 species barrier or transfer would be one of the like 0:19:54.916 --> 0:19:57.036 nightmarishly bad outcomes, right. 0:19:57.116 --> 0:19:59.676 Yes, I mean one of the reasons that we selected 0:20:00.236 --> 0:20:03.276 pigs as the species is one we've co you know, 0:20:03.396 --> 0:20:06.196 existed with these animals for thousands of years and we 0:20:06.276 --> 0:20:09.556 haven't seen that you know, that particular that type of 0:20:09.596 --> 0:20:12.676 disease transmission, and then we can edit, and then we 0:20:12.716 --> 0:20:15.596 also know how to grow animals at scale. But yes, 0:20:15.636 --> 0:20:17.196 we're always on the lookout and I think this is 0:20:17.236 --> 0:20:20.476 part of surveillance that we'll do for the foreseeable future, 0:20:21.036 --> 0:20:23.716 is on the lookout for things that we aren't paying 0:20:23.716 --> 0:20:24.756 attention for. Right. 0:20:25.276 --> 0:20:27.716 So let's talk about the first patient. Let's talk about 0:20:27.756 --> 0:20:30.556 Richard slam and the first person ever to be walking 0:20:30.596 --> 0:20:34.956 the earth with a pig kidney as far as we know, probably. 0:20:37.316 --> 0:20:37.916 Why him? 0:20:38.076 --> 0:20:40.076 What was it about his case that made him the 0:20:40.156 --> 0:20:40.796 right patient? 0:20:40.956 --> 0:20:43.236 Yeah, So it's a great question, and part of it 0:20:43.276 --> 0:20:45.836 was inspired by the work that was done at the 0:20:45.916 --> 0:20:49.316 University of Maryland in the first heart transplants, right, so 0:20:49.356 --> 0:20:52.356 we refer to those as the Bennett and Fossett transplants. 0:20:51.836 --> 0:20:55.676 The first pig heart pig heart, Yeah, which just happened. 0:20:55.676 --> 0:20:59.356 That was like a different project, right, but it just 0:20:59.356 --> 0:21:01.436 happened in the last year or so, right now, the. 0:21:01.476 --> 0:21:03.836 Last two years two years, Yeah, absolutely. And there was 0:21:03.836 --> 0:21:05.996 always this debate in the field of zeno is what 0:21:06.036 --> 0:21:09.556 patients would constitute the right patient population to go into 0:21:09.716 --> 0:21:12.276 And the team at Maryland really showed us that there's 0:21:12.316 --> 0:21:14.636 a case for compassionate use. There's a case for patients 0:21:14.636 --> 0:21:17.076 who have reached the end of the treatment options and 0:21:17.116 --> 0:21:20.036 really they're facing imminent death and we have a technology 0:21:20.036 --> 0:21:23.476 that could save their life, so shouldn't we try now. Unfortunately, 0:21:23.556 --> 0:21:27.356 you know, those gentlemen passed away within forty or fifty 0:21:27.436 --> 0:21:31.316 days post transplant. But it showed us that the regulatory 0:21:31.316 --> 0:21:34.556 agencies were open to the discussion, and we just need 0:21:34.596 --> 0:21:37.156 to define what is the right patient population in the 0:21:37.196 --> 0:21:39.836 case of kidney and so we had a discussion with 0:21:39.876 --> 0:21:43.036 the FDA back in twenty twenty two about what would 0:21:43.076 --> 0:21:45.676 be the right patient population for a formal phase one 0:21:45.716 --> 0:21:49.916 clinical study, and we'd come to agreement on patients over fifty, 0:21:50.436 --> 0:21:53.796 patients on the transplant weightlist, and patients that had failed 0:21:53.836 --> 0:21:56.316 a previous alo transplant, right, so they'd had a human 0:21:56.396 --> 0:21:58.996 kidney before, and they had it for a certain duration 0:21:59.036 --> 0:22:01.516 of time and eventually that kidney fails and you find 0:22:01.516 --> 0:22:04.436 yourself back on the transplant weightlist. And why that patient 0:22:04.476 --> 0:22:07.916 population made sense is because those patients have a very 0:22:07.956 --> 0:22:12.036 low likelihood if you're over fifty with that profile of 0:22:12.076 --> 0:22:15.036