Program: 04 | Artificial Evolution: Pig Parts for People?

Peter de Kruijff: Timothy Andrews felt exhausted.

Yes, he was 66 and yes, he'd lived with diabetes since the nineties, but in the past couple of years, something had felt different. He was more tired than ever.

So he went to see his doctor. 

Timothy Andrews: Yeah, so they did some blood tests and stuff and the next thing they told me is I had stage three kidney disease.

Most people stay at stage three for two, three years.

Peter de Kruijff: Timothy wasn't too worried.

Timothy Andrews: But then the next time I went, which was like a month later, they said, oh, you're at end stage. End stage. That's a bit of a shock. Just the word alone. End stage. They don't mean the end of the disease, they mean the end of me. What?!

And from there, I was given the choice to go on dialysis or pick a box. That's what the surgeon told me. Well, I don't want to pick a box, so let's go on dialysis and see what happens.

Peter de Kruijff: It started off great.

Timothy Andrews: Dialysis at first is like a honeymoon as they take all the poisons outta you and then, you know, it doesn't take but a month or two and you're like, ooh, I don't feel so good.

And then by three months, oh, I'm throwing up and I'm sleeping all the time. I'm tired, I'm nauseous. What is going on? It took me about six months to have a heart attack. They were telling me I was going to, on average, live to five years on dialysis and they said that the next possible kidney transplant from a human from the list would be seven years. Little bit of a gap there.

Peter de Kruijff: He didn't think he could last much longer on dialysis.

Timothy Andrews: So you're sick all the time. You're throwing up, blah, blah, blah. It goes on and on and it's tough on the body. So the heart attack's kind of an indication of how things were going, not well.

Peter de Kruijff: Dialysis was taking a heavy toll, and for Timothy, the waiting list for a kidney transplant was long. Like almost a decade.

In Australia, about 1500 people are waiting for a kidney. In the United States, it's more than 90,000. 

Timothy Andrews: So I started looking, you know, thank God for the internet. Let's see what's going on. Hey, Mass General did this pig kidney thing and put it in a guy. He was really sick … but it worked.

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Peter de Kruijff: Hi, I'm Peter de Kruijff. I'm an ABC environment reporter. For Science Friction, this is Artificial Evolution on ABC Radio National – my series on how gene technologies are reshaping the world around us.

And today, the final episode. We are covering xenotransplantation, the science of taking organs from animals and putting them into humans.

Dominique Martin: My expectation, my hope at this stage is that we are going to very soon see several people who are surviving and doing well a year out from a pig kidney transplant. 

Wayne Hawthorne: Our whole end game has been transplant patients. 

Syd Johnson: There's a lot of money being invested in xenotransplantation and a lot of effort, but of course it might still not work.

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Timothy Andrews: After the heart attack, I started looking. I said, there's gotta be another way. Slow death is not what I'm really looking for. I'm looking for some hope. Some hope. Any hope. People around me, some of the guys decided they didn't want to do dialysis anymore. They would rather die than sit in that chair. And wait to die? No hope. No hope there’s gotta be hope.

Peter de Kruijff: That's when Timothy was searching online and found out about the possibility of a pig kidney transplant.

Timothy Andrews: So that's what I did. Went down to Mass General, knocked on the door, said, hey, I wanna see this transplant people, I wanna see the xenotransplant people.

Peter de Kruijff: At Massachusetts General Hospital in Boston doctors had already performed a xenotransplantation for a guy called Richard Slayman, the first ever patient to receive a genetically edited pig kidney transplant.

Newsreader (Archive): The pig's genes were altered to make its organs less likely to be rejected by the human body. 

Peter de Kruijff: That procedure was done in March 2024. Slayman died two months later, though an autopsy revealed that issues with his heart, not the kidney had caused his death. But Timothy wasn't deterred. 

Timothy Andrews: Well, I was wheelchaired in. Dr Riella said you gotta do a lot of things first.

Peter de Kruijff: That's Dr Leonardo Riella, a nephrologist and medical director of kidney transplantation at Mass General. He's on Timothy's treating team. After that meeting, Timothy committed 100%. 

Timothy Andrews: I'll do the physical therapy, I'll do all the everything you want me to do, vaccines, whatever. I did it all. I got out of the wheelchair in less than a month through physical therapy, and I ran down that hallway to see him and says, here I am. I'm a hundred percent in.

Peter de Kruijff: Along the way, Timothy lost about 10 kilos and improved his fitness. Despite the unknowns of this highly experimental treatment, he says it wasn't a tough choice. 

Timothy Andrews: I told the doctors, I don't care if I die in a day. As long as you learn something, that's why I am here. So we can learn something. So it wasn't a hard choice for me. People around me, that might've been a different story. 

Peter de Kruijff: Some family and friends were a little more concerned. 

Timothy Andrews: Are you crazy? They've never, you know, they had no real history of this. It was a lot of naysayers. I think there's still a lot of naysayers, but that's okay. 

Peter de Kruijff: The day of the operation was January 25th, 2025. Timothy says, once things got rolling, it all happened pretty quickly, and when he woke up … 

Timothy Andrews: All of a sudden I had energy. Energy that I haven't felt in a couple years because of dialysis. I was like, what is this? I just felt tons of energy coming through my body. I danced from the table to the chair. I tap danced across the room. I was so excited feeling that it worked. I was so excited.

Peter de Kruijff: Taking organs out of animals and placing them in the humans sounds like the plot of a science fiction novel. Well, actually … I, I think it is. But xenotransplantation has got real history. 

Wayne Hawthorne: One of the first recorded cases was back in 1667, John Baptist did an infusion from a lamb – blood into a 15-year-old child who was suffering with malaise.

He didn't subsequently kill that child, but he did go on to infuse a number of patients who all died. He thus caused the very first moratorium into xenotransplants. The French government put a moratorium in place, so that was the very first recorded case of xenotransplantation in medical literature.

Peter de Kruijff: This is Wayne Hawthorne, professor of transplantation at Westmead Hospital in Sydney, and a past president of the International Xenotransplantation Association. 

Wayne Hawthorne: In the 1950s, there were baboon kidneys and hearts transplanted into patients. Unfortunately, we didn't have the technology, the immunology, the immunosuppression, or the capacity to follow those patients, and so those patients died unfortunately.

Peter de Kruijff: And we'll get to the immune suppression in a minute. But the most well known of these early cases, the one that really put xenotransplantation on the minds of the public was that of Baby Fae. Baby Fae was born in 1984 with a congenital heart defect that meant she was only expected to live for two weeks.

As her condition deteriorated, doctors chose to give her a heart transplant, a baboon heart transplant. At the time, even a human-to-human infant, heart transplant had never been done. 

Newsreader (Archive): Baby Fae got her baboon heart just over two weeks ago and until this weekend, everything had been going remarkably smoothly. She was and still is eating well and putting on weight. But in the last 48 hours, doctors at the Loma Linda Medical Center in California say that Baby Fae is now about a month old, is showing the first signs of rejecting her new heart. 

Peter de Kruijff: Now baboon was chosen because there were no human donor hearts available. Very limited numbers of infant donors is still a major problem today. Tragically Baby Fae's Xeno transplant didn't last.

Newsreader (Archive): Despite Baby Fae's death her surgeon today continued to portray the experiment as a step forward.

Wayne Hawthorne: Baby Fae was a landmark case because she survived some 21 days, but subsequently suffered rejection. So they were our early forays into xenotransplantation, and we soon realised that we needed to develop another means. And so in the early eighties, we started thinking very seriously about xenotransplantation using pigs.

Peter de Kruijff: You've probably heard of the cloning of Dolly the sheep in the mid 90s, especially if you listen to episode one in this series. But a few years later, scientists also cloned Millie.

Wayne Hawthorne: Everyone's heard of Dolly, but no one's heard of the pigs that were the forebears for xenotransplantation. So we've used a whole swathe of new technologies in xenotransplant research to develop those pigs.

Peter de Kruijff: But why would you need to develop pigs, so to speak? Well, this goes back to Baby Fae and some of those earlier xenotransplantation attempts. The body has a very effective immune system in place to protect us against foreign materials, bugs, infections, illnesses. And that includes foreign tissues like the organs of other animals.

When this tissue is introduced, the human body goes on the attack and rejects the organ. So if doctors wanted to use animal organs, they had to work out a way around that rejection. 

Wayne Hawthorne: We first thought that when we discovered that alpha gal was the protein, the epitope, the surface marker that recognised and showed pig as pig.

Peter de Kruijff: Alpha gal sits on the surface of pig cells and flags those cells as wrong to the human body.

Wayne Hawthorne: When you transplant that into a human, the human recognises it immediately is porcine and rejects it. So the first thing we had to do was actually … and that's where the first pigs were cloned, I mentioned Millie. We in Australia, we actually developed some of the first transgenic pigs that had gal knockout.

Peter de Kruijff: That means they knocked out or got rid of the gene in the pig that creates alpha gal, helping a pig kidney to go incognito in the human body. 

Wayne Hawthorne: The gal epitope is only the first. It's the thing that we need to knock out, but we also then have to express a number of other epitopes that a protein, protein markers that say, hi, I'm human. Don't attack us.

Peter de Kruijff: Yep, it gets complicated. Some pigs used for these xenotransplants have almost 70 gene edits. These edits are attempts to prevent rejection, though patients will still need a large amount of immunosuppressive drugs, then there are also efforts to eliminate the risk of a pig virus being transferred to a human via kidney transplant.

There's a whole different set of genes that get removed for that purpose. And CRISPR, the gene snipping scissors technology has helped make that process even more efficient. 

Wayne Hawthorne: CRISPR jumped us forward to the point where we could do multiple gene insertions or multiple knockouts at various points in the gene, and we could do that very, very quickly. So it's sort of a leapfrog effect, but we had already done decades of research to actually get us to the point to know what ones to actually use. 

Peter de Kruijff: Wayne has led a separate program of research into the transplantation of islet cells, which produce insulin from the pancreas of one animal to another animal that has type one diabetes so they can make insulin again.

In some of his studies that has led to the reversal of diabetes, and it also means Australia has its own gene edited pigs that could one day provide islet cells for diabetes treatment or kidneys for transplant here. 

Wayne Hawthorne: Our hope is that we can start potentially in the next few years to do a small clinical trial treating type one diabetic patients, but also then it could potentially expand to become a kidney transplant program, so that that's the broader hope.

Peter de Kruijff: Along with kidneys, other organs have also been transplanted to humans like hearts, lungs, and livers, but the kidney program is the most advanced. Well, why pigs in the first place? Well, pig organs are roughly the same size as human organs, making them a good match, and pigs can be bred quickly and in large numbers, making it easier to manipulate their genetic makeup over time. That's difficult in primates, which have far fewer offspring.

So as of right now, six people that we know of have had a genetically edited pig kidney transplant. Richard Slayman was the first, who we mentioned earlier. Next was Lisa Pisano, a woman in her 50s from New Jersey whose transplant had to be removed 'cause it wasn't getting enough blood supply, which was related to significant heart issues she had. The kidney lasted for close to two months before it had to be removed. Lisa later died.

Towana Looney from Alabama had her pig kidney transplant in late November, 2024. 

Newsreader (Archive): An Alabama woman is providing new hope for people who desperately need an organ transplant because her new kidney came from a pig.

Peter de Kruijff: It had to be removed after about four months. It had been rejected by her body. She's back on dialysis. At the time we recorded this podcast, Timothy Andrews is the fourth person to have such a transplant and is just one of three people in the world known to be living with one.

A fifth person, a 69-year-old woman from China is also reportedly living with a pig kidney after a transplant in March this year. And the sixth and most recent was a 54-year-old man, Bill Stewart, who got a kidney in June.

Timothy Andrews: I did expect some bumps in the road and I learned that every kidney transplant has bumps in the road. Some of mine just a little different because there is the pig causing it. What's causing it or the drugs causing it because there's a lot of that, a lot of drugs, there's a lot of everything. 

Peter de Kruijff: It's been almost eight months since Timothy's transplant. He's been up and down, in and out of hospital. His doctors are in pretty close contact. He's checked by the team twice a week.

Timothy Andrews: Well, right now we're at two days a week. They started at three. We got down to one for like a couple weeks and then we went back to two.

So they check me pretty often. Plus I have a heart monitor that they monitor me on all the time. I have a scale and a blood pressure machine that sends it off to the doctor, so they watch that every day.

I'm a warrior. When I committed to this a hundred percent I didn't kid. No matter how bad it gets, you do it, you get it done. You struggle on. You fight on. Sometimes it's the only thing I can think about: keeping Wilma alive.

Peter de Kruijff: Wilma, by the way, is his new kidney.

Timothy Andrews: We named her when we got her and I take care of her. She's my life now.

Peter de Kruijff: On ABC Radio National, you are listening to Artificial Evolution, a special series from Science Friction. I'm Peter de Kruijff. 

2025 has been a big year for xenotransplantation. Timothy has now lived longer than anyone else with a pig kidney. At the time of this recording, it had been seven months and three weeks, and in the US the Food and Drug Administration has approved clinical trials that will test xenotransplantation in the larger numbers of recipients later this year. 

Wayne Hawthorne: United Therapeutics. They've set up to do 10 kidney transplants. They've got approval to move forward, so they're looking at doing six kidneys first off, and then they'll subsequently push that forward to do up to 50 patients over the next couple of years, and these will be seriously unwell people. Those who are most likely not eligible for a human kidney transplant. 

The other group, eGenesis, is another commercial company. They're looking at, again, a very small pilot, probably around five or six patients to see how it goes before they'll be expanded. 

Peter de Kruijff: eGenesis is the company that's collaborating with Mass General Hospital and provided the gene-edited pig for Timothy Andrews.

For Wayne Hawthorne, this is the culmination of decades of work. 

Wayne Hawthorne: A lot of us have been in the field for 20-odd years and we've been doing a lot of pre-clinical work and working to get to this point where our whole end game has been transplant patients. We are still learning, we still have issues to get around and we are dealing with the very, very sickest patients, so we'll see things improve and as they improve and the outcomes are extended for these patients, the more we do, the better we get, the more we'll be able to do.

Peter de Kruijff: We're all familiar with human organ transplants, but xenotransplants open up a whole new world of ethical concerns.

Dominique Martin: We've had this long focus on human organs for transplantation as a really special or ethically exceptional resource that we need to sort of govern and manage very carefully. And it's all about justice in terms of who gets access.

Peter de Kruijff: Dominique Martin is Professor of Health Ethics and Professionalism at Deakin University School of Medicine. 

Dominique Martin: But now that we've got something that people have spent millions and millions of dollars developing, and it's essentially a kind of commercial product. Are we going to approach xenotransplantation with those same values and that same sort of ideology, that this is a resource to be shared equitably, or is it gonna be something that's marketised? And that's a question that we really don't have answers to yet. 

Peter de Kruijff: Dominique suggests a potential spread of disease is also an issue, though it can be managed.

Dominique Martin: My understanding is that with the current state of evidence, there's pretty high levels of confidence that we can do this safely. It does require a cautious approach, but I think particularly with the recent COVID-19 pandemic, that everyone is all too aware of just how rapidly, when you get crossover between human and non-human animal viruses, things can escalate quite rapidly.

Peter de Kruijff: Syd Johnson is a professor of bioethics at Upstate Medical University in Syracuse, New York. She isn't sold on the ethics of using animal organs in humans. 

Syd Johnson: These genetically modified animals and their organs are owned and will eventually be sold for profit by the biotech companies that are creating them.

If xenotransplantation ever works, and that is of course still a big if, but if it works. What will be the cost to buy an organ, and who's going to pay that cost?

Peter de Kruijff: Syd also has concerns about the welfare of these animal donors. 

Syd Johnson: These are novel animals. They would not exist at all except for human intervention, and they are, I think, essentially being treated as machines for the sole purpose of growing a product and disassembling them to provide these spare parts for humans. I think this is an opportunity for us to reflect on what we are doing when we are creating animals and treating them in this way and the harms that we might be causing living conscious, intelligent creatures so that a handful of biotech companies can profit from their organs. 

Peter de Kruijff: Wayne Hawthorne says the ethical system has been set up around the use of xenotransplants is strong. 

Wayne Hawthorne: We absolutely have the best ethical coverage, not just for doing research, but also the application to develop these animals in appropriate conditions for xenotransplantation.

If you look at the pork industry or even production of things like heparin or what used to be for insulin before we got humanised insulin, we bred animals for production of those products. We've stepped forward and enhanced those ethical requirements. The worst thing that can happen is people turn around and say, well, this is unethical. We don't want that to happen. We want to be able to apply this and be able to transplant as many patients as possible. So there's been huge amounts of work done in this area to help. 

Peter de Kruijff: You might be wondering about the views of different religions towards xenotransplantation. Research broadly finds that most major religions, including Christianity, Islam and Judaism don't object to xenotransplantation or consider it impermissible. We'll pop the study published this year, which looked at that question in our show notes.

Timothy Andrews: To me I think you should do it because it's life of a human. We're talking about the life of a human. Meanwhile, at every grocery store, there's 25 feet of pork being cut up and people are eating it. 

Peter de Kruijff: Timothy's taking it day by day, but he hopes to go a full year with a transplanted kidney.

Timothy Andrews: That's a big deal 'cause then it's worthwhile to take these kidneys and start using them so people can get out of that, that situation for at least a year. And they can see their grandkids and they can see whatever they want to see. How great would that be? 

Peter de Kruijff: But he doesn't think he deserves special praise for what he is done.

Timothy Andrews: Me, I'm just the guy trying to help other people. Well, I hope some of 'em … the ones that need it, get hope that there may be something out there other than sitting in that chair and waiting to die. To be able to step out of that. And be alive again. Unbelievable. 

I'm sitting here by a beautiful lake with my sister. Life is beautiful. Weather's beautiful. What more can you ask outta life?

Peter de Kruijff: That's it for this episode ,the last in our special series, Artificial Evolution on ABC Radio National. The show was made on the lands of the Gadigal, Whadjuk Noongar and Menang Noongar people. Thanks to producer Fiona Pepper, senior producer James Bullen. Special thanks to researcher Lisa Chidlow for help with archival audio for this series. Our executive producer is Petria Ladgrove and our science editor is Jonathan Webb. I am Peter de Kruijff. Thanks for listening.