DAVE DAVIES, HOST:

This is FRESH AIR. I'm Dave Davies, in today for Terry Gross. Our guest David Fajgenbaum nearly died in a hospital five times. He was a medical student in his 20s when he was diagnosed with an obscure but deadly disease that was little understood, one for which his doctors had no cure and little in the way of treatment. After coming to death's door for the fifth time, he decided to search for a treatment himself.

His story is remarkable both because of the results of his search, which you'll soon hear about, but also because of the approach he took - crowdsourcing the medical knowledge and experience with his illness around the world to find the most promising treatment. The organization he formed to connect the dots of knowledge about his disease is now applying its techniques to the quest for a treatment for COVID-19.

David Fajgenbaum is an assistant professor of medicine at the University of Pennsylvania and the associate director for the Orphan Disease Center, and he's co-founder and executive director of the Castleman Disease Collaborative Network. His book about his experience is "Chasing My Cure: A Doctor's Race To Turn Hope Into Action." I spoke to him from my home in Philadelphia.

David Fajgenbaum, welcome to FRESH AIR.

DAVID FAJGENBAUM: Thanks so much for having me, Dave.

DAVIES: Now, you didn't get the illness that's the subject of all this until - I guess you were 25. You were a high school quarterback and then went to Georgetown University, where you were also quarterback of the football team. But early in your college years, you lost your mom to brain cancer. Just tell us how that affected you and how you responded to that loss.

FAJGENBAUM: Her illness and passing just devastated me. It took me from a world and a life where I focused on football and I thought maybe I wanted to go into medicine to a world and a life where all I wanted to do was become a doctor and to chase after diseases like cancer. My mom was the most incredible person in the world, and she taught me so much throughout my life but, in particular, throughout her illness about how to live the right way. And she motivated me to want to focus my life on helping patients like her.

DAVIES: You also formed an organization to help college students grieving with a loss.

FAJGENBAUM: That's right. Just a couple of weeks before my mom passed away, we had our final conversation, and it was the first time that we had ever thought and talked about this being the end. And she was really worried about if I would be OK, if I could cope with her illness while - and her now passing while I was at college. And I promised her. I said, Mom, I'm going to be OK, and I'm going to dedicate my life towards fighting diseases like cancer and helping other young people dealing with illness or death of a loved one. And she just loved the idea. She couldn't say too many words, but she said, unconditional love.

And I went back to college, and I was completely on a mission. She passed away the end of October, and within just a few weeks, I started an organization called AMF. My mom's initials were Anne Marie Fajgenbaum. And I started this group called Ailing Mothers and Fathers for students that were dealing with the illness or death of a loved one. And it was a way to continue her memory. She was such an amazing person, and I just felt that her legacy needed to continue and her life of supporting others needed to continue on to help other college students coping with the illness or death of a loved one.

DAVIES: You were a medical student, and you'd done a few rotations when this disease that's the subject of all this hit you. How did it present itself?

FAJGENBAUM: I was a healthy third-year medical student. I was really on my way to that new thing that I was fighting for. First, it was football, and now all of a sudden I'm this - fighting to take on disease and to fight cancer. And all of a sudden I started noticing I was more tired than usual. I noticed I had some really severe abdominal pain. I noticed lumps and bumps in my neck. Didn't know what all of it meant, but I just felt like I could put it off until after the rotation that I was on. I was on an OB-GYN rotation. I just kept thinking, you know, this can wait.

And unfortunately, over the next few days, I got more and more tired, and the abdominal pain got worse. And I just felt really, really unwell. I even told a couple of my friends that I thought I was dying, which - I'm not a very dramatic person, so I clearly knew something was going wrong. But after I took my medical school exam, I went down the hall to the emergency department, and they ran some blood tests. And I'll never forget the doctor coming in the room and saying, David, your liver, your kidneys, your bone marrow, your heart and your lungs are shutting down. We have to hospitalize you right away. And they did.

And over the course of the next few days, I became deathly ill. They admitted me to the intensive care unit, where I had a retinal hemorrhage that made me blind in my left eye. I gained 70 pounds of fluid, drifted in and out of consciousness and required transfusions just to keep me alive, all with no diagnosis. And unfortunately, it would go on for a lot longer.

DAVIES: You're going through all this, and there's still no diagnosis. You know, you write that well before the symptoms were at their worst, you knew you were dying. You were sure of it. Why, do you think?

FAJGENBAUM: It's hard to put into words the fatigue that I was feeling, the pain that I was feeling, the - I'd been sick before, just like all of us, with flus and illnesses. But I - the sick that I felt was an illness like - it's hard to describe. And it just felt different from anything else I'd ever experienced. And something was telling me that it was really, really, really bad. And I, frankly, didn't think I was going to survive.

DAVIES: What do you make of this now? All of your organs were shutting down in some way. You kind of knew that. But with the experience of several years and serious hospitalizations now, what do you make of this sense that you were dying?

FAJGENBAUM: At the very basic level, I think it was that I was feeling so unwell that I just sensed that this must be what it feels like to be dying. Now that, as you said, I've undergone this experience five times, it truly is - the pain of organ failure, the confusion of having your liver and your kidneys not cleaning your blood so your brain doesn't work appropriately - it was all of these physiological things happening at once. But I think it was also just the fear of knowing that this likely meant that I would not be around much longer.

DAVIES: So you spent four weeks in the hospital in Philadelphia, where you were in medical school, and then transferred to a hospital in Raleigh, N.C., where your dad, who is also a physician, had worked. You eventually got better and were released after seven weeks, after - I guess - heavy treatment of corticosteroids, right? But still no diagnosis.

FAJGENBAUM: That's right. No diagnosis. And I knew that I had just gone through this life-threatening, near-death experience where, at one point, the doctors didn't think I would survive, and my friends and family came in the room to say their goodbyes. And all of a sudden, here we are seven weeks later, and I'm just kind of mysteriously, miraculously getting better with no diagnosis.

And I wasn't really satisfied with this idea of let's just hope that it doesn't come back that a number of my doctors had told me. And so when I got out of the hospital, I tried to get all of my medical records that I could and see if I could piece together what was going on. I was only a third-year medical student, but I hoped that maybe I could find some pattern that my doctors couldn't. Unfortunately, I did not figure out the pattern before I was back in the hospital just a few weeks later, again with all the same symptoms as before.

DAVIES: A few weeks after you had your first bout with what was then a mysterious illness, you know, you're back in the hospital in North Carolina going through the same horrific stuff again. And you want him to do a test for lymphoma. They - it comes back. You don't have lymphoma. But they have some other news. Tell us about this.

FAJGENBAUM: Yeah. They came back and told me that it's not lymphoma. And this health care professional was actually smiling she was so happy, and I was so happy it wasn't lymphoma because we were worried that it was. And she said, I've never heard of it before, but you have idiopathic multicentric Castleman disease. And I had remembered vaguely hearing it once before in med school, but I really didn't remember much about this disease. But I was just so happy that it wasn't lymphoma.

And so she left the room, and this happened to be the first time in weeks that I was alone in the hospital room. My dad and my sisters never left my side. They just so happened to not be in the room at this time. And so I pulled out my phone, and I Googled it, and I was terrified. I found this one study on the Wikipedia page that basically said that 80% of patients don't live for two years after diagnosis.

And so this - our greatest fear about it being lymphoma - actually, lymphoma's survival rates are better than what I was reading on this Wikipedia page about this disease. And I knew that it was bad. I mean, I experienced multiorgan failure. I knew this was a bad disease, whatever it was that I was facing. But I had hoped it wasn't as bad as idiopathic multicentric Castleman disease is. And one of the reasons I soon learned for why this disease has such poor outcomes is because so little was known about the disease by the medical community.

DAVIES: Right. It sort of has characteristics of cancer and characteristics of, I guess, an immune disorder. You discovered that there's actually an expert on Castleman, Dr. Frits van Rhee, who's at the University of Arkansas. You contact him, and he agrees to see you. So you're going to head down there and talk to the person who seems to know the most about it. I love this. You decide you have to get some new clothes. Why?

(LAUGHTER)

FAJGENBAUM: Yeah, I had such a large belly from all of the fluid accumulation that I couldn't fit into any of my previous clothes, and so I needed to get, basically, triple-XL outfits so that that way I could actually fit into my clothes. And actually, even just right around the time that I finally got this diagnosis, there - the real challenge was then, well, what do you do? You might have idiopathic multicentric Castleman disease, but what do you do now?

And I was transferred to Duke University Hospital, the same hospital that my mom had received all of her treatment at. And I remember passing by this sign at Duke - there is hope. And I remember when I'd seen that sign before with my mom's treatment, I had been so, so hopeful, and of course, she had passed battling her cancer. And so all of a sudden seeing it again didn't give me the same sort of hope that I had gotten from seeing that sign before. But thankfully, the doctors there gave me chemotherapy.

And thankfully, they gave it to me just in time because I was so sick when they started administering chemotherapy to me that my doctors encouraged my family to come in and say their goodbyes and now for the second time. And my family had a priest come in and administer my last rites to me. So back in November of 2010, I was prepared to die by a priest with having my last rites read to me. And I've really considered that moment when a priest came in and administered my last rites to me to kind of be the start of my overtime, extra time that I didn't think that I would have the time, but time that I'm trying to make the most of.

DAVIES: Right. Now, they give you these heavy doses of chemotherapy. They still don't understand what causes the disease. How does the chemotherapy help?

FAJGENBAUM: You're exactly right. So when you don't know what to target - so if you don't know what cell type is the problem or what mechanisms are involved in the disease, you can just kill everything. And that's kind of the approach with multiagent chemotherapy. Because the medical community didn't know what to go after, the approach is, well, let's just kind of nuke everything with chemotherapy. And that's what they did for me. And as barbaric as it sounds, it saved my life. I'm alive today because of this, you know, just-nuke-everything approach with a combination of seven different chemotherapies.

DAVIES: Right. But the drawback is you know that you can't keep doing this forever, right?

FAJGENBAUM: That's exactly right. There is a lifetime max of these drugs. There is only so much you can take before they actually start causing irreversible organ damage, cancers. There's so many side effects of this. This is not a permanent solution, but it was what we needed at the time to save my life the second and then the third time.

DAVIES: David Fajgenbaum's book is "Chasing My Cure: A Doctor's Race To Turn Hope Into Action." We'll talk more after a short break. This is FRESH AIR.

(SOUNDBITE OF TODD SICKAFOOSE'S "TINY RESISTORS")

DAVIES: This is FRESH AIR. And we're speaking with Dr. David Fajgenbaum, an assistant professor of medicine at the University of Pennsylvania. His new book is about his battle with an obscure but deadly illness, Castleman disease, and his decision to search for a treatment himself. The book is called "Chasing My Cure."

You end up going to Arkansas, where Dr. Frits van Rhee, turns out, is one of the national experts in Castleman disease. And I love this little story where you're, I guess, taking the shuttle from the airport, and the driver looks at you and says what?

FAJGENBAUM: He looks at me and he says, you have Castleman disease, right? (Laughter). And I'm like, wait a minute. I had been at some of the best medical centers in the world and no one could figure out what disease I had, and all of a sudden, here I am and the shuttle bus driver's telling me that I have Castleman disease.

And I think that - so, well, first off, because the world's expert for Castleman disease is in Little Rock, Ark., they get a lot of Castleman disease patients. And secondly, Castleman's patients, because all of our organs shut down, including our liver and our kidneys, we gain tons and tons of fluid everywhere. And so I think that me being so puffy and in my triple-XL sweatshirt that you'd asked about earlier, I think that he just must have recognized that I looked like a Castleman disease patient, and he was totally right.

DAVIES: Yeah. And it's kind of an interesting metaphor for the problem with, you know, these obscure illnesses, is that you can have people in one place, even a shuttle driver, who recognizes its symptoms because it's known some places, but medical experts elsewhere may never have heard of it.

FAJGENBAUM: That's exactly right. When you have over 10,000 different diseases, you can't expect every doctor to know everything about every disease. But that's not actually the problem. The problem isn't that every doctor doesn't know everything about every disease; the problem is that for some diseases, no doctors know anything about those diseases. And Castleman disease really falls more into that category, where there are just a few physicians and researchers who really have much of an understanding at all, at least back in 2010, about the disease.

DAVIES: So I want to move the story forward a bit here. You were - you'd been treated for several attacks of Castleman. And you talked to the - a national expert, and they found that there was one promising drug on a clinical trial, and you took that - siltuximab? Something like that?

FAJGENBAUM: That's right.

DAVIES: OK. You go on that, and you're hoping that you're better, right? You spend some time not - believing that maybe regular treatments with this drug are really going to solve the problem. Turns out, it doesn't. April 2012, it's back - a roaring attack of this dreadful set of symptoms. And in the middle of this, you realize medicine just doesn't have an answer, and you decide you're going to take this on yourself. And in doing so, you kind of learn some things about how medical research does and doesn't work. You looked at the state of knowledge about Castleman. What did you discover? What were the problems?

FAJGENBAUM: When I set out to begin to understand, well, what's being done, what's been done in the past, what's being done right now, I learned that - just as you mentioned - there was very little that was being done, and the few people that were working were not working with one another and that research was very random. I think, previously, I assumed that there was infrastructure and plans and goals and objectives within fields. But what I learned is that, actually, research happens quite randomly, where you have to basically hope that the right researcher applies for the right project and the right funding with the right skill set at the right time.

And when you have a deadly illness, you don't really have time for all of those stars to align. And so I learned pretty quickly that the most important thing that I could do would be to actually try to align the stars, to actually try to get all of these problems, solutions, resources lined up so that we could make as much progress as quickly as we could.

DAVIES: What's interesting about it is that a lot of this was just organizational, right? Because there's - there were scraps of knowledge a lot of places. I mean, dozens scores, maybe hundreds of people, doctors who had tried treatments, patients who had gone through things, some studies - but it wasn't centralized anywhere, and people weren't talking to each other. How did you solve this organizational problem or try to?

FAJGENBAUM: It wasn't easy. But the way that we started out to try to solve this problem was that we first tried to identify all the physicians and researchers and patients worldwide who knew anything about Castleman disease. We wanted to just first find everyone and then connect them online through a virtual discussion board and then eventually through in-person meetings. But the idea was that if we could get everyone together, then we could crowdsource from them. We could ask the whole community what research questions are important, and we could ask patients, what research questions are important to you? And then we could go out and we could figure out who is the best person in the world to do the studies to answer those questions?

And just to kind of give some contrast, the typical way that this works is that a research group raises money and then invites researchers to apply to use the money how they see fit. And so for a rare disease, you might get a few people that apply for that funding. And we said, well, let's not just wait and hope that those couple of people will apply for the right idea and have the right background; let's figure out what is the right study that needs to be done and who is the right person to do it, and then we'll go and recruit them into the field. We'll go and find someone who's studying another disease and get them into the Castleman field and get them to work on this.

And really importantly, as we do this research, we also will relentlessly ask what drugs are already FDA-approved that might actually have activity against this disease based on what we're learning about the disease because we knew that to develop a brand-new drug from scratch would take a decade and billions of dollars. But we knew that if we could learn more about this disease and then identify a drug that already exists, that's already available, that's FDA-approved for another condition, then we could be thinking about treating this disease in a matter of months as opposed to decades.

DAVIES: David Fajgenbaum is assistant professor of medicine at the University of Pennsylvania. His new book is "Chasing My Cure: A Doctor's Race To Turn Hope Into Action." We'll hear more of his story after a short break. Also, Maureen Corrigan reviews Benjamin Taylor's memoir about his friendship with Philip Roth. I'm Dave Davies, and this is FRESH AIR.

(SOUNDBITE OF ANAT COHEN'S "HAPPY SONG")

DAVIES: This is FRESH AIR. I'm Dave Davies, in today for Terry Gross. We're speaking with University of Pennsylvania assistant medical professor David Fajgenbaum. At the age of 25, he was diagnosed with Castleman disease, a rare, deadly illness with no known cure. After nearly dying in the hospital several times, Fajgenbaum set out to try and find his own treatment. He started the Castleman disease collaborative network, a patient-centered effort to crowdsource the most promising research, an organization that's now focused on treatments for COVID-19. His book about the experience is called "Chasing My Cure."

You get your fifth attack of Castleman while this work is going on. And you decide you're just going to take charge of your own treatment now. And, you know, I'm just going to tell listeners that this is a fascinating part of the story. And in the book, what we really see is you going through some detective work. I mean, it's almost like a Sherlock Holmes thing. And it's a little too long and involved to get through all of it here. But in the book, you can follow it. You managed to look back at your own history of the disease, get all the records from all the hospitals you've been to, even specimens that might still exist. And you come up with something. You want to just describe what you did in layman's terms?

FAJGENBAUM: Sure. So just as you said, I had been collecting samples of myself, blood samples then also lymph node tissue from a procedure during that relapse. And this is now the fifth time that I was dying in the hospital, that I spent weeks in the hospital with multi-organ failure. And I didn't know if I would survive. In fact, I didn't think I would. But I knew that if I did survive that I would need these samples, because I would need to be able to use the samples from when I was sick to try to find something that could maybe save my life.

The biggest difference between this fifth time I nearly died and the previous four times is that, at this stage, I was engaged. And I had the ultimate date in mind, which is our wedding date, May 24, 2014 - in mind as the driver to say, I need to find something. I failed to respond to all these drugs. There's nothing left for me. But I have to make it to May 24, 2014. And so thankfully, this combination of seven chemotherapies saved my life.

And when I got out of the hospital, I was able to go back to all those samples I'd been storing on myself and performed a series of experiments where, from within my experiments, I found this pattern that suggested this one communication line in the immune system called the mTOR pathway was highly activated. And what was so exciting about finding this communication line turned on is that there is a drug that was developed 30 years ago that's really good at turning it off. It's called sirolimus.

And just knowing that this pathway was on did not guarantee that blocking it would work and that taking this drug would save my life. In fact, the immune system is a very finicky system. And basically, turning off this communication line could have actually caused even more problems. No one knew because this drug had never been given to a Castleman disease patient before.

But really, knowing that I needed to try something if I wanted to make it to our wedding date, I decided to take the leap of faith and to start taking this drug as the first patient with my disease ever to take sirolimus back in early 2014. And amazingly, thankfully, I was able to make it to Caitlin and I's wedding date. And you wouldn't think this is too important, Dave, but my hair grew back just in time.

DAVIES: (Laughter).

FAJGENBAUM: And it was still very short. It looked kind of like a buzz cut. But that was actually really, really important to us. I wanted, on my wedding day, to just look like Dave and to not have that external reminder of the bald head from chemotherapy. So it was really special that I had my hair back on our wedding day.

DAVIES: Right. So this is amazing. I mean, you discover that - this pattern by looking at your own records and specimens carefully. There's this cellular communication line. And there's a drug which can treat it, sirolimus. It works. And so it's been how long since you've had an attack, that you've been on this drug?

FAJGENBAUM: It's been 76.26 months since my last relapse. And I say 76.26 months because I literally keep track of it daily and because I realize that I can't round up. I don't know if I'm going to make it to 77 months. But I also refuse to round down. My team and my family supported me so much to be able to make it to where I am. So it's 76.26 months.

DAVIES: So this drug, sirolimus, was it, like, hiding in plain sight?

FAJGENBAUM: I think that's a good way to describe it. It was already FDA-approved. It was sitting in every pharmacy that I had ever walked past during the first 3 1/2 years of my illness. It took the work that my colleagues and I did - the collaborative network, the crowdsourcing - to be able to figure this drug out as a potential solution. And now we've given it to other Castleman's patients. And we have a clinical trial open right now.

DAVIES: Now, this off-label use of FDA-approved drugs can be terrific. It can - it's also controversial, right? I mean, we had the president suggesting that people who have COVID-19 try hydroxychloroquine. And there was, in fact, a story Monday in The Philadelphia Inquirer about nursing homes in Pennsylvania that had been widely treating its nursing home patients with hydroxychloroquine. What sort of rules govern the use of these kinds of things? When you wanted to use sirolimus for Castleman, did you need some approval in order to use it?

FAJGENBAUM: So it's actually quite interesting, the off-label drug use landscape. So once a drug gets approved by the FDA for one disease, it can then be prescribed for any disease that a doctor wants to prescribe that drug for. So once it gets that initial indication it can be used in many ways, there are no restrictions that the FDA or any other governing bodies put on what you can use drugs for. The biggest rate-limiting step is whether it will get paid for, so whether the insurance company will say, oh, sure. I will pay to have sirolimus used for Castleman's even though it's never been used before for Castleman disease. So it comes down to whether it'll actually get paid for. Most of the time, insurance companies will say, wait a minute. This has never been used before. There's no data. We're not going to pay for it.

But if you can make the case to the insurance company or to the payer that this drug has a rationale for why it may work, it is a safe drug and it's potentially less expensive than the alternative - and in my case, that was months-long hospitalizations, chemotherapy that are extremely expensive - then sometimes the payer will agree to pay for that particular drug. What's really unfortunate is that when drugs are used off-label, there is no sort of tracking system to track whether they work or don't work. And currently, there are estimates as high as 30% of all prescription drugs are actually for off-label uses.

So there is a lot of off-label prescription writing that occurs. Unfortunately, there's no sort of systematic tracking when things work, when things don't work. And as a result, you're constantly in a state of limited data. And I think that's why we are all such big proponents for randomized controlled trials. So if drugs are used off-label, we need to track them systematically. And we have to make sure that that doesn't get in the way of doing really, really well-controlled clinical trials to be able to prove whether these drugs really work or not.

DAVIES: Now, people are going to know - because of the network that you've established, people who are interested in Castleman will know about Sirolimus and its effect on you. This does not, as it turns out, represent a cure for everyone with Castleman's, does it?

FAJGENBAUM: That's right. So up until now, there have been somewhere around 20 or 25 Castleman disease patients that have been treated with Sirolimus. And about one-third of those patients have improved, and so unfortunately, two-thirds have not. I think about patients like Joey (ph) who was dying in the ICU at a children's hospital, the Children's Hospital of Philadelphia, right next door to us, who had this miraculous response to Sirolimus, which was amazing. And I think about patients like Lisa (ph) in Colorado who didn't respond to first or second-line therapy, and didn't respond to Sirolimus and passed away. And it's patients like Lisa that we think about all the time.

We're thrilled for the patients like Joey. But we really, really work day in and day out for the patients like Lisa, where this drug doesn't work. Because it's helped to save some of us, but there's still many of us that need solutions. There are about 5,000 patients diagnosed each year in the U.S. with Castleman disease. And not only do these drugs have important relevance, obviously, for us with Castleman disease, but actually the cytokine storm. And what's happening in patients with Castleman disease is almost identical to the cytokine storm that we're seeing in COVID-19. And many of these drugs that we're using for Castleman disease have now become drugs that we're using against COVID-19.

DAVIES: David Fajgenbaum's book is "Chasing My Cure: A Doctor's Race To Turn Hope Into Action." We'll talk more after a break. This is FRESH AIR.

(SOUNDBITE OF RHYTHM FUTURE QUARTET'S "IBERIAN SUNRISE")

DAVIES: This is FRESH AIR. We're speaking with Dr. David Fajgenbaum, an assistant professor of medicine at the University of Pennsylvania. His new book is about his battle with an obscure but deadly illness, Castleman disease, and his decision to search for a treatment himself by building an organization to effectively crowdsource medical experience and research about the illness from around the world. His book is called "Chasing My Cure."

So the collaborative that you formed to try and share information and leads about treating Castleman is now focused on COVID-19. I mean, this is obviously an urgent public health matter. Did you see similarities between Castleman disease and COVID-19 that made this a good fit?

FAJGENBAUM: That's right. So early on in this pandemic, it became clear that the most deadly aspect of COVID-19 is actually the cytokine storm that the virus ignites. And the cytokine storm that it ignites is almost identical.

DAVIES: You want to just - you want to explain what a cytokine is?

FAJGENBAUM: Sure. So cytokines are proteins that your immune system releases to help to both fight off infections, but also to communicate to other immune cells to basically ramp up, get activated and to go into a fight mode. And so in Castleman disease, there are very, very high levels of these cytokines, which cause our immune systems to get out of control and attack our vital organs. The exact same thing happens in COVID-19. So there's - the virus appears. And when the virus is there, the immune system begins to attack it by producing these cytokines. But actually, it's the high level of cytokines that cause all of the organ damage and the deadliness of the virus. It's not actually the virus itself.

And so with this similarity between - at the very basic mechanism, what drives the deadliness of COVID-19 is almost identical to what makes Castleman disease so deadly, it's these - the cytokine storm. That was one aspect of it. The second is that we know that drug repurposing is our best shot at identifying a drug that can help patients in the short-term, so a drug that's either already FDA-approved or a drug that is maybe experimental but is not yet approved for anything that could be repurposed for COVID-19. We knew that was our best shot.

And, Dave, I found myself, in early March, thinking to myself, I really hope that some research group out there that has experience studying cytokine storms and has experience doing drug repurposing will follow our blueprint and search for drugs that can be repurposed against this cytokine storm. And I was sitting there hoping that someone would do it.

And then I realized that I needed to listen to my own advice, and that if I'm going to hope that some research lab out there that has experience with cytokine storms and repurposing would turn their effort towards this, then I would need to turn my effort towards this. This is what we've been doing to chase my cure for these years. And we felt like we needed to do what we could in the fight against COVID-19.

DAVIES: So what, exactly, did your network do?

FAJGENBAUM: Sure. So we really have taken this problem on from two angles, again, similar to the path that we took to identify a drug for me and for other Castleman's patients. The first is recognizing that, if you're going to do any drug repurposing, and if drugs are going to be tried against a disease, you have to systematically track every use of every drug to see whether it works and whether it doesn't work.

I mean, you can basically think about the state that we're in right now is that doctors are trying all kinds of things - hydroxychloroquine, remdesivir and many other drugs. Yet there's no system in place to track what's working and what's not working. And so recognizing that this wasn't being done, we decided to build a database, what we called the CORONA database - COVID-19 Registry of Off-label & New Agents. So it's a database to track all of the drugs that have been used against COVID-19 to date 'cause we want to know everything that's been tried, and we want to see what's working and what's not working. And amazingly, almost 150 different drugs have already been tried against COVID-19. And of course, we hear about a handful of them, but there are a lot of others that have already been tried as well. And so we've created this giant database from - right now it's over 11,000 patients and growing - to collect data on every drug that's been used and so that we can really dig into what's working and what's not working.

And the second part of this equation is that you want to track what's being used, but then you also want to piece together all of the data that's emerging from labs around the world to try to map out what are maybe some new drugs that we could start trying to use? What are some new pathways from all of this data that we should start going after? And interestingly, from the state of - we're finding signals that are Castleman-like, basically. A number of the features that we're seeing in the COVID-19 data, these same features we see in Castleman disease.

And one of the most promising drugs that's currently undergoing a randomized controlled trial is a drug called tocilizumab. Tocilizumab was developed 30 years ago by a Castleman's doctor, a friend of mine named Kazu Yoshizaki. And amazingly, early on in this COVID-19 epidemic, it became clear that this particular cytokine, interleukin 6, is actually very, very elevated in the most sick COVID patients, and people started trying tocilizumab. And so this drug is now being studied through a number of randomized controlled trials. But this drug developed for Castleman disease years ago is now being repurposed against COVID-19 and one of our most promising drugs on our list.

DAVIES: You know, I read that your - the team in your network scoured over 2,500 published papers already. So there's a lot of information out there if someone can manage to collect it and draw meaning from it. So you found this one drug, tocilizumab, which, you know, might be promising. Will you get attention? I mean, you know, there's just - there are zillions of words published every day about this epidemic and treatments. Are you concerned that your work might get overlooked?

FAJGENBAUM: You know, what we really want to do with this corona project is to map out everything that's being tried, to put in one place all of the studies that are being published, all of the data on every drug that's being tried so that other people can go to it and they can kind of decide for themselves what looks promising and what doesn't. We didn't build this to say this is the drug and that's not the drug; we built this to say this is where all the data is. If anyone wants to use the data, we have this very data-first approach. Anyone can use the data.

And from our perspective, we want to use the data to determine and to prioritize what drugs should go on to clinical trials. So the fact is, is that this drug is already being studied in randomized controlled trials, and that's all that we can really ask for. We want to use the database to say what's being given, what looks really promising and what should go forward to randomized controlled trial. We don't want to use the database to say this drug should be given or that drugs should not be given. So we're hopeful.

And actually, we put together a paper based on our first pass of analyses of the data and recently received favorable reviews. So hoping that that'll get published in peer-reviewed journal shortly and that we will be able to get the word out about this database. But the goal is not to say this is the drug that everyone should be on; the goal is to say these are the promising drugs. Let's make sure that we don't forget anything along the way because you're right - I think that we all have a tendency to jump on every major drug or every major headline. But we need to keep an eye on all the drugs that are being tried and make sure that we're doing this really systematically.

DAVIES: Well, David Fajgenbaum, I wish you continued good health. Thanks so much for speaking with us.

FAJGENBAUM: Thanks so much for having me.

DAVIES: David Fajgenbaum is an assistant professor of medicine at the University of Pennsylvania and executive director of the Castleman Disease Collaborative Network. His book is "Chasing My Cure: A Doctor's Race To Turn Hope Into Action."

Coming up, Maureen Corrigan reviews Benjamin Taylor's memoir about his friendship with Philip Roth. This is FRESH AIR.

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