Contents

Asai : First, I'd like to ask Professor Sawa, could you tell me about the history and development policy of Osaka University Cardiovascular Surgery so far? For example, the track record of developing heart sheets (cell sheets derived from human (self) skeletal muscle) in collaboration with Terumo is known.‍

Sawa : Osaka University Cardiovascular Surgery has a history of 100 years. As something related to medical care, we have promoted heart transplants and artificial heart treatments to help patients. We're not regenerative medicine researchers, and we're not regenerative laboratories. The ultimate theme is how to help people who die from heart failure.

Heart transplantation surgery based on the Organ Transplantation Act was performed for the first time in Japan on February 28, 1999, and since then, heart transplantation has been promoted in classrooms. In America, the Unified Corpse Provision Law was enacted in 1968, and the concept of brain death (Harvard Criteria) was established, but in Japan, the enactment of the law itself started 31 years later than in America. In addition to that, Japanese laws were strict, patients were limited, and it was difficult to catch up with America.

Under such circumstances, the cardiovascular surgery department at Osaka University began working on regenerative medicine research. This is the period when ES cells were created and the term regenerative medicine first came up. Prior to that, I was doing basic research on cell therapy, and I got to know Dr. Okano and his colleagues at Tokyo Women's Medical University and began joint research.

Until then, Dr. Okano and his colleagues hadn't thought much about clinical application, but we introduced cell sheet technology, began research and development of regenerative therapy using leg muscle cells in 2004, and began clinical application in 2007.

Around that time, Terumo had introduced FDA-approved technology to cultivate myoblasts contained in foot muscle cells, so they decided to work together as cardiac surgery.

On the Terumo side, I was trying to do it with cell injection, or injection, using a catheter, but there are many arrhythmias with that method. Joint research began by proposing that heart sheets prepared in sheet form by cultivating skeletal myoblasts contained in muscle tissue collected from patients' thighs are safer and more effective.

Terumo began clinical trials in 2012, applied for manufacturing and sales approval in 2014, and manufacturing and sales were approved in 2015. The implementation facilities are now around 10, and the facility and the team developing regenerative medicine technology have been completed. Gradually, everyone is becoming aware of what kind of patients it is effective, and at this stage, close to 100 cases of treatment using heart sheets are being carried out.

Asai : Please tell us how Cuorips was established in 2017 in the process of regenerative medicine research.

Sawa : In research and development of regenerative therapy using leg muscle cells, we decided to entrust cell development to Terumo, and we worked on clinical applications.

Dr. Shinya Yamanaka succeeded in establishing iPS cells in August,2006, just before First Inhuman was performed in 2007. We had begun clinical application with cardiomyocyte sheets using leg muscles, but there was a difference that you could tell right away at first glance, and I thought we should do it with cardiomyocytes, so we began research and development in 2008. Professor Yamanaka's research was highly evaluated, and while receiving many grants from government agencies, we succeeded in animal experiments. The world's first Proof of Concept came out in September, 2012. This is reported in a paper called Circulation.

After that, Dr. Yamanaka won the Nobel Prize in Physiology or Medicine in October, 2012, and the situation changed drastically from here on.

Large-scale regenerative medicine implementation base network project with the Ministry of Education and JST in 2013 (AMED since 2015^＊Transition) began, and four locations were selected, and one of them was our Osaka University. Osaka University became a center for the creation of myocardial regeneration therapy, and research and development accelerated rapidly from there. What led to First Inhuman in 5 years and practical application in 10 years was largely due to the fact that it was a grant of an unprecedented scale, but at the same time, the hurdles were also very high.

^{＊AMED:Japan Agency for Medical Research and Development}

Animal experiments are not that difficult, but it was difficult to prove with high accuracy the level of regulatory science that has never been done before, that is, safety and efficacy worthy of being applied for as a product. Oncogenesis, that is, how to overcome the risk of cancerization, and how to do mass culturing, these issues were gradually solved while utilizing AMED funds, and we reached a stage where practical application was imminently around 2015-16.

However, since the university was unable to obtain permission for the manufacturing and sales business, discussions progressed about establishing a company as a university venture and linking it to commercialization while transferring technology, and Qualips was established in 2017.

Cooperation with pharmaceutical companies was also an issue. Around that time, Mr. Joji Nakayama took office as the chairman of Daiichi Sankyo, and Asubio Pharma became a wholly owned subsidiary. Asbio Pharma was proceeding with research and development on regenerative medicine, and Mr. Nakayama came to me and told me they wanted to do it together. It was decided to speed up development by combining the technology developed by Asbio Pharma side with the momentum of applying it clinically to Cuorips.

In terms of commercialization and commercialization, academia was hesitant based on manufacturing costs, but we decided to work on it because we thought that if we did well, we could quickly commercialize it and quickly deliver it to people.

Daiichi Sankyo decided to invest in Cuorips, and it seems that the world was very surprised. Asubio Pharma, which was conducting research in Kobe, moved to a laboratory at Osaka University in the form of being seconded from Daiichi Sankyo.

Asai : In the end, the Asubio Pharma team joined Cuorips.‍

Sawa : Yes. Pharmaceutical companies are keenly aware of manufacturing, so we began to think that manufacturing facilities must be built quickly, and we were thinking of cultivating them at Osaka University first and then going to the next step.

Basic research was first carried out thoroughly in the base project, then tumorigenesis was gradually overcome and mass culture became possible, and an application for clinical research was made in 2018, which is exactly the 5th year. On May 16 of that year, the application was approved, and the month after I was excited to finally start clinical research, there was an earthquake with a seismic intensity of 6 or higher and the The Northern Osaka Earthquake on June 18, and all cell culture facilities at Osaka University were destroyed, and cell culture had to be carried out from scratch.

When it came to clinical research, the cell culture facility was destroyed, and we were in a situation where culture had to be redone, and the oncogenesis test, which required 1 year of observation, went back to square one.‍

Asai : At the time of that earthquake, tumorigenicity tests were running.

Asai : What happened after that?

Sawa : Oncogenesis tests were running, and iPS-derived cardiomyocytes for clinical research were being manufactured to some extent. Based on the effects of the earthquake, all cells that were once manufactured were discarded and remade from scratch. As a result, the development plan was delayed for a year and a half. However, it was delayed, but if clinical research had begun as scheduled, there might not have been time to explain it to everyone until we moved to clinical trials and discussed it.

Meanwhile, cells for clinical trials were gradually prepared at CLiC-1 (Click One, Cuorips Labo-Integrated Cell Processing Facility for Advanced Therapy-1st) around the latter half of 2019.

It's a miraculous story, but progress was made in manufacturing iPS cell-derived cardiomyocytes with CLiC-1, and it progressed smoothly thereafter. As a result, the delay due to iPS-derived cells not being able to be manufactured at Osaka University was reduced to about 3 months thanks to the fact that they can now be manufactured with CLiC-1.

Initially, clinical research began from 2018 to 19, and clinical trials were about to be conducted on several cases from around 2020. However, since clinical research was delayed, we decided to start with clinical trials. It's simpler that way. Various transplant techniques and patient selection had already been firmly established through prior research between Terumo and Osaka University.

Even if many people suddenly do clinical trials, they will probably fail. This is because it is difficult to consider what kind of patients to target. However, when we conducted clinical trials with Heart Sheets, we had experienced dozens of clinical studies, so we were able to select patients quite well, so they were approved early with conditions and deadlines. I am extremely fortunate that I was able to further improve that experience and enter this clinical trial.

Looking back, clinical trials were accelerated in reverse thanks to the earthquake. The 3 cases were over even in the midst of COVID-19 in January, July, and November 2020, and it is now possible to produce data that progresses to Cohort B.‍

Asai : When was Cohort B approved by the authorities?‍

Sawa : Cohort B was approved in August 2021. It was around the 5th wave of COVID-19, and since the number of people infected with COVID-19 was so high during the 6th, 7th, and 8th waves that followed, it became difficult to incorporate patients into clinical trials. However, during that time, we were able to firmly optimize the transport method for cardiomyocytes derived from iPS cells, and even established a method that can be stored for 72 hours, so we have been able to perform 5 cases from August of last year to the present. The fact that the university hospital teachers who cooperated with the clinical trial were very proficient in patient selection methods is also one of the reasons why the clinical trial progressed smoothly.

^{*Cohort B: Second half of physician-led clinical trials. Five patients were targeted, and the first transplant operation was performed in September 2022, and the 5th transplant operation was performed in March 2023. The difference from cohort A (3 examples), which is the first half, is that ① cardiomyocyte sheets were manufactured and cultured at our own facility (CLiC-1) and ② transplantation surgery was performed at other facilities. The company is Cohort B, manufactures cardiomyocyte sheets on a commercial scale and has been working to establish transportation methods}

Asai : Could you explain again about ischemic heart disease for which iPS cell-derived myocardial sheets are targeted?‍

Sawa : Ischemic heart disease is a disease in which the heart muscle is damaged more and more due to repeated attacks of myocardial infarctions, and there is less living myocardial muscle. As such symptoms progress, the last thing is a situation where there is only a heart transplant or artificial heart, and it is said that it is no option among medical professionals. I think this stage is the time to apply regenerative medicine.

Various drugs can be used for ischemic cardiomyopathy, but it is rarely curable with medicine. Medications are taken, and when the condition gradually progresses, bypass surgery and PCI (percutaneous coronary angioplasty) are performed.

After that, it gradually worsens over several years, and it becomes a state of hibernation requiring a heart transplant or artificial heart. Hibernation is a state in which only myocardial contractility decreases without necrosis as a result of continued decline in myocardial blood flow due to narrowing or blockage of coronary blood vessels. If it gets worse until the end, the heart will be in a state of shock, but once you get that far, there will be few heart muscles that function normally, and an artificial heart will be needed.

There are still many normal cardiomyocytes, but the drug is not effective is the timing of treatment with iPS cell-derived myocardial sheets.

In my opinion, there are tens of thousands of patients a year who are in this situation. Catheter treatment is performed in about 10% to 20% of 200,000 patients with ischemic heart disease in Japan. Furthermore, since there are roughly 10,000 bypass surgeries per year, there are probably around 30,000 to 50,000 cases in total. There are 5 to 10 times that target audience in America.

Asai : Are there any cases where a heart that once deteriorated will return with treatment so far?‍

Sawa : That's a lot.

For example, there is a test called exercise tolerance, and this number goes up a lot. As a general indicator, I would say EF, or how many ejection fractions* are there. The reason is that EF refers to the difference between when the heart stretches the most and when it shrinks.

^{*Ejection fraction: ejection fraction, ejection ratio. A typical indicator of ventricular systolic function among cardiac functions. The contractile force (pump capacity) of the left ventricle can be measured. A value obtained by dividing the amount of blood (ejection volume) released by the heart with each heartbeat by the volume of the left ventricle during the diastole phase. The normal ejection rate is 50 to 60% or more.}

If you treat a heart sheet, your heart will become smaller. This is because the heart acts like a ladle. As the pumping force gradually weakens, the heart responds by growing larger. Therefore, the difference between when it stretches and when it shrinks gradually gets smaller. At first, the difference between when it stretches and when it shrinks is about 60%. As the heart gets bigger, the difference from when it shrinks decreases to about 30%.

EF is important as an indicator, but it is also necessary to look at peakVO2 (maximum oxygen intake). This is because it is important how much the quality of life improves. According to the attached documents on the heart sheet, the median value of PeakVO2 for 6 patients enrolled in the clinical trial rose from 11.8 before surgery to 14.5 after surgery.

Incidentally, EF itself isn't that different even with the heart sheet. The question is whether it will improve by a few percent even if it goes up, but life prognosis clearly improves. The 5-year survival rate is 80% or more, about 85-90%. When internal medicine treatment is performed on the same patient, the 5-year survival rate is 50% to 60%.

Asai : In a paper reported in 2022, it was reported that exercise endurance was improved (peakVO2 (mL/min/kg): 15.4 (before transplantation) → 18.7 (half year) → 20.0 (1 year after surgery)) of 1 patient who had a cardiomyocyte sheet implanted. Why are exercise tolerance numbers improving?

(Reference) Quoted from the August 2022 report paper

Figure. Implantation of human iPS cell-derived cardiomyocyte sheets and beating patterns before and after transplantation

(A) Transplantation of human iPS cell-derived cardiomyocyte sheets onto the heart surface of patients with severe cardiomyopathy.

Left: Transplanted into the epicardium of the anterior and side walls of LV from the 4th intercostal region under IABP support.

Right: Three patches were implanted into the epicardium of the LV anterior wall and side wall.

(B) Myocardial migration patterns observed with four-dimensional CT.

The color red indicates an area of good motion, and was set to indicate less movement as the color approaches blue. The images show heart migration patterns before (pre), 6 months after transplantation, and 1 year after transplantation in chronological order.

The dotted line in the image below is the part where the patch was attached.

LV: left ventricular IABP: intra-aortic balloon pumping CT: computed tomography.

Miyagawa, S. et al. (2022) Front Cardiovasc Med

Sawa : It is thought that PeakVO2 is improved because the heart becomes smaller and softer after transplantation. As you know, blood flows from the right ventricle to the lungs and then to the left atrium. At that time, the load applied to the ventricles just before the heart contracts is called front load, and the load applied to the heart immediately after the heart contracts is called rear load. At this time, if you look at the relationship between front load and rear load, the easier it becomes as the front load decreases. As the heart muscle recovers, softens, and the entire heart becomes smaller, the burden on the lungs decreases. Then it becomes easier to breathe.

If you have a firm understanding of such a mechanism, I see, you can understand that PeakVo2 improves, this means that heart muscle has recovered, exercise tolerance has increased because it has become easier, so patients feel better and feel better.

Asai : What are the differences between autologous cells and homologous (allogeneic) cells?‍

Sawa : Autologous cells change depending on the patient's condition and cell properties. There is wide variation between those who differentiate and proliferate into cardiomyocytes and those who do not, and those who have no possibility of treatment.

Autologous cells seem safe at first glance. Certainly, when it comes to safety, your own home might be better. In the case of allogeneic cells, immunosuppressants must be used in the myocardium. However, detailed research has been carried out on how to use immunosuppressants.

I'm doing heart transplants as a doctor, so I know very well how to use immunosuppressants, but as a rule of thumb, I understand that the regenerated effects of those who have been given for 3 months and those who have been taken for 3 months or more are the same. This was the same for experiments with crab monkeys. (See, Kashiyama, N. et al. (2019) Transplantation)

If you only think about efficacy, it's not necessarily a problem between others and your own, and it would be better to say the difference between iPS and not iPS. iPS is a different company, but since they are made in the same way by the same person, the stability of the effects in the product is outstanding.

iPS currently has no choice but to choose another home, but in the future, whether or not you can choose your own home is another difficult point.‍

Asai : Other than administration of immunosuppressants, what are the differences between autologous cells and iPS-derived cardiomyocyte sheets regarding the burden when viewed from the patient's point of view?‍

Sawa : Heart sheets that cultivate autologous cells require 2 surgeries. However, in the case of iPS-derived cardiomyocyte sheets prepared in Ready to Go, only one operation is required.‍

Asai : In the case of iPS-derived cardiomyocyte sheets, it means that the burden on patients has been reduced.‍

Sawa : Furthermore, the burden and risk of opening a chest is not that big. The advantage compared to home-based surgery is that only one operation is required.‍

Asai : At the press conference at Kyushu University in February 2023, the patient's comments were very impressive. After receiving a declaration from the doctor that “there is no further treatment,” the patient received an introduction to iPS cell clinical trials and carried out. Then, even though there was a feeling that my chest was tightened in the winter, I was expressing my impression that the swelling in my body disappeared after undergoing surgery, and I felt that my body became warm.‍

Sawa : All patients who have had heart transplants in the past say that they feel that their bodies are getting warmer. When blood circulation throughout the body is poor, it closes peripheral blood vessels and tries to maintain blood pressure, so you feel cold.

The fact that it feels warm means that peripheral blood vessels open, that is, circulation is improving. I think it simply describes the patient's condition.‍

Asai : That's amazing. It's a feeling that my heart is no longer swollen, and it's a feeling that I can't easily see in a paper.‍

Sawa : Each of us had difficulties at work and in our daily lives, but 8 people have returned to society and are doing well.

Asai : Could you tell us what role did qualyps play in the development of cardiomyocyte sheets?‍

Kusanagi : Basically, our efforts are manufacturing cardiomyocytes based on Dr. Sawa's research. All cardiomyocyte sheets used in clinical trials after Professer Sawa's Cohort B were transplanted to patients manufactured at our manufacturing facility CLiC-1.‍

Sawa : I think it's a huge thing that clinical trials have been completed in the 10th year and social implementation has come into view.‍

Asai : Other than the manufacture of cardiomyocyte sheets, I have heard that there are even bigger prospects, but could you please let me know?‍

Kusanagi : Yes. The current product is aimed at patients with more severe heart failure. We are developing catheters to handle the hearts of people with slightly milder illnesses.

Also, since ventures with manufacturing facilities such as CLiC-1 are extremely rare, the CDMO business is in the form of using this manufacturing facility^＊We are doing it. Specifically, it is a business that helps small-scale ventures like us do clinical research and make products after approval.

Furthermore, we are developing regenerative factor-inducing pharmaceuticals, which we call YS development as product decentralization.

^{*CDMO business: An abbreviation for Contract Development and Manufacturing Organization. Development and manufacturing contract business.}‍

Sawa : We didn't expect much about CDMO either. Cultivating iPS cells is not easy, but we are cultivating a large number of cardiomyocytes. I think they were able to trust this kind of cell culture technology. Other developed products in Japan have at most millions of cells.

Since we are in the 100 million unit, I think the high level of technology for cultivating dozens or hundreds of people has gained trust from a technical point of view.‍

Kusanagi : Yes. As the teacher said, the fact that culture technology is very advanced is a big advantage, and we have received many inquiries.

Asai : Bio-ventures in the field of drug discovery often struggle with procurement and recruitment of people, but what do you think are the factors behind their success?‍

Kusanagi : After all, Sawa-sensei's presence is huge. Professor Sawa proceeds with things by mixing theory, clinical, and actual experience, so he is doing well in terms of application. In terms of raising funds, I've talked with various venture funds. Among them, the question from Asai-san was the most accurate in terms of content. Then, I'm having trouble with this kind of place, and when I ask if I know someone like this, they will respond right away. It can be said that this kind of response contributed very much, even in the sense of incubation.‍

Sawa : Osaka University Cardiovascular Surgery has a history of 100 years, but it's a very tough classroom. One of the words that remain there is “personality at the end.” After all, the secret to success at work is probably personality.‍

Kusanagi : Cuorips' external creditworthiness has also increased by obtaining investment from government funds. Now that we have basic research, clinical capabilities, funding, and manufacturing facilities, I think it falls into the category where it has been quite successful as a venture.‍

Asai : I thought when I did my due diligence, but I was relieved that Professor Sawa also participated in pharmaceutical affairs and was involved in negotiations with PMDA.‍

Kusanagi : I'm saying that Sawa-san is Otani Shohei from the regenerative medicine industry. In professer Sawa's case, it's about the 4-sword style. Almighty, or rather, a curious person. While there are many researchers who are only in their own field and have no interest in anything else, Professor Sawa, who has set up antennas in many fields, is a special person.‍

Asai : Regarding cooperation with companies, I got the impression that many projects were gathered at Sawa-san's place.

Asai : As we enter a period of business expansion, in-house research and joint research are progressing, and manufacturing is also being carried out. Isn't recruitment going to accelerate in the future?

Kusanagi : Yes. We would like to aim to create jobs, develop industries, and form clusters. It's what's called an ecosystem. It's a venture ecosystem where leaders like us play a role, and various technologies descend from there, and various companies come out to create one big industry. For us, it's a rewarding job worth taking on.

Asai : If this iPS cell-derived cardiomyocyte sheet is approved, it will be the world's first regenerative medicine product derived from iPS cells. You mean we're going to expand it into an ecosystem.

Kusanagi : Yes. Furthermore, I will go overseas with Sawa-san. We aim to create such a global industry.

Sawa : There may be a misstatement when it comes to saying that the desire for academia is inexhaustible, but I want to cure people all over the world. Not because they are Japanese, but because there are ways to cure people with heart failure, I think this can cure people around the world. That's why I want to expand globally, not just domestically. I don't think there are enough products that originated in Japan and have become global medical standards. Therefore, for our company to go overseas and achieve success, it probably means a lot to Japan as well. Furthermore, since Professor Yamanaka won the Nobel Prize and the country has steered to regenerative medicine, investments of about 100 billion yen have been made in the past 10 years, there is great significance in developing regenerative medicine products based on that. Also, since the heart is directly connected to life, the need is probably huge. Of course, it is not comparable to other diseases, but the heart in particular is the number one cause of death in America and Europe. I also think for the company that it will become a global presence as a qualifier that will somehow solve this problem, and what we have developed can be used globally to save people around the world, and there is nothing so good about academia.

Asai : Now that Cohort B is over, it probably means that preparations are finally being made for America.

Kusanagi : Yes. We are preparing for that time.

Sawa : I know a lot of people in America, and my subordinates are also active in America. The network is solid, so I'm looking forward to expanding it in America.

Asai : I'm looking forward to it too. Thank you so much for today.