Scientists use stem cells to create Neanderthal-like “mini-brain”

Alysson R. Muotri, Ph.D.

The evolution of modern day humans has always been a topic that has been shrouded in mystery. Some of what is known is that Neanderthals, an archaic human species that lived on this planet up until about 11,700 years ago, interbred with our species (Homo sapiens) at some point in time. Although their brains were about as big as ours, anthropologists think they must have worked differently due to the fact that they never achieved the sophisticated technology and artistry modern humans have.

Since brains do not fossilize, it has been challenging to see how these two early human species have changed over time. To help answer this question, Dr. Alysson Muotri and his team at UC San Diego created so-called “mini-brains” using stem cells and gene editing technology to better understand how the Neanderthal brain might have functioned.

For this study, Dr. Muotri and his team closely evaluated the differences in genes between modern day humans and Neanderthals. They found a total of 61 different genes, but for this study focused on one in particular that plays a role in influencing early brain development.

Brain organoids that carry a Neanderthal gene.
Image courtesy of the Muotri Lab and UCSD

Using gene editing technology, the team introduced the Neanderthal version of the gene into human stem cells. These stem cells, which have the ability to become various cell types, were then used to create brain cells. These cells eventually formed brain organoids or “mini-brains”, 3D models made of cells that can be used to analyze certain features of the human brain. Although they are far from perfect replicas, they can be used to study physical structure and other characteristics. In a previous CIRM funded study, Dr. Muotri had used “mini-brains” to model an autism spectrum disorder and help test treatments.

Dr. Muotri and his team found that the Neanderthal-like brain organoids looked very different than modern human brain organoids, having a distinctly different shape. Upon further analysis, the team found that modern and Neanderthal-like brain organoids also differed in the way their cells grow. Additionally, the way in which connections between neurons formed as well as the proteins involved in forming these connections differed between the two organoids. Finally, electrical impulses displayed higher activity at earlier stages, but didn’t synchronize in networks in Neanderthal-like brain organoids.

According to Muotri, the neural network changes in Neanderthal-like brain organoids mimic the way newborn primates acquire new abilities more rapidly than human newborns.

In a news release from UCSD, Dr. Muotri discusses the next steps in advancing this research.

“This study focused on only one gene that differed between modern humans and our extinct relatives. Next we want to take a look at the other 60 genes, and what happens when each, or a combination of two or more, are altered. We’re looking forward to this new combination of stem cell biology, neuroscience and paleogenomics.”

The full results of this study were published in Science.

Progress in the fight against Sickle Cell Disease

Marissa Cors, sickle cell disease patient advocate

Last November Marissa Cors, a patient advocate in the fight against Sickle Cell Disease (SCD), told the Stem Cellar “A stem cell cure will end generations of guilt, suffering, pain and early death. It will give SCD families relief from the financial, emotional and spiritual burden of caring someone living with SCD. It will give all of us an opportunity to have a normal life. Go to school, go to work, live with confidence.” With each passing month it seems we are getting closer to that day.

CIRM is funding four clinical trials targeting SCD and another project we are supporting has just been given the green light by the Food and Drug Administration to start a clinical trial. Clearly progress is being made.

Yesterday we got a chance to see that progress. We held a Zoom event featuring Marissa Cors and other key figures in the fight against SCD, CIRM Science Officer Dr. Ingrid Caras and Evie Junior. Evie is a pioneer in this struggle, having lived with sickle cell all his life but now hoping to live his life free of the disease. He is five months past a treatment that holds out the hope of eradicating the distorted blood cells that cause such devastation to people with the disease.

You can listen to his story, and hear about the other progress being made. Here’s a recording of the Zoom event.

You can also join Marissa every week on her live event on Facebook, Sickle Cell Experience Live.

Graphite Bio launches and will prepare for clinical trial based on CIRM-funded research

Josh Lehrer, M.D., CEO of Graphite Bio

This week saw the launch of the 45th startup company enabled by CIRM funding of translational research at California academic institutions. Graphite Bio officially launched with the help of $45M in funding led by bay area venture firms Versant Ventures and Samsara BioCapital to spinout a novel CRISPR gene editing platform from Stanford University to treat severe diseases. Graphite Bio’s lead candidate is for sickle cell disease and it harnesses CRISPR gene correction technology to correct the single DNA mutation in sickle cell disease and to restore normal hemoglobin expression in the red blood cells of sickle cell patients (Learn more about CRISPR from a previous blog post linked here).

Matt Porteus, M.D., Ph.D (left) and Maria Grazia Roncarolo, M.D. (right)
Graphite Bio scientific founders

Matt Porteus, M.D., Ph.D and Maria Grazia Roncarolo, M.D., both from Stanford University, are the company’s scientific founders. Dr. Porteus, Dr. Roncarolo, and the Stanford team are currently supported by a CIRM  late stage preclinical grant  to complete the final preclinical studies and to file an Investigational New Drug application with the FDA, which will enable Graphite Bio to commence clinical studies of the CRISPR sickle cell disease gene therapy candidate in sickle cell patients in 2021.

Josh Lehrer, M.D., was appointed CEO of Graphite Bio and elaborated on the company’s gene editing approach in a news release.

“Our flexible, site-specific approach is extremely powerful and could be used to definitively correct the underlying causes of many severe genetic diseases, and also is applicable to broader disease areas. With backing from Versant and Samsara, we look forward to progressing our novel medicines into the clinic for patients with high unmet needs.”

In a press release, Dr. Porteus take a retrospective look on his preclinical research and its progress towards a clinical trial.

“It is gratifying to see our work on new gene editing approaches being translated into novel therapies. I’m very excited to be working with Versant again on a start-up and I look forward to collaborating with Samsara and the Graphite Bio team to bring a new generation of genetic treatments to patients.”

CIRM’s funding of late stage preclinical projects such this one is critical to its funding model, which de-risks the discovery, translational development and clinical proof of concept of innovative stem cell-based treatments until they can attract industry partnerships. You can learn more about CIRM-enabled spinout companies and CIRM’s broader effort to facilitate industry partnering for its portfolio projects on CIRM’s Industry Alliance Program website.

You can contact CIRM’s Director of Business Development at the email below to learn more about the Industry Alliance Program.

Shyam Patel, Ph.D.
Director, Business Development
Email: spatel@cirm.ca.gov

Gladstone scientists respond to coronavirus pandemic

In these uncertain times, we often look to our top scientists for answers as well as potential solutions. But where does one begin to try and solve a problem of this magnitude? The first logical step is building on the supplies currently available, the work already accomplished, and the knowledge acquired.

This is the approach that the Gladstone Institutes in San Francisco is taking. Various scientists at this institution have shifted their current operations towards helping with the current coronavirus pandemic. These efforts have focused on helping with diagnostics, treatment, and prevention of COVID-19.

Diagnostics

Dr. Jennifer Doudna and Dr. Melanie Ott are collaborating in order to develop an effective method to rapidly diagnose those with COVID-19. Dr. Doudna’s work has focused on CRISPR technology, which we have talked about in detail in a previous blog post, while Dr. Ott has focused on studying viruses. By combining their expertises, these two scientists hope to develop a diagnostic tool capable of delivering rapid results and usable in areas such as airports, ports of entry, and remote communities.

Treatment

Dr. Nevan Krogan has discovered all of the human host cell proteins that COVID-19 interacts with to hijack the cell’s machinery. These proteins serve as new targets for potential drug therapies.

Since the high fatality rate of the virus is driven by lung and heart failure, Dr. Ott, Dr. Bruce Conklin, and Dr. Todd McDevitt will test effects of the virus and potential drug therapies in human lung organoids and human heart cells, both developed from human stem cells.

Dr. Warner Greene, who also focuses on the study of viruses, is screening a variety of FDA-approved drugs to identify those that could be rapidly repurposed as a treatment for COVID-19 patients or even as a preventive for high risk-groups.

Prevention

Dr. Leor Weinberger has developed a new approach to fight the spread of viruses. It is called therapeutic interfering particles (TIPs) and could be an alternative to a vaccine. TIPs are defective virus fragments that mimic the virus but are not able to replicate. They combat the virus by hijacking the cell machinery to transform virus-infected cells into factories that produce TIPS, amplifying the effect of TIPs in stopping the spread of virus. TIPs targeting COVID-19 would transmit along the same paths as the virus itself, and thus provide protection to even the most vulnerable populations.

You can read more about these groundbreaking projects in the news release linked here.

Machine learning used to pattern stem cells – a vital step in organ modeling

Gladstone researchers discovered a method to control the patterns stem cells form in a dish. The work was led by Senior Investigator Todd McDevitt (left) and his team, including (pictured) David Joy and Ashley Libby.

When someone thinks of machine learning, the first thing that comes to mind might be the technology used by Netflix or Hulu to suggest new shows based on their viewing history. But what if this technology could be applied towards advancing the field of regenerative medicine?

Thanks to a CIRM funded study, a team of scientists lead by Dr. Todd McDevitt at the Gladstone Institutes have found a way to to use machine learning to control the spacial organization of stem cells, a key process that plays a vital role in organ development. This new understanding of how stem cells organize themselves in 3D is an important step towards being able to create functional and/or personalized organs for research or organ transplants.

“We’ve shown how we can leverage the intrinsic ability of stem cells to organize,” said Dr. McDevitt in a news release from Gladstone Institutes. “This gives us a new way of engineering tissues, rather than a printing approach where you try to physically force cells into a specific configuration.”

In their normal environment, stem cells are able to form patterns as they mature and over time morph into the tissues seen in an adult organism. One type of stem cell, called an induced pluripotent stem cell (iPSC), can become nearly every cell type of the body. In fact, researchers have already found ways to direct iPSCs to become various cell types such as those in the heart or brain.

Unfortunately, attempting to replicate the pattern formation of stem cells as they mature has been challenging. Some have used 3D printing to lay out stem cells in a desired shape, but the cells often migrated away from their initial locations.

In the same news release mentioned above, Ashley Libby, a graduate student at Gladstone and co-first author of this study, said that,

“Despite the importance of organization for functioning tissues, we as scientists have had difficulty creating tissues in a dish with stem cells. Instead of an organized tissue, we often get a disorganized mix of different cell types.”

To solve this problem, the scientists used a computational model to learn how to influence stem cells into forming new arrangements, such as those that might be useful in generating personalized organs.

Previous studies conducted by Dr. McDevitt showed that blocking the expression of two genes, called ROCK1 and CDH1, affected the layout of iPS cells grown in a petri dish.

In this current study, the scientists used CRISPR/Cas9 gene editing (you can read about this technology in more detail here) to block expression of ROCK1 and CDH1 at any time by adding a drug to the iPSCs. This was done to see if they could predict stem cell arrangement based on the alterations made to ROCK1 and CDH1 at different drug doses and time periods.

The team carried out various experiments with different doses and timing. Then, the data was input into a machine-learning program designed to identify patterns, something that could take a human months to identify.

(Left) video showing simulated interactions between different stem cell populations. (Right) image of stem cells grown in conditions dictated by the machine-learning program generate a colony that forms a bull’s-eye pattern, as predicted.

The machine-learning program used the data to predict ways that ROCK1 and CDH1 affect iPSC organization. The scientists then began to see whether the program could compute how to make entirely new patterns, like a bull’s-eye or an island of cells. The team says the results were little short of astounding. Machine learning was able to accurately predict conditions that will cause stem cell colonies to form desired patterns.

The full study was published in the journal Cell Systems.

Stanford and University of Tokyo researchers crack the code for blood stem cells

Blood stem cells grown in lab

Blood stem cells offer promise for a variety of immune and blood related disorders such as sickle cell disease and leukemia. Like other stem cells, blood stem cells have the ability to generate additional blood stem cells in a process called self-renewal. Additionally, they are able to generate blood cells in a process called differentiation. These newly generated blood cells have the potential to be utilized for transplantations and gene therapies.

However, two limitations have hindered the progress made in this field. One problem relates to the amount of blood stem cells needed to make a potential transplantation or gene therapy viable. Unfortunately, it has been challenging to isolate and grow blood stem cells in large quantity needed for these approaches. A part of this reason relates to getting the blood stem cells to self-renew rather than differentiate.

The second problem involves the existing blood stem cells in the patient’s body prior to transplantation. In order for the procedure to work, the patient’s own blood stem cells must be eliminated to make space for the transplanted blood stem cells. This is done through a process known as conditioning, which typically involves chemotherapy and/or radiation. Unfortunately, chemotherapy and radiation can cause life-threatening side effects due to its toxicity, particularly in pediatric patients, such as growth retardation, infertility and secondary cancer in later life. Very sick or elderly patients are unable to tolerate this conditioning process, making them ineligible for transplants.

A CIRM funded study by a team at Stanford and the University of Tokyo has unlocked the code related to the generation of blood stem cells.

The collaborative team was able to modify the components used to grow blood stem cells. By making these modifications, which effects the growth and physical conditions of blood stem cells, the researchers have shown for the first time that it’s possible to get blood stem cells from mice to renew themselves hundreds or even thousands of times within a period of just 28 days. 

Furthermore, the team showed that when they transplanted the newly grown cells into mice that had not undergone conditioning, the donor cells had engrafted and remained functional.

The team also found that gene editing technology such as CRISPR could be used while growing an adequate supply of blood stem cells for transplantation. This opens the possibility of obtaining a patient’s own blood stem cells, correcting the problematic gene, and reintroducing these back to the patient.

The complete study was published in Nature.

In a news release, Dr. Hiromitsu Nakauchi, a senior author of the study, is quoted as saying,

“For 50 years, researchers from laboratories around the world have been seeking ways to grow these cells to large numbers. Now we’ve identified a set of conditions that allows these cells to expand in number as much as 900-fold in just one month. We believe this approach could transform how [blood] stem cell transplants and gene therapy are performed in humans.” 

Stanford scientist uses CRISPR-Cas9 and stem cells to develop potential “bubble baby” therapy

Dr. Matthew Porteus, professor of pediatrics at Stanford University.
Photo courtesy of Stanford Medicine.

Our immune system is an important and essential part of everyday life. It is crucial for fighting off colds and, with the help of vaccinations, gives us immunity to potentially lethal diseases. Unfortunately, for some infants, this innate bodily defense mechanism is not present or is severely lacking in function.

This condition is known as severe combined immunodeficiency (SCID), commonly nicknamed “bubble baby” disease because of the sterile plastic bubble these infants used to be placed in to prevent exposure to bacteria, viruses, and fungi that can cause infection. There are several forms of SCID, one of which involves a single genetic mutation on the X chromosome and is known as SCID-X1

Many infants with SCID-X1 develop chronic diarrhea, a fungal infection called thrush, and skin rashes. Additionally, these infants grow slowly in comparison to other children. Without treatment, many infants with SCID-X1 do not live beyond infancy.

SCID-X1 occurs almost predominantly in males since they only carry one X chromosome, with at least 1 in 50,000 baby boys born with this condition. Since females carry two X chromosomes, one inherited from each parent, they are unlikely to inherit two X chromosomes with the mutation present since it would require the father to have SCID-X1.

What if there was a way to address this condition by correcting the single gene mutation? Dr. Matthew Porteus at Stanford University is leading a study that has developed an approach to treat SCID-X1 that utilizes this concept.

By using CRISPR-Cas9 technology, which we have discussed in detail in a previous blog post, it is possible to delete a problematic gene and insert a corrected gene. Dr. Porteus and his team are using CRISPR-Cas9 to edit blood stem cells, which give rise to immune cells, which are the foundation of the body’s defense mechanism. In a study published in Nature, Dr. Porteus and his team have demonstrated proof of concept of this approach in an animal model.

The Stanford team was able to take blood stem cells from six infants with SCID-X1 and corrected them with CRISPR-Cas9. These corrected stem cells were then introduced into mice modeled to have SCID-X1. It was found that these mice were not only able to make immune cells, but many of the edited stem cells maintained their ability to continuously create new blood cells.

In a press release, Dr. Mara Pavel-Dinu, a member of the research team, said:

“To our knowledge, it’s the first time that human SCID-X1 cells edited with CRISPR-Cas9 have been successfully used to make human immune cells in an animal model.”

CIRM has previously awarded Dr. Porteus with a preclinical development award aimed at developing gene correction therapy for blood stem cells for SCID-X1. In addition to this, CIRM has funded two other projects conducted by Dr. Porteus related to CRISPR-Cas9. One of these projects used CRISPR-Cas 9 to develop a treatment for chronic sinusitis due to cystic fibrosis and the second project used the technology to develop an approach for treating sickle cell disease.

CIRM has also funded four clinical trials related to SCID. Two of these trials are related to SCID-X1, one being conducted at St. Jude Children’s Research Hospital and the other at Stanford University. The third trial is related to a different form of SCID known as ADA-SCID and is being conducted at UCLA in partnership with Orchard Therapeutics. Finally, the last of the four trials is related to an additional form of SCID known as ART-SCID and is being conducted at UCSF.

CRISPR-Cas9 101: an overview and the role it plays in developing therapies

Illustration courtesy of TED website

There has been a lot of conversation surrounding CRISPR-Cas9 in these recent months as well as many sensational news stories. Some of these stories highlight the promise this technology holds, while others emphasize a word of caution. But what exactly does this technology do and how does it work? Here is a breakdown that will help you better understand.

To start off, CRISPR is a naturally occurring process found in bacteria used as an immune system to defend against viruses. CRISPR simply put, are strands of DNA segments that contain repeating patterns. There are “scissor like” CRISPR proteins that have the ability to cut DNA segments. When a copy of a virus enters the bacteria, these “scissor like” proteins cut a segment of DNA from the virus and insert it into CRISPR. A copy of the viral DNA is made and another “attack” protein known as Cas9 attaches to it. By binding to the viral copy, Cas9 is able to sense that virus. When the same virus tries to enter the bacteria, Cas9 is able to seek and destroy it.

You can view a more detailed video explaining this concept below.

Many scientists analyzed this process in detail and it was eventually discovered that this CRISPR-Cas9 complex could be used to removed unwanted genes and insert a corrected copy, revolutionizing the way that we view the approach towards treating a wide variety of genetic diseases.

In fact, researchers at the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center and the University of Massachusetts Medical School have developed a strategy using this complex to treat two inherited, lethal blood disorders, sickle cell disease (SCD) and beta thalassemia. Both of these diseases involve a mutation that effects production of red blood cells, which are produced by blood stem cells. In beta-thalassemia, the mutation prevent red blood cells from being able to carry enough oxygen, leading to anemia. In SCD, the mutations cause red blood cells to take on a “sickle” shape which can block blood vessels.

By using CRISPR-Cas9 to insert a corrected copy of the gene into a patient’s own blood stem cells, this team demonstrated that functional red blood cells can then be produced. These results pay the way for other blood disorders as well.

In a press release , Dr. Daniel Bauer, an attending physician with Dana-Farber and a senior author on both of these studies stated that,

“Combining gene editing with an autologous stem-cell transplant could be a therapy for sickle-cell disease, beta-thalassemia and other blood disorders.”

In a separate study, scientists at University of Massachusetts Medical School have developed a strategy that could be used to treat genetic disorders associated with unintentional repeats or copies of small DNA segments. These problematic small segments of DNA are called microduplications and cause as many as 143 different diseases, including limb-girdle muscular dystrophy, Hermansky-Pudlak syndrome, and Tay-Sachs.

Because these are issues caused by repeats or copies of small DNA segments, the CRISPR-Cas9 complex can be used to remove microduplications without having to insert any additional genetic material.

Dr. Scot A. Wolfe, a co-investigator of this study, stated that,

“It’s like hitting the reset button. We don’t have to add any corrective genetic material, instead the cell stitches the DNA back together minus the duplication. It’s a shortcut for gene correction with potential therapeutic appeal.”

Although there has been a lot progress made with this technology, there are still concerns that need to be addressed. An article in Science mentions how two studies have shown that CRISPR can still make unintended changes to DNA, which can be potentially dangerous. In the article, Dr. Jin-Soo Kim, a CRISPR researcher at Seoul National University is quoted as saying,

“It is now important to determine which component is responsible for the collateral mutations and how to reduce or avoid them.”

Overall, CRISPR-Cas9 has revolutionized the approach of precision medicine. A wide variety of diseases are caused by small, unexpected segments of DNA. By applying this approach found in bacteria to humans, we have uncovered a way to correct these segments at the microscopic level. However, there is still much that needs to be learned and perfected before it can be utilized in patients.

Researcher claims to have made first gene-edited baby. But did it really happen?

Raelians

Claude Vorilhorn, founder of Raelism; Photo: courtesy thoughtco.com

Remember the Raelians? Probably not. But way back in 2002 the group, some described them as a cult, claimed it had created the world’s first cloned baby. The news made headlines all around the world raising fears we were stepping into uncharted scientific territory. Several weeks later the scientist brought in by the Raelians to verify their claims called it an “elaborate hoax.”

hejiankui

He Jiankui: Photo courtesy MIT Technology Review

Fast forward 16 years and a Chinese scientist named He Jiankui of Shenzhen claims he has created the first genetically modified humans. Again, it is generating headlines around the world and alarming people. In an interview with CNBC, Hank Greely, a bioethicist at Stanford, said if it happened it was “criminally reckless and I unequivocally condemn the experiment.”

The question now is did it happen, or is this just another “elaborate hoax”?

The concerns about this story are real. The scientist claims he used CRISPR to modify embryos during fertility treatments, resulting in the birth of twin girls.

CRISPR has been making headlines all of its own in the last few years as a fast, cheap and efficient way of editing genes. CIRM supports research using CRISPR for problems such as sickle cell disease. The difference being that our research works with adults so any changes in their genes are just for them. Those changes are not passed on to future generations.

The work making headlines around the world used CRISPR on embryos, meaning a child born from one of those embryos would pass those changes on to future generations. In effect, creating a new kind of human being.

This approach raises all sorts of serious issues – scientific, ethical and moral – not the least of which is that the technique could create unknown mutations down the road that would be passed on to future generations.  That’s why in the US the editing of embryos for pregnancy is banned.

But almost as soon as the news was announced there were questions raised about it. The research was not published anywhere. A hospital that the researchers named in their ethical approval documents is denying any involvement.

If it did happen, it could open a new, and potentially frightening chapter in science. In an interview on CNN, Julian Savulescu, director of the Oxford Uehiro Centre for Practical Ethics at the University of Oxford, called the use of CRISPR in this manner as “genetic Russian Roulette.”

“If true, this experiment is monstrous. Gene editing itself is experimental and is still associated with off-target mutations, capable of causing genetic problems early and later in life, including the development of cancer.”

And in an interview on the BBC, Prof Robert Winston, Professor of Science and Society at Imperial College London, said: “If this is a false report, it is scientific misconduct and deeply irresponsible. If true, it is still scientific misconduct.”

Our best hope right now is that this is just a repeat of the Raelians. Our worst fear, is that it’s not.

Has Regenerative Medicine Come of Age?

Signals logo

For the past few years the Signals blog site –  which offers an insiders’ perspectives on the world of regenerative medicine and stem cell research – has hosted what it calls a “Blog Carnival”. This is an event where bloggers from across the stem cell field are invited to submit a piece based on a common theme. This year’s theme is “Has Regenerative Medicine Come of Age?” Here’s my take on that question:

Many cultures have different traditions to mark when a child comes of age. A bar mitzvah is a Jewish custom marking a boy reaching his 13th birthday when he is considered accountable for his own actions. Among Latinos in the US a quinceañera is the name given to the coming-of-age celebration on a girl’s 15th birthday.

Regenerative Medicine (RM) doesn’t have anything quite so simple or obvious, and yet the signs are strong that if RM hasn’t quite come of age, it’s not far off.

For example, look at our experience at the California Institute for Regenerative Medicine (CIRM). When we were created by the voters of California in 2004 the world of stem cell research was still at a relatively immature phase. In fact, CIRM was created just six years after scientists first discovered a way to derive stem cells from human embryos and develop those cells in the laboratory. No surprise then that in the first few years of our existence we devoted a lot of funding to building world class research facilities and investing in basic research, to gain a deeper understanding of stem cells, what they could do and how we could use them to develop therapies.

Fast forward 14 years and we now have funded 49 projects in clinical trials – everything from stroke and cancer to spinal cord injury and HIV/AIDS – and our early funding also helped another 11 projects get into clinical trials. Clearly the field has advanced dramatically.

In addition the FDA last year approved the first two CAR-T therapies – Kymriah and Yescarta – another indication that progress is being made at many levels.

But there is still a lot of work to do. Many of the trials we are funding at the Stem Cell Agency are either Phase 1 or 2 trials. We have only a few Phase 3 trials on our books, a pattern reflected in the wider RM field. For some projects the results are very encouraging – Dr. Gary Steinberg’s work at Stanford treating people recovering from a stroke is tremendously promising. For others, the results are disappointing. We have cancelled some projects because it was clear they were not going to meet their goals. That is to be expected. These clinical trials are experiments that are testing, often for the first time ever in people, a whole new way of treating disease. Failure comes with the territory.

As the number of projects moving out of the lab and into clinical trials increases so too are the other signs of progress in RM. We recently held a workshop bringing together researchers and regulators from all over the world to explore the biggest problems in manufacturing, including how you go from making a small batch of stem cells for a few patients in an early phase clinical trial to mass producing them for thousands, if not millions of patients. We are also working with the National Institutes of Health and other stakeholders in discussing the idea of reimbursement, figuring out who pays for these therapies so they are available to the patients who need them.

And as the field advances so too do the issues we have to deal with. The discovery of the gene-editing tool CRISPR has opened up all sorts of possible new ways of developing treatments for deadly diseases. But it has also opened up a Pandora’s box of ethical issues that the field as a whole is working hard to respond to.

These are clear signs of a maturing field. Five years ago, we dreamed of having these kinds of conversations. Now they are a regular feature of any RM conference.

The simple fact that we can pose a question asking if RM has come of age is a sign all by itself that we are on the way.

Like little kids sitting in the back of a car, anxious to get to their destination, we are asking “Are we there yet?” And as every parent in the front seat of their car responds, “Not yet. But soon.”