Medeor Therapeutics Completes Enrollment in CIRM-Funded Clinical Trial for Kidney Transplant Patients

A CIRM-funded clinical trial to help kidney transplant patients avoid the need for anti-rejection or immunosuppressive medications has completed enrollment and transplantation of all patients.

Medeor Therapeutics’ MDR-101 Phase 3 multi-center clinical trial involved 30 patients; 20 of them were treated with MDR-101, and 10 control subjects were given standard care. CIRM awarded Medeor, based in South San Francisco, $18.8 million for this research in January 2018.

More than 650,000 Americans suffer from end-stage kidney disease – a life-threatening condition caused by the loss of kidney function. For these people the best treatment option is a kidney transplant from a genetically matched, living donor. Even matched patients, however, face a lifetime on immunosuppressive drugs to prevent their immune system from rejecting the transplanted organ. These drugs can be effective at preventing rejection, but they come at a cost. Because they are toxic these medications increase a transplant patient’s life-time risk of cancer, diabetes, heart disease and infections.

Medeor Therapeutics developed its MDR-101 therapy to reprogram the patient’s immune system to accept a transplanted kidney without the need for long term use of immunosuppression drugs.

The company takes peripheral blood stem cells from the organ donor and infuses them into the patient receiving the donor’s kidney. This creates a condition called “mixed chimerism” where immune cells from the donor help the patient’s immune system adapt to and tolerate the donor’s kidney. 

After a standard kidney transplant, the patient is given a combination of three anti-rejection medications which they typically have to remain on for the rest of their lives. However, the Medeor patients, by day 40 post-transplant, are only taking one medication and the hope is that immunosuppression is discontinued at the end of one year.

“Chronic kidney disease and kidney failure are a growing problem in the US, that’s why it’s so important that we find new ways to reduce the burden on patients and increase the odds of a successful transplant with long term benefit,” says Maria T. Millan, M.D., President and CEO of CIRM. “Medeor’s approach may not only reduce the likelihood of a patient’s body rejecting the transplanted organ, but it can also improve the quality of life for these people and reduce overall health care costs by eliminating the need to stay on these immunosuppressive medications for life.”

In an earlier Phase 2 trial, a majority of patients achieved mixed chimerism. Approximately 74 percent of those patients have been off all immunosuppressive drugs for more than two years, including some who continue to be off immunosuppressive medications 15 years after their surgery.

“Today’s news is a tremendous milestone not only for Medeor but for the entire transplant community. This is the first randomized, multi-center pivotal study designed specifically to stop the use of all immunosuppressive anti-rejection drugs post-transplant. This therapy can be a true game changer in our efforts to transform transplant outcomes and help patients live healthier lives,” said Dan Brennan, MD, Chief Medical Officer at Medeor Therapeutics.

If the results from this pivotal clinical trial show that MDR-101 is both safe and effective, Medeor may apply to the Food and Drug Administration (FDA) for approval to market their approach to other patients in the U.S.

A word from our Chair, several in fact

In 2005, the New Oxford American Dictionary named “podcast” its word of the year. At the time a podcast was something many had heard of but not that many actually tuned in to. My how times have changed. Now there are some two million podcasts to chose from, at least according to the New York Times, and who am I to question them.

Yesterday, in the same New York Times, TV writer Margaret Lyons, wrote about how the pandemic helped turn her from TV to podcasts: “Much in the way I grew to prefer an old-fashioned phone call to a video chat, podcasts, not television, became my go-to medium in quarantine. With their shorter lead times and intimate production values, they felt more immediate and more relevant than ever before.”

I mention this because an old colleague of ours at CIRM, Neil Littman, has just launched his own podcast and the first guest on it was Jonathan Thomas, Chair of the CIRM Board. Their conversation ranged from CIRM’s past to the future of the regenerative field as a whole, with a few interesting diversions along the way. It’s fun listening. And as Margaret Lyons said it might be more immediate and more relevant than ever before.

Cures, clinical trials and unmet medical needs

When you have a great story to tell there’s no shame in repeating it as often as you can. After all, not everyone gets to hear first time around. Or second or third time. So that’s why we wanted to give you another opportunity to tune into some of the great presentations and discussions at our recent CIRM Alpha Stem Cell Clinic Network Symposium.

It was a day of fascinating science, heart-warming, and heart-breaking, stories. A day to celebrate the progress being made and to discuss the challenges that still lie ahead.

There is a wide selection of topics from “Driving Towards a Cure” – which looks at some pioneering work being done in research targeting type 1 diabetes and HIV/AIDS – to Cancer Clinical Trials, that looks at therapies for multiple myeloma, brain cancer and leukemia.

The COVID-19 pandemic also proved the background for two detailed discussions on our funding for projects targeting the coronavirus, and for how the lessons learned from the pandemic can help us be more responsive to the needs of underserved communities.

Here’s the agenda for the day and with each topic there’s a link to the video of the presentation and conversation.

Thursday October 8, 2020

View Recording: CIRM Fellows Trainees

9:00am Welcome Mehrdad Abedi, MD, UC Davis Health, ASCC Program Director  

Catriona Jamieson, MD,  View Recording: ASCC Network Value Proposition

9:10am Session I:  Cures for Rare Diseases Innovation in Action 

Moderator: Mark Walters, MD, UCSF, ASCC Program Director 

Don Kohn, MD, UCLA – View Recording: Severe combined immunodeficiency (SCID) 

Mark Walters, MD, UCSF, ASCC Program Director – View Recording: Thalassemia 

Pawash Priyank, View Recording: Patient Experience – SCID

Olivia and Stacy Stahl, View Recording: Patient Experience – Thalassemia

10 minute panel discussion/Q&A 

BREAK

9:55am Session II: Addressing Unmet Medical Needs: Driving Towards a Cure 

Moderator: John Zaia, MD, City of Hope, ASCC Program Direction 

Mehrdad Abedi, MD, UC Davis Health, ASCC Program Director – View Recording: HIV

Manasi Jaiman, MD, MPH, ViaCyte, Vice President, Clinical Development – View Recording: Diabetes

Jeff Taylor, Patient Experience – HIV

10 minute panel discussion/Q&A 

BREAK

10:40am Session III: Cancer Clinical Trials: Networking for Impact 

Moderator: Catriona Jamieson, MD, UC San Diego, ASCC Program Director 

Daniela Bota, MD, PhD, UC Irvine, ASCC Program Director – View Recording:  Glioblastoma 

Michael Choi, MD, UC San Diego – View Recording: Cirmtuzimab

Matthew Spear, MD, Poseida Therapeutics, Chief Medical Officer – View Recording: Multiple Myeloma  

John Lapham, Patient Experience –  View Recording: Chronic lymphocytic leukemia (CLL) 

10 minute panel discussion/Q&A 

BREAK

11:30am Session IV: Responding to COVID-19 and Engaging Communities

Two live “roundtable conversation” sessions, 1 hour each.

Roundtable 1: Moderator Maria Millan, MD, CIRM 

CIRM’s / ASCC Network’s response to COVID-19 Convalescent Plasma, Cell Therapy and Novel Vaccine Approaches

Panelists

Michael Matthay, MD, UC San Francisco: ARDS Program

Rachael Callcut, MD, MSPH, FACS, UC Davis: ARDS Program 

John Zaia, MD, City of Hope: Convalescent Plasma Program 

Daniela Bota, MD, PhD, UC Irvine: Natural Killer Cells as a Treatment Strategy 

Key questions for panelists: 

  • Describe your trial or clinical program?
  • What steps did you take to provide access to disproportionately impacted communities?
  • How is it part of the overall scientific response to COVID-19? 
  • How has the ASCC Network infrastructure accelerated this response? 

Brief Break

Roundtable 2: Moderator Ysabel Duron, The Latino Cancer Institute and Latinas Contra Cancer

View Recording: Roundtable 2

Community Engagement and Lessons Learned from the COVID Programs.  

Panelists

Marsha Treadwell, PhD, UC San Francisco: Community Engagement  

Sheila Young, MD, Charles R. Drew University of Medicine and Science: Convalescent Plasma Program in the community

David Lo, MD, PhD,  UC Riverside: Bringing a public health perspective to clinical interventions

Key questions for panelists: 

  • What were important lessons learned from the COVID programs? 
  • How can CIRM and the ASCC Network achieve equipoise among communities and engender trust in clinical research? 
  • How can CIRM and the ASCC Network address structural barriers (e.g. job constrains, geographic access) that limit opportunities to participate in clinical trials?

Exploring tough questions, looking for answers

COVID-19 and social and racial injustice are two of the biggest challenges facing the US right now. This Thursday, October 8th, we are holding a conversation that explores finding answers to both.

The CIRM Alpha Stem Cell Clinic Network Symposium is going to feature presentations about advances in stem cell and regenerative research, highlighting treatments that are already in the clinic and being offered to patients.

But we’re also going to dive a little deeper into the work we support, and use it to discuss two of the most pressing issues of the day.

One of the topics being featured is research into COVID-19. To date CIRM has funded 17 different projects, including three clinical trials. We’ll talk about how these are trying to find ways to help people infected with the virus, seeing if stem cells can help restore function to organs and tissues damaged by the virus, and if we can use stem cells to help develop safe and effective vaccines.

Immediately after that we are going to use COVID-19 as a way of exploring how the people most at risk of being infected and suffering serious consequences, are also the ones most likely to be left out of the research and have most trouble accessing treatments and vaccines.

Study after study highlights how racial and ethnic minorities are underrepresented in clinical trials and disproportionately affected by debilitating diseases. We have a responsibility to change that, to ensure that the underserved are given the same opportunity to take part in clinical trials as other communities.

How do we do that, how do we change a system that has resisted change for so long, how do we overcome the mistrust that has built up in underserved communities following decades of abuse? We’ll be talking about with experts who are on the front lines of this movement.

It promises to be a lively meeting. We’d love to see you there. It’s virtual – of course – it’s open to everyone, and it’s free.

Here’s where you can register and find out more about the Symposium

CIRM-funded kidney transplant procedure eyeing faster approval

Kidney transplant surgery.

Medeor Therapeutics, which is running a CIRM-funded clinical trial to help people getting kidney transplants, just got some really good news. The US Food and Drug Administration (FDA) has just granted their product Regenerative Medicine Advanced Therapy (RMAT) designation. That’s a big deal because it means they may be able to apply for faster review and approval and get their therapy to more patients faster.

Here’s why that RMAT designation matters.

Over 650,000 Americans suffer from end-stage kidney disease – a life-threatening condition caused by the loss of kidney function. The best available treatment for these patients is a kidney transplant from a genetically matched living donor. However, patients who receive a transplant must take life-long immunosuppressive drugs to prevent their immune system from rejecting the transplanted organ. Over time, these drugs are toxic and can increase a patient’s risk of infection, heart disease, cancer and diabetes.  Despite these drugs, many patients still lose transplanted organs due to rejection.

To tackle this problem Medeor is developing a stem cell-based therapy called MDR-101. This is being tested in a Phase 3 clinical trial and it’s hoped it will eliminate the need for immunosuppressive drugs in genetically matched kidney transplant patients.

The company takes blood-forming stem cells and immune cells from the organ donor and infuses them into the patient receiving the donor’s kidney. Introducing the donor’s immune cells into the patient creates a condition called “mixed chimerism” where immune cells from the patient and the donor are able to co-exist. In this way, the patient’s immune system is able to adapt to and tolerate the donor’s kidney, potentially eliminating the need for the immunosuppressive drugs that are normally necessary to prevent transplant rejection.

So how does getting RMAT designation help that? Well, the FDA created the RMAT program to help speed up the development and review of regenerative medicine therapies that can treat, modify, reverse, or cure a serious condition. If MDR-101shows it is both safe and effective RMAT could help it get faster approval for wider use.

In a news release Giovanni Ferrara, President and CEO of Medeor, welcomed the news.

“This important designation underscores the tremendous unmet medical need for alternatives to today’s immunosuppressive therapies for transplantation. We have the potential to help people live longer, healthier lives without the need for high dose and chronic immunosuppression and we thank the FDA for this designation that will assist us progressing as efficiently as possible toward a commercially available product.”

This is the seventh CIRM-supported project that has been granted RMAT designation. The others are jCyte, Lineage, Humacyte, St. Jude’s/UCSF X-linked SCID, Poseida, Capricor

Stem Cell All-Stars, All For You

goldstein-larry

Dr. Larry Goldstein, UC San Diego

It’s not often you get a chance to hear some of the brightest minds around talk about their stem cell research and what it could mean for you, me and everyone else. That’s why we’re delighted to be bringing some of the sharpest tools in the stem cell shed together in one – virtual – place for our CIRM 2020 Grantee Meeting.

The event is Monday September 14th and Tuesday September 15th. It’s open to anyone who wants to attend and, of course, it’s all being held online so you can watch from the comfort of your own living room, or garden, or wherever you like. And, of course, it’s free.

BotaDaniela2261

Dr. Daniela Bota, UC Irvine

The list of speakers is a Who’s Who of researchers that CIRM has funded and who also happen to be among the leaders in the field. Not surprising as California is a global center for regenerative medicine. And you will of course be able to post questions for them to answer.

srivastava-deepak

Dr. Deepak Srivastava, Gladstone Institutes

The key speakers include:

Larry Goldstein: the founder and director of the UCSD Stem Cell Program talking about Alzheimer’s research

Irv Weissman: Stanford University talking about anti-cancer therapies

Daniela Bota: UC Irvine talking about COVID-19 research

Deepak Srivastava: Gladsone Institutes, talking about heart stem cells

Other topics include the latest stem cell approaches to COVID-19, spinal cord injury, blindness, Parkinson’s disease, immune disorders, spina bifida and other pediatric disorders.

You can choose one topic or come both days for all the sessions. To see the agenda for each day click here. Just one side note, this is still a work in progress so some of the sessions have not been finalized yet.

And when you are ready to register go to our Eventbrite page. It’s simple, it’s fast and it will guarantee you’ll be able to be part of this event.

We look forward to seeing you there.

Perseverance: from theory to therapy. Our story over the last year – and a half

Some of the stars of our Annual Report

It’s been a long time coming. Eighteen months to be precise. Which is a peculiarly long time for an Annual Report. The world is certainly a very different place today than when we started, and yet our core mission hasn’t changed at all, except to spring into action to make our own contribution to fighting the coronavirus.

This latest CIRM Annual Reportcovers 2019 through June 30, 2020. Why? Well, as you probably know we are running out of money and could be funding our last new awards by the end of this year. So, we wanted to produce as complete a picture of our achievements as we could – keeping in mind that we might not be around to produce a report next year.

Dr. Catriona Jamieson, UC San Diego physician and researcher

It’s a pretty jam-packed report. It covers everything from the 14 new clinical trials we have funded this year, including three specifically focused on COVID-19. It looks at the extraordinary researchers that we fund and the progress they have made, and the billions of additional dollars our funding has helped leverage for California. But at the heart of it, and at the heart of everything we do, are the patients. They’re the reason we are here. They are the reason we do what we do.

Byron Jenkins, former Naval fighter pilot who battled back from his own fight with multiple myeloma

There are stories of people like Byron Jenkins who almost died from multiple myeloma but is now back leading a full, active life with his family thanks to a CIRM-funded therapy with Poseida. There is Jordan Janz, a young man who once depended on taking 56 pills a day to keep his rare disease, cystinosis, under control but is now hoping a stem cell therapy developed by Dr. Stephanie Cherqui and her team at UC San Diego will make that something of the past.

Jordan Janz and Dr. Stephanie Cherqui

These individuals are remarkable on so many levels, not the least because they were willing to be among the first people ever to try these therapies. They are pioneers in every sense of the word.

Sneha Santosh, former CIRM Bridges student and now a researcher with Novo Nordisk

There is a lot of information in the report, charting the work we have done over the last 18 months. But it’s also a celebration of everyone who made it possible, and our way of saying thank you to the people of California who gave us this incredible honor and opportunity to do this work.

We hope you enjoy it.

Huge honor, hugely deserved for CIRM-funded stem cell researcher

Dr. Andy McMahon: Photo courtesy USC

Andy McMahon is one of the most understated, humble and low-key people you are ever likely to meet. He’s also one of the smartest. And he has a collection of titles to prove it. He is the W.M. Keck Provost and University Professor in USC’s departments of Stem Cell Biology and Regenerative Medicine at the Keck School of Medicine, and Biological Sciences at the Dornsife College of Letters, Arts and Sciences, a fellow of the American Association for the Advancement of Science, the American Academy of Arts and Sciences, the European Molecular Biology Organization, and the Royal Society.

Now you can add to that list that Andy is a member of the National Academy of Sciences (NAS). Election to the NAS is no ordinary honor. It’s one of the highest in the scientific world.

In a USC news release Dean Laura Mosqueda from the Keck School praised Andy saying: “We’re delighted that Dr. McMahon is being recognized as a newly elected member of the National Academy of Sciences. Because new members are elected by current members, this represents recognition of Dr. McMahon’s achievements by his most esteemed peers in all scientific fields.”

Not surprisingly CIRM has funded some of Andy’s work – well, we do pride ourselves on working with the best and brightest scientists – and that research is taking on added importance with the spread of COVID-19. Andy’s area of specialty is kidneys, trying to develop new ways to repair damaged or injured kidneys. Recent studies show that between 3 and 9 percent of patients with COVID-19 develop an acute kidney injury; in effect their kidneys suddenly stop working and many of these patients have to undergo dialysis to stay alive.

Even those who recover are at increased risk for developing more chronic, even end-stage kidney disease. That’s where Andy’s work could prove most useful. His team are using human stem cells to create mini artificial kidneys that have many of the same properties as the real thing. These so-called “organoids” enable us to study chronic kidney disease, come up with ideas to repair damage or slow down the progression of the disease, even help improve the chances of a successful transplant if that becomes necessary.

You can hear Andy talk about his work here:

CIRM is now funding a number of projects targeting COVID-19, including a clinical trial using convalescent plasma gel, and intends investing in more in the coming weeks and months. You can read about that here.

We are also funding several clinical trials targeting kidney failure. You can read about those on our Clinical Trials Dashboard page – diseases are listed alphabetically.

CIRM Board Meeting Highlights Important Updates to Clinical Trials

Dr. Maria T. Millan, President and CEO of CIRM, presenting the President’s Report

This past Thursday the governing Board of the California Institute for Regenerative Medicine (CIRM) were presented with an update on CIRM’s clinical portfolio, which to date includes 60 clinical trials in various areas including kidney failure, cancer, and other rare diseases.  The full President’s Report gives an update on 15 of these trials, in addition to our landmark Cure Sickle Cell Initiative with the NIH and our various educational programs.

Although we won’t be diving into extensive detail for all of these trials, we wanted to highlight several key updates made in this presentation to demonstrate how our clinical portfolio is maturing, with many of these trials moving towards registration. Classically, registration trials are large Phase 3 trials. Notably, some of the highlighted CIRM trials are small Phase 2 or earlier trials that seek to gain enough safety and efficacy data to support final FDA marketing approval. This is a trend with regenerative medicine programs where trial sizes are often small due to the fact that the affected populations are so small with some of these rare diseases. Despite this, the approaches could allow a so called “large effect size,” meaning the signal of clinical benefit per patient is strong enough to give a read of whether the therapy is working or not. CIRM programs often address rare unmet needs and utilize this approach.

For example, Orchard Therapeutics, which is conducting a phase 2 clinical trial for ADA Severe Combined Immunodeficiency (ADA-SCID), a rare immune disorder caused by a genetic mutation, has shown a long-term recovery of the immune system in 20 patients two years post treatment.  Orchard plans to submit a Biologics License Application (BLA) sometime in 2020, which is the key step necessary to obtain final approval from the Food and Drug Administration (FDA) for a therapy.

“We are thrilled to see encouraging results for this genetically modified cell therapy approach and a path forward for FDA approval,” says Maria T. Millan, MD, President and CEO of CIRM. “CIRM is proud of the role it has played in this program.  We funded the program while it was at UCLA and it is now in partnership with Orchard Therapeutics as it takes the program through this final phase toward FDA marketing approval.  Success in this program is a game changer for patients with ADA-SCID who had no other options and who had no bone marrow transplant donors. It also opens up possibilities for future approaches for this dieaseas as well as the other 6,000 genetic diseases that currently have no treatment.”    

The trial uses a gene therapy approach that takes the patient’s own blood stem cells, introduces a functional version of the ADA gene, and reintroduces these corrected blood stem cells back into the patient. From blood tests, one can readily detect whether the approach is successful from the presence of ADA and from the presence of immune cells that were not previously present. To date, it has been awarded approximately $19 million in CIRM funding.  Additionally, it has received FDA Breakthrough Therapy as well as Orphan Drug Designations, both of which are designed to accelerate  the development of the treatment.

Another trial that was highlighted is Rocket Pharmaceutical’s clinical trial for Leukocyte Adhesion Deficiency-1 (LAD-1), a rare and fatal pediatric disease that affects the body’s ability to combat infections. They have just released initial results from their first patient. This is also a gene therapy approach using the patient’s own blood stem cells. The notable aspect of this trial is that the investigators designed this small phase 1 trial of nine patients to be “registration enabling.”  This means that, if they find compelling data, they intend to bring the experience and data from this trial to the FDA to seek agreement on what would be required to get final marketing approval in order to get this treatment to patients with severe unmet medical needs in the most timely way possible.     

Preliminary results demonstrate early evidence of safety and potential efficacy.  There were visible improvements in multiple disease-related skin lesions after receiving the therapy. They are collecting more data on more patients.  To date, it has received $6.6 million in CIRM funding.

As a unique immuno-oncology approach (using the body’s immune system to battle cancer), CIRM is funding Forty Seven Inc. to conduct a clinical trial for patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), both of which are forms of cancer.  They have received Fast Track and Orphan Drug designation from the FDA.

The trial is using an antibody blocking CD47, a “don’t eat me” signal, which allows the body’s own immune cells to seek and destroy cancerous stem cells.  This is combined with chemotherapy to render the cancer stem cells more susceptible to immune destruction.  This trial has received $5 million in CIRM funding thus far.

Other registration phase trials in the CIRM portfolio include the following Phase 3 trials:

Brainstorm Cell Therapeutics, for a fatal debilitating neurodegenerative disease, Amyotrophic Lateral Sclerosis (Lou Gehrig’s disease).  That company has completed enrollment and expects top line results in the final quarter of 2020.

Humacyte, which is testing bioengineered de-cellularized vessels that are implanted to create vascular access that is repopulated by the patients own stem cells to make it more like native vessel.  The company is conducting two Phase 3 trials to compare this bioengineered vessel to synthetic grafts and to the patients’ own vessels for use in hemodialysis, a “life line” for patients with end stage renal disease. Humacyte was the first US FDA Cell Therapy program to receive the Regenerative Medicine Advanced Technologies (RMAT) in March 2017. To date, these trials have been awarded $24 million in CIRM funding.

Medeor Therapeutics has received $11.2M in CIRM funding to conduct a Phase 3 trial in combined blood stem cell and kidney transplantation to induce immunologic tolerance so that the blood stem cells teach the patient’s immune system to recognize the transplanted kidney as its own.  The goal is to remove the need for chronic immunosuppressive medications, that have its own complications. If successful, transplant recipients would not need to “trade one chronic condition for another.”

Donor blood stem cells and T cells could help patients wean off immunosuppressive drugs after organ transplant

Dr. Samuel Strober is refining a process that eliminates the need for the many immunosuppresant drugs normally required after a transplant.
Image credit: Stanford Medicine News Center

In 2019, there were over 23,000 kidney transplants in the United States, according to figures from the United Network for Organ Sharing (UNOS). These transplants can be lifesaving, but the donated organ can be perceived as a foreign invader by the patient’s immune system and attacked. In order to protect the organ from attack, transplant recipients are required to take numerous drugs that suppress the immune system, which are referred to as immunosupressive (IS) drugs. Unfortunately, these drugs, while helping protect the organ, can also cause long term problems such as hypertension, diabetes, heart disease, infection, a high concentration of fats in the blood, and cancer.

To address this problem, Dr. Samuel Strober and his team at Stanford University are conducting a CIRM-funded clinical trial that gives patients getting a kidney transplant a mixture of their own blood cells and cells from the kidney donor, a process called mixed chimerism.

Pairing patients and donors for transplants is done via Human Leukocyte Antigen (HLA) matching. HLA are markers on most cells in your body and are used by your immune system to recognize which cells belong to the body. If you are fully HLA matched that means your cells and the donor cells are immunologically compatible, and so less likely to be rejected. If they are HLA haplotypes, it means they are close but not fully matched so rejection is more likely.

In the trial, fifty-one patients with end stage renal failure that had just received a kidney transplant were infused with blood stem cells (cells that can give rise to different kind of blood cells) and T cells (a cell that plays a role in the immune response) obtained from the donor to achieve a mixed chimerism. Of the 51 patients 29 were fully HLA matched, and 22 were HLA haplotype matched.

Standard IS drugs were administered to all the patients after transplantation and the patients were monitored from six to twelve months to ensure there was no organ rejection or graft vs host disease (GVHD), a condition where donated blood stem cells attack the body.

After this period, the patients were taken off the IS drugs and the results of this trial are very promising. Twenty-four of the fully HLA matched patients with a persistent mixed chimerism for at least six months were able to stop taking the IS drugs without evidence of rejection for at least two years. Ten HLA haplotype matched patients with a persistent mixed chimerism for at least twelve months were able to stop taking some of the IS drugs without rejection.

This is encouraging news for patients undergoing any kind of transplant, leading to hope that one day all patients might be able to get a life-saving organ without having to take the IS drugs forever.

The full results of this study were published in Science Translational Medicine.