Overcoming obstacles in blood stem cell therapies

Photo Credit: OHSU Knight Cancer Institute

Today, we here at CIRM wanted to provide an update on the fascinating world of hematopoietic (blood) stem cell-based therapies.  What is the current status of this promising field and what are some of the challenges that need to be overcome? Dr. Kelly Shepard, Associate Director of Discovery and Translation here at CIRM, answers these questions and many more in the blog entry below.

There have been a number of exciting advances in regenerative medicine over the past few years, especially in the use of gene therapy and hematopoietic (blood) stem cell transplantation to treat and even cure various diseases of the blood and immune system. These studies built off groundbreaking research by Till and McCulloch in the 1950-60’s, who identified a rare and special stem cell in the bone marrow of mice that gives rise to all cells of the blood and immune system for the lifetime of the animal, the “hematopoietic stem cell”, or HSC. It wasn’t long before scientists and doctors realized the therapeutic implications of this discovery, and the journey to identify the human counterpart began. Fast forward to the present, and HSC transplantation (HSCT) has become a standard medical procedure for treating various cancers and genetic disorders of the blood. The basic premise is this: a patient with a diseased or defective blood/immune system receives an infusion of healthy HSCs, which are typically procured from donated bone marrow or umbilical cords, but in certain situations, might come from the patient him/herself. Once established in the recipient, these healthy cells will divide and regenerate a new blood and immune system over the course of the patient’s lifetime.

For HSCT to be successful, the donor cells must “engraft”, or take up permanent residence in their new environment. This usually necessitates “conditioning” the recipient with some form of chemotherapy or radiation, which eliminates some of the patient’s own cells to create room for the new arrivals. Unfortunately, conditioning creates a situation where the patient is extremely vulnerable to infections and other complications during the period of recovery, as it will take weeks for his/her blood and immune systems to be reestablished. These inherent risks mean HSC transplants can only be offered to patients with life threatening diseases such as leukemia, or to those with significant blood/immune disorders who are sufficiently healthy to tolerate the toxic conditioning regimen and to weather the extended period of recovery.

A second major issue preventing a more widespread use of HSCT is the shortage of healthy donor HSCs that are available for transplant, which must be immune matched to the recipient to prevent rejection. Immune matching is also critical to avoid a dangerous complication called graft vs. host disease, where the transplanted cells or their progeny launch an immune attack against the recipient’s organs, often leading to chronic disease and sometimes, death. Unfortunately, there are many people who have no compatible donors and for whom the risk of even a partially matched transplant is unacceptable.

Scientists and clinicians have long sought means to overcome the technical challenges of HSCT in order to “unleash” its true potential to cure and treat a wider variety of diseases, and to  make it feasible (and affordable) for a much larger number of patients. CIRM has endeavored to support novel approaches that could hopefully produce game changing advances for the field. Some of these approaches were recently highlighted in a Perspective article, published in Stem Cells Translational Medicine in early 2020, along with a discussion of other important advances in related areas, listed below. More information can be found in that article or referring to our website to learn more about the individual projects.

Approaches that could increase the availability of healthy HSCs for transplant include development of non-toxic conditioning regimens to facilitate a patient’s acceptance and recovery from the transplant procedure; novel technologies for expanding HSCs for transplant; and gene modification technologies to correct inherited mutations in HSCs.
Illustration Credit: Dr. Kelly Shepard, CIRM

Developing New Sources of Healthy and Immune Compatible HSCs for transplant

  • Exploring ways to produce HSCs from pluripotent stem cells in the lab
  • Expanding populations of HSCs that are already present in donated tissues such as cord blood
  • Using genetic engineering to “repair” defects in the DNA of HSCs from patients with inherited blood and/or immune disorders
  • Using genetic engineering to create “immune invisible” or “universal donor” HSCs that will not be rejected after transplantation

Developing Safer and More Tolerable Conditioning Regimens

  • Exploring reduced intensity forms of conditioning with drugs or radiation
  • Using antibodies rather than chemicals to free up space in the bone marrow for incoming, donor HSCs
  • Using dietary methods to free up space in the bone marrow for incoming, donor HSCs

Accelerating Reovery of Immune Function Lost Through Conditioning

  • Adding back key populations of immune cells to protect the host during regeneration of their immune system
  • Discovering new drugs and treatments to accelerate the pace of regeneration after transplant, or to prevent the death of HSCs that survived conditioning

Overcoming these scientific and technical challenges could create a paradigm shift in the way HSCT is applied and used and consequently, reduce the costs and risks associated with the procedure. In this way, the true potential of HSCT could be unleashed for the greatest good.

How quitting smoking helps your lungs regenerate; a discovery could lead to new ways to repair damaged lungs; and encouraging news in a stroke recovery trial

Photo courtesy Lindsay Fox

Smoking is one of the leading causes of preventable death not just in the US, but worldwide. According to the US Centers for Disease Control and Prevention tobacco causes an estimated seven million deaths around the world, every single year. And for every person who dies, another 30 live with a serious smoking-related illness. Clearly quitting is a good idea. Now a new study adds even more incentive to do just that.

Scientists at the Welcome Trust Sanger Institute and University College London in the UK, found that quitting smoking did more than just stop further damage to the lungs. They found that cells in the lining of the lungs that were able to avoid being damaged, were able to regrow and repopulate the lung, helping repair damaged areas.

In an article in Science Daily Dr Peter Campbell, a joint senior author of the study, said: “People who have smoked heavily for 30, 40 or more years often say to me that it’s too late to stop smoking — the damage is already done. What is so exciting about our study is that it shows that it’s never too late to quit — some of the people in our study had smoked more than 15,000 packs of cigarettes over their life, but within a few years of quitting many of the cells lining their airways showed no evidence of damage from tobacco.”

The study is published in the journal Nature.

Researchers at UCLA have also made a discovery that could help people with lung disease.

They examined the lungs of people with cancer and compared them to the lungs of healthy people. They were able to identify a group of molecules, called the Wnt/beta-catenin signaling pathway, that appear to influence the activity of stem cells that are key to maintaining healthy lungs. Too much activity can tilt the balance away from healthy lungs to ones with mutations that are more prone to developing tumors.

In a news release Dr. Brigitte Gomperts, the lead author of the study, says although this work has only been done in mice so far it has tremendous potential: “We think this could help us develop a new therapy that promotes airway health. This could not only inform the treatment of lung cancer, but help prevent its progression in the first place.”

The study is published in the journal Cell Reports.

CIRM has funded some of Dr. Gomperts earlier work in this area.

And there’s encouraging news for people trying to recover from a stroke. Results from ReNeuron’s Phase 2 clinical trial show the therapy appears to help people who have experienced some level of disability following a stroke.

ReNeuron says its CTX therapy – made from neural stem cells – was given to 23 people who had moderate to severe disability resulting from an ischemic stroke. The patients were, on average, seven months post stroke.

In the study, published in the Journal of Neurology, Neurosurgery & Psychiatry, researchers used the Modified Rankin Scale (mRS), a measure of disability and dependence to assess the impact of the therapy. The biggest improvements were seen in a group of 14 patients who had limited movement of one arm.

  • 38.5% experienced at least a one-point improvement on mRS six months after being treated.
  • 50% experienced a one-point improvement 12 months after being treated.

If that doesn’t seem like a big improvement, then consider this. Moving from an mRS 3 to 2 means that a person with a stroke regains their ability to live independently.

The therapy is now being tested in a larger patient group in the PISCES III clinical trial.

Breakthrough image could lead to better therapies

Image of a blood stem cell in its natural environment: Photo courtesy UC Merced

When it comes to using stem cells for therapy you don’t just need to understand what kinds of cell to use, you also need to understand the environment that is best for them. Trying to get stem cells to grow in the wrong environment would be like trying to breed sheep in a pond. It won’t end well.

But for years scientists struggled to understand how to create the right environment, or niche, for these cells. The niche provides a very specific micro-environment for stem cells, protecting them and enabling them to self-renew over long periods of time, helping repair damaged tissues and organs in the body.

But different stem cells need different niches, and those involve both physical and chemical properties, and getting that mixture right has been challenging. That in turn has slowed down our ability to use those cells to develop new therapies.

UC Merced’s Joel Spencer in the lab: Photo courtesy UC Merced

Now UC Merced’s Professor Joel Spencer and his team have developed a way of capturing an image of hematopoietic or blood stem cells (HSCs), inside their niche in the bone marrow. In an article on UC Merced News, he says this could be a big step forward.

“Everyone knew black holes existed, but it took until last year to directly capture an image of one due to the complexity of their environment. It’s analogous with stem cells in the bone marrow. Until now, our understanding of HSCs has been limited by the inability to directly visualize them in their native environment.

“This work brings an advancement that will open doors to understanding how these cells work which may lead to better therapeutics for hematologic disorders including cancer.”

In the past, studying HSCs involved transplanting them into a mouse or other animal that had undergone radiation to kill off its own bone marrow cells. It enabled researchers to track the HSCs but clearly the new environment was very different than the original, natural one. So, Spencer and his team developed new microscopes and imaging techniques to study cells and tissues in their natural environment.  

In the study, published in the journal Nature, Spencer says all this is only possible because of recent technological breakthroughs.

“My lab is seeking to answer biological questions that were impossible until the advancements in technology we have seen in the past couple decades. You need to be able to peer inside an organ, inside a live animal and see what’s happening as it happens.”

Being able to see how these cells behave in their natural environment may help researchers learn how to recreate that environment in the lab, and help them develop new and more effective ways of using those cells to repair damaged tissues and organs.

CIRM supported study finds that a gene associated with autism influences brain stem cells

Dr. Bennett Novitch, UCLA Broad Stem Cell Research Center
Image Credit: UCLA Broad Stem Cell Research Center

In a previous blog post, we discussed new findings in a CIRM supported study at the Salk Institute for Autism Spectrum Disorder (ASD), a developmental disorder that comes in broad ranges and primarily affects communication and behavior.

This week, a new study, also supported by CIRM, finds that a gene associated with ASD, intellectual disability, and language impairment can affect brain stem cells, which in turn, influence early brain development. Dr. Bennett Novitch and his team at UCLA evaluated a gene, called Foxp1, which has been previously studied for its function in the neurons in the developing brain.

Image showing brain cells with lower levels of Foxp1 function (left) and higher levels (right). neural stem cells are stained in green; secondary progenitors and neurons in red.
Image Credit: UCLA Broad Stem Cell Research Center

In this study, Dr. Novitch and his team looked at Foxp1 levels in the brains of developing mouse embryos. What they discovered is that, in normal developing mice the gene was active much earlier than previous studies had indicated. It turns out that the gene was active during the period when neural stem cells are just beginning to expand in numbers and generate a subset of brain cells found deep within the developing brain.

When mice lacked the gene entirely, there were fewer neural stem cells at early stages of brain development, as well as fewer brain cells deep within the developing brain. Alternatively, when the levels of the gene were above normal, the researchers found significantly more neural stem cells and brain cells deep within the developing brain. Additionally, higher levels of the neural stem cells were observed in mice with high levels of the gene even after they were born.

In a press release from UCLA, Dr. Novitch explains how the different levels of the gene can be tied to the variation of Foxp1 levels seen in ASD patients.

“What we saw was that both too much and too little Foxp1 affects the ability of neural stem cells to replicate and form certain neurons in a specific sequence in mice. And this fits with the structural and behavioral abnormalities that have been seen in human patients.”

The full study was published in Cell Reports.

CIRM funded study links rapid brain growth in autism to DNA damage

Meiyan Wang and Dr. Rusty Gage at the Salk Institute.
Image Credit: Salk Institute

Autism spectrum disorder (ASD), is a developmental disorder that comes in broad ranges and primarily affects communication and behavior. Many people with ASD also have macrocephaly, or unusually large heads. Unfortunately, understanding the underlying causes of this disorder and development of potential treatments has been slow.

However, Dr. Rusty Gage and his team at the Salk Institute in San Diego have discovered a unique pattern of DNA damage in brain cells derived from individuals with macrocephalic (larger than normal head) ASD.

In a previous study, Dr. Gage and his team discovered that brain stem cells in people with macrocephalic ASD grew more quickly compared to normal individuals. Brain stem cells have the ability to turn into various kind of cell types in the brain such as neurons. This finding led them to the possibly that the rapid growth of brain stem cells in people with macrocephalic ASD could lead to larger than normal brains.

In the current study, they continue their work by looking more closely at neural precursor cells (NPC), a certain type of brain stem cell. The researchers collected skin cells from individuals with marcocephalic ASD and normal individuals and used stem-cell reprogramming to turn these cells back into NPCs.

Cells that will eventually become neurons (brain stem cells) derived from individuals with autism spectrum disorder, shown in the right panel, exhibit increased DNA damage (shown in the red stain), compared to those derived from healthy individuals (left panel).
Image Credit: Salk Institute

As NPCs replicate and mature, it is normal for their DNA to accumulate small errors, most of which are corrected and never do any harm. But the researchers discovered that the NPCs they derived from macrocephalic ASD individuals acquired significantly higher levels of DNA damage compared to those derived from normal individuals. Furthermore, they found that the DNA damage was clustered around various genes that have been linked to ASD in separate studies.

In a news release, Dr. Gage commented on the impact of DNA damage during the cell replication process.

“Division, or replication, is one of the most dangerous things that a cell can do. Most DNA damage is repaired through a remarkably efficient repair process, but errors occur when the rate of division is altered genetically or environmentally, which can lead to long term functional defects.”

In the same news release, graduate student Meiyan Wang and first author of this study elaborates on these results and the future direction of this work.

“What the new results are telling us is that cells from people with macrocephalic autism not only proliferate more but naturally experience more replication stress. We’d like to look deeper at how replication stress and DNA damage affects neuronal function in the long term and whether adult neurons arising from these stem cells have more mutations than usual.”

The full results of this study were published in Cell Stem Cell.

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.”

Enabling the Best Choice for Patients: The Need for Effective Patient Navigation

Making sure patients get the treatment they need and not a “snake oil” substitute

We are at a turning point in regenerative medicine as the first wave of treatments have obtained FDA approval. But at the same time as we see the advance of scientifically rigorous research and regulated products we are also witnessing the continued proliferation of “unproven treatments.” This dueling environment can be overwhelming and distracting to individuals and families trying to manage life-threatening diseases.

How does a patient navigate this environment and get trusted and reliable information to help sort through their options?

CIRM teamed up with the CURA Foundation to organize a roundtable discussion intended to answer this question. The conversation included thought leaders involved in patient advocacy, therapy research and development, public policy and research funding. The roundtable was divided into three segments designed to discuss:

  1. Examples of state-of-the-art patient navigation systems,
  2. Policy, research and infrastructure needs required to expand navigation systems, and
  3. Communication needs for engaging patients and the broader community.

Examples of Navigation Systems:

This session was framed around the observation that patients often do not get the best medicines or treatments available for their condition. For example, in the area of cancer care there is evidence that the top 25% of cancers are not being treated optimally. Historic barriers to optimal treatment include cost pressures that may block access to treatments, lack of knowledge about the available treatments or the absence of experts in the location where the patient is being treated.  Much of the session focused on how these barriers are being overcome by partnerships between health care provides, employers and patients.

For example, new technologies such as DNA sequencing and other cell-based markers enable better diagnosis of a patient’s underlying disease. This information can be collected by a community hospital and shared with experts who work with the treating doctor to consider the best options for the patient. If patients need to access a specialty center for treatment, there are new models for the delivery of such care. Emphasis is placed on building a relationship with the patient and their family by surrounding them with a team that can address any questions that arise. The model of patient-centered care is being embraced by employers who are purchasing suites of services for their employees.

Patient advocacy groups have also supported efforts to get the best information about the patients’ underlying disease. Advocacy organizations have been building tools to connect patients with researchers with the aim of allowing secure and responsible sharing of medical information to drive the patient-centered development of new treatments. In a related initiative, the American Society of Hematology is creating a data hub for clinical trials for sickle cell disease. Collectively, these efforts are designed to accelerate new treatments by allowing critical data to be shared among researchers.

Essential Policy Infrastructure for Regenerative Medicine:

Session two dovetailed nicely with first discussion. There was continued emphasis on the need for additional evidence (data) to demonstrate that regenerative medicine treatments are having a significant effect on the patient’s disease. Various speakers echoed the need for patients in clinical trials to work with researchers to determine the benefits of treatments. Success stories with gene therapies in blood diseases were cited as proof of concept where treatments being evaluated in clinical trials are demonstrating a significant and sustained impact on diseases. Evidence of benefit is needed by both regulatory bodies that approve the treatments, such as the FDA, and by public and private payers / insurers that pay for treatments and patients that need to know the best option for their particular disease.

In addition, various speakers cited the continued proliferation of “unproven treatments” being marketed by for-profit centers. There was broad concern that the promotion of treatment where there is no evidence of effectiveness will mislead some patients and potentially harm the scientifically rigorous development of new treatments. Particularly for “stem cell” treatments, there was a desire to develop evaluation criteria that are clear and transparent to allow legitimate treatments to be distinguished from those with no evidence of effectiveness. One participant suggested there be a scorecard approach where specific treatments could be rated against specific indicators of safety, medical benefit and value in relation to alternative treatments. The idea would be to make this information widely available to patients, medical providers and the public to inform everything from medical decision making to advertising.

Communicating the Vision

The final session considered communication needs for the field of regenerative medicine. Patients and patient advocacy organizations described how they are using social media and other networking tools to share information and experiences in navigating their treatment options. Patient advocacy groups also described the challenges from providers of unproven treatments. In one case, a for profit “pop up” clinic had used the group’s videos in an attempt to legitimize their unproven treatment.

There was general consensus among the panelists that the field of regenerative medicine needs “trusted intermediaries” who can evaluate claims and help patients distinguish between high quality research and “snake oil”. These intermediaries should have the capacity to compile the most reliable evidence and utilize it to determine what options are available to patients. In addition, there needs to be shared decision making model where patients have the opportunity to explore options in an unbiased environment so they may make the best decision based on their specific needs and values.

Creating this kind of Navigation System will not be easy but the alternative is unacceptable. Too many vulnerable patients are being taken advantage of by the growing number of “predatory clinics” hawking expensive therapies that are both unproven and unapproved. We owe it to these patients to create a simple way for them to identify what are the most promising therapies, ones that have the highest chance of being both safe and effective. The roundtable discussion marked a starting point, bringing together many of the key players in the field, highlighting the key issues and beginning to identify possible solutions.

‘A Tornado at the Front Door, a Tsunami at the Back Door’

CIRM funds a lot of research and all of it has life-saving potential. But every once in a while you come across a story about someone benefiting from CIRM-supported research that highlights why the work we do is so important. This story is about a brilliant researcher at UC San Diego developing a treatment for a really rare disease, one that was unlikely to get funding from a big pharmaceutical company because it offered little chance for a return on its investment. At CIRM we don’t have to worry about things like that. Stories like this are our return on investment.

Our thanks to our colleagues at UCSD News for allowing us to run this piece in full.

Jordan Janz and Dr. Stephanie Cherqui in her lab at the UC San Diego School of Medicine: Photo courtesy UC San Diego

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By Heather Buschman, PhD

Born with a rare disease called cystinosis, 20-year-old Jordan Janz arrived at a crossroads: continue life as-is, toward a future most likely leading to kidney failure and an early death or become the first patient in the world to undergo a new gene-and-stem cell therapy developed over more than a decade by UC San Diego School of Medicine researchers

For the majority of Jordan Janz’s 20 years of life, most neighbors in his tiny Canadian town never knew he was sick. Janz snowboarded, hunted and fished. He hung with friends, often playing ice hockey video games. He worked in shipping and receiving for a company that makes oil pumps.

But there were times when Janz was younger that he vomited up to 13 times each day. He received a growth hormone injection every day for six years. He needed to swallow 56 pills every day just to manage his symptoms. And the medication required around-the-clock administration, which meant his mother or another family member had to get up with him every night.

“I was tired for school every day,” Janz said. “I was held back in second grade because I missed so much school. And because the medication had a bad odor to it, when I did go to school kids would ask, ‘What’s that smell?’ It was hard.”

Janz was born with cystinosis, a rare metabolic disorder that’s detected in approximately one in 100,000 live births worldwide. People with cystinosis inherit a mutation in the gene that encodes a protein called cystinosin. Cystinosin normally helps cells transport the amino acid cystine. Because cells in people with cystinosis don’t produce the cystinosin protein, cystine accumulates. Over the years, cystine crystals build up and begin to damage tissues and organs, from the kidneys and liver to muscles, eyes and brain. Numerous symptoms and adverse consequences result.

These days, Janz manages his condition. There’s a time-release version of the symptom-relieving medication now that allows him to go 12 hours between doses, allowing for a good night’s sleep. But there’s no stopping the relentless accumulation of cystine crystals, no cure for cystinosis.  

In October 2019, Janz became the first patient to receive treatment as part of a Phase I/II clinical trial to test the safety and efficacy of a unique gene therapy approach to treating cystinosis. The treatment was developed over more than a decade of research by Stephanie Cherqui, PhD, associate professor of pediatrics, and her team at University of California San Diego School of Medicine.

“The day they started looking for people for the trial, my mom picked up the phone, found a number for Dr. Cherqui, called her and put my name in as a candidate,” Janz said.

Janz’s mom, Barb Kulyk, has long followed Cherqui’s work. Like many parents of children with cystinosis, Kulyk has attended conferences, read up on research and met many other families, doctors and scientists working on the condition. Kulyk says she trusts Cherqui completely. But she was understandably nervous for her son to be the first person ever to undergo a completely new therapy.

“It’s like giving birth,” she said shortly before Janz received his gene therapy. “You’re really looking forward to the outcome, but dreading the process.”

The treatment

Cherqui’s gene therapy approach involves genetical modifying the patient’s own stem cells. To do this, her team obtained hematopoietic stem cells from Janz’s bone marrow. These stem cells are the precursors to all blood cells, including both red blood cells and immune cells. The scientists then re-engineered Janz’s stem cells in a lab using gene therapy techniques to introduce a normal version of the cystinosin gene. Lastly, they reinfused Janz with his own now-cystinosin-producing cells. The approach is akin to a bone marrow transplant — the patient is both donor and recipient.

“A bone marrow transplant can be very risky, especially when you take hematopoietic stem cells from a another person. In that case, there’s always the chance the donor’s immune cells will attack the recipient’s organs, so-called graft-versus-host disease,” Cherqui explained. “It’s a great advantage to use the patient’s own stem cells.”

As is the case for other bone marrow transplants, Janz’s gene-modified stem cells are expected to embed themselves in his bone marrow, where they should divide and differentiate to all types of blood cells. Those cells are then expected to circulate throughout his body and embed in his tissues and organs, where they should produce the normal cystinosin protein. Based on Cherqui’s preclinical data, she expects the cystinosin protein will be transferred to the surrounding diseased cells. At that point, Janz’s cells should finally be able to appropriately transport cystine for disposal — potentially alleviating his symptoms.

Before receiving his modified stem cells, Janz had to undergo chemotherapy to make space in his bone marrow for the new cells. Not unexpectedly, Janz experienced a handful of temporary chemotherapy-associated side-effects, including immune suppression, hair loss and fatigue. He also had mucositis, an inflammation of mucous membranes lining the digestive tract, which meant he couldn’t talk or eat much for a few days.

Now, only three months after his transfusion of engineered stem cells, Cherqui reports that Janz is making a good recovery, though it’s still too early to see a decrease in his cystinosis-related symptoms.

“I’ve been sleeping at least 10 hours a day for the last few weeks,” Janz said. “It’s crazy, but I know my body is just working hard to, I guess, create a new ‘me.’ So it’s no wonder I’m tired. But I’m feeling okay overall.

“One of the hardest parts for me is being inactive for so long. I’m not used to doing nothing all day. But I’m taking an online course while I wait for my immune system to rebuild. And I’m getting pretty good at video games.”

Like all Phase I/II clinical trials, the current study is designed to first test the safety and tolerability of the new treatment. Janz knows the treatment might not necessarily help him.

“When we started this trial, my mom explained it like this: ‘We have a tornado at the front door and a tsunami at the back door, and we have to pick one to go through. Neither will be any fun and we don’t know what’s going to happen, but you have to believe you will make it and go.

“So we weighed the pros and cons and, basically, if I don’t do this trial now, when I’m older I might not be healthy and strong enough for it. So I decided to go for it because, even if there are consequences from the chemotherapy, if it works I could live 20 years longer than I’m supposed to and be healthy for the rest of my life. That’s worth it.”

Besides the possible benefit to himself, Janz also sees his participation in the clinical trial as a way to contribute to the tight-knit community of families with children who have cystinosis.

“I’m willing to do if it helps the kids,” he said. “Somebody has to do it. I don’t have the money to donate to scientific conferences and stuff like that, but I can do this trial.”

The trial

If the treatment continues to meet certain criteria for safety and efficacy for Janz and one other participant after three months, two more adult participants will be enrolled. Three months after that, if the treatment continues to be safe and effective, the trial might enroll two adolescent participants. To participate in the clinical trial, individuals must meet specific eligibility requirements.

Later in the trial, Cherqui and team will begin measuring how well the treatment actually works. The specific objectives include assessing the degree to which gene-modified stem cells establish themselves in  bone marrow, how they affect cystine levels and cystine crystal counts in blood and tissues.

“This trial is the first to use gene-modified hematopoietic stem cell gene therapy to treat a multi-organ degenerative disorder for which the protein is anchored in the membrane of the lysosomes, as opposed to secreted enzymes,” Cherqui said. “We were amazed when we tested this approach in the mouse model of cystinosis — autologous stem cell transplantation reversed the disease. The tissues remained healthy, even the kidneys and the eyes.”

Trial participants are closely monitored for the first 100 days after treatment, then tested again at six, nine, 12, 18 and 24 months post-gene therapy for a variety of factors, including vital signs, cystine levels in a number of organs, kidney function, hormone function and physical well-being.

“If successful in clinical trials, this approach could provide a one-time, lifelong therapy that may prevent the need for kidney transplantation and long-term complications caused by cystine buildup,” Cherqui said.

The future

For the trial participants, all of the pre-treatment tests, the treatment itself, and monitoring afterward means a lot of travel to and long stays in San Diego.

It’s tough on Kulyk and Janz. They have to fly in from Alberta, Canada and stay in a San Diego hotel for weeks at a time. Kulyk has two older adult children, as well as a 12-year-old and a seven-year-old at home. 

“I’ve missed a lot of things with my other kids, but none of them seem to hold any grudges,” she said. “They seem to be totally fine and accepting. They’re like, ‘We’re fine, mom. You go and take care of Jordan.’”

Janz is looking forward to getting back home to his friends, his dog and his job, which provided him with paid leave while he received treatment and recovers.

For Cherqui, the search for a cystinosis cure is more than just a scientific exercise. Cherqui began working on cystinosis as a graduate student more than 20 years ago. At the time, she said, it was simply a model in which to study genetics and gene therapy.

“When you read about cystinosis, it’s just words. You don’t put a face to it. But after I met all the families, met the kids, and now that I’ve seen many of them grow up, and some of them die of the disease — now it’s a personal fight, and they are my family too.”

Patients with cystinosis typically experience kidney failure in their 20s, requiring kidney dialysis or transplantation for survival. For those born with cystinosis who make it into adulthood, the average lifespan is approximately 28 years old.

“I’m optimistic about this trial because it’s something we’ve worked so hard for and now it’s actually happening, and these families have so much hope for a better treatment,” Cherqui said. “After all the years of painstaking laboratory research, we now need to move into the clinic. If this works, it will be wonderful. If it doesn’t, we will all be disappointed but a least we’ll be able to say we tried.”

Nancy Stack, who founded the Cystinosis Research Foundation after her own daughter, Natalie, was diagnosed with the disease, calls Cherqui “the rock star of our community.”

“She cares deeply about the patients and is always available to talk, to explain her work and to give us hope,” Stack said. “She said years ago that she would never give up until she found the cure — and now we are closer to a cure than ever before.” (Read more about Natalie here.)

In addition to cystinosis, Cherqui says this type of gene therapy approach could also lead to treatment advancements for other multi-organ degenerative disorders, such as Friedreich’s ataxia and Danon disease, as well as other kidney, genetic and systemic diseases similar to cystinosis.

While they wait for the long-term results of the treatment, Kulyk is cautiously hopeful.

“Moms are used to being able to fix everything for their children — kiss boo-boos make them better, make cupcakes for school, whip up Halloween costumes out of scraps, pull a coveted toy out of thin air when it has been sold out for months.

“But we have not been able to fix this, to take it away. I not only want this disease gone for my child, I want cystinosis to be nothing more than a memory for all the children and adults living with it. I know that even if and when Jordan is cured, there will still be so much work to do, in terms of regulatory approvals and insurance coverage.

“Having hope for your child’s disease to be cured is a slippery slope. We have all been there, held hope in our hands and had to let go. But, I find myself in a familiar place, holding onto hope again and this time I am not letting go.”

Video of Dr. Cherqui and Jordan Janz talking about the therapy

For more information about the Phase I/II clinical trial for cystinosis and to learn how to enroll, call 1-844-317-7836 or email alphastemcellclinic@ucsd.edu.

Cherqui’s research has been funded by the Cystinosis Research Foundation, California Institute for Regenerative Medicine (CIRM), and National Institutes of Health. She receives additional support from the Sanford Stem Cell Clinical Center and CIRM-funded Alpha Stem Cell Clinic at UC San Diego Health, and AVROBIO.

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.

Stem Cell/Gene Therapy combo heals patients battling rare disorder

Brenden Whittaker and his dog: Photo by Colin McGuire

A few years ago, Brenden Whittaker was running out of time. Brenden was born with a rare condition called x-linked chronic granulomatous disease or XCGD. It meant he lacked a critical part of his immune system that protects against bacterial or fungal infections.

Over 22 years Brenden was in and out of the hospital hundreds of times. Twice he almost died. When antibiotics failed to clear up persistent infections surgeons had to remove parts of his lungs and liver.

Brenden felt he was running out of options. Then he signed up for a clinical trial (funded by CIRM) that would use his own stem cells to correct the problem. More than four years later Brenden is doing just fine.

And he’s not the only one. A new study, published in the journal Nature Medicine, shows that six other patients in the clinical trial are now in remission and have stopped taking any other medications.

Dr. Don Kohn: Photo courtesy UCLA

Don Kohn, the lead researcher on the team from UCLA’s Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, says that in the past the only “cure” for people with CGD was a bone marrow transplant, but that was rarely an option for most patients. In a news release he said finding a perfect match for a transplant was difficult, and even then, patients had to take powerful anti-rejection medications to stop their body rejecting the transplant. So, they developed another approach, using genetically re-engineered stem cells from the patient themselves.

“With this gene therapy, you can use a patient’s own stem cells instead of donor cells for a transplant. This means the cells are perfectly matched to the patient and it should be a much safer transplant, without the risks of rejection.”

The team removed blood stem cells from the patients and, in the lab, corrected the genetic mutation that caused CGD. They then returned those cells to the patients which, because they are stem cells, multiplied and created a new blood supply – one free of CGD – and repaired the immune system.

Brenden was the first of five patients treated in the US. Another four were treated in Europe. All were between the ages of 2 and 27 (CGD patients often die in their 20’s because of the impact of repeated infections).

  • Two patients died because of previously incurred infections
  • Six of the seven surviving patients have discontinued previous treatments
  • Four new patients have since been treated and are currently free of infections

Dr. Kohn said the results are really encouraging: “None of the patients had complications that you might normally see from donor cells and the results were as good as you’d get from a donor transplant — or better.”

The next step is for the researchers to work with the US Food and Drug Administration to get permission to carry out a larger trial, with the eventual goal of getting approval to make it available to all patients who need it.  

Regular readers of our blog will remember that Don Kohn also pioneered a similar approach in treating, and curing, children battling another rare immune disorder, severe combined immunodeficiency or SCID. You can read about that here.

As for Brenden, he is now in college and has his sights set on medical school. In 2016 we profiled him in our Annual Report and ran a long interview with him on the blog where he talked about the joys of mowing the lawn and learning to live without a deadly disease stalking him.