Super charging killer cells to fight leukemia

Colorized scanning electron micrograph of a natural killer cell.
Photo credit: National Institute of Allergy and Infectious Diseases

Racing car drivers are forever tinkering with their cars, trying to streamline them and soup up their engines because while fast is good, faster is better. Researchers do the same things with potential anti-cancer therapies, tinkering with them to make them safer and more readily available to patients while also boosting their ability to fight cancer.

That’s what researchers at the University of California San Diego (UCSD), in a CIRM-funded study, have done. They’ve taken immune system cells – with the already impressive name of ‘natural killer’ (NK) cells – and made them even deadlier to cancers.

These natural killer (NK) cells are considered one of our immune system’s frontline weapons against outside threats to our health, things like viruses and cancer. But sometimes the cancers manage to evade the NKs and spread throughout the body or, in the case of leukemia, throughout the blood.

Lots of researchers are looking at ways of taking a patient’s own NK cells and, in the lab boosting their ability to fight these cancers. However, using a patient’s own cells is both time consuming and very, very expensive.

Dan Kaufman MD

Dr. Dan Kaufman and his team at UCSD decided it would be better to try and develop an off-the-shelf approach, a therapy that could be mass produced from a single batch of NK cells and made available to anyone in need.

Using the iPSC method (which turns tissues like skin or blood into embryonic stem cell-like cells, capable of becoming any other cell in the body) they created a line of NK cells. Then they removed a gene called CISH which slows down the activities of cytokines, acting as a kind of brake or restraint on the immune system.

In a news release, Dr. Kaufman says removing CISH had a dramatic effect, boosting the power of the NK cells.

“We found that CISH-deleted iPSC-derived NK cells were able to effectively cure mice that harbor human leukemia cells, whereas mice treated with the unmodified NK cells died from the leukemia.”

Dr. Kaufman says the next step is to try and develop this approach for testing in people, to see if it can help people whose disease is not responding to conventional therapies.

“Importantly, iPSCs provide a stable platform for gene modification and since NK cells can be used as allogeneic cells (cells that come from donors) that do not need to be matched to individual patients, we can create a line of appropriately modified iPSC-derived NK cells suitable for treating hundreds or thousands of patients as a standardized, ‘off-the-shelf’ therapy.”

The study is published in the journal Cell Stem Cell.

Blocking pancreatic cancer stem cells

John Cashman

Cancer stem cells are one of the main reasons why cancers are able to survive surgery, chemotherapy and radiation. They are able to hide from those therapies and, at a future date, emerge and spread the cancer in the body once again.

Jionglia Cheng, PhD.

Jionglia Cheng, PhD., the lead author of a new CIRM-funded study, says that’s one of the reasons why pancreatic cancer has proved so difficult to treat.

“Pancreatic cancer remains a major health problem in the United States and soon will be the second most common cause of mortality due to cancer. A majority of pancreatic cancer patients are often resistant to clinical therapies. Thus, it remains a challenge to develop an efficacious clinically useful pancreatic cancer therapy.”

Dr. Cheng, a researcher with ChemRegen Inc., teamed up with John Cashman at the Human BioMolecular Research Institute and identified a compound, that seems to be effective in blocking the cancer stem cells.

In earlier studies the compound, called PAWI-2, demonstrated effectiveness in blocking breast, prostate and colon cancer. When tested in the laboratory PAWI-2 showed it was able to kill pancreatic cancer stem cells, and also was effective in targeting drug-resistant pancreatic cancer stem cells.

In addition, when PAWI-2 was used with a drug called erlotinib (brand name Tarceva) which is commonly prescribed for pancreatic cancer, the combination proved more effective against the cancer stem cells than erlotinib alone.

In a news release Dr. Cheng said: “In the future, this molecule could be used alone or with other chemotherapy albeit at lower doses, as a new therapeutic drug to combat pancreatic cancer. This may lead to much less toxicity to the patient,”

The study is published in the journal Scientific Reports.

You can bank on CIRM

Way back in 2013, the CIRM Board invested $32 million in a project to create an iPSC Bank. The goal was simple;  to collect tissue samples from people who have different diseases, turn those samples into high quality stem cell lines – the kind known as induced pluripotent stem cells (iPSC) – and create a facility where those lines can be stored and distributed to researchers who need them.

Fast forward almost seven years and that idea has now become the largest public iPSC bank in the world. The story of how that happened is the subject of a great article (by CIRM’s Dr. Stephen Lin) in the journal Science Direct.

Dr. Stephen Lin

In 2013 there was a real need for the bank. Scientists around the world were doing important research but many were creating the cells they used for that research in different ways. That made it hard to compare one study to another and come up with any kind of consistent finding. The iPSC Bank was designed to change that by creating one source for high quality cells, collected, processed and stored under a single, consistent method.

Tissue samples – either blood or skin – were collected from thousands of individuals around California. Each donor underwent a thorough consent process – including being shown a detailed brochure – to explain what iPS cells are and how the research would be done.

The diseases to be studied through this bank include:

  • Age-Related Macular Degeneration (AMD)
  • Alzheimer’s disease
  • Autism Spectrum Disorder (ASD)
  • Cardiomyopathies (heart conditions)
  • Cerebral Palsy
  • Diabetic Retinopathy
  • Epilepsy
  • Fatty Liver diseases
  • Hepatitis C (HCV)
  • Intellectual Disabilities
  • Primary Open Angle Glaucoma
  • Pulmonary Fibrosis

The samples were screened to make sure they were safe – for example the blood was tested for HBV and HIV – and then underwent rigorous quality control testing to make sure they met the highest standards.

Once approved the samples were then turned into iPSCs at a special facility at the Buck Institute in Novato and those lines were then made available to researchers around the world, both for-profit and non-profit entities.

Scientists are now able to use these cells for a wide variety of uses including disease modeling, drug discovery, drug development, and transplant studies in animal research models. It gives them a greater ability to study how a disease develops and progresses and to help discover and test new drugs or other therapies

The Bank, which is now run by FUJIFILM Cellular Dynamics, has become a powerful resource for studying genetic variation between individuals, helping scientists understand how disease and treatment vary in a diverse population. Both CIRM and Fuji Film are committed to making even more improvements and additions to the collection in the future to ensure this is a vital resource for researchers for years to come.

CIRM-funded trial for blood cancer releases promising new data


A CIRM-funded trial conducted by Oncternal Therapeutics in collaboration with UC San Diego released an interim clinical data update for patients with mantle cell lymphoma (MCL), a type of blood cancer.

The treatment being developed involves an antibody called cirmtuzumab (named after yours truly) being used with a cancer fighting drug called ibrutinib. The antibody recognizes and attaches to a protein on the surface of cancer stem cells. This attachment disables the protein, which slows the growth of the blood cancer and makes it more vulnerable to anti-cancer drugs.

Here are the highlights from the new interim clinical data:

  • Patients had received a median of two prior therapies before participating in this study including chemotherapy; autologous stem cell transplant (SCT); autologous SCT and CAR-T therapy; autologous SCT and allogeneic SCT; and ibrutinib with rituximab, a different type of antibody therapy.
  • 6 of the 12 patients in the trial experienced a Complete Response (CR), which is defined as the disappearance of all signs of cancer in response to treatment.
  • All six CRs are ongoing, including one patient who has remained in CR for more than 21 months past treatment.
  • Four of the six patients achieved CRs within four months on the combination of cirmtuzumab and ibrutinib.
  • Of the remaining 6 patients, 4 experienced a Partial Response (PR), which is defined as a decrease in the extent of the cancer in the body.
  • The remaining two patients experienced Stable Disease (SD), which is defined as neither an increase or decrease in the extent of the cancer.

The full interim clinical data update can be viewed in the press release here.

New CAR-T cell therapy using scorpion venom developed to treat brain tumors

Contributed by Wikimedia Commons (Public Domain)

Glioblastoma (GBM) is an aggressive form of cancer that begins in the brain and results in tumors that can be very difficult to treat. This condition has claimed the lives of Beau Biden, former Vice President Joe Biden’s son, and John McCain, former Senator of Arizona. However, a new approach to combat this condition is being developed at City of Hope and has just received approval from the FDA to conduct clinical trials. The innovative approach involves using a combination of chimeric antigen receptor (CAR)-T cell therapy and specific components of scorpion venom!

Before we dive into how the scorpion venom is being used, what exactly is CAR-T cell therapy?

Diagram of CAR-T Cell Therapy
Image Source: National Cancer Institute

This approach consists of using T cells, which are an immune system cell that can destroy foreign or abnormal cells, and modifying them with a protein called a chimeric antigen receptor (CAR). These newly designed CAR-T cells are able to identify and destroy cancer cells by detecting a specific protein on these cells. What makes CAR-T cell even more promising is that the specific protein detected can be set to virtually anything.

This is where the scorpion venom comes into play. One of the components of this venom is called chlorotoxin (CLTX), which has the ability to specifically bind to brain tumor cells.

Michael Barish, Ph.D. (Left), Christine Brown, Ph.D. (Center), Dongrui Wang (Right)
Photo Credit: Business Wire

For this study, Dr. Christine Brown, Dr. Michael Barish, and a team of researchers at City of Hope designed CAR-T cells using chlorotoxin in order to specifically detect and destory brain tumor cells. Now referred to as CLTX-CAR-T cells, they found that these newly engineered cells were highly effective at selectively killing brain tumor cells in animal models. What’s more remarkable is that the CLTX-CAR-T cells ignored non-tumor cells in the brain and other organs.

In a press release, Dr. Barish describes the CLTX-CAR-T cell approach in more detail.

“Much like a scorpion uses toxin components of its venom to target and kill its prey, we’re using chlorotoxin to direct the T cells to target the tumor cells with the added advantage that the CLTX-CAR T cells are mobile and actively surveilling the brain looking for appropriate target. We are not actually injecting a toxin, but exploiting CLTX’s binding properties in the design of the CAR. The idea was to develop a CAR that would target T cells to a wider variety of GBM tumor cells than the other antibody-based CARs.”

In the same press release, Dr. Brown talks about the promise of this newly developed therapy.

“Our chlorotoxin-incorporating CAR expands the populations of solid tumors potentially targeted by CAR T cell therapy, which is particularly needed for patients with cancers that are difficult to treat such as glioblastoma. This is a completely new targeting strategy for CAR T therapy with CARs incorporating a recognition structure different from other CARs.”

The first-in-human clinical trial using the CLTX-CAR T cells is now screening potential patients.

CIRM has funded a separate clinical trial conducted by Dr. Brown that also involves CAR-T cell therapy for brain tumors.

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

A video talking about this approach can also be found here.

Big time validation for early support

It’s not every day that a company and a concept that you helped support from the very beginning gets snapped up for $4.9 billion. But that’s what is happening with Forty Seven Inc. and their anti-cancer therapies. Gilead, another California company by the way, has announced it is buying Forty Seven Inc. for almost $5 billion.

The deal gives Gilead access to Forty Seven’s lead antibody therapy, magrolimab, which switches off CD47, a kind of “do not eat me” signal that cancer cells use to evade the immune system.

CIRM has supported this program from its very earliest stages, back in 2013, when it was a promising idea in need of funding. Last year we blogged about the progress it has made from a hopeful concept to an exciting therapy.

When Forty Seven Inc. went public in 2018, Dr. Irv Weissman, one of the founders of the company, attributed a lot of their success to CIRM’s support.

Dr. Irv Weissman

“The story of the funding of this work all of the way to its commercialization and the clinical trials reported in the New England Journal of Medicine is simply this: CIRM funding of a competitive grant took a mouse discovery of the CD47 ‘don’t eat me’ signal through all preclinical work to and through a phase 1 IND with the FDA. Our National Institutes of Health (NIH) did not fund any part of the clinical trial or preclinical run up to the trial, so it is fortunate for those patients and those that will follow, if the treatment continues its success in larger trials, that California voters took the state’s right action to fund research not funded by the federal government.”

Dr. Maria Millan, CIRM’s President & CEO, says the deal is a perfect example of CIRM’s value to the field of regenerative medicine and our ability to work with our grantees to make them as successful as possible.

“To say this is incredible would be an understatement! Words cannot describe how excited we are that this novel approach to battling currently untreatable malignancies has the prospect of making it to patients in need and this is a major step. Speaking on behalf of CIRM, we are very honored to have been a partner with Forty Seven Inc. from the very beginning.

CIRM Senior Science Officer, Dr. Ingrid Caras, was part of the team that helped a group of academic scientists take their work out of the lab and into the real world.

“I had the pleasure of working with and helping the Stanford team since CIRM provided the initial funding to translate the idea of developing CD47 blockade as a therapeutic approach. This was a team of superb scientists who we were fortunate to work closely with them to navigate the Regulatory environment and develop a therapeutic product. We were able to provide guidance as well as funding and assist in the ultimate success of this project.”

Forty Seven Inc. is far from the only example of this kind of support and collaboration. We have always seen ourselves as far more than just a funding agency. Money is important, absolutely. But so too is bringing the experience and expertise of our team to help academic scientists take a promising idea and turn it into a successful therapy.

After all that’s what our mission is, doing all we can to accelerate stem cell therapies to patients with unmet medical needs. And after a deal like this, Forty Seven Inc. is definitely accelerating its work.

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 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.”

Rave reviews for new Killer-T Cell study

Anytime you read a news headline that claims a new discovery “may treat all cancer” it’s time to put your skeptic’s hat on. After all, there have been so many over-hyped “discoveries” over the years that later flopped, that it would be natural to question the headline writer. And yet, this time, maybe, this one has some substance behind it.

Andrew Sewell with research fellow Garry Dolton. (Photo Credit: Cardiff University)

Researchers at the University of Cardiff in Wales have discovered a new kind of immune cell, a so-called “killer T-cell”, that appears to be able to target and kill many human cancer cells, such as those found in breast, prostate and lung cancer. At least in the lab.

The immune system is our body’s defense against all sorts of threats, from colds and flu to cancer. But many cancers are able to trick the immune system and evade detection as they spread throughout the body. The researchers found one T-cell receptor (TCR) that appears to be able to identify cancer cells and target them, but leave healthy tissues alone.

In an interview with the BBC, Prof. Andrew Sewell, the lead researcher on the study said: “There’s a chance here to treat every patient. Previously nobody believed this could be possible. It raises the prospect of a ‘one-size-fits-all’ cancer treatment, a single type of T-cell that could be capable of destroying many different types of cancers across the population.”

The study, published in the journal Nature Immunology, suggests the TCR works by using a molecule called MR1 to identify cancerous cells. MR1 is found on every cell in our body but in cancerous cells it appears to give off a different signal, which enables the TCR to identify it as a threat.

When the researchers injected this TCR into mice that had cancer it was able to clear away many of the cells. The researchers admit there is still a long way to go before they know if this approach will work in people, but Sewell says they are encouraged by their early results.

“There are plenty of hurdles to overcome. However, if this testing is successful, then I would hope this new treatment could be in use in patients in a few years’ time.”

CIRM is funding a number of clinical trials that use a similar approach to targeting cancers, taking the patient’s own immune T-cells and, in the lab, “re-educating” to be able to recognize the cancerous cells. Those cells are then returned to the patient where it’s hoped they’ll identify and destroy the cancer. You can read about those here , here, here, here, and here.

It’s official: the state of regenerative medicine is strong

A panel discussion to a packed house at the annual ARM State of the Industry briefing

Calling it a “year of dramatic impact for patients” Janet Lambert, the CEO of the Alliance for Regenerative Medicine (ARM), gave the annual “State of the Industry” briefing today in San Francisco.

The briefing is a traditional kick-off event to mark JP Morgan week in the City, a time when hotel rooms go for $1,000 a night and just reserving a table in the lobby for meetings can set you back hundreds of dollars. Fortunately, the ARM briefing is free. And worth every penny.

Janet Lambert, CEO Alliance for Regenerative Medicine

Lambert ran down the numbers that highlighted how the field is growing and expanding:

  • 987 companies world wide – most of those in the US
  • 1,000 + clinical trials
  • $9.8 billion in revenue/investments

Saying “for many of these patients these therapies don’t just bring improvements, they bring dramatic improvements” Lambert pointed out that when those 1,000 clinical trials are fully enrolled it will mean 60,000 patients getting stem cell and gene therapies. She says it’s estimated that in the coming years around half a million patients in the US alone will get one of those therapies.

More and more of the clinical trials are at advanced stages:

  • 100 Phase 3
  • 591 Phase 2
  • 381 Phase 1

The biggest sector for clinical trials is cancer, but there are also substantial numbers for central nervous system therapies, muscular skeletal and even rare diseases.

Lambert said there are two key issues facing the field in the coming year. One is improving the industry’s manufacturing capability to ensure we are able to produce the cells needed to treat large numbers of patients. As evidence she cited the fact that Pfizer and Novartis are investing hundreds of millions of dollars in in-house manufacturing facilities. 

The second key issue is reimbursement, so that companies can get paid for delivering those treatments to patients.  “There is appetite and interest in this from people around the world, but right now most conversations about reimbursement are taking place one at a time. We haven’t yet evolved to the point where we have standard models to help get products to market and help them be commercially successful.”

The forecast for the year ahead? “Sunny with some clouds. 2019 was a year of significant growth and we enter 2020 with hopes of continued expansion, as we look to grow the impact on patients.”