Tiny tools for the smallest of tasks, editing genes

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Developing new tools to edit genes

Having the right tools to do a job is important. Try using a large screwdriver to tighten the screws on your glasses and you quickly appreciate that it’s not just the type of tool that’s important, it’s also the size. The same theory applies to gene editing. And now researchers at Stanford have developed a tool that can take on even the tiniest of jobs.

The tool involves the use of CRISPR. You may well have heard about CRISPR. The magazine New Scientist described it this way: “CRISPR is a technology that can be used to edit genes and, as such, will likely change the world.” For example, CIRM is funding research using CRISPR to help children born with severe combined immunodeficiency, a rare, fatal immune disorder.  

There’s just one problem. Right now, CRISPR is usually twinned with a protein called Cas9. Together they are used to remove unwanted genes and insert a corrected copy of the bad gene. However, that CRISPR-Cas9 combination is often too big to fit into all our cells. That may seem hard to understand for folks like me with a limited science background, but trust the scientists, they aren’t making this stuff up.

To address that problem, Dr. Stanley Qi and his team at Stanford created an even smaller version, one they call CasMINI, to enable them to go where Cas9 can’t go. In an article on Fierce Biotech, Dr. Qi said this mini version has some big benefits: “If people sometimes think of Cas9 as molecular scissors, here we created a Swiss knife containing multiple functions. It is not a big one, but a miniature one that is highly portable for easy use.”

How much smaller is the miniature version compared to the standard Cas9? About half the size, 529 amino acids, compared to Cas9’s 1,368 amino acids.”

The team conclude their study in the journal Molecular Cell saying this could have widespread implications for the field: “This provides a new method to engineer compact and efficient CRISPR-Cas effectors that can be useful for broad genome engineering applications, including gene regulation, gene editing, base editing, epigenome editing, and chromatin imaging.”

Gene therapy is life-changing for children with a life-threatening brain disorder

If you have never heard of AADC deficiency count yourself lucky. It’s a rare, incurable condition that affects only around 135 children worldwide but it’s impact on those children and their families is devastating. The children can’t speak, can’t feed themselves or hold up their head, they have severe mood swings and often suffer from insomnia.

But Dr. Krystof Bankiewicz, a doctor and researcher at the University of California San Francisco (UCSF), is using techniques he developed treating Parkinson’s disease to help those children. Full disclosure here, CIRM is funding Dr. Bankiewicz’s Parkinson’s clinical trial.

In AADC deficiency the children lack a critical enzyme that helps the brain make serotonin and dopamine, so called “chemical messengers” that help the cells in the brain communicate with each other. In his AADC clinical trial Dr. Bankiewicz and his team created a tiny opening in the skull and then inserted a functional copy of the AADC gene into two regions of the brain thought to have most benefit – the substantia nigra and ventral tegmental area of the brainstem.

Image showing target areas for AADC gene insertion: Courtesy UCSF

When the clinical trial began none of the seven children were able to sit up on their own, only two had any ability to control their head movement and just one could grasp an object in their hands. Six of the seven were described as moody or irritable and six suffered from insomnia.

In a news release Dr. Bankiewicz says the impact of the gene therapy was quite impressive: “Remarkably, these episodes were the first to disappear and they never returned. In the months that followed, many patients experienced life-changing improvements. Not only did they begin laughing and have improved mood, but some were able to start speaking and even walking.”

Those weren’t the only improvements, at the end of one year:

  • All seven children had better control of their head and body.
  • Four of the children were able to sit up by themselves.
  • Three patients could grasp and hold objects.
  • Two were able to walk with some support.

Two and a half years after the surgery:

  • One child was able to walk without any support.
  • One child could speak with a vocabulary of 50 words.
  • One child could communicate using an assistive device.

The parents also reported big improvements in mood and ability to sleep.

UCSF posted some videos of the children before and after the surgery and you can see for yourself the big difference in the children. It’s not a cure, but for families that had nothing in the past, it is a true gift.

The study is published in the journal Nature Communications.

CIRM funded trial may pave way for gene therapy to treat different diseases

Image Description: Jordan Janz (left) and Dr. Stephanie Cherqui (right)

According to the  National Organization for Rare Disorders (NORD), a disease is consider rare if it affects fewer than 200,000 people. If you combine the over 7,000 known rare diseases, about 30 million people in the U.S. are affected by one of these conditions. A majority of these conditions have no cure or have very few treatment options, but a CIRM funded trial (approximately $12 million) for a rare pediatric disease has showed promising results in one patient using a gene therapy approach. The hope for the field as a whole is that this proof of concept might pave the way to use gene therapy to treat other diseases.

Cystinosis is a rare disease that primarily affects children and young adults, and leads to premature death, usually in early adulthood.  Patients inherit defective copies of a gene that results in abnormal accumulation of cystine (hence the name cystinosis) in all cells of the body.  This buildup of cystine can lead to multi-organ failure, with some of earliest and most pronounced effects on the kidneys, eyes, thyroid, muscle, and pancreas.  Many patients suffer end-stage kidney failure and severe vision defects in childhood, and as they get older, they are at increased risk for heart disease, diabetes, bone defects, and neuromuscular problems.  There is currently a drug treatment for cystinosis, but it only delays the progression of the disease, has severe side effects, and is expensive.

Dr. Stephane Cherqui at UC San Diego (UCSD), in partnership with AVROBIO, is conducting a clinical trial that uses a gene therapy approach to modify a patient’s own blood stem cells with a functional version of the defective gene. The corrected stem cells are then reintroduced into the patient with the hope that they will give rise to blood cells that will reduce cystine buildup in the body.  

22 year old Jordan Janz was born with cystinosis and was taking anywhere from 40 to 60 pills a day as part of his treatment. Unfortunately the medication affected his body odor, leaving him smelling like rotten eggs or stinky cheese. In 2019, Jordan was the first of three patients to participate in Dr. Cherqui’s trial and the results have been remarkable. Tests have shown that the cystine in his eyes, skin and muscle have greatly decreased. Instead of the 40-60 pills a day, he just takes vitamins and specific nutrients his body needs. What’s more is that he no longer has a problem with body odor caused by the pills he once had to take. Although it will take much more time know if Jordan was cured of the disease, he says that he feels “essentially cured”.

In an article from the Associated Press, Jordan is optimistic about his future.

“I have more of a life now. I’m going to school. I’m hoping to open up my own business one day.”

You can learn more about Jordan by watching the video below:

Although gene therapy approaches still need to be closely studied, they have enormous potential for treating patients. CIRM has funded other clinical trials that use gene therapy approaches for different genetic diseases including X-SCID, ADA-SCID, ART-SCID, X-CGD, and sickle cell disease.

Stem cell gene therapy for Fabry disease shows positive results in patients

Darren Bidulka rests after his modified blood stem cells were transplanted into him at the Foothills Medical Centre in Calgary in 2017, allowing him to stop his enzyme therapy. (From left): Dr. Jeffrey Medin, Medical College of Wisconsin, Dr. Aneal Khan, the experimental trial lead in Calgary, and Darren Bidulka. Image Credit: Darren Bidulka

Fabry disease is an X-linked genetic disorder that can damage major organs and shorten lifespan. Without a functional version of a gene called GLA, our bodies are unable to make the correct version of an enzyme that breaks down a fat, and that in turn can lead to problems in the kidneys, heart and brain. It is estimated that one person in 40,000 to 60,000 has the disease and it affects men more severely than women since men only have one copy of the X chromosome. Current treatment consists of enzyme therapy infusions every two weeks but there is currently no cure for Fabry disease. 

However, a Canadian research team is conducting the world’s first pilot study to treat Fabry disease using a stem cell gene therapy approach. The researchers collected the patient’s own blood stem cells and used gene therapy to insert copies of the fully functional gene into the stem cells, allowing them to make the correct version of the enzyme. The newly modified stem cells were then transplanted back into each patient.

Five men participated in this trial and the results so far have been very encouraging. After treatment with the stem cell gene therapy, all patients began producing the corrected version of the enzyme to near normal levels within one week. With these initial results, all five patients were allowed to stop their biweekly enzyme therapy infusions. So far, only three patients decided to do so and are stable.

In a news release, Darren Bidulka, the first patient to be treated in the study, talked about how life changing this stem cell gene therapy has been for him.

“I’m really happy that this worked. What an amazing result in an utterly fascinating experience. I consider this a great success. I can lead a more normal life now without scheduling enzyme therapy every two weeks. This research is also incredibly important for many patients all over the world, who will benefit from these findings.”

CIRM is no stranger to stem cell gene therapy and its potential having funded clinical trials in various areas such as severe combined immunodeficiency (bubble baby disease), cystinosis, sickle cell disease, and various others. The broad range of genetic diseases it has been used in to treat patients further highlights its importance in scientific research.

The full results of this study were published in Nature Communications.

First patient in CIRM funded X-CGD trial gives back by working in patient care

Brenden Whittaker

Brenden Whittaker was born with a rare genetic disorder called X-linked chronic granulomatous disease (X-CGD). This condition affects the immune system’s ability to fight off common germs, specifically bacteria and fungi, and can result in infections that would only be mild for healthy people. Unfortunately for Brenden, he has suffered life-threatening infections that have required him to be hospitalized hundreds of times throughout most of his childhood. At only 16 years old, he got a very bad case of pneumonia that resulted in having tissue from his right lung removed. By age 22, the treatments he had received to fight off infections had stopped working entirely.

His prognosis looked grim, but fortunately he was informed of a CIRM-funded clinical trial conducted by Dr. Don Kohn to treat his condition. He would go on to become the first participant in this trial, which involved taking his blood stem cells, using gene therapy to correct the X-CGD mutation, and reintroducing these modified cells back into his body. Following his treatment, blood tests confirmed that the treatment produced enough corrected cells for Brenden to now be protected from severe infection.

Before the CIRM-funded treatment, the chances of severe infection were virtually everywhere, something many of us might better understand given everything going on with COVID-19. But now with a new lease on life, Brenden is giving back to the very community that helped him in his time of need. He is currently working as a patient care associate at his local hospital in Ohio. Considered an essential worker, Brenden’s responsibilities include taking patients’ vital signs, helping them eat and get cleaned up, and going for walks around the unit with those who are able to do so. He also plans to attend nursing school in the future.

In a news release, Brenden talks about wanting to give back to those in similar situations as him and demonstrates true selflessness.

“My job entails doing anything I can to make a patient’s time in the hospital a little bit easier while at the same time helping the doctors and nurses monitor for any new health developments. From the nurses who sat with me holding my hand and telling me about their lives when I was up in the middle of the night with a fever, to the patient transporters who remembered my name and talked with me the whole way to surgery, to the doctors who wouldn’t give up until they found an option that worked for me, these people are the reason the hospital setting is the only place I want to work. If I can help even one person the way these people have helped me, I will be happy.”

In addition to Brenden, five additional patients who received the same treatment for X-CGD are also doing well. This same gene therapy approach for blood stem cells was used in another CIRM-funded trial for SCID, another kind of genetic immune disorder. The SCID trial resulted in over 50 babies being cured of the condition, including little Evie, who is featured on the cover of CIRM’s 18-month report.

CIRM supported study of gene silencer blocks ALS degeneration, saves motor function

Dr. Martin Marsala, UC San Diego

Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s disease, is a neurodegenerative disease that destroys the nerve cells in the brain and spinal cord. As a result of ALS, the motor neurons that enable bodily movement and muscle control are harmed, which can make it difficult to move, speak, eat, and breathe. This condition usually affects people from age 40 to 70, but individuals in their 20s and 30s have also been known to develop ALS. Unfortunately there is no cure for this condition.

However, a study supported by CIRM and conducted by Dr. Martin Marsala at UC San Diego is using a mouse model to look at an approach that uses a gene silencer to protect motor neurons before or shortly after ALS symptoms start to develop.

The gene silencer works by turning off a targeted gene and is delivered via injection. In the case of ALS, previous research suggests that mutations in a gene called SOD1 may cause motor neuronal cell death, resulting in ALS. For this study, Dr. Marsala and his team injected the gene silencer at two sites in the spinal cord in adult mice expressing an ALS-causing mutation of the SOD1 gene. The mice injected did not yet display symptoms of ALS or had only begun showing symptoms.

In mice not yet showing ALS symptoms, they displayed normal neurological function with no onset ALS symptoms after treatment. Additionally, near complete protection of motor neurons and other cells was observed. In mice that had just began showing ALS symptoms, the injection blocked further disease progression as well as further harm to remaining motor neurons. Both of these groups of mice lived without negative side effects for the duration of the study.

In a news release, Dr. Marsala talks about what these results mean for the study of ALS.

“At present, this therapeutic approach provides the most potent therapy ever demonstrated in mouse models of mutated SOD1 gene-linked ALS.”

The next steps for this research would be to conduct additional safety studies with a larger animal model in order to determine an optimal, safe dose for the treatment.

The full results of this study were published in Nature Medicine.

In addition to supporting this research for ALS, CIRM has funded two clinical trials in the field as well. One of these trials is being conducted by BrainStorm Cell Therapeutics and the other trial is being by Cedars-Sinai Medical Center.

One family’s fight to save their son’s life, and how stem cells made it possible

CIRM’s mission is very simple: to accelerate stem cell treatments to patients with unmet medical needs. Anne Klein’s son, Everett, was a poster boy for that statement. Born with a fatal immune disorder Everett faced a bleak future. But Anne and husband Brian were not about to give up. The following story is one Anne wrote for Parents magazine. It’s testament to the power of stem cells to save lives, but even more importantly to the power of love and the determination of a family to save their son.

My Son Was Born With ‘Bubble Boy’ Disease—But A Gene Therapy Trial Saved His Life

Everett Schmitt. Photo: Meg Kumin

I wish more than anything that my son Everett had not been born with severe combined immunodeficiency (SCID). But I know he is actually one of the lucky unlucky ones. By Anne Klein

As a child in the ’80s, I watched a news story about David Vetter. David was known as “the boy in the bubble” because he was born with severe combined immunodeficiency (SCID), a rare genetic disease that leaves babies with very little or no immune system. To protect him, David lived his entire life in a plastic bubble that kept him separated from a world filled with germs and illnesses that would have taken his life—likely before his first birthday.

I was struck by David’s story. It was heartbreaking and seemed so otherworldly. What would it be like to spend your childhood in an isolation chamber with family, doctors, reporters, and the world looking in on you? I found it devastating that an experimental bone marrow transplant didn’t end up saving his life; instead it led to fatal complications. His mother, Carol Ann Demaret, touched his bare hand for the first and last time when he was 12 years old.

I couldn’t have known that almost 30 years later, my own son, Everett, would be born with SCID too.

Everett’s SCID diagnosis

At birth, Everett was big, beautiful, and looked perfectly healthy. My husband Brian and I already had a 2-and-a-half-year-old son, Alden, so we were less anxious as parents when we brought Everett home. I didn’t run errands with Alden until he was at least a month old, but Everett was out and about with us within a few days of being born. After all, we thought we knew what to expect.

But two weeks after Everett’s birth, a doctor called to discuss Everett’s newborn screening test results. I listened in disbelief as he explained that Everett’s blood sample indicated he may have an immune deficiency.

“He may need a bone marrow transplant,” the doctor told me.

I was shocked. Everett’s checkup with his pediatrician just two days earlier went swimmingly. I hung up and held on to the doctor’s assurance that there was a 40 percent chance Everett’s test result was a false positive.

After five grueling days of waiting for additional test results and answers, I received the call: Everett had virtually no immune system. He needed to be quickly admitted to UCSF Benioff Children’s Hospital in California so they could keep him isolated and prepare to give him a stem cell transplant. UCSF diagnosed him specifically with SCID-X1, the same form David battled.

Beginning SCID treatment

The hospital was 90 miles and more than two hours away from home. Our family of four had to be split into two, with me staying in the hospital primarily with Everett and Brian and Alden remaining at home, except for short visits. The sudden upheaval left Alden confused, shaken, and sad. Brian and I quickly transformed into helicopter parents, neurotically focused on every imaginable contact with germs, even the mildest of which could be life-threatening to Everett.

When he was 7 weeks old, Everett received a stem cell transplant with me as his donor, but the transplant failed because my immune cells began attacking his body. Over his short life, Everett has also spent more than six months collectively in the hospital and more than three years in semi-isolation at home. He’s endured countless biopsies, ultrasounds, CT scans, infusions, blood draws, trips to the emergency department, and medical transports via ambulance or helicopter.

Gene therapy to treat SCID

At age 2, his liver almost failed and a case of pneumonia required breathing support with sedation. That’s when a doctor came into the pediatric intensive care unit and said, “When Everett gets through this, we need to do something else for him.” He recommended a gene therapy clinical trial at the National Institutes of Health (NIH) that was finally showing success in patients over age 2 whose transplants had failed. This was the first group of SCID-X1 patients to receive gene therapy using a lentiviral vector combined with a light dose of chemotherapy.

After the complications from our son’s initial stem cell transplant, Brian and I didn’t want to do another stem cell transplant using donor cells. My donor cells were at war with his body and cells from another donor could do the same. Also, the odds of Everett having a suitable donor on the bone marrow registry were extremely small since he didn’t have one as a newborn. At the NIH, he would receive a transplant with his own, perfectly matched, gene-corrected cells. They would be right at home.

Other treatment options would likely only partially restore his immunity and require him to receive infusions of donor antibodies for life, as was the case with his first transplant. Prior gene therapy trials produced similarly incomplete results and several participants developed leukemia. The NIH trial was the first one showing promise in fully restoring immunity, without a risk of cancer. Brian and I felt it was Everett’s best option. Without hesitation, we flew across the country for his treatment. Everett received the gene therapy in September 2016 when he was 3, becoming the youngest patient NIH’s clinical trial has treated.

Everett’s recovery

It’s been more than two years since Everett received gene therapy and now more than ever, he has the best hope of developing a fully functioning immune system. He just received his first vaccine to test his ability to mount a response. Now 6 years old, he’s completed kindergarten and has been to Disney World. He plays in the dirt and loves shows and movies from the ’80s (maybe some of the same ones David enjoyed).

Everett knows he has been through a lot and that his doctors “fixed his DNA,” but he’s focused largely on other things. He’s vocal when confronted with medical pain or trauma, but seems to block out the experiences shortly afterwards. It’s sad for Brian and me that Everett developed these coping skills at such a young age, but we’re so grateful he is otherwise expressive and enjoys engaging with others. Once in the middle of the night, he woke us up as he stood in the hallway, exclaiming, “I’m going back to bed, but I just want you to know that I love you with all my heart!”

I wish more than anything that Everett had not been born with such a terrible disease and I could erase all the trauma, isolation, and pain. But I know that he is actually one of the lucky unlucky ones. Everett is fortunate his disease was caught early by SCID newborn screening, which became available in California not long before his birth. Without this test, we would not have known he had SCID until he became dangerously ill. His prognosis would have been much worse, even under the care of his truly brilliant and remarkable doctors, some of whom cared for David decades earlier.

Carol-Ann-mother-of-David-Vetter-meeting-Everett-Schmitt
Everett Schmitt meeting David Vetter’s mom Carol Ann Demaret. Photo – Brian Schmitt

When Everett was 4, soon after the gene therapy gave him the immunity he desperately needed, our family was fortunate enough to cross paths with David’s mom, Carol Ann, at an Immune Deficiency Foundation event. Throughout my life, I had seen her in pictures and on television with David. In person, she was warm, gracious, and humble. When I introduced her to Everett and explained that he had SCID just like David, she looked at Everett with loving eyes and asked if she could touch him. As she touched Everett’s shoulder and they locked eyes, Brian and I looked on with profound gratitude.

Anne Klein is a parent, scientist, and a patient advocate for two gene therapy trials funded by the California Institute for Regenerative Medicine. She is passionate about helping parents of children with SCID navigate treatment options for their child.

You can read about the clinical trials we are funding for SCID here, here, here and here.

CIRM-funded therapy helps “bubble babies” lead a normal life

Ja’Ceon Golden; ‘cured” of SCID

At CIRM we are very cautious about using the “c” word. Saying someone has been “cured” is a powerful statement but one that loses its meaning when over used or used inappropriately. However, in the case of a new study from U.C. San Francisco and St. Jude Children’s Research Hospital in Memphis, saying “cure” is not just accurate, it’s a celebration of something that would have seemed impossible just a few years ago.

The research focuses on children with a specific form of Severe Combined Immunodeficiency (SCID) called X-Linked SCID. It’s also known as “bubble baby” disease because children born with this condition lack a functioning immune system, so even a simple infection could be fatal and in the past they were kept inside sterile plastic bubbles to protect them.

In this study, published in the New England Journal of Medicine, researchers took blood stem cells from the child and, in the lab, genetically re-engineered them to correct the defective gene, and then infused them back into the child. Over time they multiplied and created a new blood supply, one free of the defect, which helped repair the immune system.

In a news release Dr. Ewelina Mamcarz, the lead author of the study, announced that ten children have been treated with this method.

“These patients are toddlers now, who are responding to vaccinations and have immune systems to make all immune cells they need for protection from infections as they explore the world and live normal lives. This is a first for patients with SCID-X1.”

The ten children were treated at both St. Jude and at UCSF and CIRM funded the UCSF arm of the clinical trial.

The story, not surprisingly, got a lot of attention in the media including this fine piece by CNN.

Oh, and by the way we are also funding three other clinical trials targeting different forms of SCID. One with UCLA’s Don Kohn,  one with Stanford’s Judy Shizuru, and one with UCSF’s Mort Cowan

Gene therapy gives patient a cure and a new lease on life

Brenden Whittaker (left), of Ohio, is a patient born with a rare genetic immune disease who was treated at the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center in a CIRM funded gene therapy trial. Dr. David Williams (on right) is Brenden’s treating physician.
Photo courtesy of Rose Lincoln – Harvard Staff Photographer

Pursuing an education can be quite the challenge in itself without the added pressure of external factors. For Brenden Whittaker, a 25 year old from Ohio, the constant trips to the hospital and debilitating nature of an inherited genetic disease made this goal particularly challenging and, for most of his life, out of sight.

Brenden was born with chronic granulomatous disease (CGD), a rare genetic disorder that affects the proper function of neutrophils, a type of white blood cell that is an essential part of the body’s immune system. This leads to recurring bacterial and fungal infections and the formation of granulomas, which are clumps of infected tissue that arise as the body attempts to isolate infections it cannot combat. People with CGD are often hospitalized routinely and the granulomas themselves can obstruct digestive pathways and other pathways in the body. Antibiotics are used in an attempt to prevent infections from occurring, but eventually patients stop responding to them. One in two people with CGD do not live past the age of 40.

In Brenden’s case, when the antibiotics he relied on started failing, the doctors had to resort to surgery to cut out an infected lobe of his liver and half his right lung. Although the surgery was successful, it would only be a matter of time before a vital organ was infected and surgery would no longer be an option.

This ultimately lead to Brenden becoming the first patient in a CGD gene therapy trial at the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center.  The trial, lead by UCLA’s Dr. Don Kohn thanks to a CIRM grant, combats the disease by correcting the dysfunctional gene inside a patient’s blood stem cells. The patient’s corrected blood stem cells are then reintroduced, allowing the body to produce properly functioning neutrophils, rebooting the immune system.

It’s been a little over three years since Brenden received this treatment in late 2015, and the results have been remarkable. Dr. David Williams, Brenden’s treating physician, expected Brenden’s body to produce at least 10 percent of the functional neutrophils, enough so that Brenden’s immune system would provide protection similar to somebody without CGD. The results were over 50 percent, greatly exceeding expectations.

Brenden Whittaker mowing the lawn in the backyard of his home in Columbus, Ohio. He is able to do many more things without the fear of infection since participating in the trial. Photo courtesy of Colin McGuire

In an article published by The Harvard Gazette, Becky Whittaker, Brendan’s mother, is quoted as saying, ““Each day that he’s free of infection, he’s able to go to class, he’s able to work at his part-time job, he’s able to mess around playing with the dog or hanging out with friends…[this] is a day I truly don’t believe he would have had beyond 2015 had something not been done.”

In addition to the changes to his immune system, the gene therapy has reinvigorated Brenden’s drive for the future. Living with CGD had caused Brenden to miss out on much of his schooling throughout the years, having to take constant pauses from his academics at a community college. Now, Brenden aims to graduate with an associate’s degree in health sciences in the spring and transfer to Ohio State in the fall for a bachelor’s degree program. In addition to this, Brenden now has dreams of attending medical school.

In The Harvard Gazette article, Brenden elaborates on why he wants to go to medical school saying, ” Just being the patient for so long, I want to give back. There are so many people who’ve been there for me — doctors, nurses who’ve been there for me [and] helped me for so long.”

In a press release dated February 25, 2019, Orchard Therapeutics, a biopharmaceutical company that is continuing the aforementioned approach for CGD, announced that six patients treated have shown adequate neutrophil function 12 months post treatment. Furthermore, these six patients no longer receive antibiotics related to CGD. Orchard Therapeutics also announced that they are in the process of designing a registrational trial for CGD.

Key Steps Along the Way To Finding Treatments for HIV on World AIDS Day

Today, December 1st,  is World AIDS Day. It’s a day to acknowledge the progress that is being made in HIV prevention and treatment around the world but also to renew our commitment to a future free of HIV. This year’s theme is Leadership. Commitment. Impact.  At CIRM we are funding a number of projects focused on HIV/AIDS, so we asked Jeff Sheehy, the patient advocate for HIV/AIDS on the CIRM Board to offer his perspective on the fight against the virus.

jeff-sheehy

At CIRM we talk about and hope for cures, but our actual mission is “accelerating stem cell treatments to patients with unmet medical needs.”

For those of us in the HIV/AIDS community, we are tremendously excited about finding a cure for HIV.  We have the example of Timothy Brown, aka the “Berlin Patient”, the only person cured of HIV.

Multiple Shots on Goal

Different approaches to a cure are under investigation with multiple clinical trials.  CIRM is funding three clinical trials using cell/gene therapy in attempts to genetically modify blood forming stem cells to resist infection with HIV.  While we hope this leads to a cure, community activists have come together to urge a look at something short of a “home run.”

A subset of HIV patients go on treatment, control the virus in their blood to the point where it can’t be detected by common diagnostic tests, but never see their crucial immune fighting CD4 T cells return to normal levels after decimation by HIV.

For instance, I have been on antiretroviral therapy since 1997.  My CD4 T cells had dropped precipitously, dangerous close to the level of 200.  At that level, I would have had an AIDS diagnosis and would have been extremely vulnerable to a whole host of opportunistic infections.  Fortunately, my virus was controlled within a few weeks and within a year, my CD T cells had returned to normal levels.

For the immunological non-responders I described above, that doesn’t happen.  So while the virus is under control, their T cell counts remain low and they are very susceptible to opportunistic infections and are at much greater risk of dying.

Immunological non-responders (INRs) are usually patients who had AIDS when they were diagnosed, meaning they presented with very low CD4 T cell counts.  Many are also older.  We had hoped that with frequent testing, treatment upon diagnosis and robust healthcare systems, this population would be less of a factor.  Yet in San Francisco with its very comprehensive and sophisticated testing and treatment protocols, 16% of newly diagnosed patients in 2015 had full blown AIDS.

Until we make greater progress in testing and treating people with HIV, we can expect to see immunological non-responders who will experience sub-optimal health outcomes and who will be more difficult to treat and keep alive.

Boosting the Immune System

A major cell/gene trial for HIV targeted this population.  Their obvious unmet medical need and their greater morbidity/mortality balanced the risks of first in man gene therapy.  Sangamo, a CIRM grantee, used zinc finger nucleases to snip out a receptor, CCR5, on the surface of CD4 T cells taken from INR patients.  That receptor is a door that HIV uses to enter cells.  Some people naturally lack the receptor and usually are unable to be infected with HIV.  The Berlin Patient had his entire immune system replaced with cells from someone lacking CCR5.

Most of the patients in that first trial saw their CD4 T cells rise sharply.  The amount of HIV circulating in their gut decreased.  They experienced a high degree of modification and persistence in T stem cells, which replenish the T cell population.  And most importantly, some who regularly experienced opportunistic infections such as my friend and study participant Matt Sharp who came down with pneumonia every winter, had several healthy seasons.

Missed Opportunities

Unfortunately, the drive for a cure pushed development of the product in a different direction.  This is in large part to regulatory challenges.  A prior trial started in the late 90’s by Chiron tested a cytokine, IL 2, to see if administering it could increase T cells.  It did, but proving that these new T cells did anything was illusive and development ceased.  Another cytokine, IL 7, was moving down the development pathway when the company developing it, Cytheris, ceased business.  The pivotal trial would have required enrolling 4,000 participants, a daunting and expensive prospect.  This was due to the need to demonstrate clinical impact of the new cells in a diverse group of patients.

Given the unmet need, HIV activists have looked at the Sangamo trial, amongst others, and have initiated a dialogue with the FDA.  Activists are exploring seeking orphan drug status since the population of INRs is relatively small.

Charting a New Course

They have also discussed trial designs looking at markers of immune activity and discussed potentially identifying a segment of INRs where clinical efficacy could be shown with far, far fewer participants.

Activists are calling for companies to join them in developing products for INRs.  I’ve included the press release issued yesterday by community advocates below.

With the collaboration of the HIV activist community, this could be a unique opportunity for cell/gene companies to actually get a therapy through the FDA. On this World AIDS Day, let’s consider the value of a solid single that serves patients in need while work continues on the home run.

NEWS RELEASE: HIV Activists Seek to Accelerate Development of Immune Enhancing Therapies for Immunologic Non-Responders.

Dialogues with FDA, scientists and industry encourage consideration of orphan drug designations for therapies to help the immunologic non-responder population and exploration of novel endpoints to reduce the size of efficacy trials.

November 30, 2016 – A coalition of HIV/AIDS activists are calling for renewed attention to HIV-positive people termed immunologic non-responders (INRs), who experience sub-optimal immune system reconstitution despite years of viral load suppression by antiretroviral therapy. Studies have shown that INR patients remain at increased risk of illness and death compared to HIV-positive people who have better restoration of immune function on current drug therapies. Risk factors for becoming an INR include older age and a low CD4 count at the time of treatment initiation. To date, efforts to develop immune enhancing interventions for this population have proven challenging, despite some candidates from small companies showing signs of promise.

“We believe there is an urgent need to find ways to encourage and accelerate development of therapies to reduce the health risks faced by INR patients,” stated Nelson Vergel of the Program for Wellness Restoration (PoWeR), who initiated the activist coalition. “For example, Orphan Drug designations[i] could be granted to encourage faster-track approval of promising therapies.  These interventions may eventually help not only INRs but also people with other immune deficiency conditions”.

Along with funding, a major challenge for approval of any potential therapy is proving its efficacy. While INRs face significantly increased risk of serious morbidities and mortality compared to HIV-positive individuals with more robust immune reconstitution, demonstrating a reduction in the incidence of these outcomes would likely require expensive and lengthy clinical trials involving thousands of individuals. Activists are therefore encouraging the US Food & Drug Administration (FDA), industry and researchers to evaluate potential surrogate markers of efficacy such as relative improvements in clinical problems that may be more frequent in INR patients, such as upper respiratory infections, gastrointestinal disease, and other health issues.

“Given the risks faced by INR patients, every effort should be made to assess whether less burdensome pathways toward approval are feasible, without compromising the regulatory requirement for compelling evidence of safety and efficacy”, said Richard Jefferys of the Treatment Action Group.

The coalition is advocating that scientists, biotech and pharmaceutical companies pursue therapeutic candidates for INRs. For example, while gene and anti-inflammatory therapies for HIV are being assessed in the context of cure research, there is also evidence that they may have potential to promote immune reconstitution and reduce markers associated with risk of morbidity and mortality in INR patients. Therapeutic research should also be accompanied by robust study of the etiology and mechanisms of sub-optimal immune responses.

“While there is, appropriately, a major research focus on curing HIV, we must be alert to evidence that candidate therapies could have benefits for INR patients, and be willing to study them in this context”, argued Matt Sharp, a coalition member and INR who experienced enhanced immune reconstitution and improved health and quality of life after receiving an experimental gene therapy.

The coalition has held an initial conference call with FDA to discuss the issue. Minutes are available online.

The coalition is now aiming to convene a broader dialogue with various drug companies on the development of therapies for INR patients. Stakeholders who are interested in becoming involved are encouraged to contact coalition representatives.

[i] The Orphan Drug Act incentivizes the development of treatments for rare conditions. For more information, see:  http://www.fda.gov/ForIndustry/DevelopingProductsforRareDiseasesConditions/ucm2005525.htm

For more information:

Richard Jefferys

Michael Palm Basic Science, Vaccines & Cure Project Director
Treatment Action Group richard.jefferys@treatmentactiongroup.org

Nelson Vergel, Program for Wellness Restoration programforwellness@gmail.com