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

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

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

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

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

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

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

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

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

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

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

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

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

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

Stem Cell Agency’s supporting role in advancing research for rare diseases

Orchard

The recent agreement transferring GSK’s rare disease gene therapies to Orchard Therapeutics was good news for both companies and for the patients who are hoping this research could lead to new treatments, even cures, for some rare diseases. It was also good news for CIRM, which played a key role in helping Orchard grow to the point where this deal was possible.

In a news releaseMaria Millan, CIRM’s President & CEO, said:

“At CIRM, our value proposition is centered around our ability to advance the field of regenerative medicine in many different ways. Our funding and partnership has enabled the smooth transfer of Dr. Kohn’s technology from the academic to the industry setting while conducting this important pivotal clinical trial. With our help, Orchard was able to attract more outside investment and now it is able to grow its pipeline utilizing this platform gene therapy approach.”

Under the deal, GSK not only transfers its rare disease gene therapy portfolio to Orchard, it also becomes a shareholder in the company with a 19.9 percent equity stake. GSK is also eligible to receive royalties and commercial milestone payments. This agreement is both a recognition of Orchard’s expertise in this area, and the financial potential of developing treatments for rare conditions.

Dr. Millan says it’s further proof that the agency’s impact on the field of regenerative medicine extends far beyond the funding it offers companies like Orchard.

“Accelerating stem cell therapies to patients with unmet medical needs involves a lot more than just funding research; it involves supporting the research at every stage and creating partnerships to help it fulfill its potential. We invest when others are not ready to take a chance on a promising but early stage project. That early support not only helps the scientists get the data they need to show their work has potential, but it also takes some of the risk out of investments by venture capitalists or larger pharmaceutical companies.”

CIRM’s early support helped UCLA’s Don Kohn, MD, develop a stem cell therapy for severe combined immunodeficiency (SCID). This therapy is now Orchard’s lead program in ADA-SCID, OTL-101.

Sohel Talib, CIRM’s Associate Director Therapeutics and Industry Alliance, says this approach has transformed the lives of dozens of children born with this usually fatal immune disorder.

“This gene correction approach for severe combined immunodeficiency (SCID) has already transformed the lives of dozens of children treated in early trials and CIRM is pleased to be a partner on the confirmatory trial for this transformative treatment for patients born with this fatal immune disorder.”

Dr. Donald B. Kohn UCLA MIMG BSCRC Faculty 180118Dr. Kohn, now a member of Orchard’s scientific advisory board, said:

“CIRM funding has been essential to the overall success of my work, supporting me in navigating the complex regulatory steps of drug development, including interactions with FDA and toxicology studies that enhanced and helped drive the ADA-SCID clinical trial.”

CIRM funding has allowed Orchard Therapeutics to expand its technical operations footprint in California, which now includes facilities in Foster City and Menlo Park, bringing new jobs and generating taxes for the state and local community.

Mark Rothera, Orchard’s President and CEO, commented:

“The partnership with CIRM has been an important catalyst in the continued growth of Orchard Therapeutics as a leading company transforming the lives of patients with rare diseases through innovative gene therapies. The funding and advice from CIRM allowed Orchard to accelerate the development of OTL-101 and to build a manufacturing platform to support our development pipeline which includes 5 clinical and additional preclinical programs for potentially transformative gene therapies”.

Since CIRM was created by the voters of California the Agency has been able to use its support for research to leverage an additional $1.9 billion in funds for California. That money comes in the form of co-funding from companies to support their own projects, partnerships between outside investors or industry groups with CIRM-funded companies to help advance research, and additional funding that companies are able to attract to a project because of CIRM funding.