Welcome back to our “Throwback Thursday” series on the Stem Cellar. Over the years, we’ve accumulated an arsenal of exciting stem cell stories about advances towards stem cell-based cures for serious diseases. Today we’re featuring stories about the progress of CIRM-funded clinical trials for the treatment of a devastating, usually fatal, primary immune disease that strikes newborn babies.
‘Bubble baby disease’ will one day be a thing of the past. That’s a bold statement, but I say it with confidence because of the recent advancements in stem cell gene therapies that are curing infants of this life-threatening immune disease.
The scientific name for ‘bubble baby disease’ is severe combined immunodeficiency (SCID). It prevents the proper development of important immune cells called B and T cells, leaving newborns without a functioning immune system. Because of this, SCID babies are highly susceptible to deadly infections, and without treatment, most of these babies do not live past their first year. Even a simple cold virus can be fatal.
Scientists are working hard to develop stem cell-based gene therapies that will cure SCID babies in their first months of life before they succumb to infections. The technology involves taking blood stem cells from a patient’s bone marrow and genetically correcting the SCID mutation in the DNA of these cells. The corrected stem cells are then transplanted back into the patient where they can grow and regenerate a healthy immune system. Early-stage clinical trials testing these stem cell gene therapies are showing very encouraging results. We’ll share a few of these stories with you below.
CIRM-funded trials for SCID
CIRM is funding three clinical trials, one from UCLA, one at Stanford and one from UCSF & St. Jude Children’s Research Hospital, that are treating different forms of SCID using stem cell gene therapies.
Adenosine Deaminase-Deficient SCID
The first trial is targeting a form of the disease called adenosine deaminase-deficient SCID or ADA-SCID. Patients with ADA-SCID are unable to make an enzyme that is essential for the function of infection-fighting immune cells called lymphocytes. Without working lymphocytes, infants eventually are diagnosed with SCID at 6 months. ADA-SCID occurs in approximately 1 in 200,000 newborns and makes up 15% of SCID cases.
CIRM is funding a Phase 2 trial for ADA-SCID that is testing a stem cell gene therapy called OTL-101 developed by Dr. Don Kohn and his team at UCLA and a company called Orchard Therapeutics. 10 patients were treated in the trial, and amazingly, nine of these patients were cured of their disease. The 10th patient was a teenager who received the treatment knowing that it might not work as it does in infants. You can read more about this trial in our blog from earlier this year.
In a recent news release, Orchard Therapeutics announced that the US Food and Drug Administration (FDA) has awarded Rare Pediatric Disease Designation to OTL-101, meaning that the company will qualify for priority review for drug approval by the FDA. You can read more about what this designation means in this blog.
The second SCID trial CIRM is funding is treating patients with X-linked SCID. These patients have a genetic mutation on a gene located on the X-chromosome that causes the disease. Because of this, the disease usually affects boys who have inherited the mutation from their mothers. X-linked SCID is the most common form of SCID and appears in 1 in 60,000 infants.
UCSF and St. Jude Children’s Research Hospital are conducting a Phase 1/2 trial for X-linked SCID. The trial, led by Dr. Brian Sorrentino, is transplanting a patient’s own genetically modified blood stem cells back into their body to give them a healthy new immune system. Patients do receive chemotherapy to remove their diseased bone marrow, but doctors at UCSF are optimizing low doses of chemotherapy for each patient to minimize any long-term effects. According to a UCSF news release, the trial is planning to treat 15 children over the next five years. Some of these patients have already been treated and we will likely get updates on their progress next year.
CIRM is also funding a third clinical trial out of Stanford University that is hoping to make bone marrow transplants safer for X-linked SCID patients. The team, led by Dr. Judy Shizuru, is developing a therapy that will remove unhealthy blood stem cells from SCID patients to improve the survival and engraftment of healthy bone marrow transplants. You can read more about this trial on our clinical trials page.
SCID Patients Cured by Stem Cells
These clinical trial results are definitely exciting, but what is more exciting are the patient stories that we have to share. We’ve spoken with a few of the families whose children participated in the UCLA and UCSF/St. Jude trials, and we asked them to share their stories so that other families can know that there is hope. They are truly inspiring stories of heartbreak and joyful celebration.
Evie is a now six-year-old girl who was diagnosed with ADA-SCID when she was just a few months old. She is now cured thanks to Don Kohn and the UCLA trial. Her mom gave a very moving presentation about Evie’s journey at the CIRM Bridges Trainee Annual Meeting this past July. You can watch the 20-minute talk below:
Ronnie, who is still less than a year old, was diagnosed with X-linked SCID just days after he was born. Luckily doctors told his parents about the UCSF/St. Jude trial and Ronnie was given the life-saving stem cell gene therapy before he was six months old. Now Ronnie is building a healthy immune system and is doing well back at home with his family. Ronnie’s dad Pawash shared his families moving story at our September Board meeting and you can watch it here.
Our mission at CIRM is to accelerate stem cell treatments to patients with unmet medical needs. We hope that by funding promising clinical trials like the ones mentioned in this blog, that one day soon there will be approved stem cell therapies for patients with SCID and other life-threatening diseases.