Statement from CIRM on the FDA Approval of Gene Therapies for Sickle Cell Disease

The California Institute for Regenerative Medicine (CIRM) applauds and acknowledges the historic significance of the Food and Drug Administration (FDA) approval of Vertex and CRISPR Therapeutics’ CRISPR-based gene therapy (Casgevy) for sickle cell disease.  

As the first regulatory authorization of a CRISPR-based gene editing therapy in the world, this brings forth a new era of treatment options for people living with sickle cell disease, a condition that affects more than 100,000 Americans and 20 million people worldwide.  

“As the first regulatory authorization for a CRISPR-based gene-editing therapy in the world, this approval not only marks a milestone in the advancement of cell and gene therapies, but it also marks a transformative step in the treatment landscape for the millions of people impacted by sickle cell disease,” said CIRM Vice President of Therapeutics Development, Abla Creasey, PhD. 

By leveraging CRISPR gene editing, this therapy has the potential to provide a more effective and potentially curative solution compared to traditional treatments. The FDA also approved another gene therapy for sickle cell disease (Lyfgenia) from bluebird bio based on long-standing lentivirus vector technology. 

Through the Cure Sickle Cell Initiative, CIRM, with funding from the National Heart, Lung, and Blood Institute, remains committed to funding cell and gene therapy programs that will accelerate the development of gene therapies to treat sickle cell disease, as well as create a collaborative, patient-focused research environment. 

CIRM recognizes that long-term innovation is needed to lower the costs of gene therapies, reduce the burden of the treatment on the patient, and make these therapies more accessible. 

CIRM and NHLBI are co-funding two clinical trials testing different types of gene therapy approaches for patients with severe sickle cell disease. Those include a pivotal Phase 2 trial led by David A. Williams, MD of Boston Children’s Hospital and a Phase 1 trial led by Mark Walters, MD of UCSF Benioff Children’s Hospital Oakland. 

In the Phase 2 clinical trial led by Williams, investigators will take a patient’s own blood stem cells and insert a novel engineered gene to silence abnormal hemoglobin and induce normal fetal hemoglobin expression. The modified blood stem cells are then reintroduced back into the patient. The goal of this therapy is the production of normal shaped red blood cells that are robust and able to transport normal amounts of oxygen, thereby reducing the severity of the disease.  

“As a researcher involved in development of new therapies to treat sickle cell disease and as a clinician caring for children with this terrible disease, I am elated to see FDA approval of two different effective genetic therapies. I anxiously await access of these therapies by patients with severe disease as well as the continued development of additional options for curative therapies for our patients,” said Dr. Williams, who has consulted for Vertex Pharmaceuticals and bluebird bio. 

In the Phase 1 trial led by Walters, patients will be transplanted with their own blood stem cells that have been edited with CRISPR-Cas9 to correct the disease-causing mutation in the beta globin gene. This trial will begin enrolling patients in California in 2024.   

Please direct any inquiries to Koren Temple-Perry, Senior Director of Marketing & Communications at press@cirm.ca.gov.

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