Promising Results Shown for CRISPR
CRISPR has shown promising results in preliminary clinical studies to correct sickle cell disease and treat blindness, transthyretin amyloidosis, and hereditary angioedema. A new study in collaboration with University College London and Great Ormond Street Hospital for Children investigated the potential feasibility of base-edited CD7-targeted chimeric antigen receptor (BE-CAR7) T cells to induce remission in children with relapsed/refractory (r/r) CD7-positive T-cell acute lymphoblastic leukemia (T-ALL), prior to an allo-stem cell transplant (allo-SCT). To circumvent the challenges associated with human leukocyte antigen (HLA) barriers that prevent or severely hinder the use of CAR-T therapies, scientists have developed a CRISPR-based and guided cytidine deamination process that mediates a highly precise C→U→T conversion that directly disrupts gene expression without causing DNA breaks.
The novelty of the study included 4 key milestones. The first is deleting all existing T-cell cell surface markers with no need for HLA matching, making them universal and allowing for the possibility of having ready-made “off-the-shelf” CAR-T therapies. Second, remove CD7 to avoid T-cell fratricide when introduced to a new host. Third, the deletion of CD52, which makes T-cells invisible to some of the potent drugs the patient may receive during therapy. Finally, adding CAR that recognizes CD7 receptors, thus targeting T-cell leukemia. Using this technology, a 13-year-old girl named Alyssa was the first ever reported to receive the BE-CAR7 therapy. Diagnosed in 2021 and after chemotherapy and a bone marrow transplant, before the based-edited treatment, her medical team could not control her cancer. She entered remission within a month after the administration of BE-CAR7 and received a second bone marrow transplant to restore her immune function. Six months post-transplant, her cancer remains undetectable.
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Author: Canan Schuman, PharmD/PhD
Canan Schumann is Chief Editor for Axxiem and for Axxiem's blog "BiotechOntheWeb". When not writing for Axxiem, Canan works as a Clinical Research Scientist II at the Research and Development Department at Molecular Testing Labs, developing endpoint assays for the detection of infectious disease and cancer. Canan currently resides in Portland, Oregon, where he received his Honors Bachelor of Science (HBS), Doctor of Pharmacy (PharmD.), and his Doctor of Philosophy (Ph.D.) in Biopharmaceutics at Oregon State University.