Novel Treatment Shows Promise for Acute Lymphoblastic Leukemia

Thanks to gene-editing treatment, 2 babies who had leukemia have a longer lease on life. Researchers from University College London, Great Ormond Street Hospital National Health Service Trust, King’s College, and Sheffield Children’s Hospital, in the United Kingdom used genetically engineered white blood cells from healthy individuals to target the cancer cells.

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One infant was 11 months old, and the second was 16 months old. Both had refractory relapsed B-cell acute lymphoblastic leukemia and had undergone multidrug treatments. Although the potential of the method has been demonstrated in autologous and human-leukocyte-antigen–matched allogeneic settings, the researchers say, “the infrastructure and expertise required to produce personalized cell products present challenges, and low T cell counts in heavily treated individuals may preclude autologous approaches.”

The treatment involves lymphodepleting chemotherapy and anti-CD52 serotherapy, followed by a single-dose infusion of universal CAR19 cells (autologous T cells engineered to express chimeric antigen receptor against the B-cell antigen CD19). This “bridge-to-transplantation strategy” demonstrates the therapeutic potential of gene-editing technology, the researchers say.

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Just 28 days after the treatment, molecular markers showed remission in both infants. The treatments were well tolerated. The first infant had an immune reaction (cytopenia and graft-vs-host disease [GVHD] in skin and marrow) in the 2 months after the infusion and was treated with steroids and bone marrow transplantation. The other baby had no adverse reactions apart from mild skin GVHD that reversed “promptly” with topical steroids and an episode of “unexplained irritability” in the 3 weeks after infusion.

The first and second infant remained cancer free 18 and 12 months later.

Source:

Qasim W, Zhan H, Samarasinghe S, et al. Sci Transl Med. 2017;9(374):pii: eaaj2013.
doi: 10.1126/scitranslmed.aaj2013.