(kropekk_pl, Pixabay)
5 September 2017. The Food and Drug Administration stopped two clinical trials testing genetically engineered T-cells from the immune system to treat leukemia, after a participant in one trial died. Cellectis S.A., based in New York and Paris, yesterday announced the temporary halt in its early-stage trials after FDA put a temporary clinical hold on the studies.
Cellectis develops therapies that genetically engineer T-cells from the immune system to treat cancer, by adding chimeric antigen receptors, proteins attracting antibodies that bind to and destroy blood-related cancer cells. Current methods producing chimeric antigen receptor T-cells, known as CAR T-cells, produce promising results in patients with leukemia and other blood-related cancers.
Those current methods, however, are also time-consuming and dangerous for some patients. T-cells are taken from patients, then genetically engineered and cultured in the lab, for later infusion back into the individual, which can take several weeks to produce sufficient numbers of cells. Before the re-engineered cells can be introduced, patients must also undergo chemotherapy both as a cancer therapy, and to remove other immune system cells that can dilute the potency of the infused re-engineered T-cells. FDA halted other clinical trials of CAR T-cells, when one or more participants died, but the agency last month approved the first such treatments for one form of leukemia.
Unlike these other techniques, Cellectics is developing off-the-shelf CAR T-cell treatments, it calls Universal CAR T-cells, or UCARTs. These treatments use T-cells from healthy donors, rather than a patient’s own T-cells, genetically engineered to match the attributes of specific cancer types. As reported in Science & Enterprise in January 2017, the company developed engineered T-cells that in the lab target low-oxygen concentrations feeding tumor growth.
The clinical trials stopped by FDA are testing the safety of UCARTs with two related types of leukemia. The clinical trial where the patient died is testing a treatment for blastic plasmacytoid dendritic cell neoplasm, a form of acute myeloid leukemia. The patient is a 78 year-old man, the first participant enrolled in the study, who according to Cellectis received a UCART dose without incident. But the patient developed cytokine-release syndrome, a complex of immune-system reactions to immunotherapies that worsened with complications, and did not respond to treatment.
The second trial is testing UCARTs in patients with acute myeloid leukemia. The first participant in that trial, a 58 year-old woman, received a UCART dose and also developed cytokine-release syndrome, but later responded to treatments that resolved the reactions. The company says no graft-versus-host disease, an immune-system reaction to donated cells, occurred in either of the patients.
Cellectis says it is working with FDA to investigate and resolve these cases to resume the trials, perhaps with a lower UCART dose.
More from Science & Enterprise:
- Simple Cell Programming Designed for Gene Therapies
- Engineered T-Cell Company Acquired for $11.9 Billion
- Engineered Immune Cells to be Explored for Solid Tumors
- $10M Cancer Immunotherapy Research Fund Launched
- Nanoparticles Boost T-Cells to Fight Leukemia
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