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Four in 10 patients with aggressive lymphoma were cancer-free 15 months after treatment with engineered immune cells, according to new US clinical trial results.
The study involved 108 patients with large B cell lymphoma who didn’t respond to standard treatment. Around 6 in 10 patients were alive 15 months after the CAR T cell treatment, known as axi-cel (Yescarta).
“The long term follow-up results of the ZUMA-1 trial show that axi-cel remissions can last years, and these are patients that did not respond to chemotherapy,” said Dr Locke, one of the lead researchers on the trial.
Professor Karl Peggs, an immunotherapy expert at University College London, called the results exciting, and said the study had formed the basis for the treatment being approved quickly in the US.
“The follow-up in this study is still fairly short, so we don’t yet know the long-term effects of this treatment. But it’s a significant step forward,” he added.
A new breed of treatment
CAR T cell therapy aims to boost the immune system’s ability to recognise and destroy cancer cells. It focuses on one type of white blood cell, called a T cell.
In the study, patients’ T cells were extracted and altered by genetic engineering. This helps the T cells to recognise a specific molecule on the surface of the cancer cells when they’re infused back into the patient’s bloodstream.
The study was published in the New England Journal of Medicine (NEJM) and presented at the American Society of Hematology (ASH) Annual Meeting.
Dr Martin Pule, a Cancer Research UK-funded blood cancer expert, said: “The publication of these results is a landmark moment in CAR T cell therapy.
“Remarkably, patients whose disease disappeared remain cancer-free. There is room for improvement however since most patients did not become cancer-free.”
Pule said that other studies are looking at ways of boosting response rates.
“Hopefully they will build on these successful results,” he added.
The trial also highlighted the potential aggressive nature of the treatment. Everyone on the trial experienced some side effects, although not all were linked to the treatment.
Peggs and Pule added that studies are also underway in the UK to test the treatment in patients with aggressive B cell lymphoma who have stopped responding to treatment or whose disease has come back.
More evidence of long-term effect
The trial involved people with either large B cell lymphoma and follicular lymphoma who didn’t respond to standard treatments. Patients on the trial were treated with a different CAR T cell therapy called CTL019 (Kymriah).
After six months, six of the 14 people with large B cell lymphoma were cancer-free, as were 10 of the 14 people with follicular lymphoma. These responses were maintained for an average of 28 months after treatment.
Neelapu, S. et al. (2017) Axicabtagene Ciloleucel CAR T-Cell Therapy in Refractory Large B-Cell Lymphoma, NEJM. DOI: 10.1056/NEJMoa1707447
Schuster, SJ. et al. (2017) Chimeric Antigen Receptor T Cells in Refractory B-Cell Lymphomas, NEJM. DOI: 10.1056/NEJMoa1708566