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London - A new form of cancer treatment has resulted in five leukaemia patients experiencing complete remission, with no detectable cancerous cells, scientists have announced.
Doctors treating the patients said early trial results demonstrated that it may be possible to use a gene-therapy technique to control cancers in relapsed leukaemia patients.
This could allow them to have vital bone-marrow transplants with a donor’s blood stem cells, leading to a complete cure.
The patients had all had a serious relapse of B-cell acute lymphoblastic leukaemia, a form of cancer that affects white blood cells.
They had initially undergone chemotherapy to control their cancers but, as often happens, the disease returned and could not be treated further by the same approach because the cancerous cells had developed resistance to the drugs.
However, the new development allowed them to receive transfusions of their own immune cells that had been genetically modified with an extra cancer-fighting gene.
In this form of targeted immunotherapy, developed at the Memorial Sloan-Kettering Cancer Centre in New York, an extra gene is inserted into the patients’ white blood cells, enabling them to identify and destroy cancerous cells in the bloodstream.
“Patients with relapsed B-cell acute lymphoblastic leukaemia resistant to chemotherapy have a particularly poor prognosis,” said Renier Brentjens of the cancer centre and lead author of the study published in the journal Science Translational Medicine. “This ability… to achieve complete remissions in all of these very sick patients is what makes these findings so remarkable and this novel therapy so promising,” Dr Brentjens said.
After the targeted immunotherapy, four of the five patients underwent a bone marrow transplant and three have remained in remission for between five and 24 months.
One patient died from unrelated complications.
“By serving as a bridge to stem-cell transplants, this therapy could potentially help cure adult patients with B-cell acute lymphoblastic leukaemia who have relapsed and who are chemotherapy resistant. Otherwise, these patients have a virtually incurable disease,” Brentjens said.
“This (potential) can then make patients eligible for stem cell transplantation – which can lead to a cure.
“Although it’s early days for these trials, the approach of modifying a patient’s T-cells (white blood cells) to attack their cancer is looking increasingly like one that will, in time, have a place alongside more traditional treatments like chemotherapy, radiotherapy and surgery,” Brentjens added.
The results of this small study showed why immunotherapy had generated such excitement, said Professor Paul Moss, who runs the Birmingham Cancer Research UK Centre. – The Independent