Sunday, 17 February, 2019

'Extraordinary' results in cell treatment to combat cancer

More than half of the terminally ill trial participants were in remission SUPPLIED More than half of the terminally ill trial participants were in remission
Melissa Porter | 16 February, 2016, 06:47

They were found to be there 14 years later.

Patients with Chronic Lymphocyte Leukaemia showed similar results. This is really a revolution.

The technique has only been tried on patients with blood cancers but the team hope that the studies could progress to patients with solid tumours.

Treatment involves extracting T-cells from a patient's blood and genetically modifying them to carry receptors, which let the cells recognise and attack cancer cells. Scientists around the world are perfecting the technique, and a series of trials have shown it to have remarkable potential.

Unlike cancer drugs, T-cells multiply in the body and can produce a long-lasting immune response against tumours, which scientists refer to as a "living drug". His lecture, "Engineering T Cells for Safe and Effective Cancer Immunotherapy", is one of three that will be presented.

Professor Chiara Bonini, a haematologist at San Raffaele Scientific Institute and Vita e Salute San Raffaele University in Milan, said: "T-cells are a living drug, and, in particular, they have the potential to persist in our body for our whole lives". Our findings have profound implications for the design of T-cell-based immunotherapies.

British experts have described the research results as "exciting". And 10 of 11 patients who had previously undergone CAR-T cell therapy with a mixed bag of engineered T-cells were in remission after being treated with just the engineered memory cells, Riddell reported.

In preliminary clinical trials, CAR-T cell therapy using the memory T cells eliminated cancer in 27 of 29 patients with acute lymphoblastic leukaemia, or ALL, for whom other treatments had failed.

Little Layla Richards was given a T-cell treatment so experimental it had only been tested on mice.

The treatment wiped out Layla's cancer. Being in remission is not the same as saying they were cured because the symptoms can return. Central memory T cells (TCMs) are of special interest: TCMs can engraft, expand, and persist long-term, even at very low numbers of transferred cells.

"In the laboratory and in clinical trials, we are seeing dramatic responses in patients with tumours that are resistant to conventional high-dose chemotherapy", said Dr Stanley Riddell, of the Fred Hutchinson Cancer Research Centre in Seattle. Patients with other blood cancers saw response rates of greater than 80 percent, with more than half experiencing complete remission. However, they said the improvements seen in some patients who had failed every other course of treatment were unprecedented.

Most of the patients in the study were facing death within two to five months. "This is unprecedented in medicine, to be honest, to get response rates in this range in these very advanced patients".

"We have a long ways to go", said Prof Riddell. Some of these patients do relapse, we are cognisant of that. "Some of these memory T-cells will persist through the entire life of the organism, and so if you encounter the same pathogen - say if the same strain of flu comes back ten years later - then you have memory T cells that remember it from ten years earlier and kill it quickly so you don't even know you're infected". That opens the door for getting more creative and making better cells'. For example, clinical trials of adoptive T cell therapy are yielding highly promising results.

Also at the symposium, Dr. Dirk Busch, an infection immunology researcher at the Technical University of Munich, Germany, discussed advanced cell processing technologies that have been developed at the TUM and are being applied to gene and cell therapy, and a preclinical study aimed at safeguarding against treatment-related toxicity. She stressed that it "doesn't yet work for all patients ... we still need more results from more trials ... but there's a lot of hope this type of therapy could save lives".