T cells cure for cancer?

Some leukaemia patients who had exhausted other treatment options have no trace of the disease more than four years after being given an experimental type of therapy called CAR T cells in a small pilot study.

The 14-patient study, which began in the summer of 2010, enrolled patients who had failed to benefit from standard treatments for chronic lymphocytic leukaemia (CLL), a cancer of white blood cells that most commonly affects adults.

They were given one treatment, a therapy developed by the University of Pennsylvania in the US and licensed to Swiss drugmaker Novartis AG. Patients have since been monitored to assess durability of the therapy’s benefits.

The treatment is made by taking immune system soldiers called T cells from the body, genetically modifying them to have cancer-spotting abilities of antibodies and then infusing the altered cells back into the patient.

The first patient to receive the therapy is cancer-free after five years and another of the first three enrolled patients also remains in remission, the university revealed.

All signs of cancer disappeared in four patients, or 29 per cent, but one of them died almost two years after therapy due to an unrelated infection.

“The durability of the remissions we have observed in this study are remarkable and have given us great hope that personalised cell therapies are going to be important options for patients,” said Dr David Porter, director of blood and marrow transplantation at the university’s Abramson Cancer Centre.

Another four patients achieved some reduction in tumours, with responses lasting an average of about seven months. Six patients, or 43 per cent, failed to respond to therapy, and their leukaemia progressed within one to nine months.

Novartis plans next year to seek marketing approval of CTL019 to treat paediatric patients with another cancer of the white blood cells, acute lymphoblastic leukaemia. Although it can occur in adults, it is the most common type of cancer in children.

Novartis is considered in the lead among a handful of companies racing to develop and launch CAR T cells to treat blood cancers, including Kite Pharma Inc, Juno Therapeutics Inc and Bluebird Bio Inc.

But the therapies can cause a life-threatening inflammation called cytokine release syndrome, which was seen in all patients who responded to CTL019 in the university study. All patients recovered from the inflammation, including some treated with steroids.