New cord blood transplant treatment holds promise for blood cancer patients

Associate Professor William Hwang with Ms Judith Chew, the first patient in Asia to undergo a stem cell transplant using the Nicord cord blood expansion technique. ST PHOTO: DESMOND WEE

SINGAPORE - A new treatment technique involving cord blood transplants could offer patients with diseases such as blood cancers a lower risk of infection and higher likelihood of surviving the transplant, if the current trial proves successful.

The technique involves culturing and growing cells from a single unit of cord blood in the laboratory over three weeks to produce more stem cells.

More than one-third of patients worldwide die from cord blood transplants that contain a low number of stem cells.

The new technique, called the Nicord cord blood expansion technique, has shown promise with a mortality rate of less than 10 per cent, said Associate Professor William Hwang, a senior consultant at the Singapore General Hospital's (SGH) Department of Haematology.

For conventional cord blood transplants which contain a high number of stem cells, the current mortality rate is also less than 10 per cent.

Prof Hwang said long-term survival using the new technique has not been definitively proven.

The trial is being conducted by Gamida Cell, a biotechnology company which develops cellular and immune therapeutics, and Duke University Medical Centre in the United States.

Besides increasing the number of cells, the second phase of the clinical trial showed a reduction in the average number of total infections during the first 100 days after transplant.

It was 3.7 per patient for the new technique compared to 4.9 per patient for the standard cord blood transplant group.

In addition, during the first 100 days after transplant, the new technique reduced the average number of hospitalisation days to 30 from 50..

These figures are based on 36 patients from Singapore, Europe and the US who took part in the trial's second phase from 2013 to 2017.

The third phase started in November 2016 and is expected to be completed in December 2019, with 120 patients being recruited globally.

Prof Hwang said a patient's suitability to receive the new treatment depends on his ability to wait for the cells to be grown.

"If the patient has a disease that cannot wait, for example, a previous transplant failed and the patient has a low blood count for a long time, I might say, just use the (conventional) cord blood transplant," he added.

But for diseases such as acute leukaemia where the disease is in remission and can be maintained in that state, then the new treatment technique is recommended.

Other alternatives like donated bone marrow and peripheral blood are currently the preferred treatment for patients with blood diseases and bone marrow failure because they have a faster recovery period of around 14 and 17 days respectively.

In comparison, patients need around 25 days to recover from conventional cord blood transplants.

But using donated bone marrow and peripheral blood require exact matches, which are hard to find.

More than 80 stem cell transplants are performed at SGH every year on average, out of which four are cord blood transplants.

Ms Judith Chew, 53, is the first patient in Asia to receive a cord blood transplant using the new technique.

The business consultant suffers from acute myeloid leukaemia, a cancer of the blood and bone marrow, and was diagnosed in October 2016. She had to undergo chemotherapy to lower her white blood cell count before the operation in May last year.

"The entire process was really very manageable for me, and I'm most happy with the recovery process," said Ms Chew, who only needed a month's stay at SGH.

Correction note: The article was edited for clarity.

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