The five-year-old British boy, Oscar Saxelby-Lee, whose medical case received widespread support and attention, is undergoing an experimental treatment known as CAR T-cell Therapy, at the National University Hospital (NUH).
The toddler from Worcester, England, was diagnosed with acute lymphoblastic leukaemia in December 2018 and had undergone a battery of treatments in 2019 to treat his condition; with no respite. Oscar becomes only the second child to receive a CAR T-cell Therapy. Five-year-old, Zac Oliver from Shropshire, England received the same treatment at Children's Hospital of Philadelphia, USA, in 2018 for the same form of cancer that Oscar is battling.
An unexpected diagnosis
Oscar, who had shown visible symptoms of distress such as extreme lethargy and difficulty in movement, was taken to the hospital in December 2018. Three days after Christmas, his parents received the shattering news of a grim diagnosis for Oscar: Acute lymphoblastic leukaemia (ALL). ALL is an aggressive form of blood cancer that originates in lymphocytes or white blood cells (WBCs) in the bone marrow and invades the bloodstream.
"It was diagnosed and told to us over the phone. We had a bit of intuition that something wasn't right â but not leukaemia. That was the last thing on our minds," said Olivia Saxelby, Oscar's mother
A timely diagnosis saved Oscar's life as it could have killed him in weeks had it gone undiagnosed. He was rushed to the hospital and chemotherapy treatment commenced immediately.
2019- A year of treatments to save Oscar's life
In less than a month, the doctors ascertained that the chemotherapy was ineffective, and stronger courses did little to change this. By March 2019, the doctors decided that the number of cancer cells in the boy's blood required a bone marrow transplant to improve his condition. Oscar finally received a transplant after finding a donor. But it was not enough. In April, after the fourth round of chemotherapy, the doctors declared that the regular treatment was not effective enough to arrest the toddler's ALL.
He received a stem cell transplant along with more isolated conditioning and radiotherapy in May. However, stem cell treatment could not cure his cancer. Cancer cells were found in his bone marrow in August, and his condition worsened drastically by November. The second round of stem cell therapy in October proved equally ineffective.
So far, Oscar's treatment had been free as it was covered by the National Health Service(NHS). However, the experimental treatment that could save his life was available outside the UK, in Singapore, and it was not covered by NHS. With Â£500,000 (S$885,000) required for the treatment and costs, his parents turned to Grace Kelly Childhood Cancer Trust for assistance. With the contributions from thousands of people who answered the family's call through a crowdfunding campaign, the funds were raised in three weeks.
Oscar was off to Singapore to receive CAR T-cell Therapy under the care of Allen Yeoh, head of paediatric oncology at NUH.
What is CAR T-cell Therapy?
A T-cell is a form of lymphocyte or white blood cell(WBC) that plays an important role in the immune system of the body. For the treatment, blood is withdrawn from the patient's body and all the WBCs are separated and pumped back sans the T-cells. Now, the collected T-cells are re-engineered in the lab.
They are genetically modified by the introduction of an external DNA such as that of an inactive virus. Due to this, the T-cells develop special receptors called Chimeric antigen receptors (CARs) on their surfacesâgiving them the ability to identify the antigen on the targeted tumour or cancer cells. These re-engineered T-cells are now called CAR T-cells.
These newly modified attacker cells are multiplied by the millions in the lab to combat cancer cells. After producing a sufficient amount of CAR T-cells required for treatment, they are sent to the hospital. Typically, before the CAR T-cells are introduced into the patient's blood, a round of chemotherapy is administered to the patient in order to give them a chance to take hold and multiply after introduction. Finally, the engineered CAR T-cells are put into the patient's bloodstream.
After the introduction, the receptors on the CAR T-cells are attracted to the antigens on the cancer cells and seek them out. They attack the cancer cells and destroy them. Post the killing of cancer cells, the CAR T-cells may remain in the patient's system to prevent their return.
Racing against time to save Oscar
As soon as Oscar reached NUH, the medical teams tasked with Oscar's treatment began working around the clock to produce the CAR T-cells required to treat him. They also began helping the boy build himself mentally and psychologically to bear the effects of the treatment.
"When they came, while we were working on the cells, we wanted him to be stronger. Basically we took everything off and let him enjoy himself," Yeoh said to CNA.
Oscar was allowed to visit the local zoo and decorate Christmas trees, among other things, in order to keep him in good spirit. He was back in NUH on 18 December. However, the level of cancer cells in his body was at 7 per cent. "It's very fast. These cells are even worse because they have seen all the chemotherapy, have evaded the bone marrow transplant cells in general," Yeoh explained.
Going ahead with the therapy
On Christmas day, Oscar's parents decided that it was time to take the next step and go ahead with the therapy. The following day, the child was allowed to walk around the ward for a short while before facing the side-effects of the treatment that would leave him distress as the therapy does its job.
"It feels surreal, but it also feels like nothing has changed because we just haven't seen a difference yet and we don't know what's happening. It's really tough," said his mother to BBC.
The family will now have to wait for a few days to know how the treatment will pan out and if it will help Oscar beat cancer once and for all.