New treatment offers hope for patients battling rare blood cancer

“This is not a frontline treatment; it is intended for a very select group of patients who are resistant to chemotherapy or bone marrow transplant, offering a chance to those who would otherwise have none,” said Prof Allen Yeoh, Head and Senior Consultant, Division of Paediatric Haematology and Oncology, Department of Paediatrics, Khoo Teck Puat – National University Children’s Medical Institute (KTP-NUCMI), NUH.

How the therapy works

Cancer cells often develop mechanisms to evade recognition by T-cells, a type of white blood cell that defends the body against infections. The therapy involves collecting the patient’s own T-cells and genetically modifying them to specifically target and destroy cancer cells.

Once the T-cells are collected, they are sent to a laboratory, where they are combined with a chimeric antigen receptor (CAR), a specially designed receptor that binds to and destroys cancer cells. After patients receive a specific type of chemotherapy to stimulate the growth of these modified T-cells, the CAR-T cells are infused back into the body. The anti-CD7 CAR protein then guides the T-cells to attack T-leukaemia cells that carry the CD7 protein on their surface.

The results from the trial

Of the 17 patients who received CD7 CAR-T therapy — all of whom had T-ALL that was either resistant to chemotherapy or had relapsed — 16 achieved complete remission within a month. Leukaemic cells became undetectable, even with ultra-sensitive flow cytometry tests capable of identifying one cancerous cell among 10,000 normal cells. Notably, the first patient treated has remained in remission for five years, without the need for further chemotherapy or a bone marrow transplant. 

Moreover, the side effects experienced by the patients were mild — a remarkable outcome, given their high tumour burden and the intensive treatments they had undergone prior to the trial.

An encouraging future for CAR-T therapy

While initially developed to treat T-ALL, CD7 CAR-T therapy has also shown encouraging results in other cancers, such as B-cell lymphoma, multiple myeloma and chronic lymphocytic leukaemia. “The next challenge for all of us in this field is how we can extend these therapies to other forms of cancer,” said Prof Campana. “Can we treat breast cancer, lung cancer, colon cancer or prostate cancer?”

The therapy may even offer a potential cure for other conditions, such as autoimmune diseases, added Prof Yeoh. Since it has the ability to ‘adjust’ the immune system, it holds significant promise for conditions where the immune system is ‘overactive’. 

Prof Yeoh highlighted a common thread among the trial patients, who came from all over the world: their “unique determination” to live. “One patient described it as being in a dark tunnel with a train coming," he shared. “You get hit, but you don’t die. Then, you get up and prepare for the next train.” 

When asked why he continues to pursue this work, Prof Yeoh said, “I have to give light to the patients. We are breaking down the tunnel to find a way out for them.”

This commitment to transforming lives through innovative treatments like CD7 CAR-T therapy is exemplified in the case of Maria.

“There was a time when we couldn’t believe this day would come – that she (Maria) could live like a normal teen,” said Mrs Vesna Schreierer. “She can finally be a child again.”