Immunotherapy trial holds hope for children needing stem cell transplants

A new immunotherapy treatment will be studied in clinical trials, with the aim of preventing dangerous side effects for children who have to undergo stem cell transplants.

Stem cell transplants for blood cancers or inherited immune deficiencies are high-risk procedures that are required to cure otherwise life-threatening diseases, but many patients develop viral complications.

The trial will involve up to 20 children aged between three months and 18 years who need stem cell transplants from a family member to treat blood cancers or genetic immune deficiencies.

The immunotherapies will be manufactured at QIMR Berghofer Medical Research Institute in Brisbane and will be administered at participating clinical trial sites at the Queensland Children’s Hospital, the Children’s Hospital at Westmead, Sydney Children’s Hospital and the Royal Children’s Hospital in Melbourne.

The Head of QIMR Berghofer’s Centre for Immunotherapy and Vaccine Development, Professor Rajiv Khanna AO, said the cellular immunotherapy is made by turbocharging immune cells taken from the same person who donated their stem cells for the child’s transplant.

“Before patients receive a stem cell transplant, certain immune cells — like killer T cells and B cells — are removed from the donor’s cells. This lowers the risk of potentially fatal complications like graft-versus-host disease, where the donor’s immune cells attack the recipient’s tissues,” Professor Khanna explained.

“But this necessary step of removing immune cells from the stem cells leaves transplant patients at high risk of developing viral infections. Up to 60% of stem cell transplant patients have clinical complications with one or more viruses because they don’t have the disease-fighting T cells and B cells to control infection.

“By taking white blood cells from the same donor and training them in the laboratory to recognise and destroy cells infected with the four most common viruses that affect these patients, we hope to effectively prevent complications arising.”

In the first stage of the clinical trial, the donor’s blood is collected ahead of the stem cell transplant and turbocharged at QIMR Berghofer’s cell therapy manufacturing facility, Q-Gen Cell Therapeutics.

Within a few weeks, the child receives their stem cell transplant as part of their standard treatment. Once the transplant has engrafted, the patient will start receiving fortnightly T cell immunotherapy infusions aimed at boosting their immune system before they show any signs of viral complications.

Dr Chris Fraser, a paediatric oncologist and Director of the Blood and Marrow Transplant Program at Queensland Children’s Hospital, said the timing of the immunotherapy is important because viral complications could occur as early as a month post-transplant.

“We want to continue to boost the patient’s immune system every fortnight so they’re protected against cytomegalovirus, Epstein–Barr virus, BK virus and adenovirus, and their stem cell transplant can work effectively to kill off their blood cancer or correct their immune deficiency,” Dr Fraser said.

“The immunotherapy will continue for approximately two months, after which we will follow these patients for eight months or more to confirm the therapy is safe.

“Stem cell transplants for blood cancers or inherited immune deficiencies are high-risk procedures that are required to cure otherwise life-threatening diseases. Our aim is to see if this new therapy can be safely used in these vulnerable children, and in the future we hope that T cell immunotherapy may be used to reduce the risk of potentially fatal viral infections after transplantation.”

The clinical trial will be open to children who need donor stem cells from a family member whose bone marrow is not an exact match.

The trial is jointly supported by QIMR Berghofer Medical Research Institute and the Children’s Hospital Foundation.

Children’s Hospital Foundation CEO Rosie Simpson said the organisation was proud to help fund the clinical trial as the Foundation increases its support of innovative research into areas such as immunotherapy to ensure sick Queensland children receive the very best possible care and treatment.

“The Children’s Hospital Foundation is focused on helping enable world-class research and clinical trials that advance treatment options for sick kids and improve their chances of survival,” Simpson said.

“This trial provides important hope of better outcomes for the families going through the stem cell transplant process, and also adds to the growing wealth of knowledge on how best to treat viral complications.”

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