Dr Michael Seah
Clinical posts from members and guests of the Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM) from various international medical and scientific conferences on HIV, AIDS, viral hepatitis, and sexual health.
Advances in cellular therapy in cancer and HIV
Dr Carl June presented how novel therapeutics have the potential for an HIV cure. His work in the development of Chimeric Antigen Receptor (CAR) T cells have been instrumental in the cure of lymphoid malignancies. There are similarities in CD4 cell dysfunction between cancer, which causes exhaustion of T cells, and HIV, which causes deletion of HIV specific cells.
CAR T cell therapies use synthetic biology, tools of genetic engineering and genome editing to install a competent immune system into an immunocompromised host. In cancer therapy, an individual's T cells are harvested and geneticically engineered to make the T cells stably express CAR, conferring novel antigen specificity. They are reinfused into the patient to become personal "serial killer" cells. In almost 400 patients accumlating 1500 patient years, there have been no acute T cell toxicity events (ie. no conversion to acute leukaemia). Success has been seen out to 5 years with complete cure of a paediatric patient with advanced ALL and an older adult with extensive CLL.
Unfortunately there are no CAR T cell trials in HIV currently in progress, but it is likely to be an area of future research, with work towards an HIV cure.
The issues faced with this sort of technology are based around time, cost and the need for an individual's cells to be genetically engineered for each patient. Consideration of a blood bank model or central manufacturing strategy could advance implementation. Automated genetic engineering methods could allow CAR T cell treatments to be scalable, with lower coats and increased access. A government-industry-philanthropic partnership for combined funding could be a way ahead.