Clinical-stage oncology company Prescient Therapeutics (ASX: PTX) has revealed new data that demonstrates the capability of its OmniCAR cell therapy technology in killing multiple cancer cells.
The company is presenting this pre-clinical data this week at a cell therapy conference in California, US known as the ‘Cell and Gene Meeting on the Mesa’.
In its conference presentation, Prescient said OmniCAR’s key attributes include a dose response relationship that exhibits tumour killing activity and high potency, a demonstrated re-arming of OmniCAR-T cells, and sequential arming to re-direct OmniCAR-T cells from one cancer antigen to another.
This most recent work was conducted in collaboration with the Peter MacCallum Cancer Centre in Melbourne, Victoria and Prescient director of scientific affairs Dr Rebecca Lim said data continues to be “extremely positive”.
“Our most recent work… showed that OmniCAR-T cells begin antigen-directed killing of tumour cells in vitro as soon as they are armed.
“The team also showed that OmniCAR-T cells could be re-armed and continue to kill tumour cells without loss of cytotoxicity,” she added.
Dr Lim described the early wins as “extremely encouraging”.
“Excitingly, we saw for the first time the real-time ‘switchability’ of the OmniCAR system where the tumour killing ability of the OmniCAR-T cells could be redirected towards a different antigen through the addition of a different binder.”
“We look forward to the next phase of pre-clinical testing where the OmniCAR technology will be put through its paces using gold standard cancer models.”
Cells able to be redirected to different antigen target
Prescient is developing OmniCAR programs for next-generation CAR-T therapies for acute myeloid leukemia (AML), Her2-plus solid tumours including breast, ovarian and gastric cancers, and the brain cancer known as glioblastoma multiforme (GBM).
In particular, GBM is characterised by antigen heterogeneity and rapid mutations that drive rapid progression of the cancer. These characteristic make CAR-T and other therapies challenging as they rely on single antigen targeting.
Prescient is seeking to overcome these limitations with the development of OmniCAR to enable mutli-antigen targeting.
In a novel experiment, OmniCAR was tested sequentially against a co-culture of GBM cells expressing antigens, Her2 or EGFRviii. OmniCAR-T cells pre-armed with EGFRviii binders demonstrated rapid cytotoxicity against those GBM cells expressing EGFRviii.
Meanwhile, subsequent administration of Her2 binders demonstrated rapid switching of OmniCAR-T cells arming with Her2, and corresponding rapid cytotoxicity against Her2-plus GBM cells.
According to Prescient this shows that OmniCAR cells can be redirected to a different antigen target upon administration of a different SpyTagged binder without needing new cells. In each case, OmniCAR exhibited highly targeted tumour killing.
Prescient believes this highly novel feature will also be important in developing OmniCAR for AML, which is another cancer characterised by high antigen heterogeneity, rapid mutations and rapid disease progression.
Yet to discover true limits of OmniCAR technology
Prescient managing director and chief executive officer Steven Yatomi-Clarke said the large body of work accomplished so quickly and successfully is a credit to the team and its collaborators at Peter MacCallum Cancer Centre.
“Importantly, none of these tests have even been optimised, so we have yet to see the true limits of this technology,” he said.
“OmniCAR is proving to be a predictable and powerful system to work with. We look forward to sharing updates as our programs progress.”