The latest preclinical data for Sareum Holdings Plc’s (LON:SAR) checkpoint kinase 1 (Chk1) inhibitor candidate continues to demonstrate its potential as a cancer-fighting treatment.
SRA735 – the official name of the Chk1 inhibitor – was licensed by Sierra Oncology Inc (NASDAQ:SRRA) (formerly ProNAi) last September and the US-listed company holds the exclusive worldwide licence for its development.
READ: Sareum rockets after licensing deal
Sareum said the preclinical data – which was presented at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics held in Philadelphia over the weekend – supported the ongoing development strategy implemented by Sierra.
The results from recent experiments showed that SRA737 can work with “sub-therapeutic” doses of gemcitabine (an existing chemo drug) to kill cancer cells.
"The data generated from these experiments are consistent with recent findings from our research and demonstrate that a potent and selective Chk1 inhibitor such as SRA737 can effectively synergize with sub-therapeutic doses of gemcitabine to induce replication catastrophe and tumour cell death," said Dr Alan Eastman, professor at the Geisel School of Medicine at Dartmouth.
WATCH: Take a look at the presentation
The combination of a Chk1 inhibitor and gemcitabine was also seen to induce high levels of replication stress (RS) on cancer cells.
In typical cancer progression RS will generally occur at low to mild levels and high levels thought to have a negative impact on cancer growth.
Cancer cells are highly reliant on Chk1 to manage RS in order to survive and continue multiplying, so by having a Chk1 inhibitor – SRA735 – there is nothing to temper rising RS levels.
On top of that, gemcitabine is already thought to cause RS. So with the combination of SRA735 and gemcitabine, one agent increases RS levels and the other stops them from being lowered.
"Tumours harbouring high levels of intrinsic or exogenous forms of replication stress are potential candidates for therapeutic intervention using SRA737,” said Sierra chief executive Nick Glover.
“We are actively leveraging these concepts in our ongoing monotherapy and low-dose gemcitabine combination clinical trials."
In afterrnoon trading, Sareum shares were 25%, or 0.02p lower at 0.98p.
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