Australian therapeutic antibody development company Patrys (ASX:PAB) has announced results from a recently completed pre-clinical study that it says validates the potential to use its full-size IgG deoxymab, PATDX3, for synthetic lethality strategies to treat relevant cancers.
Patrys said its deoxymabs have a number of novel properties that are not typically found in antibodies and offer the potential to develop new antibody-based therapeutic strategies for treating cancer.
“One of these is the ability to enter the cell and cell nucleus and block the DNA Damage Response (DDR) systems,” said the company.
“In tumours with pre-existing mutations that compromise their DDR systems, such as cancers with a mutation in the BRCA2 gene, the additional inhibition from adding a deoxymab may result in the accumulation of DNA damage that can ultimately kill the tumour cells.
“This approach is known as ‘synthetic lethality’ and has been successfully used in certain tumours with several new small molecule cancer drugs,” it said.
The company said that in a pre-clinical colon cancer study in mice treated with PAT-DX3, tumours with a compromised DDR system showed a 71 per cent reduction in growth, significantly more than the 35 per cent reduction in growth in tumours with an intact DDR mechanism.
Patrys CEO and managing director Dr James Campbell said, “This is an exciting and important result that shows for the first time the comparative effects of a Patrys deoxymab on tumours with or without DDR mutations in the same animal.
“This study was requested by a potential partner as part of Patrys’ ongoing business development activities. This study confirms the potential to use deoxymabs as a single agent to treat cancers which have pre-existing mutations that compromise their DDR systems, including BRCA2-negative breast cancer and other cancers.
“In addition, Patrys is looking at using deoxymabs in combination with DNA damaging therapies, such as radiation and chemotherapies, and as a delivery agent for small molecules and nucleic acids.”