Therapeutic antibody development company Patrys (ASX:PAB) has announced new preclinical data for its full-sized IgG antibody, PAT-DX3.
The company said results from a new study support the potential to use deoxymabs to deliver small molecule therapeutics and gene editing technologies across the blood-brain barrier to treat various neurological targets and conditions.
The study was conducted by a contract research organisation that radioactively labelled both PAT-DX3 and a control antibody to monitor their relative uptake into various tissues over the course of four days.
The study’s goal was to establish the distribution of PAT-DX3 in a range of different tissues to assist in the selection of future targets and payloads for future potential antibody-drug conjugate (ADC) development programs.
Patrys said the study found that the uptake into the brain of PAT-DX3 was higher than that of a control antibody soon after injection and that this persisted for the duration of the study period.
"The area under the curve (AUC) of PAT-DX3, a measurement of overall drug exposure, was approximately seven times greater for PAT-DX3 than it was for the control antibody in this study, with significant concentrations of antibody still in the brain after four days," said the company.
"The ability of PAT-DX3 to cross the blood-brain barrier is consistent with current data which indicates that Patrys’ deoxymabs enter cells using the ENT2 transporter protein; a protein which is highly expressed in the neural vasculature."
Elevated levels of PAT-DX3 were found in brain tissue but not in a range of other tissues including the lung, the liver and the thyroid adding further support to this proposed mechanism for crossing the blood-brain barrier.
Patrys CEO and managing director Dr James Campbell said, “This is an important result that opens up a range of potential applications for Patrys and its development partners. PAT-DX3 appears to outperform antibodies specifically developed by other companies for the delivery of payloads to brain tissue.
"Unlike deoxymabs, none of these other antibodies are able to deliver their payloads into the cell and the cell nucleus. These properties open up a range of applications for using deoxymabs to deliver small molecule therapeutics and gene editing technologies directed to various neurological targets and conditions. As we advance PAT-DX1 towards the first clinical trial in cancer patients in H2 CY2023, it is very exciting for Patrys to be able to identify additional applications for PAT-DX3 that may open up new development or partnering opportunities for the company.”