Animal data shows potential for Patrys’ PAT-DX1 drug to help radiation fight aggressive brain tumours

Therapeutic antibody developer Patrys (ASX: PAB) has revealed new pre-clinical animal data that points to the potential for its lead candidate drug PAT-DX1 to improve survival rates for patients with highly aggressive forms of brain tumours.

The company today released results from a newly completed study at the Yale School of Medicine, which involved using a glioblastoma tumour explant to generate brain tumours in mice.

Glioblastoma (GBM) is an aggressive, highly malignant form of brain cancer characterised by rapid cellular reproduction.

The condition’s current treatment is surgical resection followed by radiation and chemotherapy, which are associated with many side effects.

Yale’s study tested the effects of PAT-DX1, low-dose radiation, and a combination of the two, on tumour growth and mouse survival.

According to Patrys, the animal data showed that using PAT-DX1 increased tumour suppression, with an 87% reduction in tumour size relative to the control group observed two weeks after starting treatment. This is compared to a 52% tumour reduction using low-dose radiation alone.

In addition, using PAT-DX1 in combination with low-dose radiation resulted in an even greater tumour reduction rate of 93% compared to the control group.

Furthermore, the survival rate of mice being treated with PAT-DX1 was 41% higher than the control group, while the combination treatment group was 71% higher.

Patrys chief executive officer and managing director Dr James Campbell said the data demonstrates that PAT-DX1 enhances the efficacy of low dose radiation, potentially improving the standard of care, while reducing side effects.

“Radiation therapy often results in significant morbidity and severe side effects, particularly in elderly populations,” he said.

“The ability to improve clinical outcomes by reducing the dose of radiation required, could be an important advancement in the treatment of GBM,” Dr Campbell added.

The study was part of Patrys’ broader program to identify and optimise dosing regimens for future studies.

The company said ongoing studies will explore several radiation and PAT-DX1 dosing regimens to inform and guide the design of clinical trials.

According to Patrys, about 17% of all primary brain cancers are GBMs, with close to 12,000 new cases diagnosed in the US each year and a median survival period (using currently available treatments) of about 15 months.

Deoxymab 3E10 patent granted in Europe

Last week, Patrys announced it has been granted a European patent for its novel technology platform Deoxymab 3E10, the DNA damage-repair antibody that forms the basis of its drug PAT-DX1.

The patent, “Cell-penetrating anti-DNA antibodies and uses thereof to inhibit DNA repair”, covers methods of using the Deoxymab 3E10 technology, including PAT-DX1, as treatment for a range of cancers and malignancies such as gliomas, metastases, breast, pancreatic, ovarian and prostrate cancers, and melanomas.

This patent follows the grant of patents in the US in 2017 and Japan and China in 2018.

Patrys also has more than 20 pending patent applications across nine patent families.

Dr Campbell said Europe represents an important region where many global pharmaceutical and biotechnology companies are based.

“Having secured patent protection in some of the world’s largest pharmaceutical markets including US, Europe, China and Japan, Patrys is well positioned to preserve future product sales in key target markets,” he said.