Pre-clinical trials using Patrys’ (ASX: PAB) proprietary PAT-DX1 drug have revealed enhanced survival rates for animals suffering from ab aggressive form of brain cancer known as glioblastoma.
Tissues from the human glioblastoma tumour were explanted onto mice, which were then treated with Patrys’ PAT-DX1 drug by tail vein injection.
Mice that had received PAT-DX1 were found to survive 20% longer than the control group, with no toxicity observed.
PAT-DX1 is a DNA damage-repair antibody that can penetrate a cell’s nuclei and bind to the DNA. The drug can then inhibit the DNA repair process in cells with mutations or repair deficiencies while leaving healthy cells alone. As cancer cells contain mutations and DNA repair deficiencies, PAT-DX1 can kill the cells.
“The observation that PAT-DX1 enhanced survival of animals with MGMT-unmethylated glioblastoma is significant and a positive signal for Patrys’ on going pre-clinical research,” Patrys chief executive officer and managing director Dr James Campbell said.
He added the trial results were consistent with previous observations that PAT-DX1 was able to cross the brain blood barrier and reduce the tumour size in animal models.
The brain blood barrier is a protective layer of endothelial cells that only allow certain molecules to pass through, including most cancer drugs.
“Patrys believes that this model, based on human tumour explants, is one of the best animal models for glioblastoma, and is encouraged by this data that shows that PAT-DX1 has single agent activity against glioblastoma with now apparent toxicity,” he said.
The trial also investigated the impact of combining PAT-DX1 with LYNPARZA which is the poly polymerase inhibitor olaparib.
Results showed that PAT-DX1 on its own was more effective than olaparib, alone. Combining the drugs did not produce any “significant improvement” on solely treating with PAT-DX1.
Patrys’ claimed this was likely due to olaparib’s inability to cross the blood brain barrier.
The company is also working on combining nanoparticles to its PAT-DX1 such as its PAT-DX1-NP drug, to improve targeting of brain tumours in mouse models with glioblastoma.
PAT-DX1-NP has yielded more significant localisation action on cancer cells when trialled on mice with xenograft triple negative breast cancer tumours, as well as nearby axillary lymph node metastases.
The company hopes this will be just as effective in targeting glioblastoma.
“Patrys continues with its pre-clinical work to optimise dosing and scheduling of PAT-DX1 in a range of cancers and is simultaneously progressing pre-manufacturing activities,” Dr Campbell said.
Glioblastoma is an aggressive and highly malignant form of brain cancer and accounts for 17% of all brain cancers.
Around 12,000 new cases of glioblastoma are diagnosed each year in the United States, with current treatments limited to surgery, radiation and chemotherapy.
This particular form of brain cancer has a 15-month survival rate.
By early afternoon trade, Patrys’ share price had shot up almost 26% to A$0.068.