Aussie cancer drug developer Patrys jumped 400 per cent on Thursday after demonstrating its PAT-DX1 antibody had killed brain cancer cells in the lab.

Patrys (ASX:PAB) shares climbed from 0.4c to 2.2c with almost 300 million shares trading hands.

Antibodies have been used as drugs for some 20 years – but typically they are used to bind to protein markers on a cell surface which may identify the presence of a tumour.

PAT-DX1 was “a very different sort of antibody”, Patrys chief James Campbell told Stockhead.

“It doesn’t bind to proteins on the surface but instead is taken up into the cell and binds to DNA where it interferes with DNA repair.”

“This is absolutely unique,” Mr Campbell said. “This is a discovery that came out of Yale University in the United States. No one else is doing these sort of cell-penetrating antibodies.”

In a series of lab experiments, Patry’s PAT-DX1 was shown to kill brain cancer tissue.

The antibody was placed on brain cancer tumours cut out of seven human patients.

In five of the seven cases, DX1 killed the brain cancer cells, Mr Campbell said.

“We licensed this about 18 months ago and today is the first time we’ve been able to talk about the humanised version of this antibody.”

A humanised drug is one that has been adapted for use in the human body, often following trials in animals.

The results were “very, very exciting”, Mr Campbell said.

“People have been interested in Patrys, but waiting to see the results. We are delighted to live up to the promise that we believe this asset has.”

In another experiment, DX1 showed signs of effectiveness in mice infected with aggressive breast cancer. DX1 was also shown to kill cancer cells in culture.

“We certainly believe we have a strong intellectual property position,” Mr Campbell said.

“The first patent on this was granted in the US a couple of months ago and there have been a series of recent patent filings.

“We have a very clear vision of where this technology goes.

“Our goal is to get this into the clinic, but it will take several years for that,” Mr Campbell said.

“There are a range of things around manufacturing, safety studies, toxicology, but it’s a fairly well-trod path. Patrys is a company that has done clinical trials in the past.”