World-first gene editing treatment to eliminate angioedema life changing, patient says

Auckland woman Bev Tanner. Photo: Supplied

An Auckland woman with a rare disease that caused unpredictable and dangerous swelling - sometimes of her entire body - says a world-first gene editing treatment has been life changing.

Bev Tanner was one of just 10 patients internationally who took part in an initial trial of the therapy led by Auckland University.

She has hereditary angioedema - a condition that took 17 years to be properly diagnosed.

An attack would start with a small red mark on her arm, then a few hours later her whole arm would be "swollen up like a rubber glove".

"Then my legs, my back, my whole internal organs, anything on my body could swell up. My throat could swell closed. And that happened all the time," she said.

Sometimes she would vomit every 15 to 20 minutes for several days.

"By the time I got diagnosed I was in bed four or five days a week."

After diagnosis she was put on a heavy duty steroid for 13 years that minimised the severity of the attacks but caused weight gain and meant she had to be regularly checked for liver damage.

When she got the opportunity to go on the trial she was nervous.

"It was a hard decision, I hummed and hahed for quite a while," she thought.

She decided she could help other people so they would not have to go through 17 years of "thinking you're a hypochondriac and being sick all the time and no-one knows what's wrong with you".

In August 2022, she became the eighth person on the trial and since then she has not had an attack and does not take medication.

Clinical immunologist and Auckland University honorary associate professor Hilary Longhurst led the work which was done with Amsterdam and Cambridge universities and funded by an American biotech company, Intellia Therapeutics.

Dr Hilary Longhurst Photo: Supplied

It is a type of therapy known as a CRISPR and this one, called NTLA-2002, is a single dose infusion into a vein that introduces a genetic treatment to the liver where the problem begins.

"It will go into the nucleus and it will find very, very specifically the gene that is causing the problem and it will just cut that gene," Longhurst said.

The clinical collaboration with the two other universities came after many years of research on the therapy, much of it in the United States, she said.

She had been confident it would work well on patients but there was always a small degree of uncertainty that it would not act as expected until the results came in.

"I've been so excited and happy for my patients," she said.

Longhurst thought it would be a permanent cure for the symptoms of hereditary angioedema - which was often found throughout families.

However, such a small trial was not enough to determine that, so now a larger, double-blind trial was under way meaning neither the participants nor their doctors know whether they are on the treatment or a placebo.

She hoped the therapy would eventually be able to be applied to other conditions.

Tanner and other trial participants would continue to be monitored for 15 years.

A paper on the research was published on Thursday in the New England Journal of Medicine.