A Regina mother who was one of the first ALS patients to test a new treatment is now celebrating its accelerated approval in Canada for adults with an ultra-rare form of the disease.

Paula Trefiak's remarkable experience on tofersen, a medication sold under the brand name Qalsody, is reflective of why researchers are calling the drug a breakthrough.

"My life has completely changed. I am actually looking forward to retirement now. I never thought I would ever get to retirement," Trefiak, 43, told CBC News.

People diagnosed with amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disorder also known as Lou Gehrig's disease, have a life expectancy of two to five years. They become trapped in their body, losing the ability to move, speak, chew and eventually breathe.

Health Canada confirms it has granted conditional approval to Qalsody to treat adults with ALS in cases linked to a mutation in the superoxide dismutase 1 (SOD1) gene.

Paula Trefiak's grandmother, second from the left, and her sisters. Three of the five women died from ALS. (Submitted by Paula Trefiak)

Ottawa expedited access to the drug under a program that recognizes it would be unethical to withhold it from patients, but pharmaceutical company Biogen must still complete additional clinical trials.

The drug is not yet covered under public or private drug programs.

Family history

Trefiak, 43, realized she had a pretty good chance of developing ALS when her father was diagnosed with the disease in 2001. She can count 26 people in her family who have died from the disease in her lifetime.

These are Paula Trefiak's great-grandfather's sisters. All four died from ALS within a five-year period. There were 10 siblings in the family and seven died from the disease. (Submitted by Paula Trefiak)

Most ALS cases are sporadic, but a small fraction are genetic. About three per cent of all ALS cases are linked to a mutation in the SOD1 gene.

Despite her family history, Trefiak said doctors were reluctant to send her for genetic testing when she was in her early 20s. She recounts one doctor telling her, "You're too young to have it. And there's no cure. There's no treatment. So it's best not to find out."

By 2010, her muscles began to cramp for hours and Trefiak felt certain she had inherited the gene variant. She was diagnosed with ALS in February 2016, at the age of 34.

Her prognosis was dire. There were no treatments available.

"It was absolutely devastating. I had three young children, and to know that I was going to lose my ability to hug them, to kiss them, and that they were going to lose their childhoods becoming my caregivers," she said.

Paula Trefiak with her three children in March 2016, a month after she was diagnosed with ALS. (Submitted by Paula Trefiak)

Nine months later, she got a phone call that gave her some hope. She was invited to the Neuro Hospital in Montreal to take part in a clinical trial designed for people with ALS caused by a mutation in the SOD1 gene.

She believes she received the placebo in that clinical trial, but began the full dosage of 100 mg in early 2018, during the open label portion of the study.

By then, involuntary muscle twitches in her face and lip were causing drooling and stuttering. She was too weak to continue her jobs as a fitness instructor and emergency medical responder, and had to give up on her schooling to become a dental hygienist because she couldn't hold the instruments any longer.

Within nine months of taking the drug, many of the symptoms reversed.

Clinical trials

Dr. Angela Genge is a neurologist, director of the ALS Centre of Excellent at The Neuro in Montreal and lead investigator in the clinical trials.

She said the medication actually modifies the disease itself and slows — even stops — the progression.

"It is able to stop the disease in its tracks on a significant number of patients or people living with ALS," Genge said. "[Qalsody] is actually a huge breakthrough."

Genge points to the fact that Paula Trefiak is still alive.

"People are not dying who are successfully on the treatment," the neurologist said, emphasizing the drug is not a cure and that benefits only continue as long as the drug is taken.

Paula Trefiak is thrilled to have a treatment that controls her ALS, but must receive an injection in her spine every four weeks. It's not a cure. (Submitted by Paula Trefiak)

Today, Trefiak runs and dances.

"I'm a ballet dancer. I couldn't even get up on my toes anymore and now I can hold myself up on with full body weight on one foot and I'm back wearing my three-inch heels again," she said.

WATCH | Paula Trefiak recorded involuntary muscle twitching in her face in 2017. See how she has improved: 

Paula Trefiak recorded involuntary muscle twitching in her face in 2017. See how she improved

Regina ALS patient Paula Trefiak took part in clinical trials for a drug that has slowed the progression of the disease and reversed most of her symptoms.

Exciting possibilities

Dr. Genge said this treatment is already inspiring other research on therapies for forms of ALS not caused by SOD1, as well as the drug's impact on people who have the gene mutation but have yet to show symptoms.

"So that we catch people at the very, very, very beginning, so they never actually develop anything significant and we can treat them right away," Genge said, noting blood tests can reveal when the disease activates.

That's also exciting for Trefiak. She has three children who may have inherited the gene mutation. This drug could stop them from developing ALS symptoms and help them live long lives.