As Chantelle Lindsay lay in a Halifax hospital bed struggling for every breath as she neared the end of her battle with cystic fibrosis, she sent her mother a text: "Are you OK?"

"I'm OK if you're OK," her mother replied.

"I'll fight until I can't fight anymore," the 23-year-old promised.

Her father, Mark Lindsay, said Chantelle kept her word. And in his daughter's last hours, he vowed to continue fighting to bring a new drug therapy for cystic fibrosis to Canada, so other patients can benefit from the treatment his daughter couldn't access.

Her death from the fatal genetic disease has become a rallying cry for advocates who say the federal government's recent changes to drug-pricing regulations are preventing "life-saving" medicines from reaching Canada.

Mark Lindsay said his mission is to ensure that no other lives are lost in the Canadian government's "chess game" with the pharmaceutical industry.

"It's just a back-and-forth game between them to see who's going to give first," Mark Lindsay said. "She happened to be one of the pawns to leave the game."

Family, friends, former teammates, fellow patients and strangers touched by Chantelle Lindsay's story are among those expected to gather at a memorial service in her hometown of Truro, N.S., on Wednesday.

When his daughter was hospitalized in late December, Mark Lindsay said he petitioned lawmakers and the drug manufacturer for permission to have Chantelle put on Trikafta, a drug that has been approved to treat cystic fibrosis in the U.S., but is unavailable in Canada.

By the time the family heard back, Mark Lindsay said Chantelle's lung function had deteriorated to the point that she needed a ventilator. Their request was rejected.

Health Canada said the drug's manufacturer, Vertex, hasn't submitted Trikafta for approval for use in Canada, and it can't force the company to do so.

Vertex can't comment on products that haven't received market authorization in Canada, a spokeswoman said, but the company raised concerns that Canada's recent drug-pricing reforms could limit access to treatments for rare diseases.

Health Canada announced long-awaited amendments last summer to patented medicine regulations, which include allowing the arm's-length Patented Medicine Prices Review Board to consider whether the price of a drug reflects the value it has for patients.

A spokesman for Health Canada said in an email that the amendments will make prescription drugs more affordable and accessible, and save Canadians an estimated $13 billion in the next decade.

Geoffroy Legault-Thivierge said evidence suggests the regulations won't limit access to new medicines, saying other countries with lower prices see drugs introduced on similar timelines.

Canadian pharmaceutical lobby group Innovative Medicines Canada, which filed a lawsuit against Ottawa in response to the regulations, said at least 10 drug launches have been delayed since the new regulations were unveiled.

A spokeswoman for the Patented Medicine Prices Review Board said it would be "premature" for pharmaceutical companies to make decisions based on the draft guidelines, because the agency is considering making "significant changes" before they're finalized.

Isabelle Rodier said possible revisions include extending the "grace period" to give patent-holders 18 months to comply with the new list of price ceilings after the regulations take effect in July.

The agency is also considering narrowing its criteria for which patented medicines are deemed to be at higher risk of excessive pricing, so that only a "minority" of drugs would be subjected to rigorous review, she said.

But Dr. John Wallenburg, chief scientific officer at Cystic Fibrosis Canada, said the prospect of policy adjustments does little to quell the climate of "uncertainty" that has big pharma spooked and patients fearing for their lives.

Wallenburg said Trikafta could be a "miracle drug" for many of the estimated 4,300 Canadians who have cystic fibrosis, because it not only manages symptoms, but addresses the underlying cause of the disease.

He said the three-drug therapy has proven effective in treating people with the most common of the 1,700 genetic mutations that have been linked to cystic fibrosis, representing roughly 90 per cent of patients.

Trikafta targets a faulty protein that causes the buildup of mucus that clogs the lungs and gums up the digestive system. Many patients on the drug have seen dramatic clinical improvements, Wallenburg said, which could change the course of the progressive disease over time.

But such a medical breakthrough comes at a price -- roughly US$300,000 a year -- that Canadian authorities seem unwilling to pay, Wallenburg said.

As the pharmaceutical industry moves towards "precision medicine," narrowly targeted treatments based on a genetic understanding of diseases, he worries Canada will be left out of the next wave of innovation.

Wallenburg said he lost his lost daughter to cystic fibrosis in 2014 a week before her 28th birthday. One of the things he's found most difficult in his job is confronting how patients in his daughter's situation have survived with access to the right treatment.

"To imagine that you lose your daughter when the drug is there, just because of some bureaucratic hiccup, the tragedy is indescribable," he said.

As the story of Chantelle's fight has spread across social media, Mark Lindsay said the outpouring of generosity has been overwhelming.

The Go Vinyl For Chantelle Facebook group is awash in purple -- the colour representing cystic fibrosis -- with tributes to his daughter, including a local hockey team that taped up their sticks in solidarity with the avid athlete.

Some supporters are selling off wares to support the cause, while Mark Lindsay said he received a cheque from a pensioner who asked him not to cash it until next month's payment comes.

But patients shouldn't have to rely on the kindness of strangers to access the treatments they need, he said. That's the government's job, and as a father, he's entreating lawmakers to spare other parents the grief that his family has suffered.

"There's people dying every day," he said. "Chantelle's just one that got some attention, but how many others are still out there struggling, wondering, 'Is it tomorrow? Is it the next day?"'

This report by The Canadian Press was first published Feb. 25, 2020.