Pfizer's COVID-19 pill could have real impact in Canada — if we can roll it out fast enough
Logistical issues, speed in prescribing and real-world data still need to be sorted out
After Canada approved a new treatment for COVID-19, Pfizer's highly effective oral therapeutic Paxlovid, experts are hopeful the highly sought after pill can help control a devastating Omicron-driven surge — if it's rolled out fast enough.
"I think it will be an effective tool in high-risk individuals if they can get tested quick enough to be able to be in the window for therapeutic benefit," said Dr. Amesh Adalja, an infectious diseases physician and senior scholar at the Johns Hopkins Center for Health Security in Baltimore.
"If you can get it to people fast enough to keep them from needing hospitalizations, then that basically solves the major problem that we're facing."
But questions remain as to whether the provinces and territories will be able to get the drug out to sick, vulnerable Canadians within the recommended five-day window, helping to ease the pressure on hospitals until current COVID-19 levels subside.
"Obviously this is a very promising development, but there's still some work that lies ahead," Dr. Isaac Bogoch, an infectious diseases physician and member of Ontario's COVID-19 vaccine task force, told CBC News Network on Monday.
"That's fantastic we've crossed that first step. We also now, of course, need to distribute it to the provinces and to have the provinces work out how it's actually going to be administered."
WATCH | Paxlovid shows great promise despite logistical hurdles, says Dr. Isaac Bogoch:
Canada 'dragging our feet' on rollout plan
Canada's Chief Public Health Officer Dr. Theresa Tam said Monday the antiviral treatment — made up of nirmatrelvir and ritonavir — will be in "high demand" and that officials anticipate initial supply "will not be great anywhere" as they work with provinces and territories to determine how best to roll it out.
Dr. David Naylor, who led the federal inquiry into Canada's national response to the 2003 SARS epidemic and co-chair of the federal government's COVID-19 immunity task force, said recently he's been "very frustrated" with the pace of approval.
Canada needs a Paxlovid rollout plan involving both virtual and ambulatory care, he said — one that can confirm the presence of the virus in a patient, assess the severity of their illness, prescribe the pill quickly and to ensure that available doses reach those who need it most.
"So far as I can tell, we're also dragging our feet on that front," he told CBC News. "Countless thousands of Canadians are seriously ill at home with COVID-19 and, from what I see and hear, many are feeling abandoned."
Naylor said Canada can also develop helplines for those eligible for the treatment, provide clear information on its benefits and co-ordinate outpatient care to support patients at home — instead of assuming their situation is "irrelevant" unless they're hospitalized.
After several months of clinical trials, Pfizer had reported in November that Paxlovid reduced the risk of hospitalization or death by an impressive 89 per cent compared with a placebo in non-hospitalized high-risk adults with COVID-19.
Canada has pre-purchased one million doses of the drug, with the first batch of 30,000 to be distributed on a per-capita basis and more arriving in the coming days. It will no doubt spark a rapid push to disperse the treatment to those at highest risk as soon as possible.
But getting that limited supply out in time to mitigate the pressure on hospitals will be no small feat — and the impact likely won't be felt anytime soon.
"There's almost certainly not going to be enough supply to really make a population impact," said Dr. Allison McGeer, a medical microbiologist and infectious disease specialist at Toronto's Mount Sinai Hospital.
"Not that it isn't a good thing, not that we shouldn't be using it."
WATCH | Health minister says 120,000 Paxlovid treatments expected by March; 30,000 already distributed:
Canada needs 'rapid turnaround' for Paxlovid
The medication will be most effective in those at highest risk of severe illness, whether due to age, underlying health conditions, comorbidities or those who are unvaccinated.
High-risk patients also need to take the drug within five days of symptom onset — something Tam said highlights one of the "key challenges" of the highly sought after treatment.
"It has to be used very early after symptom onset — the sooner, the better — and really not after five days," said Bogoch. "So you really have to think how are you going to get this out to people in need and really have that rapid turnaround time."
There are "logistical hurdles" that lie ahead for Canada with Paxlovid, Bogoch said, and provinces and territories need to ensure there is "equitable access" to the drug — especially in communities that are disproportionately impacted and under-serviced.
An ideal rollout of Paxlovid would involve patients getting an at-home rapid antigen or PCR test, calling a hotline or their family doctor for information on the drug, and then having it dispensed to their local pharmacy or delivered to them directly at home, said Adalja.
But finding those high-risk patients within the five-day window will be tricky — especially given the fact that COVID-19 testing capacity is currently overwhelmed across much of Canada.
B.C. Provincial Health Officer Dr. Bonnie Henry recently told CBC News that she believes COVID-19 testing strategies should be shifted to symptomatic patients at highest risk of severe illness, in order to identify them and deliver treatment in a timely fashion.
"Shifting our strategy for people who might need monoclonal antibodies or [Paxlovid], making sure we can get those to people who are at risk of hospitalization and more severe illness quickly," she said. "Those are the focus that we need to put on our testing right now."
More data needed on real-world effectiveness
While clinical trials showed the pill is highly effective at preventing the worst outcomes of COVID-19, Bogoch said it's important to remember the available data supporting the medication's use was released by Pfizer and hasn't yet been subject to peer review.
"We have great data from the pharmaceutical company, but this is all very early. And I think it would strike more confidence in the general public if we saw [it] peer reviewed and more transparency over the data," he said.
"Having said that, everything we've heard about this pill seems very promising."
The clinical trial data for Paxlovid was so strong that an independent group of medical experts monitoring the trial recommended stopping it early, which is standard practice when early results show such a clear benefit.
Fewer than one per cent of patients taking the medication in clinical trials needed to be hospitalized and none of them died. In the placebo group, seven per cent of patients were hospitalized and there were also seven deaths.
Study participants were unvaccinated, with mild-to-moderate COVID-19, and were considered high risk for hospitalization due to health problems like obesity, diabetes or heart disease.
By comparison, though, Merck's COVID-19 antiviral pill, Molnupiravir, was initially found to be 50 per cent effective in preventing severe illness, hospitalization and death — but that dropped to 30 per cent after more data became available.
"Obviously, with time, we'll get more and more access to [Paxlovid], we'll have a better understanding of how well it works," said Bogoch. "But we can't underplay how significant this is. This is a big step forward."
ABOUT THE AUTHOR
