Medavie Blue Cross' first drug trends report reveals weight management as the lead cost driver, with no signs of uptake slowing
Specialty drugs continue to drive cost trends across Medavie Blue Cross’ book of business, but weight management had the single largest impact on overall spend in 2025, representing 2.7 per cent of total spending, according to the insurer’s inaugural drug trends report.
While coverage for these drugs remains uneven across benefits plans, Medavie includes them as standard, noted Marie-Hélène Dugal, national drug strategy lead at Medavie Blue Cross’ Montreal office.
“About 45 per cent of plans now cover weight management. When looking only at these plans, weight management drugs make up 5 per cent of total spending, placing them third among all drug categories for this group,” said Medavie in the report.
Yet, even with incomplete coverage across the market, the headline finding according to Dugal is the arrival of weight management drugs being included in the top 10 therapeutic categories for the first time.
Among plans that did cover GLP-1s, the category ranked just behind diabetes. Dugal underscored how central these drugs have become to the cost conversation heading into 2026. Still, she cautions that declining costs in a therapeutic category don’t always signal declining demand.
“When we see certain categories slow down, it's not always because we're seeing fewer diagnosis or fewer prescriptions, but simply the arrival of one blockbuster drug being turned into a generic just has that effect on the spend in that particular category,” explained Dugal, pointing to ADHD as the clearest example. She said that claimant numbers and prescription volumes continue to rise, yet a full year of generic availability in 2025 pulled costs down.
“Even though the generic actually came out before, we're really seeing that shift down in terms of cost. Once that's happened, things stabilize, and then you can truly see the impact of the continuing trend in terms of the utilization,” she added.
Why Wegovy changed the equation
According to Dugal, the arrival of Wegovy in 2024 marked a turning point for weight management drug uptake. Saxenda, an older GLP-1, required daily injections, which she noted was a barrier for many patients. But it was Wegovy's weekly dosing, combined with stronger clinical results and a better safety profile, that removed that friction.
"The tolerability, the efficacy, and then the ease of administration, that's where you really hit that magic formula where Wegovy clearly took off," Dugal said, noting the drug displaced Saxenda in utilization almost entirely.
Plan design also played a role, Dugal said, as Medavie shifted its approach around 2019–2020, making weight management a standard benefit category with prior authorization rather than capping coverage at an arbitrary dollar maximum.
But many plans in the broader market never made that change, leaving older structures in place just as public awareness of GLP-1s surged through social media and word of mouth around Ozempic. Dugal said the clinical side has shifted too, with physicians moving toward treating obesity as a chronic disease rather than a lifestyle issue.
The categorization problem
Other findings from Medavie’s report are the growing impact of specialty drugs for skin conditions like psoriasis and atopic dermatitis, which started to register meaningfully in 2025. But she emphasized that plan sponsors should be cautious when comparing trend data across the industry, particularly as different PBMs categorize drugs differently, and those methodological choices shape the results.
For instance, a drug used overwhelmingly for Crohn's disease, could show up under dermatology in one carrier's report if that carrier assigns drugs based on the first indication approved by Health Canada, noted Dugal.
"That can actually drive a lot of the differences you might see between PBMs or carriers in these trends," she said.
Meanwhile, inflammatory conditions remain the top therapeutic drug category, a position they have held for several years. Dugal noted that the category encompasses drugs used across rheumatoid arthritis, psoriasis, Crohn's disease, and ulcerative colitis - conditions that share autoimmune mechanisms and are often treated by the same medications.
Medavie's approach categorizes drugs based on how they’re actually used within its private plan clients, which can produce different rankings than other methodologies. Dugal cited rituximab as an example. It falls under inflammatory conditions on Medavie's book because that reflects private plan utilization, even though the same drug would sit under oncology in a public plan context. But plan sponsors often don’t realize the extent to which categorization decisions affect trend reports, she said, adding that makes it difficult to draw direct comparisons.
That’s why she often encourages plan sponsors to examine their own data alongside these reports to identify where they may be outliers and where plan design changes could help, she said.
Additional findings from the report also found that specialty therapies are beginning to replace traditional treatments for conditions that were once managed at far lower cost. Notably, Dugal pointed to the approval of Xolair for asthma as a turning point, a condition long treated with inhalers suddenly had a therapy costing thousands of dollars, she said.
According to Dugal, the same pattern is playing out across conditions like atopic dermatitis, where creams and standard medications fall short for a subset of patients with more severe or treatment-resistant cases.
“Not everybody responds to the same degree to standard therapy so when you combine these factors together, that's where you find there’s still unmet needs to really manage a condition that can be life-threatening and very impactful for your quality of life, longevity, etc. so you need to have this condition well under control,” she said.
Managing specialty drug costs
That reality puts pressure on plan sponsors to ensure that access to high-cost therapies is governed by clear clinical criteria, said Dugal, adding prior authorization is essential, calling it "the single most important tool to manage specialty drug costs," she said.
The process ensures patients have exhausted standard treatments and ruled out other contributing factors before moving to a biologic or specialty therapy.
When a specialty drug loses patent protection and a generic or biosimilar enters the market, Medavie reassesses whether prior authorization is still warranted, noted Dugal. Even at a lower price point, some drugs carry a risk of off-label use that justifies maintaining clinical oversight.
According to Dugal, without prior authorization, plan sponsors have limited visibility into what they are paying for. She framed the relationship between specialty drug classification and prior authorization as overlapping but not identical as some drugs that aren’t classified as a specialty drug still sit on Medavie's prior authorization program.
She pointed to Botox as one example, where the risk of claims for cosmetic use makes clinical validation necessary regardless of how the drug is categorized.
“Every pharmaceutical company is investing in research and trying to find and fill these unmet needs,” said Dugal. “By design, you tend to find smaller pockets of patients with unmet needs. So that's where you end up with novel treatments being more targeted to a smaller number, and therefore naturally that fits into the specialty definition.”
