2. Dupixent

Sanofi and partner Regeneron's Dupixent type 2 inflammation treatment is on an advertising roll, boosting brand spending by more than $200 million in 2020.

Brand: Dupixent
Company: Sanofi and Regeneron
What is it: IL-13 immunology drug
2020 spend: $409.8 million
2019 spend: $199.4 million

Sanofi and Regeneron’s Dupixent was just one of the pharma spending crowd in 2019, but that all changed last year when the blockbuster dropped an extra $200 million on advertising.

All told, Dupixent spent more than $409 million across its two approved indications in asthma and atopic dermatitis—and that in just its second full year of advertising. The brand overtook Pfizer's Xeljanz to claim the No. 2 spot on this year's list based on Kantar data.

And it’s only likely to continue. Sanofi and Regeneron are looking to snag more indications—the two are conducting trials in eight different diseases, including eosinophilic esophagitis—and counting on its type 2 inflammation-fighting to get it to more than $11 billion in annual sales. Dupixent sales topped $4 billion in 2020 sales on meteoric 75% year-over-year growth.

RELATED: All eyes on Regeneron's COVID-19 antibodies, but Dupixent's still driving the bus

Four TV ads for atopic dermatitis ran last year, with real patients and a “Roll-up Your Sleeves” theme that included offers of financial help for people facing difficulties during the pandemic.

In asthma, Sanofi and Regeneron continued their play on the brand name, encouraging patients to “Du-More” with less asthma, and adding three additional TV commercials last year.

However, the drugmakers still have plenty of education and marketing ahead for both consumers and physicians. Dupixent holds only a 6% share of the 2.2 million eligible patients in eczema “leaving much more room to grow,” Regeneron told investors in February.

RELATED: Despite strong data from a would-be rival, Sanofi and Regeneron's Dupixent can grow in asthma: analyst

And as SVB Leerink analyst Geoffrey Porges pointed out early this year, Dupixent could face competition from AbbVie's Rinvoq's pending approval in atopic dermatitis this year, but there is still plenty of room for both. And with a surprise delay for Rinvoq's app—amid safety questions for its drug class—Dupixent will at least have a lock on the market for longer than expected.

Analysts also expect a still emerging opportunity for Dupixent in the allergy category. Evercore ISI analyst Josh Schimmer noted positive phase 2 results for Dupixent in conjunction with Aimmune's Palfozia approved to treat peanut allergies. Regeneron promised data at an upcoming meeting that could "meaningfully expand" the already sizeable type 2 helper T cells (Th2) market, Schimmer said.

2. Dupixent