AbbVie's Rinvoq tops Dupixent in eczema showdown, but safety issues will limit use, analysts say

AbbVie
AbbVie is counting on Rinvoq to fill its forthcoming Humira sales gap after the elder drug loses U.S. exclusivity. (AbbVie)

Sanofi and Regeneron blockbuster Dupixent has set a high efficacy bar for all who dare to challenge it in atopic dermatitis, or eczema—but AbbVie’s Rinvoq has leapt right over it. Unfortunately for the Illinois drugmaker, though, analysts expect safety issues to hobble its sales potential.

In a phase 3b head-to-head study, Rinvoq showed it could help more patients hit a score of 75 on the Eczema Area and Severity Index (EASI) than its competitor could by Week 16. Seventy-one percent of Rinvoq patients reached the benchmark, compared with just 61% of Dupixent patients.

Rinvoq also came out on top for a range of secondary endpoints. For one, it helped patients show improvements faster: After a week of treatment, 44% of those in the Rinvoq arm had reached EASI 75, versus 18% of those taking Dupixent. And Rinvoq reduced itch by 31%—a figure that easily beat Dupixent’s 9%.

RELATED: AbbVie's Rinvoq scores pivotal trial win in eczema. But do dermatologists trust JAK inhibitors?

But the AbbVie drug was also dogged by the same safety issues that have cropped up in its past.

The study examined the med at a 30-mg dose—twice as high as the 15-mg dose that’s currently approved in rheumatoid arthritis. And that higher dose previously had come along with increased risk of serious side effects, including infections, gastric perforation and cancer, Bernstein analyst Ronny Gal noted.

“AbbVie has been developing both the 15 mg and the 30 mg, with the thinking that with (a) younger and healthier patient population, higher dose—that could deliver better efficacy—would still be safe enough,” Gal wrote in a note to clients.

In the head-to-head tilt, Rinvoq’s rate of serious side effects wasn’t all that much higher than Dupixent’s—2.9% versus 1.2%—but AbbVie did report one case of death that it pinned on severe infection, a known issue associated with Rinvoq use.

Now, “the approvability of the 30 mg dose is probably a question because of the risk-reward,” Gal said, especially given that atopic dermatitis is a “non-progressive disease” that “may not justify even a less frequent fatality.”

Overall, Gal sees Rinvoq becoming a treatment for patients who have already received Dupixent; SVB Leerink analyst Geoffrey Porges agreed in his own note to clients, adding that the drug “may see some modest frontline use in patients that are needle-phobic or -avoidant.” Still, Rinvoq could hit $3 billion in atopic dermatitis sales, Gal figures, given the market’s massive size.

RELATED: AbbVie's arthritis hotshot Rinvoq grabs a win in ulcerative colitis

Now back to the good news for AbbVie, which is working to build up Rinvoq and fellow new immunology loss Skyrizi as it prepares to hemorrhage sales for best-seller Humira: “Rinvoq is emerging as a potent immunology product that can step up to the plate … as Humira’s value erodes,” Porges wrote, pointing to positive ulcerative colitis data that AbbVie unveiled earlier this week.

“With potential approvals in AD, ankylosing spondylitis, and psoriatic arthritis in 1H 2021, we believe Rinvoq, along with Skyrizi, will continue to impress with strong sales growth in 2021, serving as positive catalysts for the stock throughout the year,” he said.