AbbVie pads Humira follow-up Skyrizi's blockbuster potential with positive 2-year data

AbbVie already has high hopes for newly approved immunology drug Skyrizi as its old megablockbuster Humira starts to fall. Now, it has rolled out results to back longer-term use of the new IL-23 inhibitor in plaque psoriasis.

After continuous treatment for two years, 72% of Skyrizi patients saw a 100% improvement in the Psoriasis Area and Severity Index (PASI 100), a commonly used evaluation of psoriasis in clinical trials. Using static physician global assessment (sPGA), a metric that resembles assessments physicians perform in clinical practice, investigators recorded 73% patients achieved clear skin.

Interestingly, among patients who originally scored clear or almost clear skin (sPGA 0 or 1) on Skyrizi and were then switched to placebo, symptoms initially rebounded in some of them. But 84% of those patients regained sPGA 0/1 after 16 weeks of re-treatment with the AbbVie drug.

“Our studies demonstrated that Skyrizi can not only offer complete skin clearance at two years of treatment for the majority of patients, but re-treatment with Skyrizi after a relapse can help patients regain skin clearance in just 16 weeks,” AbbVie’s vice president of immunology development, Marek Honczarenko, said in a statement.

The new data came from the ongoing IMMhance phase 3 study, where patients who previously achieved sPGA 0/1 at week 28 were re-randomized to continue Skyrizi or withdraw from the drug. During the second phase, Skyrizi’s skin-clearance ability showed up in more patients as time went by. Between one year and week 94, the percentage who reached complete skin clearance (sPGA 0) increased from 65% to 73%, AbbVie said.

RELATED: AbbVie shakes up psoriasis field with blockbuster-to-be newcomer Skyrizi

“[T]he study further demonstrates the significant rates of complete skin clearance that can be achieved with continuous treatment at the recommended dose,” said study investigator Melinda Gooderham. “These data underscore the lasting impact this new treatment option could provide for people living with psoriasis.”

Skyrizi was launched a few weeks ago into the highly competitive immunology market. Apart from old anti-TNF top sellers like Humira, many other interleukin inhibitors are jockeying for share of the psoriasis market, including Johnson & Johnson’s fellow anti-IL-23 drug Tremfya, Novartis’ IL-17 antibody Cosentyx and Eli Lilly’s Taltz, among others.  

AbbVie has touted Skyrizi’s remarkable skin clearance ability, and SVB Leerink analyst Geoffrey Porges has also labeled the drug as having “best-in-category efficacy.” But at least one of its rivals has played down the threat.

RELATED: AbbVie's discounting Humira to aid Skyrizi's launch—and a price war could follow: analyst

“We don’t think there’s anything clinically to be gained from [Skyrizi] entering the market at all,” Novartis’ pharma chief Paul Hudson—who’s now heading for the top job at Sanofi—said on the company’s first-quarter earnings call in April on the same day Skyrizi nabbed its FDA go-ahead. He argued that “more than skin is needed to be treated.”

One key to ensuring Skyrizi’s success is dependent on how fast AbbVie can transfer its Humira patients to the new drug before the U.S. biosimilar competition starts in 2023. To that end, the Illinois pharma is already offering discounts on Humira to secure favorable formulary treatment for Skyrizi.

Editor's Note: The story has been updated to clarify that not all Skyrizi patients re-randomized to placebo in the IMMhance study experienced a relapse.