Can Lilly JAK Olumiant, plagued by side effects, really challenge Dupixent in dermatitis?

Eli Lilly and Incyte's JAK med Olumiant scored a phase 3 trial win in atopic dermatitis. (Eli Lilly)

Eli Lilly and Incyte's Olumiant has run up against safety hurdles in the past. But can those hurdles stop the drugmakers from adding another feather to the drug’s cap, this time in the booming—and increasingly competitive—atopic dermatitis (AD) market?

Adding Olumiant to standard-of-care corticosteroids significantly cleared AD trial patients’ skin over placebo at 16 weeks. Those were the findings from the drug’s phase 3 trial Breeze-Ad7, the third of five placebo-controlled trials for Olumiant in AD, Lilly said in a release.

Lilly said it plans to release top-line data from the remaining two phase 3 trials in late 2019 and early 2020.

Strong performances could set up Olumiant as a potential late entry into a field dominated by Regeneron and Sanofi’s Dupixent, the first-to-market med. But that doesn't mean Olumiant could seriously challenge the reigning star.

SVB Leerink analyst Geoffrey Porges pointed to Dupixent's higher response rates—as well as a pulmonary embolism reported in the Olumiant arm.

"We believe that we now know enough about the current generation of JAK inhibitors to more or less dismiss them as threats to Dupi in benign dermatological and atopic indications," he wrote.

Olumiant, which last year won approval to treat rheumatoid arthritis (RA) with its 2-milligram dose after an initial rejection, has faced blowback from the FDA for its higher dose as safety concerns have derailed its sales push.

Regulators slapped a Black Box warning on Olumiant’s 2-milligram dose for risk of infections, malignancy and thrombosis. For the higher dose, the FDA knocked Lilly and Incyte for unclear safety and efficacy data after an advisory committee voted to turn it down.

RELATED: AbbVie's Rinvoq label portends safety warnings for future JAKs—including Gilead's

Olumiant isn’t the only JAK inhibitor facing safety scrutiny from the FDA: AbbVie’s recent blockbuster approval for JAK med Rinvoq came with a similar Black Box warning for infections, malignancy and thrombosis. That label could become the standard for the JAK class, analysts said, potentially capping sales for the class on the whole.

But Lilly has fought to clear Olumiant's reputation. In June, it touted seven-year safety data for Olumiant’s 4-milligram dose showing roughly the same rate of adverse events—including deep vein thrombosis and pulmonary embolism—as patients treated with placebo.

Still, with that safety scrutiny lingering over its head, Olumiant will have a serious disadvantage against Dupixent, Porges wrote.

"In these diseases, there is no reason, or real inclination, for physicians and patients to take the risk of a JAK inhibitor, even when they offer the convenience of daily oral formulation," he said.

Driven by Dupixent’s strong—and growing—sales, Regeneron and Sanofi’s 12-year-old antibody partnership finally turned a profit in the second quarter for the first time. The drug turned in an impressive $557 million in sales on the quarter, boosted by eczema and AD, which Marion McCourt, Regeneron’s SVP of commercial operations, called “major drivers” for the med.

RELATED: Watch out, Dupixent. Pfizer's new JAK inhibitor could come after your eczema market

The drug has also seen strong uptake in severe asthma, where 80% of patients starting Dupixent haven’t taken a biologic before, while the rest are switches from rivals such as GlaxoSmithKline's Nucala. Earlier this month, Dupixent also scored an approval to treat adolescents AD patients in Europe and posted positive phase 3 top-line results for AD in children ages 6 to 11. Before that, it racked up a first-of-its-kind approval to treat sinusitis with nasal polyps.

Another JAK challenger in AD, Pfizer's abrocitinib, also posted a phase 3 trial win in the indication back in May.