Pfizer says its JAK drug topped Dupixent in a head-to-head eczema test — but you'll have to wait on the data
Just a few hours after Sanofi and Regeneron unveiled a new slate of data for Dupixent in children with eczema, Pfizer released its own results for a JAK challenger. And they come from the first such trial showing a direct head-to-head comparison between the two.
The New York-based drug giant uncorked topline data from a Phase III study pitting its abrocitinib against Dupixent, saying the experimental drug notched superiority over the blockbuster in moderate to severe atopic dermatitis. Abrocitinib met both primary endpoints, Pfizer said, with a higher proportion of patients achieving at least a four-point improvement over baseline in an itchiness scale and at least 90% improvement on an eczema index.
“The results from our first formal head-to-head trial for abrocitinib illustrate its potential for meaningful symptom relief for patients,” said Pfizer inflammation and immunology chief Michael Corbo in a statement. “We’re pleased that the study findings show the potential impact abrocitinib could have to help people living with moderate to severe atopic dermatitis in reducing their itch significantly and in achieving near complete skin clearance.”
Pfizer did not release any p-values in the update, and added the company will share the data with the FDA “at the appropriate time.”
Pfizer has been releasing data for abrocitinib, its next-gen follow-up on Xeljanz, in a steady flow over the past few years, positioning the program as a competitor to Regeneron and Sanofi’s blockbuster. Researchers have completed at least five Phase III studies evaluating abrocitinib, comparing the candidate on various measures against placebo, such as lowering the rate of flare-ups and common eczema scales.
But Monday’s results mark the first time Pfizer has given a peek at direct head-to-head, pivotal results between its program and Dupixent, though the two have been measured in exploratory endpoints in previous studies.
In the study, patients were randomized to receive either 200 mg of oral abrocitinib once a day, or a 300 mg injection of Dupixent every other week after a 600 mg induction dose. Researchers reported for abrocitinib at least a 4-point improvement in the severity of Peak Pruritus Numerical Rating Scale (PP-NRS4) from baseline at week 2 and at least a 90% improvement in the Eczema Area and Severity Index (EASI)-90 from baseline at week 4.
Regarding safety, always under the spotlight when it comes to the JAK class, Pfizer said a larger percentage of patients taking abrocitinib saw side effects compared to Dupixent, but noted serious and severe side effect rates were similar in both arms. Two deaths occurred in the abrocitinib arm but were deemed unrelated to treatment — one patient died due to Covid-19, and another due to an intracranial hemorrhage and cardiorespiratory arrest.
The public will have to wait for exact safety figures, but such concerns for abrocitinib and other oral JAK inhibitors are nothing new. Previous studies for abrocitinib have shown platelet counts dropping 26% for the 200 mg dose compared with essentially no reduction on placebo, though they eventually returned to normal. Some analysts have speculated the drug — or any other JAK, for that matter — may never be considered safe enough to truly challenge Dupixent on the market.
Regulators have not weighed in much, but have continually pushed back the PDUFA dates for multiple JAK drugs in eczema, including abrocitinib, Eli Lilly’s Olumiant and AbbVie’s Rinvoq. Olumiant and Rinvoq both sport black box warnings after winning approvals for rheumatoid arthritis. Pfizer has been down this road before as well with another JAK inhibitor in Xeljanz, which regulators said necessitated a warning back in 2019.