Chalk one up for Pfizer’s eczema hopeful—the JAK inhibitor beat placebo at reducing itch and skin inflammation in a third phase 3 study. The drug also posted a slight edge over Sanofi and Regeneron’s Dupixent (dupilumab) on an itch-related measure.
The topline data come from an 837-patient study pitting two dose levels of Pfizer’s abrocitinib, a daily pill, against placebo and Dupixent, an injection given twice per month. For 16 weeks, the placebo group received a pill placebo, to mimic abrocitinib, and an injected placebo, to mimic Dupixent. Patients in the treatment arms received either abrocitinib with the injected placebo or Dupixent with the pill placebo. During the trial, they continued using topical treatments such as nonmedicated moisturizers, corticosteroids or PDE4 inhibitors.
At weeks 12 and 16, abrocitinib met the trial’s co-primary endpoints, beating placebo at clearing patients’ skin as measured by the Investigator Global Assessment, and improving eczema symptoms, such as itch and skin inflammation, by at least 75% as measured by the Eczema Area and Severity Index.
Dupixent beat placebo, too, but it didn’t match abrocitinib at reducing itch severity, as measured by the Peak Pruritus Numerical Rating Scale during the second week of treatment. The higher dose of abrocitinib, 200 mg, achieved a “clinically significant reduction in itch” over Dupixent. The lower dose did “numerically” better than Dupixent but did not hit statistical significance.
Side effects affected patients taking placebo, Dupixent and the lower dose of abrocitinib at about the same rate (53%, 50% and 51%, respectively). More patients on the higher dose of abrocitinib (62%) experienced side effects.
The data echo the results of two other phase 3 studies testing abrocitinib against placebo. The three studies will support regulatory filings for the drug, slated for later this year. Of course, Pfizer will face other competitors than placebo if the drug comes to market, but its performance against Dupixent is an early clue that it can rise to the challenge.
“It was helpful to study abrocitinib in combination with topical therapies to provide data relevant to the real-world setting,” Michael Corbo, Ph.D., chief development officer, inflammation and immunology, Pfizer Global Product Development, said in a statement Wednesday. “The addition of an active control was also important to better understand the significance of this potential new medicine and we’re encouraged by the positive data from this trial.”
Although abrocitinib must be taken daily, unlike twice-monthly Dupixent, it may still be more appealing to patients than Dupixent or Dermira’s lebrikizumab, which are both injected.
Lebrikizumab isn’t the only other drug chasing Dupixent; Eli Lilly and AbbVie are testing their rheumatoid arthritis drugs Olumiant and Rinvoq in atopic dermatitis, too. If all three JAK inhibitors are approved, the following questions could play a role in their uptake:
“Doctors we have spoken with debate the following: 1) Safety of JAKs versus ILs such as REGN’s Dupixent, 2) If all three oral JAKs will have black box/safety warnings or will some not have black box warnings, 3) Which drug has the fastest onset of action and efficacy to treat itch, 4) Which of the three will be the market leader, and, 5) Will there be one leading drug that will take all the share or can more than one oral JAK compete in this market, despite safety concerns,” Cantor Fitzgerald analyst Louise Chen wrote in a note to clients.