Pfizer offers 3rd round of JAK data, this time in kids. Can it compete?
Pfizer has released the 3rd round of large and late-stage data for their JAK inhibitor and they say — well, they say pretty much what the first 2 studies said, just in a new set of patients.
The latest study, called JADE TEEN, was the first to study their JAK inhibitor abrocitinib exclusively on children and adolescents, testing it against placebo in just under 300 atopic dermatitis patients age 12 to 18. The youth population for AD is significant, with between 15% and 20% of children affected annually by the inflammatory condition worldwide.
As in the adult studies — which allowed for patients as young as 12 but had a mean age as high as 35 — the trial met its two primary endpoints: a pair of metrics that measures how much the drug reduces area of redness and itchiness. But also like the adult studies, the teens on the drug arm showed higher rates of adverse effects. The full details weren’t disclosed, but 62.8% of patients on the high dose drug arm had side effects, compared to 52.1% for placebo.
In atopic dermatitis, Pfizer is going up against an entrenched competitor in Regeneron and Sanofi’s Dupixent, an IL-4/IL-13 inhibitor. In that struggle, the NJ pharma has a few things for them: It’s given orally as opposed to subcutaneously, and overall it has looked similar in its ability to treat the itch and pain that afflict patients.
“The effect of abrocitinib was fast onset and could be observed as early as week 2, which concurred our KOL’s impression in previous interviews,” Jefferies’ Biren Amin wrote in a note to investors after the last round of abrocitinib data was published in JAMA on June 3. “Our KOL considers JAKi as an attractive option for severe pts who are uncontrolled by dupi.”
JAK inhibitors, though, have broadly faced questions about their safety, questions that have limited the adoption of drugs that were long thought to have blockbuster potential. AbbVie’s JAK inhibitor Rinvoq, for instance, got a blackbox warning after studies showed 1% of patients got a serious infection, opportunistic infection, or herpes zoster. In the JAMA study, 1.9% of patients on 100mg got a serious infection but none on 200mg. Two 200mg patients, though, were infected with herpes.
There were also concerns about platelet reduction, with platelet counts dropping 26% for the 200mg dose and 19% for the 100mg group compared to essentially no reduction on placebo, though they eventually returned to normal.
The latest top line readout can’t answer those questions. Analysts will have to wait for the full data. Still, with Sanofi and Regeneron reporting over $2 billion in sales from Dupixent and atopic dermatitis affecting up to 20% of children and 3% adults, it’s a market that could have room for multiple competitors.
Pfizer, which has gained a breakthrough therapy designation for the drug, is planning to file for FDA approval later this year.