After a Phase 2 flop, Brinsupri exits the race to market for the chronic skin disease hidradenitis suppurativa, but other companies, including Incyte, Novartis and UCB, have recently notched clinical and regulatory victories.
Insmed will no longer develop its recently approved lung disease drug Brinsupri for a skin condition called hidradenitis suppurativa after a disappointing mid-stage showing, leaving more room for other drugmakers in this space to forge ahead.
Data from the Phase 2b CEDAR study, disclosed in a news release on Tuesday, showed “no signal of efficacy,” according to analysts at William Blair, telling investors in a note the same day that the placebo arm outperformed both Brinsupri doses that Insmed studied.
Indeed, the biotech reported that at 16 weeks, total abscess and inflammatory nodule count dropped by 45.5% and 40.3% in patients on 10-mg and 40-mg Brinsupri, respectively, whereas placebo comparators saw a 57.1% reduction in the same endpoint. CEDAR also missed its secondary endpoints, Insmed said on Tuesday without specifying what those were or providing specific data.
Following the mid-stage miss, Insmed will scrap the development of Brinsupri in hidradenitis suppurativa.
That clears the way for other drugmakers, many of which have seen clinical and regulatory success in the condition in recent weeks. Incyte’s JAK1 inhibitor povorcitinib, for instance, maintained significant clinical benefit through 54 weeks of follow-up in two Phase 3 studies presented at the recently concluded American Academy of Dermatology meeting.
Similarly, UCB announced in October last year that its IL-17A and IL-17F blocker Bimzelx sustained symptom improvements through three years of follow-up. The FDA approved Bimzelx for hidradenitis suppurativa in November 2024.
Also in the game is Novartis, which in October 2023 secured the FDA’s greenlight for Cosentyx as the first new biologic for the skin disease in almost a decade. Last month, the pharma expanded Cosentyx’s label to also include pediatric patients 12 years and up.
“We are not surprised by the negative results,” analysts at Guggenheim Partners told investors in a Tuesday note, referring to Insmed’s CEDAR outcome. The firm had assigned only a 10% probability of success to the study, which reflected “the company’s own low expectations for this trial.”
The bearish view of CEDAR, the analysts continued, was driven by “the lack of established animal models” for hidradenitis suppurativa and “the absence of compelling pre-clinical data” to back Brinsupri’s mechanism of action for the disease.
William Blair was likewise unsurprised by CEDAR’s failure, additionally pointing to Brinsupri’s previous failure in a mid-stage rhinosinusitis study. Data released in December 2025 showed that placebo again numerically outperformed both 4-mg and 10-mg doses of Brinsupri at easing sinus symptoms in patients with chronic rhinosinusitis without nasal polyps.
Brinsupri is an orally available DPP1 inhibitor that works by suppressing pro-inflammatory cascades. The drug was approved for non-cystic fibrosis bronchiectasis in August 2025, becoming the first treatment for the disease and the first DPP1 blocker cleared by the FDA. In January, Insmed reported $144.6 million in fourth-quarter sales for Brinsupri—a figure that William Blair in a Jan. 9 note called a “blowout sales performance.”
