Insmed’s Brin supplement has failed for the second time in four months in a mid-term trial aimed at expanding its use to new indications.
New Jersey Biotechnology, Inc. has revealed that a Phase 2B study of Brin supplement in adults with moderate to severe hidradenitis suppurativa (HS) failed to meet its primary or secondary endpoints in either the 10 mg or 40 mg once-daily groups. Due to this result, the company will terminate the program.
The debacle comes after Insmed reported the failure of another Brin supplement trial testing a first-in-class dipeptidyl peptidase 1 (DPP1) inhibitor in patients with chronic rhinosinusitis without nasal polyps (CRSsNP).
Its Phase 2 trial similarly failed, failing to meet its primary or secondary endpoints at either the 10 mg or 40 mg doses. The results were so conclusive that Insmed also discontinued development of Brin Supplement, which showed signs of this.
In a 214-patient HS study, Brin supplements failed to outperform placebo, with patients in the 10 mg and 40 mg treatment groups having a 46% and 40% reduction in total abscess and inflammatory nodule (AN) numbers, respectively, compared to 57% in the control group. HS is an inflammatory skin disease that causes painful lumps, abscesses, and scarring in the sweat gland area.
Treatment-emergent adverse events (TEAEs) were more common in the 10 mg group (55%) than in the placebo (46%) or 40 mg (43%) groups, with three serious TEAEs occurring in the 10 mg group compared to one in each of the other treatment groups.
The lack of established animal models in HS “makes clinical development particularly difficult” in this indication, Insmed’s chief medical officer Martina Flammer, MD, said in a release.
“While we are disappointed with the results, we hope that the insights gained from this study will contribute to a broader scientific understanding of HS,” Flammer added.
Analysts at Mizuho Securities said the “singing silver lining” from the trial was that it confirmed Brinsuppli’s “excellent safety/tolerability profile.”
William Blair analyst Matt Phipps, Ph.D., wrote in a note to clients that InsMed’s failure in the HS study is “not surprising given the challenges of HS clinical trials (particularly with high placebo rates) and the lack of preclinical evidence supporting DPP1 inhibition in this indication.”
Phipps said his rating for InsMed remains unchanged because expectations for the announcement are “very low,” adding that he expects the impact on the company’s stock to be “minimal.”
Insmed stock rose nearly 1% before U.S. markets opened on Wednesday.
In contrast, when InsMed revealed in December that it had failed in CRSsNP, an indication that would have delivered a large number of patients, Mizuho analysts lowered their peak annual sales forecast for Brin Supplement from $16 billion to $11 billion.
Brinsupplement was approved in August last year as a treatment for the chronic lung disease bronchiectasis. Despite being on the market for just over four months, InsMed reported sales of Brin Supplement at $173 million last year. The consensus estimate for first-quarter revenue is $198 million, according to Visible Alpha.

