Izokibep is a small therapeutic protein inhibitor of IL-17A.

Acelyrin Inc’s Izokibep achieved higher orders of Hidradenitis Suppurativa Clinical Responses (HiSCR) in open label Part A of a Phase 2b/3 trial.

Izokibep has been administered to over 300 patients, some for up to three years. It is a small therapeutic protein inhibitor of interleukin-17A (IL-17A). With high potency and small molecular size – about one tenth the size of a traditional monoclonal antibody – izokibep can reach high drug exposure levels through a single, subcutaneous injection that monoclonal antibodies otherwise require IV administration to achieve. 

The double-blind, placebo-controlled Part B of this Phase 2b/3 trial is ongoing and based on the Part A results, Acelyrin will accelerate initiation of the second confirmatory trial in HS.

The 30-patient open label Part A of the Phase 2b/3 trial evaluated clinical response and safety of izokibep administered to patients with moderate-to-severe HS via subcutaneous injection.

Izokibep demonstrated higher orders of HiSCR, where low-to-no placebo responses have been reported historically. The safety data reported were consistent with previous trials of izokibep as well as the IL-17Ai class as a whole. Notably, there was no evidence of increased risk of infection and no candida infections were reported in this trial.

"We are thrilled to be seeing these higher orders of HiSCR response and a safety profile consistent with previous trials of izokibep and no increase of infection, including candida, " says Shao-Lee Lin, MD, PhD, founder and CEO of Acelyrin, in a news release. "In addition to the data previously presented in psoriatic arthritis, these results in a second disease indication further support the hypothesis that the high potency and small size of izokibep could lead to clinically meaningful and differentiated impact in multiple diseases, especially those with difficult to treat tissues. Based on these data, we are pleased to prioritize development of izokibep in HS, potentially accelerating its availability to patients."

The full data from Part A of this trial will be presented at a future scientific meeting.