ACELYRIN, INC. has announced promising new data and updates from its clinical programs, particularly focusing on izokibep, a small protein therapeutic targeting IL-17A. The company reported these updates alongside its second-quarter 2023 financial results, highlighting progress in trials for Hidradenitis Suppurativa (HS) and Psoriatic Arthritis (PsA).
Izokibep Demonstrates Early Improvements in Hidradenitis Suppurativa
New data from Part A of the Phase 2b/3 trial of izokibep in HS demonstrated that two-thirds of patients experienced improvements in the number of draining tunnels as early as week 4. This analysis, although based on a small dataset, suggests a rapid onset of action. Part B of the trial, which is placebo-controlled, has completed enrollment, with top-line data expected in the third quarter of 2023.
The company remains focused on achieving high orders of response, such as HiSCR100, a stringent measure of disease control in HS. This measure requires both abscess/nodule resolution and the absence of new draining tunnels. The early improvements in draining tunnels observed in Part A are believed to be linked to the full control of active inflammation.
An independent Data Monitoring Committee (DMC) reviewed unblinded efficacy and safety data from Part B and confirmed the dose of 160mg QW for the second Phase 3 trial in HS. This dose confirmation aligns with the hypothesis that higher exposures are required in HS, potentially leading to clinically meaningful benefits due to izokibep's high potency and small size.
Accelerated Timeline for Psoriatic Arthritis Trial Results
Enrollment has been completed in the Phase 2b/3 randomized controlled trial of izokibep in Psoriatic Arthritis (PsA). Top-line data is now expected in the first quarter of 2024, accelerated from the previously anticipated mid-2024 timeline. Prior data from a Phase 2 trial in PsA showed continued improvements beyond 16 weeks, with 79% of participants receiving izokibep 80 mg Q2W achieving ACR50 response at 46 weeks, compared to 52% at week 16. Higher measures of clinical response were also observed, including 50% achieving ACR70 response, 71% achieving PASI100 response, and 89% achieving enthesitis resolution.
Expansion into Uveitis and Axial Spondyloarthritis
A Phase 2b/3 trial evaluating izokibep in uveitis is currently enrolling. ACELYRIN plans to initiate a Phase 3 program to evaluate izokibep for the treatment of axial spondyloarthritis (AxSpA) in 2024. The decision to expand into AxSpA is supported by the high rates of enthesitis resolution demonstrated in the Phase 2 PsA trial, suggesting potential benefits for patients with this disease.
Lonigutamab for Thyroid Eye Disease and SLRN-517 for Mast Cell Disorders
ACELYRIN is also developing lonigutamab, a subcutaneously delivered anti-IGF-1R monoclonal antibody for thyroid eye disease (TED). Top-line results from the Phase 1/2 Proof-of-Concept (PoC) trial of lonigutamab are expected by late 2023/early 2024.
SLRN-517, a fully human monoclonal antibody targeting c-KIT, is being developed for various allergy and inflammatory diseases driven by mast cells. Top-line results from the Phase 1/2 PoC trial of SLRN-517 are expected in the second half of 2024.
Financial Position
ACELYRIN reported a strong cash position of $823.0 million as of June 30, 2023, including gross proceeds from its recent IPO of $621.0 million. The company anticipates that these funds will support operations through key milestones across all three clinical programs.
