Hidradenitis Suppurativa Phase 2b Study of Izokibep

A Phase 2b Study to Evaluate the Efficacy and Safety of Izokibep in Subjects With Moderate to Severe Hidradenitis Suppurativa

Izokibep is a potent and selective inhibitor of interleukin 17A (IL-17A) that is being developed for treatment of hidradenitis suppurativa (HS).

This study will evaluate the efficacy, safety, and immunogenicity of izokibep administered subcutaneously (SC) in adult subjects with moderate to severe HS.

Study Overview

• Status: Completed
• Conditions: Hidradenitis Suppurativa
• Intervention / Treatment: Drug: Izokibep; Drug: Placebo to izokibep

• Study Type: Interventional
• Enrollment (Actual): 205
• Phase: Phase 2

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • London, Ontario, Canada, N6A 2C2
      • Clinical Research Site
    • Markham, Ontario, Canada, L3P 1X2
      • Clinical Research Site
    • Waterloo, Ontario, Canada, N2J 1C4
      • Clinical Research Site
  • Quebec
    • Québec, Quebec, Canada, G1N 4V3
      • Clinical Research Site
  • Saskatchewan
    • Saskatoon, Saskatchewan, Canada, S7K 2C1
      • Clinical Research Site
• Germany
  • Schwerin, Germany, 19055
    • Clinical Research Site
  • NI
    • Bad Bentheim, NI, Germany, 48455
      • Clinical Research Site
  • Northwest
    • Bochum, Northwest, Germany, 44791
      • Clinical Research Site
  • SH
    • Kiel, SH, Germany, 24105
      • Clinical Research Site
    • Kiel, SH, Germany, 24148
      • Clinical Research Site
• Hungary
  • BU
    • Budapest, BU, Hungary, 1036
      • Clinical Research Site
  • HB
    • Debrecen, HB, Hungary, 4032
      • Clinical Research Site
• Poland
  • Lublin, Poland, 20-573
    • Clinical Research Site
  • Szczecin, Poland, 70-332
    • Clinical Research Site
  • DS
    • Wrocław, DS, Poland, 50-566
      • Clinical Research Site
    • Wrocław, DS, Poland, 51-318
      • Clinical Research Site
  • MA
    • Krakow, MA, Poland, 30-510
      • Clinical Research Site
    • Kraków, MA, Poland, 31-147
      • Clinical Research Site
  • PD
    • Bialystok, PD, Poland, 15-453
      • Clinical Research Site
  • SL
    • Katowice, SL, Poland, 40-615
      • Clinical Research Site
• Spain
  • Barcelona, Spain, 8036
    • Clinical Research Site
  • PM
    • Palma De Mallorca, PM, Spain, 07120
      • Clinical Research Site
  • PO
    • Pontevedra, PO, Spain, 36001
      • Clinical Research Site
  • V
    • Manises, V, Spain, 46940
      • Clinical Research Site
• United States
  • Alabama
    • Birmingham, Alabama, United States, 35233-3110
      • Clinical Research Site
  • California
    • Encino, California, United States, 91436-2428
      • Clinical Research Site
    • Fountain Valley, California, United States, 92708-3701
      • Clinical Research Site
    • Los Angeles, California, United States, 90033
      • Clinical Research Site
    • Los Angeles, California, United States, 90045-3606
      • Clinical Research Site
  • Florida
    • Ocala, Florida, United States, 34470
      • Clinical Research Site
    • Tampa, Florida, United States, 33624-2038
      • Clinical Research Site
  • Georgia
    • Sandy Springs, Georgia, United States, 30328
      • Clinical Research Site
    • Savannah, Georgia, United States, 31406
      • Clinical Research Site
  • Illinois
    • Rolling Meadows, Illinois, United States, 60008-3811
      • Clinical Research Site
  • Indiana
    • Indianapolis, Indiana, United States, 46250
      • Clinical Research Site
    • Plainfield, Indiana, United States, 46168
      • Clinical Research Site
  • Kentucky
    • Murray, Kentucky, United States, 42071-2515
      • Clinical Research Site
  • Louisiana
    • Baton Rouge, Louisiana, United States, 70808
      • Clinical Research Site
  • New York
    • New York, New York, United States, 10028-3001
      • Clinical Research Site
  • Ohio
    • Mason, Ohio, United States, 45040-4520
      • Clinical Research Site
  • Oregon
    • Portland, Oregon, United States, 97223
      • Clinical Research Site
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19103-4708
      • Clinical Research Site
    • Pittsburgh, Pennsylvania, United States, 15213-3403
      • Clinical Research Site
  • Texas
    • Webster, Texas, United States, 77598
      • Clinical Research Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

General

• Subject has provided signed informed consent including consenting to comply with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.
• 18 years to 75 years of age

Type of Subject and Disease Characteristics

• Diagnosis of hidradenitis suppurativa (HS) for ≥ 1 year prior to first dose of study drug.
• Hidradenitis suppurativa lesions present in ≥ 2 distinct anatomic areas, one of which is Hurley Stage II or III.
• A total abscess and inflammatory nodule (AN) count of ≥ 5 at screening and Day 1 prior to enrollment/randomization.
• Subject must have had an inadequate response to oral antibiotics OR exhibited recurrence after discontinuation to, OR demonstrated intolerance to, OR have a contraindication to oral antibiotics for treatment of their HS.
• Must agree to use daily over-the-counter topical antiseptics.
• Subject must be willing to complete a daily skin pain diary for at least 3 days prior to Day 1 visit.

Exclusion Criteria:

Medical Conditions

• Draining fistula count of > 20.
• Outpatient surgery ≤ 8 weeks prior or inpatient surgery ≤ 12 weeks prior to enrollment/randomization.
• Other active skin disease or condition that could interfere with study assessments.
• Chronic pain not associated with HS.
• Uncontrolled, clinically significant system disease.
• History of demyelinating disease or neurological symptoms suggestive of demyelinating disease.
• Malignancy within 5 years.
• The subject is at risk of self-harm or harm to others.
• Active infection or history of certain infections.
• Tuberculosis or fungal infection seen on available chest x-ray taken ≤ 3 months of screening or at screening (Exception: documented evidence of completed treatment and clinically resolved).
• Known history of human immunodeficiency virus (HIV).

Other protocol defined inclusion/exclusion criteria may apply.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Part A (Open-label) izokibep every week; Participants will receive izokibep every week from Day 1 through Week 31	Drug: Izokibep; Biologic: IL-17A inhibitor Form: Solution for injection Route of administration: Subcutaneous (SC)
Experimental: Part B (Double-blind) izokibep every other week; Participants will receive izokibep every other week for 30 weeks.	Drug: Izokibep; Biologic: IL-17A inhibitor Form: Solution for injection Route of administration: Subcutaneous (SC)
Placebo Comparator: Part B (Double-blind) placebo every other week; Participants will receive placebo every other week up to Week 14, then izokibep from Week 16 to Week 30.	Drug: Placebo to izokibep; Form: Solution for injection Route of administration: Subcutaneous (SC)
Experimental: Part B (Double-blind) izokibep every week; Participants will receive izokibep every week for 31 weeks.	Drug: Izokibep; Biologic: IL-17A inhibitor Form: Solution for injection Route of administration: Subcutaneous (SC)
Placebo Comparator: Part B (Double-blind) placebo every week; Participants will receive placebo every week up to Week 15, then izokibep from Week 16 to Week 31.	Drug: Placebo to izokibep; Form: Solution for injection Route of administration: Subcutaneous (SC)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Part A: Number of Participants Who Achieved Hidradenitis Suppurativa Clinical Response 75 (HiSCR75) at Week 12	HiSCR75 was defined as at least a 75% reduction from baseline in the total abscess and inflammatory nodule count, with no increase from baseline in abscess or draining fistula count.	Part A: Baseline to Week 12
Part B: Number of Participants Who Achieved HiSCR75 at Week 16	HiSCR75 was defined as at least a 75% reduction from baseline in the total abscess and inflammatory nodule count, with no increase from baseline in abscess or draining fistula count.	Part B: Baseline to Week 16

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Part A: Number of Participants With Treatment-emergent Adverse Events (TEAEs)	An adverse event (AE) referred to any untoward medical occurrence in a clinical study participant, regardless of a causal relationship with the study treatment. TEAEs included any event occurring after the participant received the study treatment. Clinically significant changes in vital signs, electrocardiograms, and laboratory tests recorded after treatment administration were documented as TEAEs. Serious TEAEs (SAEs) were untoward medical occurrences after the first dose, irrespective of a causal link to the study treatment, that led to death, were life-threatening, required hospitalization or its prolongation, caused significant disability, resulted in congenital anomalies, or were considered other medically important events.	Part A: Screening (Day -28) to Follow-up (Week 45), for a total of 49 weeks
Part A: Number of Participants Testing Positive for Anti-drug Antibodies (ADAs)	Blood samples were collected at different time points throughout the study.	Baseline, Week 16, Week 32, Week 39
Part B: Number of Participants Who Achieved HiSCR90 at Week 16	HiSCR90 was defined as at least a 90% reduction from baseline in the total abscess and inflammatory nodule count, with no increase from baseline in abscess or draining fistula count	Part B: Baseline to Week 16
Part B: Number of Participants Who Achieved HiSCR100 at Week 16	HiSCR100 was defined as at least a 100% reduction from baseline in the total abscess and inflammatory nodule count, with no increase from baseline in abscess or draining fistula count.	Part B: Baseline to Week 16
Part B: Number of Participants Who Achieved HiSCR50 at Week 16	HiSCR50 was defined as at least a 50% reduction from baseline in the total abscess and inflammatory nodule count, with no increase from baseline in abscess or draining fistula count	Part B: Baseline to Week 16
Part B: Percentage of Participants Who Experienced ≥ 1 Disease Flare Through 16 Weeks of Treatment	A flare was defined as ≥ 25% increase in AN count with a minimum increase of 2 AN relative to baseline. Missing data of abscess and inflammatory nodules counts at scheduled visits are imputed assuming monotone missingness pattern. Predictors in the regression model for missing values at Week 4 are Baseline Hurley stage, baseline abscess count, baseline inflammatory nodule count, baseline draining fistula count, sex, race, age, body mass index (BMI) and prior Biologic/JAK inhibitor use for HS. Predictors in the regression model for missing values after Week 4 are all of these variables, plus counts of abscess, inflammatory nodule, and draining fistula at prior scheduled assessment. Missing flare values in both the placebo and izokibep groups are imputed using observed data from the placebo group only.	Part B: Day 1 through to Week 16
Part B: Number of Participants With Hurley Stage II at Baseline Who Achieved AN Count of 0, 1, or 2	The percentage of participants with baseline Hurley Stage II who achieved AN count of 0, 1, or 2 at Week 16. Hurley stages: Stage 1 - solitary or multiple, isolated abscess formation without scarring or sinus tracts Stage 2 - recurrent abscesses, single or multiple widely separated lesions, with sinus tract formation Stage 3 - diffuse or broad involvement, with multiple interconnected sinus tracts and abscesses.	Part B: Week 16
Part B: Number of Participants Who Achieved at Least a 3-Point Reduction From Baseline in Numeric Rating Scale (NRS) in Patient Global Assessment of Skin Pain at Its Worst at Week 16 Among Participants With Baseline NRS ≥ 4	The Patient Global Assessment of Skin Pain is a NRS that consists of scores from 0 to 10 with 0 indicating "no skin pain" and 10 indicating "pain as bad as you can imagine".	Part B: Baseline to Week 16
Part B: Number of Participants With TEAEs of Special Interest	Adverse events of special interest were adverse events in the following categories: candida infection, inflammatory bowel disease, suicidal ideation, malignancies, major cardiovascular and cerebrovascular events, tuberculosis, infections, cytopenias and hypersensitivity reactions.	Part B: Screening (Day -28) to Follow-up (Week 45), for a total of 49 weeks
Part B: Number of Participants With TEAEs	An AE referred to any untoward medical occurrence in a clinical study participant, regardless of a causal relationship with the study treatment. TEAEs included any event occurring after the participant received the study treatment. Clinically significant changes in vital signs, electrocardiograms, and laboratory tests recorded after treatment administration were documented as TEAEs. SAEs were untoward medical occurrences after the first dose, irrespective of a causal link to the study treatment, that led to death, were life-threatening, required hospitalization or its prolongation, caused significant disability, resulted in congenital anomalies, or were considered other medically important events.	Part B: Screening (Day -28) to Follow-up (Week 45), for a total of 49 weeks
Part B: Number of Participants Testing Positive for ADAs	Blood samples were collected at different time points throughout the study.	Up to 39 weeks

Collaborators and Investigators

• Sponsor: ACELYRIN Inc.
• Investigators: Study Director: Donald Betah, MD, ACELYRIN Inc.

Study record dates

Study Major Dates

• Study Start (Actual): May 5, 2022
• Primary Completion (Actual): August 2, 2023
• Study Completion (Actual): February 21, 2024

Study Registration Dates

• First Submitted: April 12, 2022
• First Submitted That Met QC Criteria: April 28, 2022
• First Posted (Actual): May 2, 2022

Study Record Updates

• Last Update Posted (Actual): June 3, 2025
• Last Update Submitted That Met QC Criteria: May 16, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: hidradenitis suppurativa; Izokibep
• Additional Relevant MeSH Terms: Infections; Skin Diseases; Bacterial Infections; Bacterial Infections and Mycoses; Sweat Gland Diseases; Skin Diseases, Bacterial; Skin Diseases, Infectious; Suppuration; Hidradenitis Suppurativa; Hidradenitis
• Other Study ID Numbers: 21102; 2021-005713-13 (EudraCT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No