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Hidradenitis SuppurativaPhase 3NCT05905783

Hidradenitis Suppurativa Study of Izokibep

A Phase 3 study testing Izokibep in people with Hidradenitis Suppurativa, run by ACELYRIN Inc. at 98 sites in 8 countries.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record
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Trial summary

Izokibep is a small protein molecule that acts as a selective, potent inhibitor of interleukin 17A, to which it binds with high affinity. This study investigates izokibep in participants with active Hidradenitis Suppurativa (HS), including tumor necrosis factor-alpha inhibitor (TNFi) naïve participants, and those who… Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Hidradenitis Suppurativa
What is being tested?
Izokibep
Type of treatment
Injection or infusion
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
258 participants
Where
98 sitesin 8 countries
Study dates
22 Jun 2023to 27 Jan 2025
Phase
Phase 3
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • General
  • Participant has provided signed informed consent including consenting to comply with the requirements and restrictions listed in the informed consent form (ICF) and in protocol
  • 18 years of age or older
  • No known history of active tuberculosis unless adequately treated according to World Health Organization/Center for Disease Control and Prevention therapeutic guidance and determined to be fully recovered by a tuberculosis specialist
  • Type of Participant and Disease Characteristics
  • Diagnosis of HS for ≥ 6 months prior to first dose of study drug
Show all 11Show fewer
  • Hidradenitis suppurativa lesions present in ≥ 2 distinct anatomic areas, one of which is Hurley Stage II or Hurley Stage III
  • A total AN count of ≥ 5 at screening and Day 1 prior to enrollment/randomization
  • Participant 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 or a minimum of 3 days a week over-the-counter topical antiseptics
  • Participant must be willing to complete a daily skin pain diary

Who cannot join

  • 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
  • History of active inflammatory bowel disease (IBD) OR symptoms within the last year that may be suggestive of IBD
  • Chronic pain not associated with HS
Show all 14Show fewer
  • Uncontrolled, clinically significant system disease
  • History of demyelinating disease or neurological symptoms suggestive of demyelinating disease
  • Malignancy within 5 years
  • The participant 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 within 3 months prior to first dose of study drug 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

Trial locations and contacts

98 sites in 8 countries.

98 sites in 8 countries

United States50 sites

  • Clinical Research Site

    Arlington, Texas, 76011

  • Clinical Research Site

    Atlanta, Georgia, 30315

  • Clinical Research Site

    Baton Rouge, Louisiana, 70808

  • Clinical Research Site

    Baton Rouge, Louisiana, 70809

  • Clinical Research Site

    Birmingham, Alabama, 35233

  • Clinical Research Site

    Boardman, Ohio, 44512

  • Clinical Research Site

    Boca Raton, Florida, 33486

  • Clinical Research Site

    Boston, Massachusetts, 02215

  • Clinical Research Site

    Brandon, Florida, 33511

  • Clinical Research Site

    Canton, Michigan, 48187

  • Clinical Research Site

    Charlotte, North Carolina, 28277

  • Clinical Research Site

    Charlottesville, Virginia, 22908

  • Clinical Research Site

    Coral Gables, Florida, 33134

  • Clinical Research Site

    Encino, California, 91436

  • Clinical Research Site

    Fayetteville, Arkansas, 72703

  • Clinical Research Site

    Fountain Valley, California, 92708

  • Clinical Research Site

    Fremont, California, 94538

  • Clinical Research Site

    Frisco, Texas, 75034

  • Clinical Research Site

    Hershey, Pennsylvania, 17033

  • Clinical Research Site

    Hollywood, Florida, 33021

  • Clinical Research Site

    Indianapolis, Indiana, 46250

  • Clinical Research Site

    Largo, Maryland, 20774

  • Clinical Research Site

    Lebanon, New Hampshire, 03766

  • Clinical Research Site

    Los Angeles, California, 90045

  • Clinical Research Site

    Mason, Ohio, 45040

  • Clinical Research Site

    Murray, Kentucky, 42071

  • Clinical Research Site

    New Orleans, Louisiana, 70115

  • Clinical Research Site

    New York, New York, 10128

  • Clinical Research Site

    Pflugerville, Texas, 78660

  • Clinical Research Site

    Pittsburgh, Pennsylvania, 15213

  • Clinical Research Site

    Plainfield, Indiana, 46168

  • Clinical Research Site

    Portland, Oregon, 97223

  • Clinical Research Site

    San Antonio, Texas, 78218

  • Clinical Research Site

    Sandy Springs, Georgia, 30328

  • Clinical Research Site

    Santa Monica, California, 90404

  • Clinical Research Site

    Savannah, Georgia, 31419

  • Clinical Research Site

    Scottsdale, Arizona, 85255

  • Clinical Research Site

    Scottsdale, Arizona, 85260

  • Clinical Research Site

    Springfield, Illinois, 62702

  • Clinical Research Site

    Springfield, Ohio, 45505

  • Clinical Research Site

    Springville, Utah, 84663

  • Clinical Research Site

    Sugarloaf, Pennsylvania, 18249

  • Clinical Research Site

    Tampa, Florida, 33607

  • Clinical Research Site

    Tampa, Florida, 33613

  • Clinical Research Site

    The Woodlands, Texas, 77380

  • Clinical Research Site

    Thompson's Station, Tennessee, 37179

  • Clinical Research Site

    Topeka, Kansas, 66614

  • Clinical Research Site

    Troy, Michigan, 48084

  • Clinical Research Site

    Webster, Texas, 77598

  • Clinical Research Site

    West Jordan, Utah, 84088

Other trials in United States

Japan11 sites

  • Clinical Research Site

    Fukuoka, Fukoka Prefecture, 814-0180

  • Clinical Research Site

    Kawasaki, Kanagawa, 216-8511

  • Clinical Research Site

    Kitakyushu, Fukuoka, 807-8555

  • Clinical Research Site

    Kyoto, Kyoto, 602-8566

  • Clinical Research Site

    Nishinomiya, 663-8186

  • Clinical Research Site

    Obihiro, Hokkaido Prefecture, 080-0013

  • Clinical Research Site

    Osaka, Osaka, 589-8511

  • Clinical Research Site

    Sapporo, Hokkaido Prefecture, 060-0063

  • Clinical Research Site

    Shinjuku-Ku, Tokyo, 160-0023

  • Clinical Research Site

    tabashi City, Tokyo, 173-8610

  • Clinical Research Site

    Yokohama, Kanagawa, 236-0004

Other trials in Japan

Canada10 sites

  • Clinical Research Site

    Edmonton, Alberta, T6G1C3

  • Clinical Research Site

    Edmonton, Alberta, T6H4J8

  • Clinical Research Site

    North Bay, Ontario, P1B 3Z7

  • Clinical Research Site

    Peterborough, Ontario, K9J5K2

  • Clinical Research Site

    Saskatoon, Saskatchewan, S7K2C1

  • Clinical Research Site

    Toronto, Ontario, M2N3A6

  • Clinical Research Site

    Toronto, Ontario, M4W2N4

  • Clinical Research Site

    Toronto, Ontario, M5A3R6

  • Clinical Research Site

    Waterloo, Ontario, N2J1C4

  • Clinical Research Site

    Winnipeg, Manitoba, R3M3Z4

Other trials in Canada

Poland9 sites

  • Clinical Research Site

    Katowice, Silesian Voivodeship, 40-611

  • Clinical Research Site

    Krakow, Lesser Poland Voivodeship, 30-001

  • Clinical Research Site

    Krakow, Lesser Poland Voivodeship, 90-436

  • Clinical Research Site

    Lodz, Łódź Voivodeship, 90-265

  • Clinical Research Site

    Lublin, Lublin Voivodeship, 20-573

  • Clinical Research Site

    Ożarowice, Silesian Voivodeship, 42-624

  • Clinical Research Site

    Sosnowiec, Silesian Voivodeship, 41-218

  • Clinical Research Site

    Wroclaw, Lower Silesian Voivodeship, 50-566

  • Clinical Research Site

    Wroclaw, Lower Silesian Voivodeship, 51-318

Other trials in Poland

Spain6 sites

  • Clinical Research Site

    Badalona, Catalonia, 08916

  • Clinical Research Site

    Barcelona, Catalonia, 08041

  • Clinical Research Site

    Madrid, 28031

  • Clinical Research Site

    Manises, Valencia, 46940

  • Clinical Research Site

    Palma de Mallorca, Balearic Islands, 07120

  • Clinical Research Site

    Seville, Andalusia, 41009

Other trials in Spain

Germany5 sites

  • Clinical Research Site

    Bad Bentheim, Lower Saxony, 48455

  • Clinical Research Site

    Darmstadt, Hesse, 64283

  • Clinical Research Site

    Kiel, Schleswig-Holstein, 24148

  • Clinical Research Site

    Leipzig, Saxony, 04103

  • Clinical Research Site

    Mainz, Rhineland-Palatinate, 55128

Other trials in Germany

France4 sites

  • Clinical Research Site

    Dijon, Bourgogne-Franche-Comté, 21000

  • Clinical Research Site

    Montpellier, Occitanie, 34090

  • Clinical Research Site

    Nantes, Pays de la Loire Region, 44000

  • Clinical Research Site

    Toulon, 83000

Other trials in France

Hungary3 sites

  • Clinical Research Site

    Budapest, 1036

  • Clinical Research Site

    Debrecen, Hajdú-Bihar, 4032

  • Clinical Research Site

    Zalaegerszeg, Zala County, 8900

Other trials in Hungary

About this study

Official title: A Randomized, Double-blind, Placebo-controlled, Multicenter, Phase 3 Study to Evaluate the Efficacy and Safety of Izokibep in Subjects With Moderate to Severe Hidradenitis Suppurativa

Izokibep is a small protein molecule that acts as a selective, potent inhibitor of interleukin 17A, to which it binds with high affinity. This study investigates izokibep in participants with active Hidradenitis Suppurativa (HS), including tumor necrosis factor-alpha inhibitor (TNFi) naïve participants, and those who had an inadequate response or intolerance to TNFi, or for whom TNFi is contraindicated.

Being tested
Placebo, Izokibep
Medical subject headings
Hidradenitis Suppurativa

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PlaceboDrug

    Solution for injection

  • IzokibepDrug

    Solution for injection

Study groups in NCT05905783
Study groupRoleWhat they receive
Group 1ExperimentalParticipants will receive placebo as a subcutaneous (SC) injection every week (QW) from Day 1 to Week 15. Participants will then receive izokibep as a SC injection QW from Week 16 to Week 51.
Receives: Drug: Placebo; Drug: Izokibep
Group 2ExperimentalParticipants will receive izokibep QW from Day 1 to Week 51.
Receives: Drug: Izokibep

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Percentage of Participants Achieving Hidradenitis Suppurativa Clinical Response 75 (HiSCR75) at Week 12

    The percentage of participants achieving HiSCR75 was defined as meeting all 3 criteria below:

    • ([abscess and inflammatory nodule (AN) count at baseline - AN count at current visit] / AN count at baseline) × 100% ≥ 75%
    • Abscess count at baseline ≥ abscess count at the current visit
    • Draining fistula count at baseline ≥ draining fistula count at the current visit.

    HiSCR75 was evaluated using nonresponse imputation (NRI) and multiple imputation (MI) methods.

    Measured: Week 12

Secondary outcomes (9)

  1. Percentage of Participants Achieving HiSCR90 at Week 12

    The percentage of participants achieving HiSCR90 was defined as meeting all 3 criteria below:

    • ([AN count at baseline - AN count at current visit] / AN count at baseline) × 100% ≥ 90%
    • Abscess count at baseline ≥ abscess count at the current visit
    • Draining fistula count at baseline ≥ draining fistula count at the current visit.

    HiSCR90 was evaluated using nonresponse imputation (NRI) and multiple imputation (MI) methods.

    Measured: Week 12

  2. Percentage of Participants Achieving HiSCR100 at Week 12

    The percentage of participants achieving HiSCR100 was defined as meeting all 3 criteria below:

    • ([AN count at baseline - AN count at current visit] / AN count at baseline) × 100% = 100%
    • Abscess count at baseline ≥ abscess count at the current visit
    • Draining fistula count at baseline ≥ draining fistula count at the current visit.

    HiSCR100 was evaluated using nonresponse imputation (NRI) and multiple imputation (MI) methods.

    Measured: Week 12

  3. Percentage of Participants Achieving HiSCR50 at Week 12

    The percentage of participants achieving HiSCR50 was defined as meeting all 3 criteria below:

    • [(AN count at baseline - AN count at current visit) / AN count at baseline] × 100% ≥ 50%
    • Abscess count at baseline ≥ abscess count at the current visit
    • Draining fistula count at baseline ≥ draining fistula count at the current visit.

    HiSCR50 was evaluated using nonresponse imputation (NRI) and multiple imputation (MI) methods.

    Measured: Week 12

  4. Percentage of Participants Who Experienced One or More (≥ 1) Disease Flare at Week 12

    HS flares were defined as ≥ 25% increase in AN count with a minimum increase of 2 AN relative to baseline, i.e. participants must meet all the following criteria:

    • (AN count at current visit- AN count at baseline) / AN count at baseline ×100% ≥ 25%
    • AN count at current visit- AN count at baseline ≥ 2.

    Participants who received antibiotic therapy that could affect HS were imputed as non-response (NRI). Other participants with missing data were imputed with multiple imputation.

    Measured: Up to Week 12

  5. Change From Baseline in Dermatology Life Quality Index (DLQI)

    DLQI included 10 items arranged in 6 categories: symptoms and feelings, daily activity, leisure, work or study, interpersonal relationships, and treatment. The total score could range from 0 (no impact to life quality) to 30 (maximum impact).

    Measured: Baseline and Week 12

  6. Percentage of Participants With Baseline Hurley Stage II Who Achieved AN Count of 0, 1, or 2 at Week 12

    Calculated as observed values of 0, 1, or 2 for AN count (abscess count + inflammatory nodule count).

    AN count of 0, 1, or 2 was evaluated using nonresponse imputation (NRI) and multiple imputation (MI) methods.

    Measured: Week 12

  7. Percentage of Participants With Baseline NRS ≥ 4 Achieving at Least 3-point Reduction at Week 12 in Numeric Rating Scale (NRS) Patient Global Assessment of Skin Pain at Its Worst

    NRS in Patient Global Assessment of Skin Pain ranged from 0 (no skin pain) to 10 (skin pain bad as you can imagine). The skin pain score at each visit was calculated using average of daily scores among the 7 days up to and including the day of visit, with a minimum of 4 days (consecutive or non-consecutive) with scores required.

    Reduction in NRS was evaluated using nonresponse imputation (NRI) and multiple imputation (MI) methods.

    Measured: Week 12

  8. Number of Participants With Treatment-emergent Adverse Events (TEAEs), Serious AEs (SAEs) and Adverse Event of Special Interest (AESIs) in Period 1

    An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study drug, whether or not considered related to the study drug.

    An SAE is defined as any untoward medical occurrence that, at any dose, meets one or more of the criteria listed: results in death, is life threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, or is an important medical event.

    The following events of special interest were monitored in this study: candida infection; inflammatory bowel disease (IBD); suicidal ideation; malignancies; major adverse cardiovascular and cerebrovascular events; tuberculosis; infections; cytopenias and systemic hypersensitivity reactions.

    Clinically significant changes in vital signs and laboratory tests recorded after treatment administration were documented as TEAEs.

    Measured: Up to Week 16

  9. Number of Participants With TEAEs, SAEs and AESIs in Period 2

    An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study drug, whether or not considered related to the study drug.

    An SAE is defined as any untoward medical occurrence that, at any dose, meets one or more of the criteria listed: results in death, is life threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, or is an important medical event.

    The following events of special interest were monitored in this study: candida infection; IBD; suicidal ideation; malignancies; major adverse cardiovascular and cerebrovascular events; tuberculosis; infections; cytopenias and systemic hypersensitivity reactions.

    Clinically significant changes in vital signs and laboratory tests recorded after treatment administration were documented as TEAEs.

    Measured: From Week 16 to follow-up, Week 59

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted15 Jun 2023
  2. Study start22 Jun 2023
  3. Primary completion24 Jul 2024
  4. Study completion27 Jan 2025

Why it stopped: Per our 13Aug24 press release, we announced discontinuation of internal development in this indication. This decision was not due to safety reasons.

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Double blind
Who is masked
Participant, Investigator
Enrolment
258 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05905783
Sponsor's protocol ID
22107
Other IDs
2022-503160-33-00
Status last verified
Dec 2024
First submitted
7 Jun 2023
Last updated
15 Oct 2025
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Undecided

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Izokibep in people with Hidradenitis Suppurativa, run by ACELYRIN Inc. at 98 sites in 8 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 11 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: stopped early, as of the sponsor's last update on 15 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 98 sites in United States, Japan, Canada, Poland, Spain and 3 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 15 Oct 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Percentage of Participants Achieving Hidradenitis Suppurativa Clinical Response 75 (HiSCR75) at Week 12 (time frame: Week 12). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05905783.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Oct 2025.

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