Hidradenitis SuppurativaPhase 2NCT05355805
Hidradenitis Suppurativa Phase 2b Study of Izokibep
A Phase 2 study testing Izokibep in people with Hidradenitis Suppurativa, run by ACELYRIN Inc. at 44 sites in 6 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- 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
- 205 participants
- Where
- 44 sitesin 6 countries
- Study dates
- 5 May 2022to 21 Feb 2024
- Phase
- Phase 2
- 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 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
Show all 10Show fewer
- 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.
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.
- Chronic pain not associated with HS.
- Uncontrolled, clinically significant system disease.
Show all 13Show fewer
- 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.
Trial locations and contacts
44 sites in 6 countries.
44 sites in 6 countries
United States20 sites
Clinical Research Site
Baton Rouge, Louisiana, 70808
Clinical Research Site
Birmingham, Alabama, 35233-3110
Clinical Research Site
Encino, California, 91436-2428
Clinical Research Site
Fountain Valley, California, 92708-3701
Clinical Research Site
Indianapolis, Indiana, 46250
Clinical Research Site
Los Angeles, California, 90033
Clinical Research Site
Los Angeles, California, 90045-3606
Clinical Research Site
Mason, Ohio, 45040-4520
Clinical Research Site
Murray, Kentucky, 42071-2515
Clinical Research Site
New York, New York, 10028-3001
Clinical Research Site
Ocala, Florida, 34470
Clinical Research Site
Philadelphia, Pennsylvania, 19103-4708
Clinical Research Site
Pittsburgh, Pennsylvania, 15213-3403
Clinical Research Site
Plainfield, Indiana, 46168
Clinical Research Site
Portland, Oregon, 97223
Clinical Research Site
Rolling Meadows, Illinois, 60008-3811
Clinical Research Site
Sandy Springs, Georgia, 30328
Clinical Research Site
Savannah, Georgia, 31406
Clinical Research Site
Tampa, Florida, 33624-2038
Clinical Research Site
Webster, Texas, 77598
Poland8 sites
Clinical Research Site
Bialystok, Podlaskie Voivodeship, 15-453
Clinical Research Site
Katowice, Silesian Voivodeship, 40-615
Clinical Research Site
Krakow, Lesser Poland Voivodeship, 30-510
Clinical Research Site
Krakow, Lesser Poland Voivodeship, 31-147
Clinical Research Site
Lublin, 20-573
Clinical Research Site
Szczecin, 70-332
Clinical Research Site
Wroclaw, Lower Silesian Voivodeship, 50-566
Clinical Research Site
Wroclaw, Lower Silesian Voivodeship, 51-318
Canada5 sites
Clinical Research Site
London, Ontario, N6A 2C2
Clinical Research Site
Markham, Ontario, L3P 1X2
Clinical Research Site
Québec, Quebec, G1N 4V3
Clinical Research Site
Saskatoon, Saskatchewan, S7K 2C1
Clinical Research Site
Waterloo, Ontario, N2J 1C4
Germany5 sites
Clinical Research Site
Bad Bentheim, Lower Saxony, 48455
Clinical Research Site
Bochum, Northwest, 44791
Clinical Research Site
Kiel, Schleswig-Holstein, 24105
Clinical Research Site
Kiel, Schleswig-Holstein, 24148
Clinical Research Site
Schwerin, 19055
Spain4 sites
Clinical Research Site
Barcelona, 8036
Clinical Research Site
Manises, V, 46940
Clinical Research Site
Palma de Mallorca, PM, 07120
Clinical Research Site
Pontevedra, PO, 36001
Hungary2 sites
Clinical Research Site
Budapest, BU, 1036
Clinical Research Site
Debrecen, HB, 4032
About this study
Official title: 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.
- Conditions
- Hidradenitis Suppurativa
- Being tested
- Izokibep, Placebo to izokibep
- Keywords
- hidradenitis suppurativa, 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.
IzokibepDrug
Biologic: IL-17A inhibitor
Form: Solution for injection
Route of administration: Subcutaneous (SC)
Placebo to izokibepDrug
Form: Solution for injection
Route of administration: Subcutaneous (SC)
| Study group | Role | What they receive |
|---|---|---|
| Part A (Open-label) izokibep every week | Experimental | Participants will receive izokibep every week from Day 1 through Week 31 Receives: Drug: Izokibep |
| Part B (Double-blind) izokibep every week | Experimental | Participants will receive izokibep every week for 31 weeks. Receives: Drug: Izokibep |
| Part B (Double-blind) izokibep every other week | Experimental | Participants will receive izokibep every other week for 30 weeks. Receives: Drug: Izokibep |
| Part B (Double-blind) placebo every week | Placebo comparator | Participants will receive placebo every week up to Week 15, then izokibep from Week 16 to Week 31. Receives: Drug: Placebo to izokibep |
| Part B (Double-blind) placebo every other week | Placebo comparator | Participants will receive placebo every other week up to Week 14, then izokibep from Week 16 to Week 30. Receives: Drug: Placebo to izokibep |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: Part B: Baseline to Week 16
Secondary outcomes (11)
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.
Measured: 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.
Measured: 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
Measured: 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.
Measured: 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
Measured: 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.
Measured: 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.
Measured: 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".
Measured: 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.
Measured: 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.
Measured: 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.
Measured: Up to 39 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 May 2022
- Study start5 May 2022
- Primary completion2 Aug 2023
- Study completion21 Feb 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Hidradenitis SuppurativaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 205 participants (actual)
Sponsor and investigators
- Lead sponsor
- ACELYRIN Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Donald Betah, MD, Study director, ACELYRIN Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05355805
- Sponsor's protocol ID
- 21102
- Other IDs
- 2021-005713-13
- Status last verified
- Mar 2025
- First submitted
- 12 Apr 2022
- Last updated
- 3 Jun 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 3 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2b Study to Evaluate the Efficacy and Safety of Izokibep in Subjects With Moderate to Severe Hidradenitis Suppurativa
- ClinicalTrials.gov ID
- NCT05355805
- Acronym / sponsor ID
- 21102
- Conditions
- Hidradenitis Suppurativa
- Keywords
- hidradenitis suppurativa, Izokibep
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 205 participants (actual)
- Lead sponsor
- ACELYRIN Inc.Industry (pharma, biotech, devices)
- Study start
- 5 May 2022 (actual)
- Primary completion
- 2 Aug 2023 (actual)
- Study completion
- 21 Feb 2024 (actual)
- First posted
- 2 May 2022 (actual)
- Results
- Posted 25 Sep 2024
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| Part A (Open-label) izokibep every week | Experimental | Drug: IzokibepParticipants will receive izokibep every week from Day 1 through Week 31 |
| Part B (Double-blind) izokibep every week | Experimental | Drug: IzokibepParticipants will receive izokibep every week for 31 weeks. |
| Part B (Double-blind) izokibep every other week | Experimental | Drug: IzokibepParticipants will receive izokibep every other week for 30 weeks. |
| Part B (Double-blind) placebo every week | Placebo comparator | Drug: Placebo to izokibepParticipants will receive placebo every week up to Week 15, then izokibep from Week 16 to Week 31. |
| Part B (Double-blind) placebo every other week | Placebo comparator | Drug: Placebo to izokibepParticipants will receive placebo every other week up to Week 14, then izokibep from Week 16 to Week 30. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- 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.
Key exclusion criteria (13 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| IzokibepBiologic: IL-17A inhibitor Form: Solution for injection Route of administration: Subcutaneous (SC) | Drug | Part A (Open-label) izokibep every week, Part B (Double-blind) izokibep every other week, Part B (Double-blind) izokibep every week |
| Placebo to izokibepForm: Solution for injection Route of administration: Subcutaneous (SC) | Drug | Part B (Double-blind) placebo every other week, Part B (Double-blind) placebo every week |
Primary outcome
Part A: Number of Participants Who Achieved Hidradenitis Suppurativa Clinical Response 75 (HiSCR75) at Week 12
Time frame: Part A: Baseline to 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 B: Number of Participants Who Achieved HiSCR75 at Week 16
Time frame: Part B: Baseline to 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.
11 secondary outcomes
Part A: Number of Participants With Treatment-emergent Adverse Events (TEAEs)
Time frame: 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)
Time frame: Baseline, Week 16, Week 32, Week 39
Part B: Number of Participants Who Achieved HiSCR90 at Week 16
Time frame: Part B: Baseline to Week 16
Part B: Number of Participants Who Achieved HiSCR100 at Week 16
Time frame: Part B: Baseline to Week 16
Part B: Number of Participants Who Achieved HiSCR50 at Week 16
Time frame: Part B: Baseline to Week 16
Part B: Percentage of Participants Who Experienced ≥ 1 Disease Flare Through 16 Weeks of Treatment
Time frame: 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
Time frame: 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
Time frame: Part B: Baseline to Week 16
Part B: Number of Participants With TEAEs of Special Interest
Time frame: Part B: Screening (Day -28) to Follow-up (Week 45), for a total of 49 weeks
Part B: Number of Participants With TEAEs
Time frame: 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
Time frame: Up to 39 weeks
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Jun 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Donald Betah, MD study director
ACELYRIN Inc.
44 sites in 6 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Izokibep in people with Hidradenitis Suppurativa, run by ACELYRIN Inc. at 44 sites in 6 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 10 inclusion and 13 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: finished, as of the sponsor's last update on 3 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 44 sites in United States, Poland, Canada, Germany, Spain and 1 more country. 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. Some participants in this study may receive a placebo. 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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 25 Sep 2024). 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?
Part A: Number of Participants Who Achieved Hidradenitis Suppurativa Clinical Response 75 (HiSCR75) at Week 12 (time frame: Part A: Baseline to Week 12). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 3 Jun 2025.