HUMAN IGG1 MONOCLONAL ANTIBODY AGAINST INTERLEUKIN 21 for Hidradenitis suppurativa (moderate-to-severe)

Inclusion criteria

• {"criterion_text":"- 1. Male or female between 18 and 65 years old inclusive.\n- 2. A body mass index (BMI) of ≤40 kg/m2 and body weight of ≥45 kg at the time of signing the informed consent.\n- 3. Ability to understand and willing to comply with trial requirements as per Investigator’s opinion.\n- 4. Provide written informed consent in accordance with institutional and regulatory guidelines.\n- 5. A diagnosis of moderate-to-severe HS defined as a total of ≥5 inflammatory lesions (ie, number of abscesses plus number of inflammatory nodules) at both the Screening and Baseline visits, with a clinical history of HS for at least 6 months.\n- 6. HS lesions present in at least 2 distinct anatomic areas (eg, left and right axilla), one of which must be at least Hurley Stage II or Hurley Stage III at both the Screening and Baseline visits.\n- 7. History of inadequate response, or intolerance or contraindication, to a course of a systemic antibiotics for treatment of HS at the Screening visit, including participants who responded to course(s) of systemic antibiotic(s) and subsequently exhibited recurrence after discontinuation of the antibiotic, as assessed by the Investigator through trial participant interview and review of medical history.\n- 8. Agree to use, preferably daily but at least 3 days per week, over-the-counter topical antiseptics on their HS lesions throughout the entirety of the study from at least 2 weeks prior to the Baseline visit.\n- 9. Participants who are woman of child-bearing potential (WOCBP) and male participants must agree to the requirements for the avoidance of pregnancy and exposure of the participant’s partner to LAD328 during the trial"}

Exclusion criteria

• {"criterion_text":"- 1. Syndromic HS, ie, HS associated with genetic background, follicular plugging or structural disorders, autoinflammatory pathogenesis, as per Investigator’s judgment.\n- 7. Hypersensitivity or systemic reaction to a prior biologic (antibody-based) therapy (regardless of indication), that was clinically significant, as per judgment of Investigator.\n- 8. Any medical or psychiatric condition that, in the opinion of the Investigator, could jeopardize or would compromise the trial participant’s ability to participate to comply with the trial requirements, as determined by the Investigator based on protocol required assessments.\n- 9. Active chronic or acute infection requiring treatment with systemic antimicrobials, antivirals, antiparasitic, antiprotozoals, or antifungals within 2 weeks before Baseline, or fever > 38°C during within 1 week before Baseline.\n- 13. Positive test result at Screening for hepatitis B surface antigen (HBsAg), or antibody to hepatitis B core antigen (anti-HBc antibody), or antibody to the hepatitis C virus (anti-HCV), or antibody to the human immunodeficiency virus (anti-HIV-1/2 antibody).\n- 14. History within 1 year prior to Screening of alcohol or drug abuse, as per Investigator’s judgment.\n- 15. Major surgery (eg, open-heart surgery or organ transplant surgery) within the 3 months prior to the Baseline visit or has major surgery pre-planned for the time of participation in this trial at XXXX.\n- 16. Prior treatment with LAD328\n- 17. Live and attenuated vaccinations 4 weeks prior to XXXX or is planning to receive any such vaccine during the trial.\n- 18. Intention to use any concomitant medication or therapy that is not permitted by this protocol or failure to meet the required wash-out period for a particular prohibited medication prior to XXXX\n- 19. Inadequate response to 2 or more biologics for HS (eg, adalimumab, secukinumab and bimekizumab) having different MoAs (classes), as per the Investigator’s judgment.\n- 10. Active tuberculosis (TB), a positive TB test at Screening, or history of active or latent TB, regardless of prior treatment.\n- 20. Females who are pregnant or breast-feeding or seeking to become pregnant during the trial or for approximately XXXX after the last dose of investigational medicinal product (IMP).\n- 21. Institutionalised because of legal or regulatory order.\n- 22. An employee or relative of the Sponsor, Clinical Research Organization (CRO) or other vendor, clinical trial site, or is an individual or employee otherwise directly involved with the conduct of the trial or is an immediate family member of such an individual.\n- 11. History of malignancy within past 5 years prior to Baseline (other than successfully treated basal cell or squamous cell carcinoma of the skin), regardless of outcome.\n- 12. History of liver disease or clinically significant abnormal (as per judgment of Investigator) liver function test(s) at Screening.\n- 2. HS with >20 draining tunnels either at the Screening or Baseline visits.\n- 3. Presence of skin comorbidities that may interfere with trial assessments, in the opinion of the Investigator (eg, cystic acne, follicular pyodermas, bacterial cellulitis, actinomycosis, candida intertrigo and extensive condyloma).\n- 4. Surgical intervention for the treatment of HS within 3 months prior to Baseline.\n- 5. Ongoing medical conditions (eg, inflammatory bowel disease, rheumatoid arthritis, systemic lupus erythematosus and sarcoidosis) requiring systemic immunosuppressive/immunomodulating treatments (eg, methotrexate, ciclosporin, corticosteroids, XXXX agents and JAK inhibitors) during the trial.\n- 6. Known or suspected hypersensitivity to trial product or any of its excipients."}

Primary endpoints

• {"endpoint_text":"- Proportion of participants achieving IHS4-55 at XXXX.","definition_or_measurement_approach":""}
• {"endpoint_text":"- Safety: Frequency and severity of TEAEs, SAEs, AESIs and AEs leading to discontinuation.","definition_or_measurement_approach":""}
• {"endpoint_text":"- Safety: Vital signs, ECG and clinical laboratory parameters.","definition_or_measurement_approach":""}

Methods

• Site-based recruitment using study flyers and brochures (K2_Recruitment material Study Flyer; Study Brochure).
• Site study overview flipcharts for investigator/clinic use (K2_Recruitment material Study Overview Flipchart).
• Referral email templates for digital referrals to sites (K2_Recruitment material Referral email_Redacted).
• Investigator memos and country-specific recruitment instructions (e.g., K1_Recruitment_Investigator memo for France).

France

Earliest CTIS Part Ii Submission Date

02-03-2026

Latest Decision Or Authorization Date

09-04-2026

Processing Time Days

38

Number Of Sites

5

Bulgaria

Earliest CTIS Part Ii Submission Date

04-03-2026

Latest Decision Or Authorization Date

01-04-2026

Processing Time Days

28

Number Of Sites

7

Poland

Earliest CTIS Part Ii Submission Date

04-03-2026

Latest Decision Or Authorization Date

09-04-2026

Processing Time Days

36

Number Of Sites

6

Spain

Earliest CTIS Part Ii Submission Date

12-03-2026

Latest Decision Or Authorization Date

01-04-2026

Processing Time Days

20

Number Of Sites

7

Germany

Earliest CTIS Part Ii Submission Date

02-03-2026

Latest Decision Or Authorization Date

09-04-2026

Processing Time Days

38

Number Of Sites

6

Primary sponsor

Full Name

Almirall S.A.

Organisation Type

Pharmaceutical company

Country Of Registered Address

Spain

Contract research organisations

Name

Endpoint Clinical Inc.

Responsibilities

sponsorDuties codes: [3]

Name

Fortrea Inc.

Responsibilities

sponsorDuties codes: [1,12,13,5,8]

Name

Eresearchtechnology Inc.

Responsibilities

sponsorDuties codes: [15] (ECG)

Name

Labconnect LLC

Responsibilities

sponsorDuties codes: [4]

Name

Veeva Systems Inc.

Responsibilities

sponsorDuties codes: [15 (e_COA), 7]

Name

Alcura Health Espana S.A.

Responsibilities

sponsorDuties codes: [14]

Third parties

• {"country":"United States","full_name":"Endpoint Clinical Inc.","duties_or_roles":"sponsorDuties codes: [3]","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Fortrea Inc.","duties_or_roles":"sponsorDuties codes: [1,12,13,5,8]","organisation_type":"Pharmaceutical company"}
• {"country":"Spain","full_name":"Alcura Health Espana S.A.","duties_or_roles":"sponsorDuties codes: [14]","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Eresearchtechnology Inc.","duties_or_roles":"sponsorDuties codes: [15] (ECG)","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Labconnect LLC","duties_or_roles":"sponsorDuties codes: [4]","organisation_type":"Laboratory/Research/Testing facility"}
• {"country":"United States","full_name":"Veeva Systems Inc.","duties_or_roles":"sponsorDuties codes: [15 (e_COA), 7]","organisation_type":"Non-Pharmaceutical company"}