BCX17725 for Netherton syndrome

Inclusion criteria

• {"criterion_text":"- Able to provide written informed consent. Adolescent participants should provide assent (age determined by applicable institutional policy) with parent/legal guardian consent."}
• {"criterion_text":"- Male or non-pregnant, non-lactating female, aged 12 to 65 years, inclusive, with a confirmed diagnosis of NS. Note: Participants without pre-existing documentation of SPINK5 gene variant(s) confirming NS diagnosis will be required to provide a blood sample for genetic testing at screening."}
• {"criterion_text":"- IGA score ≥ 3 and an IASI score of ≥ 16 at screening and Day 1 (baseline)."}
• {"criterion_text":"- Females of childbearing potential and males with female partners of childbearing potential, must agree to follow the contraception requirements outlined in Section 5.3 of the protocol from screening until 90 days after the last dose of BCX17725."}
• {"criterion_text":"- Participant (or, where applicable, parent/legal guardian) is willing and able to understand and comply with all applicable study requirements, including:a.a.\tAvailable to complete the entire study duration; b: Able to understand the study procedures including the ability to complete any self assessment questionnaires or instruments; c: Willing to have skin strip samples collected"}

Exclusion criteria

• {"criterion_text":"- Apart from a diagnosis of NS, any clinically significant disease or condition (eg, medical, psychiatric, or social) that, in the opinion of the investigator, would interfere with the participant’s ability to participate in the study or increase the risk of participation for that participant."}
• {"criterion_text":"- Any abnormal laboratory parameter at screening or Day 1 that, in the opinion of the investigator, is clinically significant and relevant for this study, including but not limited to those listed below. Enrollment of a participant with a laboratory value outside of the reference range may be permissible if the abnormality is documented by the investigator not to be of clinical significance. a.\tAST, ALT, or total bilirubin value > 1.5 × ULN b.\tPlatelet count < 150,000/µL"}
• {"criterion_text":"- History of anaphylaxis or other severe reaction to any biologic or protein therapeutic agent, which, in the opinion of the investigator or sponsor medical monitor, should contraindicate their participation in this study."}
• {"criterion_text":"- History of sensitivity to any component of the IMP."}
• {"criterion_text":"- Receipt of any investigational drug, systemic biologic, or systemic immunoglobulin within 8 weeks prior to Day 1 or anticipated receipt during the study (excluding potential receipt of BCX17725 during the study). Note: Individuals who participate in Part 3 may additionally participate in Part 4, providing they meet all applicable eligibility criteria for Part 4 and experienced no significant safety concerns related to BCX17725 administration in Part 3. Part 3 participants qualifying for Part 4 enrollment will be subject to the washout period as described above"}
• {"criterion_text":"- Use of systemic retinoids, other systemic immunosuppressants, systemic corticosteroids, or phototherapy within 4 weeks prior to Day 1 or anticipated use during the study."}
• {"criterion_text":"- Use of ultra-high to medium potency topical corticosteroids (WHO Classes 1 to 5 or equivalent; see Appendix 3) within 2 weeks prior to Day 1 or anticipated use during the study."}
• {"criterion_text":"- Participant is pregnant, planning to become pregnant, or having been pregnant within 90 days before Day 1, or lactating."}
• {"criterion_text":"- Any other skin disease that may interfere with planned NS skin evaluations."}
• {"criterion_text":"- Any infection requiring treatment with systemic antibiotics, antivirals, antiparasitics, or antifungals within 2 weeks prior to Day 1."}
• {"criterion_text":"- History of malignancy within 5 years prior to screening, with exception of adequately treated non-melanoma skin or superficial bladder cancer, curatively treated carcinoma in situ of the cervix, or other curatively treated solid tumor deemed by the investigator and medical monitor to be at low risk for recurrence."}
• {"criterion_text":"- Any clinically significant history of a cardiovascular abnormality, including but not limited to angina, known coronary artery disease, myocardial infarction, clinically significant cardiac arrhythmias, left ventricular hypertrophy, cardiomyopathy, or aortic stenosis."}
• {"criterion_text":"- History of significant drug or alcohol abuse in the 6 months prior to screening or a positive drugs of abuse screen (not supported by a legitimate prescription) at screening."}
• {"criterion_text":"- Positive test result for HIV at screening."}
• {"criterion_text":"- Active hepatitis B virus infection, determined by positive test result for hepatitis B surface antigen, at screening."}
• {"criterion_text":"- Active hepatitis C infection, determined as HCV RNA above the limit of detection in participants with positive HCV antibody titer, at screening."}

Primary endpoints

• {"endpoint_text":"- Effectiveness : Primary Effectiveness Endpoint: •\tChange from baseline in Ichthyosis Area and Severity Index (IASI) score at Week 12","definition_or_measurement_approach":"Change from baseline in Ichthyosis Area and Severity Index (IASI) score at Week 12."}
• {"endpoint_text":"- Safety : Incidence of TEAEs through End-of-Study (EOS)","definition_or_measurement_approach":"Incidence of treatment-emergent adverse events (TEAEs) through End-of-Study (EOS)."}
• {"endpoint_text":"- PK : Concentration of BCX17725 in serum through EOS","definition_or_measurement_approach":"Concentration of BCX17725 measured in serum through End-of-Study (EOS)."}

Secondary endpoints

• {"endpoint_text":"- Effectiveness : Key Secondary Effectiveness Endpoints: • Change from baseline in Investigator Global Assessment (IGA) score at Week 12 Change from baseline in the Worst Itch Numerical Rating Scale (NRS) score at Week 12","definition_or_measurement_approach":"Change from baseline in Investigator Global Assessment (IGA) score at Week 12; Change from baseline in Worst Itch Numerical Rating Scale (NRS) score at Week 12."}

Netherlands

Earliest CTIS Part Ii Submission Date

13-01-2026

Latest Decision Or Authorization Date

20-01-2026

Processing Time Days

7

Number Of Sites

2

Number Of Participants

2

Germany

Earliest CTIS Part Ii Submission Date

15-12-2025

Latest Decision Or Authorization Date

21-01-2026

Processing Time Days

37

Number Of Sites

1

Number Of Participants

2

France

Earliest CTIS Part Ii Submission Date

01-12-2025

Latest Decision Or Authorization Date

23-01-2026

Processing Time Days

53

Number Of Sites

1

Number Of Participants

2

Primary sponsor

Full Name

Biocryst Pharmaceuticals Inc.

Organisation Type

Pharmaceutical company

Country Of Registered Address

United States

Third parties

• {"country":"United Kingdom","full_name":"AMS Advanced Medical Services Limited","duties_or_roles":"sponsorDuties codes: 1, 12, 2, 5","organisation_type":"Pharmaceutical company"}
• {"country":"Ireland","full_name":"Millmount Healthcare Limited","duties_or_roles":"sponsorDuties code: 14","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Discovery Life Sciences LLC","duties_or_roles":"Laboratory services for PK, Immunogenicity","organisation_type":"Laboratory/Research/Testing facility"}
• {"country":"United States","full_name":"Trulab Inc.","duties_or_roles":"Biospecimen tracking and sample management","organisation_type":"Pharmaceutical company"}
• {"country":"Australia","full_name":"Agilex Biolabs Pty Limited","duties_or_roles":"Laboratory services for PK, Immunogenicity","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Vitro Vivo Biotech","duties_or_roles":"Laboratory Services for skin biopsy samples","organisation_type":"Industry"}
• {"country":"United States","full_name":"Biocryst Pharmaceuticals Inc.","duties_or_roles":"Laboratory services for PK, Immunogenicity","organisation_type":"Pharmaceutical company"}
• {"country":"United Kingdom","full_name":"Iqvia Biotech Limited","duties_or_roles":"Management of Greenphire","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Pharmaron (Boston) Lab Services LLC","duties_or_roles":"laboratory services for PD","organisation_type":"Industry"}