A Study of the Safety, Tolerability, Pharmacokinetics, and Immunogenicity of BCX17725

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Biocryst Pharmaceuticals Inc.

Participant type

Pediatric, Patients

Age range

0-17 years, 18-64 years

Gender

Male and Female

Therapeutic area

Diseases [C] - Skin and Connective Tissue Diseases [C17]

Trial duration

31 Mar 2026 → ongoing

Decision date (initial)

2026-01-23

Transition trial

No

Low-intervention

No

Rare-disease indication

Yes

Vulnerable population

Yes

Funding sources

BioCryst Pharmaceuticals Inc

External identifiers

EU CT number

2025-521973-16-00

WHO UTN

U1111-1303-9510

ClinicalTrials.gov

NCT06539507

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Safety, Pharmacokinetic

Effectiveness: To evaluate the therapeutic potential of BCX17725 in adult and adolescent participants with NS.
Safety: To evaluate the safety and tolerability of BCX17725 when administered for 12 weeks in adult and adolescent participants with NS.
PK:To characterize BCX17725 concentrations in serum of adult and adolescent participants with NS.

Conditions and MedDRA coding

Netherton Syndrome

Study design 1 period

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 5

1. Able to provide written informed consent. Adolescent participants should provide assent (age determined by applicable institutional policy) with parent/legal guardian consent.
2. 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.
3. IGA score ≥ 3 and an IASI score of ≥ 16 at screening and Day 1 (baseline).
4. 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.
5. Participant (or, where applicable, parent/legal guardian) is willing and able to understand and comply with all applicable study requirements, including:a.a. Available 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 16

1. 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.
2. Any other skin disease that may interfere with planned NS skin evaluations.
3. Any infection requiring treatment with systemic antibiotics, antivirals, antiparasitics, or antifungals within 2 weeks prior to Day 1.
4. 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.
5. 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.
6. 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.
7. Positive test result for HIV at screening.
8. Active hepatitis B virus infection, determined by positive test result for hepatitis B surface antigen, at screening.
9. Active hepatitis C infection, determined as HCV RNA above the limit of detection in participants with positive HCV antibody titer, at screening.
10. 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. AST, ALT, or total bilirubin value > 1.5 × ULN b. Platelet count < 150,000/µL
11. 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.
12. History of sensitivity to any component of the IMP.
13. 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
14. Use of systemic retinoids, other systemic immunosuppressants, systemic corticosteroids, or phototherapy within 4 weeks prior to Day 1 or anticipated use during the study.
15. 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.
16. Participant is pregnant, planning to become pregnant, or having been pregnant within 90 days before Day 1, or lactating.

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 3

1. Effectiveness : Primary Effectiveness Endpoint: • Change from baseline in Ichthyosis Area and Severity Index (IASI) score at Week 12
2. Safety : Incidence of TEAEs through End-of-Study (EOS)
3. PK : Concentration of BCX17725 in serum through EOS

Secondary endpoints 1

1. 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

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Biocryst Pharmaceuticals Inc.

Sponsor organisation

Biocryst Pharmaceuticals Inc.

Address

4505 Emperor Boulevard Suite 200

City

Durham

Postcode

27703-8457

Country

United States

Scientific contact point

Organisation

Biocryst Pharmaceuticals Inc.

Contact name

Study Director, BioCryst Pharmaceuticals Inc.

Public contact point

Organisation

Biocryst Pharmaceuticals Inc.

Contact name

Study Director, BioCryst Pharmaceuticals Inc.

Third parties 9

Locations

3 EU/EEA countries · 4 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 60 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

4 submissions — initial application plus substantial / non-substantial modifications