A Phase 1 interventional study of BCX17725 and Placebo in Netherton Syndrome, sponsored by BioCryst Pharmaceuticals. Active, not recruiting at 12 sites in 5 countries. Open to participants aged 12 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-06.
Sponsored by BioCryst Pharmaceuticals · Phase 1, Interventional, and Treatment
This is a first-in-human, Phase 1/1b, 4-part study that includes the evaluation of safety, tolerability, pharmacokinetics (PK), and immunogenicity of BCX17725 when administered via single and multiple doses in healthy adult participants (Parts 1 and 2), and multiple doses in adult participants with Netherton syndrome (Part 3). In Part 4, the effectiveness, safety, and tolerability of BCX17725 when administered via multiple IV and/or SC doses through 12 weeks will be evaluated in adult and adolescent participants with Netherton syndrome.
Parts 1 and 2 are randomized, placebo-controlled, single-ascending-dose (SAD) and multiple-ascending-dose (MAD) study parts, respectively, in healthy participants. Part 3 will evaluate multiple dose administrations in participants with Netherton syndrome in an open-label design. Part 4 will evaluate multiple administrations of BCX17725 in participants with Netherton syndrome in an open-label study design over 12 weeks, with an 8-week post-treatment follow-up period.
22 studies on the registry are indexed under Netherton Syndrome; 5 are open to participants now.
This study's enrollment of 76 is above the median of 16 across 19 interventional studies indexed under Netherton Syndrome.
Browse Netherton Syndrome studies →BioCryst Pharmaceuticals is the lead sponsor of 54 studies on the registry; 1 is open to participants now.
Of its 10 completed or terminated interventional studies of FDA-regulated products, 8 (80%) have results posted.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants randomized to BCX17725 will receive BCX17725 as a single dose in sequential ascending dose cohorts
Drug: BCX17725
Participants randomized to placebo will receive placebo as a single dose
Drug: Placebo
Participants randomized to BCX17725 will receive BCX17725 as multiple doses in sequential ascending dose cohorts
Drug: BCX17725
Participants randomized to placebo will receive placebo as multiple doses
Drug: Placebo
Participants will receive BCX17725 as multiple doses
Drug: BCX17725
Participants will receive BCX17725 as multiple doses
Drug: BCX17725
BCX17725 for injection
Placebo for injection
Incidence of treatment-emergent adverse events (TEAEs)
Incidence of TEAEs as assessed by Common Terminology Criteria for Adverse Events (CTCAE) from screening through end-of-study (EOS) in each study part
Time frame: From screening through EOS (ie, through Day 78 in Parts 1 and 3, and Day 106 in Part 2)
Change from baseline in Ichthyosis Area and Severity Index (IASI) score at Week 12 (Part 4)
IASI measures the severity of erythema (IASI-E) and scaling (IASI-S); the maximum sub-scores for the IASI-E and IASI-S being 24, and the maximum total IASI score being 48. Higher scores indicate worse clinical outcome.
Time frame: From baseline to Week 12
Maximum observed serum concentration (Cmax)
Cmax of BCX17725
Time frame: Up to Day 64 (Part 1), Day 92 (Part 2), and Day 78 (Part 3)
Time to maximum observed serum concentration (Tmax)
Time to Cmax of BCX17725
Time frame: Up to Day 64 (Part 1), Day 92 (Part 2), and Day 78 (Part 3)
Area under the serum concentration-time curve (AUC) from time 0 to the time of last measurable concentration (AUC0-t)
AUC0-t of BCX17725
Time frame: Up to Day 64 (Part 1), Day 92 (Part 2), and Day 78 (Part 3)
Terminal elimination half-life (t1/2)
Terminal elimination half-life (t1/2) of BCX17725
Time frame: Up to Day 64 (Part 1), Day 92 (Part 2), and Day 78 (Part 3)
Number of participants who are anti-drug antibody (ADA)-positive (baseline and post-baseline) and number of participants who have treatment-emergent ADAs
Incidence of ADAs to BCX17725
Time frame: Day 1 pre-dose and up to Day 64 (Part 1), Day 92 (Part 2), and Day 78 (Part 3)
Change from baseline in Investigator Global Assessment (IGA) score at Week 12 (Part 4)
IGA assesses the overall severity of a participant's NS skin disease based on a 5-point scale (0, clear; 1, almost clear; 2, mild; 3, moderate; and 4, severe). Higher scores indicate worse clinical outcome.
Time frame: From baseline to Week 12
Change from baseline in Worst Itch Numerical Rating Score (NRS) at Week 12 (Part 4)
Worst Itch Numerical Rating Scale (NRS) is a self-rated, single-item scale designed for assessing the worst itch in the past 7 days. The scale uses an 11-point NRS, scored from 0 (no itch) to 10 (worst possible itch). Higher scores indicate worse clinical outcome.
Time frame: From baseline to Week 12
Incidence of TEAEs (Part 4)
Incidence of TEAEs as assessed by CTCAE
Time frame: From baseline through Week 20
Serum concentrations of BCX17725 (Part 4)
Serum concentrations of BCX17725
Time frame: From baseline through Week 20
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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