A 3-part Study of SYX-5219 in Healthy Volunteers and Participants With Atopic Dermatitis

NCT07558668 | Recruiting Phase 1 FDA Drug

• 1 other identifier: SYX-5219-101
• Study Type: interventional
• Target: 149
• Locations: 6 countries
• Sites: 14

Brief Summary

The purpose of this study is to evaluate the study drug, SYX-5219, in a multi-part First-in-Human (FiH) study to be conducted in healthy volunteers and participants with Atopic Dermatitis (AD). The objectives of this study are to determine the safety, tolerability and levels of SYX-5219 in the blood and urine when SYX-5219 is given in each part of the study (SAD, MAD, Food Effect and Participants with AD). The study will be split into up to 3 parts as follows:

• Part 1 - Single Ascending Dose (SAD) and Food Effect in healthy volunteers
• Part 2 - Multiple Ascending Dose (MAD) in healthy volunteers
• Part 3 - Multiple Dose in Participants with AD - enrolling up to 45 males and females with a confirmed diagnosis of AD of at least 6 months, evaluating multiple dose administrations of SYX-5219 or placebo daily over a period of 42 days.

Conditions

Moderate to Severe Atopic Dermatitis

Outcome Measures

Primary Outcomes (1)

• The Proportion of Participants With Treatment-Emergent Adverse Events

  The number of participants who reported a treatment-emergent adverse event (TEAE) will be summarised.

  Adverse events are collected from the date of consent until up to 10 days after the dose in Part 1 (Day 11), 14 days after the last dose in Part 2 (Day 28) and up to Day 56 in Part 3.

Secondary Outcomes (2)

• Concentrations of SYX5219 in Plasma

  For Part 1: 14 timepoints from pre-dose Day 1 up to 120 h post-dose Day 6. For Part 2: 28 timepoints from pre-dose Day 1 up to Day 19. For Part 3: 8 timepoints from pre-dose Day 1 up to Day 56.

• Concentrations of SYX5219 in Urine

  For Part 1: continuous urine collection from Day 1 up to 48 hr post-dose on Day 2. For Part 2: continuous urine collection from Day 1 up to 48 hr post-dose on Day 2 and Day 14 up to 48 hr post-dose on Day 16.

Other Outcomes (10)

• Percent change from baseline in the Eczema Area and Severity Index (EASI) - Part 3

  For Part 3: Measured at screening, Day 1, Day 8, Day 15, Day 29, Day 43 & Day 56.

• Proportion of participants achieving a 50% 75% and 90% reduction of EASI (EASI50 and EASI75 and EASI90) - Part 3

  For Part 3: Measured at screening, Day 1, Day 8, Day 15, Day 29, Day 43 & Day 56.

• Proportion of participants achieving a minimum 2- grade improvement from baseline in validated Investigator Global Assessment (vIGA) score to clear (0) or almost clear (1) - Part 3

  For Part 3: Measured at screening, Day 1, Day 8, Day 15, Day 29, Day 43 & Day 56.

Study Arms (3)

Part 1 Single Ascending Dose (SAD)

EXPERIMENTAL

Single dose of SYX-5219 (active or matching placebo) administered on Day 1 for all cohorts and Day 1 of each treatment period for food effect cohorts (in fasted and fed conditions).

Drug: SYX-5219 Oral Capsule

Part 2 Multiple Ascending Dose (MAD)

EXPERIMENTAL

Multiple doses of SYX-5219 (active or matching placebo) administered once or twice daily for all cohorts.

Drug: SYX-5219 Oral Capsule

Part 3 AD Participants Multiple Doses

EXPERIMENTAL

Multiple doses of SYX-5219 (active or matching placebo) administered twice daily for multiple dose administration

Drug: SYX-5219 Oral Capsule

Interventions

SYX-5219 Oral Capsule DRUG

Oral Capsule to be administered at each specific dose level within each cohort

Part 1 Single Ascending Dose (SAD); Part 2 Multiple Ascending Dose (MAD); Part 3 AD Participants Multiple Doses

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Parts 1 \& 2
• Healthy male and female participant, between ≥ 18 to ≤ 65 years of age, inclusive, with a BMI of body mass index (BMI) of 18-32 kg/m2.
• Female participant of non-childbearing potential or female of childbearing potential that is sexually abstinent.
• No clinically significant abnormalities in laboratory, vital signs or ECG measurements.
• Part 3
• Male and female participants with clinically confirmed diagnosis of active AD, between ≥ 18 to ≤ 65 years of age, inclusive, with a BMI of body mass index (BMI) of ≤40 kg/m2.
• Meet minimum AD entry criteria;
• AD covering ≥10% of the body surface area (BSA) at screening and baseline.
• Eczema Area and Severity Index (EASI) score ≥16 at screening and baseline.
• Validated Investigator's Global Assessment (vIGA) score of ≥ 3 (moderate) at screening and baseline.
• Peak Pruritus NRS score of ≥ 4 at screening and baseline.

You may not qualify if:

• Parts 1 \& 2
• Use of prescription or non-prescription drugs, including vitamins, herbal and dietary supplements within 35 days or 5 half-lives (whichever is longer) prior to the first dose of IMP.
• Part 3
• Any clinically significant medical condition or physical/laboratory/ECG/vital signs abnormality that would, in the opinion of the Investigator, put the participant at undue risk.

Sponsors & Collaborators

• Sitryx Therapeutics Ltd: lead

Study Sites (14)

Sitryx Clinical Site

Arkansas City, Arkansas, 72117, United States

RECRUITING

Sitryx Clinical Site

Fremont, California, 94538, United States

RECRUITING

Sitryx Clinical Site

Plainfield, Indiana, 46168, United States

RECRUITING

Sitryx Clinical Site

Boardman, Ohio, 44512, United States

RECRUITING

Sitryx Clinical Site

Philadelphia, Pennsylvania, 19103, United States

RECRUITING

Sitryx Clinical Site

Bountiful, Utah, 84010, United States

RECRUITING

Sitryx Clinical Site

Sofia, 1404, Bulgaria

RECRUITING

Sitryx Clinical Site

Herlev, Herlev, 2730, Denmark

NOT YET RECRUITING

Sitryx Clinical Site

Berlin, 10117, Germany

RECRUITING

Sitryx Clinical Site

Frankfurt, 60596, Germany

RECRUITING

Sitryx Clinical Site

Freiburg im Breisgau, 79106, Germany

ACTIVE NOT RECRUITING

Sitryx Clinical Site

Dublin, D08 NHY1, Ireland

RECRUITING

Sitryx Clinical Site

Manchester, M23 9QZ, United Kingdom

RECRUITING

Sitryx Clinical Site

Merthyr Tydfil, CF48 4DR, United Kingdom

RECRUITING

Study Officials

• Sitryx Therapeutics

  Study Sponsor

  STUDY DIRECTOR

Central Study Contacts

Sitryx Therapeutics

CONTACT

+44 (0)1865 648401; info@sitryx.com

Sitryx Therapeutics

CONTACT

+44 (0) 1865 648401; info@sitryx.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: Double-Blind
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 22, 2026
• First Posted: April 30, 2026
• Study Start: February 26, 2025
• Primary Completion (Estimated): August 30, 2026
• Study Completion (Estimated): September 30, 2026
• Last Updated: April 30, 2026

Record last verified: 2026-04

Locations

DK (1); BU (1); DE (3); GB (2); IE (1); US (6)