TRB-061 injections for healthy adults and people with moderate-to-severe atopic dermatitis

A Phase 1a/1b Randomized, Double-Blind, Placebo-Controlled, 3-Part Study to Investigate the Safety, Pharmacokinetics, and Pharmacodynamics of Single and Multiple Subcutaneous Doses of TRB-061 in Healthy Participants and in Patients With Moderate-to-Severe Atopic Dermatitis

This trial will test subcutaneous TRB-061 injections in healthy adults and adults with moderate-to-severe atopic dermatitis to check safety, dosing, and how the drug acts in the body.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 115 (estimated)
• Ages: 18 Years to 70 Years
• Sex: All
• Sponsor: TRex Bio, Inc. (Industry-sponsored)
• Locations: 14 sites (Belconnen, Australian Capital Territory and 13 other locations)
• Trial ID: NCT06934252 on ClinicalTrials.gov

What this trial studies

This randomized, double-blind, placebo-controlled Phase 1a/1b program includes single-ascending dose (SAD) and multiple-ascending dose (MAD) parts in healthy volunteers and a Phase 1b repeat-dosing part in patients with moderate-to-severe atopic dermatitis. In SAD healthy volunteers are dosed in cohorts of 8 (6 active, 2 placebo) with safety review before escalation; MAD healthy volunteers receive three doses Q4W over 8 weeks. The Phase 1b patient portion randomizes participants 1:1:1 to two active dose levels or placebo for four doses over 12 weeks, with an option for placebo recipients to receive active treatment after the primary period. Follow-up periods of roughly 10–12 weeks are included to monitor safety, pharmacokinetics, and pharmacodynamics.

Who should consider this trial

Good fit: Adults 18–70 who are either healthy volunteers meeting weight/BMI and non-smoking criteria for Parts 1–2 or patients with confirmed moderate-to-severe AD (EASI ≥16, BSA ≥10%, vIGA-AD ≥3, pruritus NRS ≥3) for Part 3.

Not a fit: People with mild AD, children, pregnant or breastfeeding individuals, current smokers above the trial limit, or those with significant lab or ECG abnormalities or outside the BMI/weight ranges are unlikely to qualify or benefit from this early-phase study.

Why it matters

Potential benefit: If successful, TRB-061 could provide a new injectable option that reduces inflammation and itch for people with moderate-to-severe atopic dermatitis.

How similar studies have performed: Other injectable, targeted therapies for atopic dermatitis have shown clear clinical benefit, but TRB-061 itself is in early-phase testing with limited prior patient data.

Eligibility criteria

Inclusion Criteria:

1. Male or female participants aged 18 to 70 years, inclusive, at the time of informed consent.
2. Body weight ≥50 kg and body mass index (BMI) between 18.5 and 35.0 kg/m², inclusive.
3. Participant is in good general health as determined by the investigator, based on medical history, physical examination, and clinical laboratory tests.
4. For healthy participants (Parts 1 and 2): no clinically significant abnormalities in laboratory results, ECGs, or physical exams at screening.
5. For participants in Part 3: Confirmed diagnosis of AD with onset of symptoms at least 1 year prior to Screening.
6. Must be nonpregnant and nonlactating with negative pregnancy tests at screening and prior to dosing.
7. Must be a non-smoker or ≤5 cigarettes per week for the past 6 months (SAD/MAD only).
8. Moderate-to-severe AD at Screening and at Day 1 visit as defined by:

   1. EASI score ≥16,
   2. BSA affected ≥10%,
   3. vIGA-AD score ≥3, and
   4. Pruritus NRS score ≥3.

Exclusion Criteria:

1. History of any clinically significant disease or disorder which, in the opinion of the investigator, may put the participant at risk or interfere with study results.
2. History or presence of any condition requiring systemic immunosuppressive or immunomodulatory therapy within a defined period before screening.
3. Use of any biologic agent (e.g., monoclonal antibodies) within 3 months or 5 half-lives (whichever is longer) before Day 1.
4. Participation in another investigational drug trial within 30 days or 5 half-lives of the investigational product (whichever is longer) before Day 1.
5. History of hypersensitivity or allergic reaction to any component of the study drug or placebo formulation.
6. Known active or latent tuberculosis (TB) infection or history of incomplete TB treatment.
7. Positive test at screening for hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) RNA, or human immunodeficiency virus (HIV).
8. Active infection or history of serious infections within 4 weeks prior to Day 1.
9. History of malignancy (except treated and cured non-melanoma skin cancers or cervical carcinoma in situ).
10. Pregnant or breastfeeding women, or women planning to become pregnant during the study or within a specified time after the last dose.
11. Clinically significant ECG abnormalities (e.g., QTcF \>470 ms) or other cardiac risk factors.
12. Abnormal laboratory values at screening.
13. Use of live vaccines within 4 weeks before Day 1.
14. Use of systemic corticosteroids, immunosuppressants, or immunomodulatory drugs within protocol-defined washout periods (Part 3 Phase 1b only).
15. Active COVID-19 infection or symptoms, or positive COVID-19 test at screening.
16. History of alcohol or drug abuse within the past year.
17. Use of tobacco/nicotine products beyond protocol-allowed limits.
18. Positive cotinine test at check-in (SAD/MAD only).
19. Any other reason, in the opinion of the investigator or sponsor, that would make the participant unsuitable for participation in the study.
20. Any medical or psychiatric condition that, in the opinion of the Investigator or Sponsor's medical monitor, would place the participant at risk, interfere with study participation, or interfere with the interpretation of study results.
21. Surgery within the past 90 days prior to dosing as determined by the Investigator or Sponsor's medical monitor to be clinically relevant or planned surgery to be performed during the study and 30 days after the last dose of study drug.

Where this trial is running

Belconnen, Australian Capital Territory and 13 other locations

• Paratus Clinical Research - Canberra Trial Clinic — Belconnen, Australian Capital Territory, Australia (Not_yet_recruiting)
• Paratus Clinical Brisbane Pty Ltd — Albion, Brisbane, Australia (Not_yet_recruiting)
• Paratus Clinical Research Western Sydney — Blacktown, New South Wales, Australia (Not_yet_recruiting)
• Paratus Clinical Research Central Coast — Kanwal, New South Wales, Australia (Not_yet_recruiting)
• Cornerstone Centre for Clinical Research — Coorparoo, Queensland, Australia (Not_yet_recruiting)
• CMAX Clinical Research Pty Ltd — Adelaide, South Australia, Australia (Recruiting)
• Paratus Clinical Research Melbourne — Melbourne, Victoria, Australia (Not_yet_recruiting)
• Momentum Clinical Research Pukekohe — Pukekohe, Auckland, New Zealand (Not_yet_recruiting)
• Momentum Clinical Research Dunedin — Dunedin, Otago, New Zealand (Not_yet_recruiting)
• Pacific Clinical Research Network-Tasman — Nelson, Tasman District, New Zealand (Not_yet_recruiting)
• Medical Research Institute of New Zealand — Newtown, Wellington Region, New Zealand (Not_yet_recruiting)
• Pacific Clinical Research Network-Wellington — Upper Hutt, Wellington Region, New Zealand (Not_yet_recruiting)
• Momentum Clinical Research Kapiti — Waikanae, Wellington Region, New Zealand (Not_yet_recruiting)
• Pacific Clinical Research Network-West Auckland — Auckland, New Zealand (Not_yet_recruiting)

Study contacts

• Study coordinator: Study Director

Conditions Moderate-to-severe Atopic Dermatitis