A Proof of Concept, Phase 1 Study of CGB-600 for the Topical Treatment of Non-Segmented Facial Vitiligo

Safety and Effectiveness of CGB-600 Gel for the Treatment of Non-Segmental Facial Vitiligo: A Randomized, Double-Blind, Vehicle-Controlled Phase 1 Proof of Concept Study (Study No. CGB-600-02)

The goal of this clinical trial is to learn if drug CGB-600 works to treat vitiligo on the face and neck in participants between 18-60 years of age. It will also learn about the safety of CGB-600. The main questions it aims to answer are:

Does CGB-600 decrease the severity of vitiligo on the face and neck? What medical problems do participants have when taking drug CGB-600? Researchers will compare CGB-600 to a non-active drug (vehicle) to see if CGB-600 works to treat vitiligo.

Participants will:

Apply face twice daily for a period of 24 weeks. Visit the clinic 8 times for checkups and tests.

Study Overview

• Status: Recruiting
• Conditions: Vitiligo
• Intervention / Treatment: Drug: Drug: CGB-600 gel, experimental drug; Other: placebo: gel vehicle

• Study Type: Interventional
• Enrollment (Estimated): 36
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Nitin Joshi, Ph.D.; Phone Number: 650-996-1845; Email: njoshi@cagebio.com

Study Locations

• Turkey (Türkiye)
  • Turkey
    • Ankara, Turkey, Turkey (Türkiye), 06800
      • Recruiting
      • Ankara T.C. Ministry of Health
      • Contact: Sezin U Acikel, Assoc. Prof.; Phone Number: +90 312 552 60 84; Email: sezinunlu87@gmail.com
      • Principal Investigator: Sezin U Acikel, Assoc. Prof.
    • Istanbul, Turkey, Turkey (Türkiye), 34116
      • Recruiting
      • Istanbul Universitesi faculty of Medicine
      • Contact: Algun P Ekinci, Prof. Dr.; Phone Number: 35014/35015 +90 212 440 00 00; Email: algun.ekinci@istanbul.edu.tr
      • Principal Investigator: Algun P Ekinci, Prof. Dr.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Adult (18 to 60 years old) diagnosed with non-segmental vitiligo on the face or neck. Dermoscopy and a Wood's Lamp Examination should be performed to confirm the diagnosis.
2. Facial and/or neck involvement with 1-3 vitiligo lesions (total combined area of lesions ≥ 6 cm² and ≤ 40 cm² and ≥75% depigmentation) for at least 3 months (90 days) prior to Baseline.
3. Vitiligo involvement ≤ 20% total body surface area (BSA).
4. Is otherwise in good health and free from any disease, condition, or constraint that, in the Investigator's opinion, might interfere with the conduct of the study
5. Stable disease, as judged by the investigator and patient report. Facial lesions must have been present ≤ 5 years with no new lesions or progression within 90 days prior to Baseline
6. Is not currently taking any medication for vitiligo in oral, topical, or any other form, including over-the-counter (OTC) and/or cosmetic products
7. Agrees to refrain from any other treatment modalities, including lights, lasers, or other medical devices, prescription or otherwise, for vitiligo for 4 weeks (28 days) before and during the study treatment (see Table 5.1 for complete list)
8. Agrees to refrain from using any lotions, creams, liquids, or other topical products at the treatment site during the study treatment period unless directed to do so by the investigator
9. Agrees to review and sign a written informed consent form
10. Can understand and comply with the study requirements as judged by the investigator

11. Females of childbearing potential (FOCBP) must have a negative urine pregnancy test and must agree to use a highly effective form of contraception or abstinence and be willing to remain on that same method of birth control throughout the study.

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Exclusion Criteria:

• 1. Females who are pregnant, breastfeeding, or of childbearing potential and not practicing reliable birth control

  2. History of segmental or mixed vitiligo

  3. Vitiligo affecting only external genitalia or hands/feet

  4. History of skin cancer or pre-cancerous lesions in the treatment area

  5. Past use of topical or systemic vitiligo treatments within 4 weeks (28 days) prior to Baseline 6. Current active use of topical corticosteroids on the face or immunomodulatory therapies within 4 weeks (28 days) prior to Baseline

  7. Use of biological, investigational, or experimental therapy 3 months before Baseline that could potentially interfere with the study participation or assessment

  8. Known hypersensitivity to any components of the intervention or vehicle

  9. History of melanocyte-keratinocyte transplantation procedure (MKTP) or other surgical treatments for vitiligo

  10. Uncontrolled thyroid function or other medical conditions that could interfere with study participation or assessment

  11. Use within 4 weeks (28 days) prior to Baseline (washout period) of 1) oral, intravenous or intralesional corticosteroids, 2) UVA/UVB therapy, 3) non-prescription UV light sources, 4) any oral or topical Janus kinase inhibitor (JAKi), or 5) cytotoxic drugs

  12. Has demonstrated resistance to previous JAKi treatment, topical or systemic

  13. Has clinically significant laboratory anomalies or vital signs, as judged by the investigator, that would interfere with the conduct or interpretation of study results

  14. Has any inflammations or any active skin diseases on the face and/or neck including complete leukotrichia or facial lesions that would interfere with study participation or assessment

  15. Is currently participating in another investigational medication or device study or has participated in a clinical trial within 30 days of the intended start of study treatment

  16. Is unable or unwilling to comply with any of the study requirements

  17. Has medical or psychiatric conditions or a personal situation that may increase the risk associated with study participation or may interfere with interpretation of study results or subject compliance and, in the opinion of the Principal Investigator (PI), makes the subject inappropriate for study entry

  18. Clinically significant alcohol or drug abuse, or history of poor cooperation or unreliability

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CGB-600 gel	Drug: Drug: CGB-600 gel, experimental drug; experimental drug
Placebo Comparator: vehicle gel	Other: placebo: gel vehicle; placebo gel

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Safety and tolerability: Overall Incidence of tabulated safety events. [Time Frame: From enrollment to end of study at 24 weeks]	From enrollment to end of study at 24 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
evaluate effectiveness Percent of participants achieving ≥ 50% reduction in Facial Vitiligo Area Scoring Index (F-VASI) score in the treated target area from baseline at Week 24	from enrollment to end of study (24 weeks)

Collaborators and Investigators

• Sponsor: CAGE Bio Inc.

Study record dates

Study Major Dates

• Study Start (Actual): July 25, 2025
• Primary Completion (Estimated): November 30, 2026
• Study Completion (Estimated): November 30, 2026

Study Registration Dates

• First Submitted: January 14, 2026
• First Submitted That Met QC Criteria: January 21, 2026
• First Posted (Actual): January 22, 2026

Study Record Updates

• Last Update Posted (Actual): January 22, 2026
• Last Update Submitted That Met QC Criteria: January 21, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Skin Diseases; Hypopigmentation; Pigmentation Disorders; Skin and Connective Tissue Diseases; Vitiligo; Pharmaceutical Preparations; Drugs, Investigational
• Other Study ID Numbers: CGB-600-02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No