A Study to Investigate Safety and Efficacy of KB111 for the Treatment of Hailey-Hailey Disease (HALITE-1)

An Open-Label Study to Investigate Safety and Preliminary Efficacy of KB111 for the Treatment of Hailey-Hailey Disease

An open-label study to evaluate the safety and efficacy of KB111 in pediatric and adult subjects with Hailey-Hailey Disease

Study Overview

• Status: Recruiting
• Conditions: Skin Diseases; Hailey Hailey Disease; Lesion Skin
• Intervention / Treatment: Biological: KB111

Detailed Description

This clinical study will investigate the safety, tolerability, and preliminary efficacy of open-label KB111 in pediatric and adult subjects with Hailey-Hailey Disease (HHD). Up to 7 subjects will be administered topical KB111 to treat HHD lesions for 12 weeks. KB111 will be administered in the home setting by a trained designee. The Investigator (or designee) will contact subjects weekly (or their parent/legal guardian) to assess for any adverse events or changes in medications, treatments, or procedures. Preliminary efficacy will be assessed by investigator assessments, patient-reported impressions of severity and molecular analysis of skin biopsies. A safety follow-up visit will occur 4 weeks after treatment stops.

• Study Type: Interventional
• Enrollment (Estimated): 7
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Brittani Agostini; Phone Number: 412-586-5830; Email: CNE@krystalbio.com

Study Locations

• United States
  • Florida
    • Miami, Florida, United States, 33156
      • Recruiting
      • Pediatric Skin Research
      • Contact: Jean Marco Varanese; Phone Number: +1 786-585-5774

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• The participant must have read, understood, and signed an Institutional Review Board (IRB)- approved Informed Consent Form and must be willing and able to comply with study procedures and instructions
• Aged ≥ 12 years of age at the time of informed consent/assent
• Documented clinical diagnosis of HHD with confirmed ATP2C1 variant by genetic testing
• A negative pregnancy test prior to initial dose for subjects of child-bearing potential
• If taking systemic therapies, subject must be on a stable dosing regimen 1 month prior to Screening and throughout the 12-week treatment period
• An acceptable form of contraception must be taken from the first dose (Week 1) through 3 months after the last dose of IP for subjects of childbearing potential

Exclusion Criteria:

• Participation in another clinical study or treatment with an investigational agent 30 days or 5 half-lives, whichever is longer, prior to initial dosing in Week 1
• Participant who is pregnant or nursing
• Participant who is unwilling to comply with contraception requirements per protocol (for subjects of child-bearing potential)
• Participant who is known to be non-compliant or is unlikely to comply with the requirements of the study protocol, in the opinion of the Investigator
• Presence of any dermatologic or systemic condition that might hinder the efficacy of the study treatment or its evaluation, could possibly interfere with the interpretation of study results, or could be judged by the Investigator to be incompatible with the study visit schedule or conduct

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: KB111	Biological: KB111; KB111 is a replication-defective, non-integrating herpes simplex virus (HSV-1)-based vector encoding functional, full-length human ATP2C1 protein combined with a gel for topical application.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To evaluate the safety and tolerability of KB111	Number of subjects with treatment related adverse events as assessed by CTCAE v5	12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To evaluate the effect of KB111 on patient-reported lesion severity throughout the treatment period.	Change from baseline using a patient reported 5-point multi-item scale where signs and symptoms are rated from none (0) to extreme (4)	12 weeks
To evaluate the effect of KB111 on patient-reported global impression of severity throughout the treatment period	Change from baseline using a patient reported 5-point multi-item scale where signs and symptoms are rated from none (0) to extreme (4)	12 weeks
To evaluate the effect of KB111 on Investigator-based assessments of lesion severity	Change from baseline in the Investigator's assessment using a 5-point scale where 0 is clear and 4 is severe	12 weeks
To evaluate the effect of KB111 on Investigator-based assessment of global severity	Change from baseline in the Investigator's assessment using a 5-point scale where 0 is clear and 4 is severe	12 weeks

Collaborators and Investigators

• Sponsor: Krystal Biotech, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): May 6, 2026
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: July 8, 2026
• First Submitted That Met QC Criteria: July 16, 2026
• First Posted (Actual): July 21, 2026

Study Record Updates

• Last Update Posted (Actual): July 21, 2026
• Last Update Submitted That Met QC Criteria: July 16, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Genetic Diseases, Inborn; Skin Diseases, Genetic; Skin Diseases, Vesiculobullous; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Skin and Connective Tissue Diseases; Skin Diseases; Pemphigus, Benign Familial
• Other Study ID Numbers: KB111-A

Drug and device information, study documents

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