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A Study Comparing KB801 Verse Placebo in Patients With Stage 2 or 3 Neurotrophic Keratitis

A Phase 1/2, Multicenter, Double-Masked, Placebo-Controlled Study of KB801 in Subjects With Stage 2 or 3 Neurotrophic Keratitis

Status
Recruiting
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06999733
Acronym
EMERALD-1
Enrollment
60
Registered
2025-05-31
Start date
2025-07-07
Completion date
2027-12-01
Last updated
2026-02-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Neurotrophic Keratitis

Keywords

Neurotrophic Keratitis, Persistent Corneal Epithelial Defect, Corneal Epithelial Defect

Brief summary

The Sponsor is developing KB801, a replication-defective, non-integrating herpes simplex virus type 1 (HSV-1)-derived vector engineered to deliver functional full-length human nerve growth factor (NGF) to the corneas of people with Stage 2 or 3 neurotrophic keratitis (NK) via topical application. This is a Phase 1/2, multicenter, double-masked, placebo-controlled study to evaluate the safety, tolerability, and preliminary efficacy of KB801 in these subjects.

Detailed description

Subjects will will be randomized 1:1 to receive KB801 or placebo (vehicle) topically to the study eye daily for 8 weeks. Subjects will return for a follow-up visit 2- weeks after finishing treatment to monitor for safety and durability of corneal healing. Safety follow-up visits will then occur every 3 months through approximately 1 year on study.

Interventions

BIOLOGICALKB801

Ophthalmic suspension of replication-defective, non-integrating herpes simplex virus type 1 (HSV-1)-based vector delivering functional, full-length human nerve growth factor (NGF)

DRUGPlacebo

Vehicle

Sponsors

Krystal Biotech, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. The subject 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. 2. Aged ≥ 18 years at the time of informed consent. 3. Diagnosis of Stage 2 or Stage 3 NK, as defined by the Mackie criteria. 4. Persistent corneal epithelial defect (PCED) between Screening 1 and Screening 2 without clinical improvement during that time. PCED is defined as a focal loss of the cornea's outermost cell layer and can include involvement of the deeper stromal layers (i.e., corneal ulcer). 5. PCED at Screening 1 must have a minimum of 1 mm of any linear measurement of defect. 6. A negative pregnancy test at Screening 1 and Day 1 for women of child-bearing potential.

Exclusion criteria

1. An active ocular infection (bacterial, viral, fungal or protozoal) or active ocular inflammation not related to NK in the study eye as assessed by Investigator at Screening 1 or 2. 2. Use of any prohibited therapies at Screening or anticipated need for topical treatments other than the investigational product or products allowed per protocol in the study eye from Screening through the study Treatment Period a. Sufficient washout of prohibited therapies must occur prior to meeting eligibility criteria. 3. Anticipated use of therapeutic contact lenses or contact lens wear for refractive correction during the study Treatment Period in the study eye. 4. Evidence of corneal ulceration involving the posterior third of the corneal stroma, corneal melting, descemetocele, impending or perforation in the study eye at the time of Screening 1 or 2. 5. PCED at Screening 1 or 2 of \> 8 mm maximum linear measurement in any eye. 6. The central 3 mm of corneas contain PCED bilaterally at Screening 1 or 2. 7. Anticipated need for punctal occlusion of the study eye during the Treatment Period. 8. Presence or history of any ocular or systemic disorder or 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 (e.g., progressive or degenerative corneal or retinal conditions, uveitis, optic neuritis, poorly controlled diabetes, autoimmune disease, systemic infection, neoplastic diseases). 9. Participation in another clinical study or treatment with an investigational agent 30 days or 5 half-lives, whichever is longer, prior to Day 1 (participation in a non-interventional observational study is permitted). 10. Intraocular surgery on the eligible eye(s) within 6 months prior to Screening 1, and any ophthalmic condition that may require surgery on the study eye during the Treatment Period. An exception to the preceding statement is allowed if, in the opinion of the Investigator, the ocular surgery is deemed the cause of the NK. 11. Corneal transplantation (i.e., keratoplasty) of the study eye within the past 2 years or a history of multiple keratoplasty operations to the study eye regardless of timing. This includes full- or partial-thickness, or endothelial keratoplasty. 12. Subject who is pregnant or nursing. 13. Subject who is unwilling to comply with contraception requirements per-protocol (for subjects of childbearing potential). 14. Subject who is known to be noncompliant or is unlikely to comply with the requirements of the study protocol, in the opinion of the Investigator.

Design outcomes

Primary

MeasureTime frameDescription
To evaluate safety and tolerability of KB801 based upon assessment of adverse events (frequency, severity, relatedness).8 weeksNumber of subjects with treatment related adverse events as assessed by CTCAE v5.
To evaluate the effect of KB801 on complete healing of the Persistent Corneal Epithelial Defect (PCED) in subjects with Stage 2 or Stage 3 NK8 weeksProportion of subjects receiving KB801 exhibiting complete PCED closure at Week 8 compared to those receiving placebo.

Secondary

MeasureTime frameDescription
To evaluate the effect of KB801 on complete healing of the PCED in subjects with Stage 2 or 3 NK10 weeksProportion of subjects receiving KB801 with complete PCED closure at Weeks 4, 6 and 10 compared to those receiving placebo.
To evaluate the effect of KB801 on conventional healing of the PCED in subjects with Stage 2 or 3 NK10 weeksProportion of subjects receiving KB801 achieving \<0.5-mm lesion size at Weeks 4, 6, 8, and 10 compared to those receiving placebo.

Countries

United States

Contacts

CONTACTDavid Sweet, MD, PhD
dsweet@krystalbio.com412-586-5830
CONTACTBrittani Agostini, RN, CCRC
bagostini@krystalbio.com412-586-5830

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 28, 2026