Chemical BurnsPhase 2SYMBOLCLINICALNCT07329569
Treatment of Severe Ocular Chemical Burns by Subconjunctival Injection of Allogeneic Mesenchymal Stem Cells: An Open-Label, Single-Arm, Multicenter Phase II Trial
A Phase 2 study testing Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days. in people with Chemical Burns and Ocular Burns, run by Fondation Ophtalmologique Adolphe de Rothschild.
Trial summary
Severe chemical burns of the eye are serious injuries that can cause intense inflammation of the ocular surface and destroy limbal epithelial stem cells, which are essential for corneal healing. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Chemical Burns, Ocular Burns
- What is being tested?
- Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days.
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 21 participants
- Where
- No sites listed yet
- Study dates
- Mar 2026to Apr 2030
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 18 years
- Unilateral or bilateral chemical burn of the ocular surface
- Severe ocular chemical burn of at least one eye, classified as stage VI according to the Dua severity classification (involving the entire limbus and conjunctiva)
- Time from chemical injury to enrollment ≤ 15 days
- Patient has received full study information and has provided written informed consent
- Affiliated with or beneficiary of a social security or health insurance system
Who cannot join
- Imminent corneal perforation (loss of more than two-thirds of corneal thickness)
- Ocular infection
- Eyelid tissue loss with permanent corneal exposure
- Known allergy or hypersensitivity to human albumin preparations
- History of total or partial limbal stem cell deficiency prior to the chemical injury
- Uncontrolled glaucoma prior to the ocular burn
Show all 15Show fewer
- Recipient of a solid organ or cell transplant
- Severe or uncontrolled renal, hepatic, hematologic, gastrointestinal, pulmonary, psychiatric, or cardiac disease, or any uncontrolled intercurrent illness
- Active infection, including chronic or localized infections
- History of malignancy (except completely resected localized basal cell carcinoma of the skin or cervical carcinoma in situ) within the past 5 years, whether treated or untreated, with or without evidence of recurrence or metastasis at screening
- Current treatment with systemic immunosuppressive medications (including systemic corticosteroids, TNF-α antagonists, azathioprine, methotrexate, mycophenolate mofetil)
- Adults under legal protection, individuals deprived of liberty by judicial or administrative decision, individuals receiving compulsory psychiatric care, or individuals admitted to a health or social care institution for purposes other than research
- Pregnant or breastfeeding women
- Women of childbearing potential who do not agree to use effective contraception throughout the study period (up to 12 months after the last injection)
- Participation in another interventional clinical trial during the study follow-up period
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Severe chemical burns of the eye are serious injuries that can cause intense inflammation of the ocular surface and destroy limbal epithelial stem cells, which are essential for corneal healing. These injuries may lead to severe vision loss, blindness, or even loss of the eye despite standard medical and surgical treatments. Current therapies aim to control inflammation and promote healing, but outcomes remain poor in the most severe cases.
This Phase II clinical trial, called SYMBOL-Clinical, is designed to evaluate the safety and potential effectiveness of allogeneic bone marrow-derived mesenchymal stem cells (BM-MSCs) administered by subconjunctival injection in patients with severe ocular chemical burns (stage VI according to the Dua classification). Mesenchymal stem cells have shown anti-inflammatory and tissue-protective effects in preclinical studies, mainly through the release of paracrine factors that support healing.
Read more
This is an open-label, single-arm, multicenter study conducted in 13 centers in France and coordinated by the Adolphe de Rothschild Foundation Hospital. Adult patients (18 years or older) with a recent severe chemical burn of the ocular surface (within 15 days of injury) may be eligible to participate.
Participants will receive a subconjunctival injection of 5 million allogeneic BM-MSCs in the affected eye. A second injection may be administered within 21 days if corneal healing remains insufficient, as assessed by an expert ophthalmologist. All injections are performed under strict sterile conditions, with local anesthesia and conscious sedation when needed.
The primary objective of the study is to assess:
Safety, by monitoring the occurrence, type, and severity of adverse events.
Effectiveness, defined as preservation of the eye without corneal perforation at 6 months after the first injection.
Secondary objectives include evaluating corneal epithelial healing, limbal stem cell deficiency, conjunctival fibrosis, ocular surface inflammation, visual acuity, corneal thickness, the need for additional eye surgeries, and the use of local immunosuppressive treatments over a 12-month follow-up period.
Patients will be followed closely with regular ophthalmologic examinations, imaging (including anterior segment OCT), visual acuity testing, and safety assessments for up to 12 months after treatment. The total duration of participation for each patient is approximately 13 months, and the overall study duration is expected to be up to 49 months.
The study plans to enroll between 12 and 21 evaluable patients, using a two-stage Simon design to allow early stopping if the treatment does not show sufficient benefit.
The results of this study may help determine whether subconjunctival injection of allogeneic mesenchymal stem cells is a safe and promising treatment option for patients with the most severe forms of ocular chemical burns.
- Conditions
- Chemical Burns, Ocular Burns
- Being tested
- Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days.
- Keywords
- severe chemical burns of the ocular surface, subconjunctival administration of allogeneic BM-MSCs
- Medical subject headings
- Burns, Chemical
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days.Biological
Subconjunctival injection of a 1 mL suspension containing 5 million allogeneic BM-MSCs. A single injection or one repeat injection may be administered within 21 days if corneal epithelialization remains below 25%, as assessed by an expert clinician at the Adolphe de Rothschild Foundation Hospital, based on evaluation performed 7 to 10 days after the first injection.
| Study group | Role | What they receive |
|---|---|---|
| Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days. | Experimental | Subconjunctival injection of a 1 mL suspension containing 5 million allogeneic BM-MSCs. A single injection or one repeat injection may be administered within 21 days if corneal epithelialization remains below 25%, as assessed by an expert clinician at the Adolphe de Rothschild Foundation Hospital, based on evaluation performed 7 to 10 days after the first injection. Receives: Biological: Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety: Incidence, type, and severity of adverse events.
incidence, type, and severity of adverse events.
Measured: From the first allogeneic BM-MSC injection through 6 months after the first injection.
Secondary outcomes (1)
Efficacy: Absence of corneal perforation
Absence of corneal perforation as assessed by the clinician; any suspected perforation will be confirmed by the coordinating expert physician based on slit-lamp photographs and corneal OCT images
Measured: 6 months after first injection of allogeneic BM-MSCs
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jan 2026
- Study startMar 2026 (estimated)
- Primary completionSep 2029 (estimated)
- Study completionApr 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Chemical BurnsStudies of the same condition, open and under way.
- More trials run by Fondation Ophtalmologique Adolphe de RothschildThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 21 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Fondation Ophtalmologique Adolphe de Rothschild
- Sponsor type
- Research network
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07329569
- Sponsor's protocol ID
- DGT_2025_2
- Other IDs
- 170641
- Acronym
- SYMBOLCLINICAL
- Status last verified
- Dec 2025
- First submitted
- 29 Dec 2025
- Last updated
- 9 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Treatment of Severe Ocular Chemical Burns by Subconjunctival Injection of Allogeneic Mesenchymal Stem Cells: An Open-Label, Single-Arm, Multicenter Phase II Trial
- ClinicalTrials.gov ID
- NCT07329569
- Acronym / sponsor ID
- SYMBOLCLINICAL / DGT_2025_2
- Conditions
- Chemical Burns, Ocular Burns
- Keywords
- severe chemical burns of the ocular surface, subconjunctival administration of allogeneic BM-MSCs
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 21 participants (estimated)
- Lead sponsor
- Fondation Ophtalmologique Adolphe de RothschildResearch network
- Study start
- Mar 2026 (estimated)
- Primary completion
- Sep 2029 (estimated)
- Study completion
- Apr 2030 (estimated)
- First posted
- 9 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Severe chemical burns of the eye are serious injuries that can cause intense inflammation of the ocular surface and destroy limbal epithelial stem cells, which are essential for corneal healing. These injuries may lead to severe vision loss, blindness, or even loss of the eye despite standard medical and surgical treatments. Current therapies aim to control inflammation and promote healing, but outcomes remain poor in the most severe cases.
This Phase II clinical trial, called SYMBOL-Clinical, is designed to evaluate the safety and potential effectiveness of allogeneic bone marrow-derived mesenchymal stem cells (BM-MSCs) administered by subconjunctival injection in patients with severe ocular chemical burns (stage VI according to the Dua classification). Mesenchymal stem cells have shown anti-inflammatory and tissue-protective effects in preclinical studies, mainly through the release of paracrine factors that support healing.
This is an open-label, single-arm, multicenter study conducted in 13 centers in France and coordinated by the Adolphe de Rothschild Foundation Hospital. Adult patients (18 years or older) with a recent severe chemical burn of the ocular surface (within 15 days of injury) may be eligible to participate.
Participants will receive a subconjunctival injection of 5 million allogeneic BM-MSCs in the affected eye. A second injection may be administered within 21 days if corneal healing remains insufficient, as assessed by an expert ophthalmologist. All injections are performed under strict sterile conditions, with local anesthesia and conscious sedation when needed.
The primary objective of the study is to assess:
Safety, by monitoring the occurrence, type, and severity of adverse events.
Effectiveness, defined as preservation of the eye without corneal perforation at 6 months after the first injection.
Secondary objectives include evaluating corneal epithelial healing, limbal stem cell deficiency, conjunctival fibrosis, ocular surface inflammation, visual acuity, corneal thickness, the need for additional eye surgeries, and the use of local immunosuppressive treatments over a 12-month follow-up period.
Patients will be followed closely with regular ophthalmologic examinations, imaging (including anterior segment OCT), visual acuity testing, and safety assessments for up to 12 months after treatment. The total duration of participation for each patient is approximately 13 months, and the overall study duration is expected to be up to 49 months.
The study plans to enroll between 12 and 21 evaluable patients, using a two-stage Simon design to allow early stopping if the treatment does not show sufficient benefit.
The results of this study may help determine whether subconjunctival injection of allogeneic mesenchymal stem cells is a safe and promising treatment option for patients with the most severe forms of ocular chemical burns.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days. | Experimental | Biological: Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days.Subconjunctival injection of a 1 mL suspension containing 5 million allogeneic BM-MSCs. A single injection or one repeat injection may be administered within 21 days if corneal epithelialization remains below 25%, as assessed by an expert clinician at the Adolphe de Rothschild Foundation Hospital, based on evaluation performed 7 to 10 days after the first injection. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age ≥ 18 years
- Unilateral or bilateral chemical burn of the ocular surface
- Severe ocular chemical burn of at least one eye, classified as stage VI according to the Dua severity classification (involving the entire limbus and conjunctiva)
- Time from chemical injury to enrollment ≤ 15 days
- Patient has received full study information and has provided written informed consent
Key exclusion criteria (15 listed)
- Imminent corneal perforation (loss of more than two-thirds of corneal thickness)
- Ocular infection
- Eyelid tissue loss with permanent corneal exposure
- Known allergy or hypersensitivity to human albumin preparations
- History of total or partial limbal stem cell deficiency prior to the chemical injury
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days.Subconjunctival injection of a 1 mL suspension containing 5 million allogeneic BM-MSCs. A single injection or one repeat injection may be administered within 21 days if corneal epithelialization remains below 25%, as assessed by an expert clinician at the Adolphe de Rothschild Foundation Hospital, based on evaluation performed 7 to 10 days after the first injection. | Biological | Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days. |
Primary outcome
Safety: Incidence, type, and severity of adverse events.
Time frame: From the first allogeneic BM-MSC injection through 6 months after the first injection.
incidence, type, and severity of adverse events.
1 secondary outcome
Efficacy: Absence of corneal perforation
Time frame: 6 months after first injection of allogeneic BM-MSCs
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Jan 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Subconjunctival injection of 1 mL with 5 million allogeneic BM-MSCs; one repeat within 21 days. in people with Chemical Burns and Ocular Burns, run by Fondation Ophtalmologique Adolphe de Rothschild.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 9 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Damien GUINDOLET, MD-PHD (+331 48 03 69 23, dguindolet@for.paris), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety: Incidence, type, and severity of adverse events. (time frame: From the first allogeneic BM-MSC injection through 6 months after the first injection.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Jan 2026; AzTrials last refreshed its copy on 8 Nov 2026.