A Phase 2/3 interventional study of AC-203 and Vehicle in Generalized Epidermolysis Bullosa Simplex, sponsored by TWi Biotechnology, Inc.. Active, not recruiting at 30 sites in 18 countries. Open to participants aged 6 Months and older. Per ClinicalTrials.gov, last updated 2026-07-09.
Sponsored by TWi Biotechnology, Inc. · Phase 2/3, Interventional, and Treatment
The proposed Phase 2/3 trial with double-blind and open-label extension phases is an international, multicenter study designed to assess the efficacy and safety of diacerein 1% ointment in patients with generalized EBS.
Epidermolysis bullosa simplex (EBS) is a genetic skin disorder characterized by skin fragility and recurrent blister formation, primarily caused by mutations in keratins 5 and 14. EBS has 3 common subtypes based on clinical severity and manifestations: localized EBS, intermediate EBS and severe EBS. Severe EBS and intermediate EBS collectively are also known as generalized EBS due to widespread blistering.
Disruption of the keratin 5/14 filament network in basal keratinocytes is a key factor in EBS pathogenesis, compromising skin integrity. The severity of EBS is linked to the extent of keratin mutations disrupting this network, particularly resulting in keratin aggregates in severe cases. Recent studies suggest that mutated keratin proteins can trigger inflammation, exacerbating EBS. Elevated proinflammatory cytokines, like IL-1β and IL-6, are observed in EBS patients, and IFN-γ may mediate inflammation, promoting keratin aggregations. As a result, targeting inflammation is considered a potential therapeutic approach in EBS.
AC-203 (diacerein 1% ointment) is a topical formulation of diacerein, well-known for its ability to inhibit IL-1β and other proinflammatory cytokines. Moreover, diacerein and its active metabolite, rhein, have demonstrated ability in reducing keratin aggregates in keratinocytes derived from severe EBS. Taken together, with its anti-inflammatory property and ability to diminish keratin aggregation, AC-203 shows promise in reducing the clinical severity of EBS.
20 studies on the registry are indexed under Epidermolysis Bullosa Simplex; 5 are open to participants now.
This study's planned enrollment of 80 is above the median of 19 across 17 interventional studies indexed under Epidermolysis Bullosa Simplex.
Browse Epidermolysis Bullosa Simplex studies →TWi Biotechnology, Inc. is the lead sponsor of 11 studies on the registry; none are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Double-blind, AC-203 Diacerein 1% ointment, QD
Drug: AC-203
Double-blind, Vehicle ointment, QD
Drug: Vehicle
Open-label extension phase, AC-203 Diacerein 1% ointment, QD
Drug: AC-203
The investigational product is formulated as 1% topical ointment
Vehicle-only control study medication is the same formulation as investigational product without active ingredient
Proportion of patients achieving treatment success on the IGA of the Treatment Area, in which treatment success is defined as a score of 0 or 1 with at least a 2-point reduction
The static IGA is the investigator's visual clinical assessment of the average overall intensity of lesions in the designated Treatment Area at a particular time point. EBS-IGA is a 5-point scale is a 5-point scale (clear=0; almost clear=1; mild=2; moderate=3; severe=4)
Time frame: from Baseline A (Visit 2/Day 1) to Week 8 (Visit 5/EOT)
Change in % BSA of EBS lesions in the Treatment Area
The Body Surface Area (BSA) of the Assessment Area will be collected for all lesions included within the Treatment Area using the palmar method
Time frame: from Baseline A (Visit 2/Day 1) to Week 8 (Visit 5/EOT)
Change in pain intensity score
Wong-Baker FACES® Pain Rating Scale will be used for patients 3 years and older.
Time frame: Baseline A (Visit 2/Day 1) to Week 8 (Visit 5/EOT)
Change in pruritus intensity score
ItchyQuant will be used for patients aged 6 years and older, including adult patients
Time frame: from Baseline A (Visit 2/Day 1) to Week 8 (Visit 5/EOT)
Change in EBDASI score (skin activity)
The EBDASI is a valid and reliable EB-specific outcome measurement tool to assess the overall extent of disease activity and damage in patients with various subtypes of EB, including EBS. Section I (skin), the severity of disease, including erosion/blisters/crusting etc., will be measured at 12 different skin sites.
Time frame: from Baseline A (Visit 2/Day 1) to Week 8 (Visit 5/EOT).
Change in the QOLEB score
The Life Epidermolysis Bullosa (QOLEB) questionnaire is a valid and reliable, EB-specific QOL measurement tool, for the quantification of QOL in patients with various subtypes of EB, including EBS. It consists of 17 questions with four response choices from "not at all" to "constant"
Time frame: from Baseline A (Visit 2/Day 1) to Week 8 (Visit 5/EOT)
Plan to share: No
No publications or documents are linked to this record.
Ran from Apr 2024 to primary completion in Jun 2026, 26 months.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Diacerein
Epidermolysis Bullosa Simplex →
TWi Biotechnology, Inc.