Erythropoietic Protoporphyria (EPP)stEPPNCT07567131
Observational Study of Adults and Adolescents With Erythropoietic Protoporphyria (EPP) and X-linked Porphyria (XLP)
An observational study of Erythropoietic Protoporphyria (EPP) and X-Linked Porphyria (XLP), run by Portal Therapeutics, Inc. at 19 sites in 9 countries.
Trial summary
The purpose of this study is to collect information about the effects of EPP/XLP in adults and adolescents. This is an observational study in which participants will not receive any treatment. Study details include: The study duration will be up to 6 months for each participant. Read more about this study
- Who is it for?
- Ages 12 years and older
- Conditions the study is for
- Erythropoietic Protoporphyria (EPP), X-Linked Porphyria (XLP)
- How many people
- 50 participants
- Where
- 19 sitesin 9 countries
- Study dates
- 30 Apr 2026to 1 Apr 2027
- Phase
- Observational
- 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 12 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: The study design and key inclusion criteria are focused on EPP/XLP and are inclusive of all potential participants, including those from underrepresented racial and ethnic populations. The sites and countries selected have diverse populations and the potential to enroll diverse participants.
Who may be able to join
- Aged 12 years and older.
- Confirmed diagnosis of EPP or XLP as follows:
- Genetic confirmation of EPP (FECH mutation with reduced ferrochelatase activity) OR
- Genetic confirmation of XLP (ALAS2 gain-of-function mutation) OR
- Elevated free PPIX levels in RBCs consistent with EPP/XLP, supported by clinical and/or family history.
- Currently has symptoms of EPP/XLP.
Show all 12Show fewer
- History of consistent, non-painful prodrome within approximately 45 minutes of sunlight exposure and prior to phototoxic attacks, as self-reported by the participant.
- Willing and able to wear a light dosimetry device during the study.
- Willing and able to complete a daily diary of EPP/XLP symptoms.
- Willing and able to keep skin sites chosen for provocative sunlight exposure testing covered by opaque material when outside or exposed to potentially triggering light beginning 2 days prior to testing.
- Willing and able to provide informed consent and/or assent for the study.
- Study participants and LAR (as appropriate) are willing and able to comply with study visits and study procedures.
Who cannot join
- Diagnosis of another porphyria or another photodermatosis that may confound the characterization of EPP/XLP.
- Has a clinically significant disease or condition that, at the discretion of the Investigator or Sponsor, would interfere with the evaluation of EPP/XLP or study participation, or would make study participation not in the best interest of the participant.
- Is taking, or has taken within 60 days of Day 1, any medication, vitamin, or supplement that alters sensitivity to light exposure (eg, afamelanotide, melanotan, beta carotene, dersimelagon, or bitopertin).
- Concurrent or anticipated participation in an interventional clinical trial during the study period.
Trial locations and contacts
19 sites in 9 countries. Contact the study team or a site near you to ask about taking part.
19 sites in 9 countries
United States5 sites, 5 recruiting
- Recruiting
Massachusetts General Hospital
Boston, Massachusetts, 02114
Narmene Bensaber, 206-681-0218, nbensaber@mgh.harvard.edu
- Recruiting
University of Texas Health - Ertan Digestive Disease Center
Houston, Texas, 77030
Iram Abbasi, 713-500-8908, Iram.S.Abbasi@uth.tmc.edu
- Recruiting
Mount Sinai School of Medicine
New York, New York, 10029
Silvia Gunderson, 646-385-4611, silvia.gunderson@mssm.edu
- Not yet recruiting
Temple University
Philadelphia, Pennsylvania, 19121
Penny Rothberg, 215-214-1515, penny.rothberg@temple.edu
- Recruiting
Wake Forest University Baptist Health - Dept of Gastroenterology
Wake Forest, North Carolina, 27587
Denise Faust, 336.713.1442, denise.faust@advocatehealth.org
United Kingdom4 sites, 4 recruiting
- Recruiting
University Hospital of Wales
Cardiff
Mim Evans, +44 02921 847061, mim.evans@wales.nhs.uk
- Recruiting
Ninewells Hospital
Dundee
Caroline Tee, +44 (0)1382 660111, tascfeasibility.tayside@nhs.scot
- Recruiting
Guy's Hospital
London
Matthew Osmond, +44 077 1769 7435, matthew.osmond2@nhs.net
- Recruiting
Salford Royal Hospital
Manchester
Jacqueline Howe, +44 (0)161 206 8015, jacqueline.howe@manchester.ac.uk
France2 sites, 2 recruiting
- Not yet recruiting
Centre Hospitalier Universitaire de Bordeaux - Hopital Saint - Andre
Bordeaux
Jean Delaune, +33 0557822433, Jean.delaune@chu-bordeaux.fr
- Not yet recruiting
AP-HP Hopital Bichat - Claude Bernard
Paris
Jonathan Lehacaut, 01.40.25.71.48, jonathan.lehacaut@aphp.fr
Italy2 sites, 2 recruiting
- Not yet recruiting
Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico di Milano
Milan
Elena Di Pierro, +02 55033297, elena.dipierro@policlinico.mi.it
- Not yet recruiting
Azienda Ospedaliero-Universitaria di Modena
Modena
Chiara Boarini, +39 (0) 594222722, cboarini@unimore.it
Spain2 sites, 2 recruiting
- Recruiting
Hospital Universitario 12 de Octubre
Madrid
Patricia Ortiz, +34630742050, patricia.ortiz@ebers.es
- Not yet recruiting
Consorcio Hospital General Universitario de Valencia
Valencia
Alexanda Boix Navarro, +34 963131800, alexa_boix@hotmail.com
Belgium1 site, 1 recruiting
- Not yet recruiting
UZ Leuven
Leuven
Sarah Brike, +32 16 34 62 32, sarah.brike@uzleuven.be
Canada1 site, 1 recruiting
- Not yet recruiting
University of Alberta Hospital
Edmonton
Samridhi Dhand, 873-688-8200, samridhi.dhand@primesiteresearch.com
Norway1 site, 1 recruiting
- Not yet recruiting
Haukeland University Hospital
Bergen
Janice Andersen, +47 55973170, jacd@helse-bergen.no
Turkey (Türkiye)1 site, 1 recruiting
- Not yet recruiting
Gazi University Faculty of Medicine
Ankara
Fatih Ezgu, +90 312 202 6001, fatih.ezgu@gmail.com
About this study
Official title: Prospective Clinical Assessment Study in Adolescents and Adults With Erythropoietic Protoporphyria (EPP) and X-Linked Porphyria (XLP) (STEPP)
The purpose of this study is to collect information about the effects of EPP/XLP in adults and adolescents. This is an observational study in which participants will not receive any treatment. Study details include:
- The study duration will be up to 6 months for each participant.
- After Screening, participants will have a Baseline (Day 1) visit and return for visits every 4 weeks through 24 weeks.
- Assessments to evaluate EPP/XLP will include clinical laboratory tests, physical exams, vital signs measurement, blood draws for PPIX concentration, reporting of EPP/XLP-related symptoms (including completion of a daily diary), light dosimetry.
- Keywords
- EPP, XLP
- Medical subject headings
- Protoporphyria, Erythropoietic
What is being measured
The primary outcome is the main question the study is designed to answer.
Plasma Protoporphyrin IX (PPIX) Levels Over Time
Plasma protoporphyrin IX (PPIX) concentrations measured at specified study visits.
Measured: Screening; Baseline; Weeks 4, 8, 12, 16, 20, 24
Clinical History of Phototoxic Symptoms and Prodrome Timing
Medical history of EPP/XLP symptoms, including time to onset of prodromal sensations and occurrence of phototoxic reactions.
Measured: Screening, Baseline, Weeks 4, 8, 12, 16, 20, 24
Skin Damage Manifestations
Skin damage manifestations associated with EPP/XLP, including swelling, erythema, and chronic skin changes.
Measured: Screening, Baseline, Weeks 4, 8, 12, 16, 20, 24
Light Exposure and Phototoxic Reaction Data From Daily Diary
Daily recorded light exposure (including time spent outdoors), light dosimetry measurements, and occurrence of phototoxic reactions as captured in participant diaries.
Measured: Screening, Baseline, Weeks 4, 8, 12, 16, 20, 24
Sunlight Exposure Required to Induce Prodromal Symptoms
Amount of sunlight exposure associated with onset of prodromal symptoms, along with corresponding plasma protoporphyrin IX (PPIX) levels.
Measured: Baseline and Weeks 4, 8, 12, 16, 20
Secondary outcomes (1)
Liver Function Test Results
Blood levels of liver function parameters (e.g., alanine aminotransferase [ALT], aspartate aminotransferase [AST], bilirubin) and corresponding plasma protoporphyrin IX (PPIX) levels.
Measured: Baseline and Weeks 4, 8, 12, 16, 20, 24
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 May 2026
- Study start30 Apr 2026 (estimated)
- Primary completion1 Mar 2027 (estimated)
- Study completion1 Apr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Erythropoietic Protoporphyria (EPP)Studies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Portal Therapeutics, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07567131
- Sponsor's protocol ID
- PORT-77-001
- Acronym
- stEPP
- Status last verified
- Apr 2026
- First submitted
- 15 Apr 2026
- Last updated
- 5 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: What may be shared: De-identified individual participant data (no direct identifiers) Who can access it: Qualified researchers with a scientifically sound research proposal Conditions for access: Submission and approval of a research proposal Execution of a data sharing agreement (DSA) Compliance with privacy regulations (e.g., GDPR, HIPAA as applicable) How it will be shared: Through a secure data access process managed by the sponsor or designated data-sharing platform Timing: Typically after study completion and/or publication of primary results Purpose: To support further research on EPP and XLP while protecting participant confidentiality
Study at a glance
From the registry record, last updated by the sponsor on 5 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prospective Clinical Assessment Study in Adolescents and Adults With Erythropoietic Protoporphyria (EPP) and X-Linked Porphyria (XLP) (STEPP)
- ClinicalTrials.gov ID
- NCT07567131
- Acronym / sponsor ID
- stEPP / PORT-77-001
- Keywords
- EPP, XLP
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Portal Therapeutics, Inc.Industry (pharma, biotech, devices)
- Study start
- 30 Apr 2026 (estimated)
- Primary completion
- 1 Mar 2027 (estimated)
- Study completion
- 1 Apr 2027 (estimated)
- First posted
- 5 May 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.
The purpose of this study is to collect information about the effects of EPP/XLP in adults and adolescents. This is an observational study in which participants will not receive any treatment. Study details include:
- The study duration will be up to 6 months for each participant.
- After Screening, participants will have a Baseline (Day 1) visit and return for visits every 4 weeks through 24 weeks.
- Assessments to evaluate EPP/XLP will include clinical laboratory tests, physical exams, vital signs measurement, blood draws for PPIX concentration, reporting of EPP/XLP-related symptoms (including completion of a daily diary), light dosimetry.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 12 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- The study design and key inclusion criteria are focused on EPP/XLP and are inclusive of all potential participants, including those from underrepresented racial and ethnic populations. The sites and countries selected have diverse populations and the potential to enroll diverse participants.
Key inclusion criteria (12 listed)
- Aged 12 years and older.
- Confirmed diagnosis of EPP or XLP as follows:
- Currently has symptoms of EPP/XLP.
- History of consistent, non-painful prodrome within approximately 45 minutes of sunlight exposure and prior to phototoxic attacks, as self-reported by the participant.
- Willing and able to wear a light dosimetry device during the study.
Key exclusion criteria (4 listed)
- Diagnosis of another porphyria or another photodermatosis that may confound the characterization of EPP/XLP.
- Has a clinically significant disease or condition that, at the discretion of the Investigator or Sponsor, would interfere with the evaluation of EPP/XLP or study participation, or would make study participation not in the best interest of the participant.
- Is taking, or has taken within 60 days of Day 1, any medication, vitamin, or supplement that alters sensitivity to light exposure (eg, afamelanotide, melanotan, beta carotene, dersimelagon, or bitopertin).
- Concurrent or anticipated participation in an interventional clinical trial during the study period.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Plasma Protoporphyrin IX (PPIX) Levels Over Time
Time frame: Screening; Baseline; Weeks 4, 8, 12, 16, 20, 24
Plasma protoporphyrin IX (PPIX) concentrations measured at specified study visits.
Clinical History of Phototoxic Symptoms and Prodrome Timing
Time frame: Screening, Baseline, Weeks 4, 8, 12, 16, 20, 24
Medical history of EPP/XLP symptoms, including time to onset of prodromal sensations and occurrence of phototoxic reactions.
Skin Damage Manifestations
Time frame: Screening, Baseline, Weeks 4, 8, 12, 16, 20, 24
Skin damage manifestations associated with EPP/XLP, including swelling, erythema, and chronic skin changes.
Light Exposure and Phototoxic Reaction Data From Daily Diary
Time frame: Screening, Baseline, Weeks 4, 8, 12, 16, 20, 24
Daily recorded light exposure (including time spent outdoors), light dosimetry measurements, and occurrence of phototoxic reactions as captured in participant diaries.
Sunlight Exposure Required to Induce Prodromal Symptoms
Time frame: Baseline and Weeks 4, 8, 12, 16, 20
Amount of sunlight exposure associated with onset of prodromal symptoms, along with corresponding plasma protoporphyrin IX (PPIX) levels.
1 secondary outcome
Liver Function Test Results
Time frame: Baseline and Weeks 4, 8, 12, 16, 20, 24
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 5 May 2026.
- Individual participant dataSharing planned: Yes. What may be shared: De-identified individual participant data (no direct identifiers) Who can access it: Qualified researchers with a scientifically sound research proposal Conditions for access: Submission and approval of a research proposal Execution of a data sharing agreement (DSA) Compliance with privacy regulations (e.g., GDPR, HIPAA as applicable) How it will be shared: Through a secure data access process managed by the sponsor or designated data-sharing platform Timing: Typically after study completion and/or publication of primary results Purpose: To support further research on EPP and XLP while protecting participant confidentiality
Related trials for Erythropoietic Protoporphyria (EPP)
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Extension Study to Evaluate Safety and Tolerability of Oral Dersimelagon (MT-7117) in Subjects With Erythropoietic Protoporphyria (EPP) or X-Linked Protoporphyria (XLP)
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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.
19 sites in 9 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Erythropoietic Protoporphyria (EPP) and X-Linked Porphyria (XLP), run by Portal Therapeutics, Inc. at 19 sites in 9 countries.
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 12 inclusion and 4 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: looking for participants now, as of the sponsor's last update on 5 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 19 sites in United States, United Kingdom, France, Italy, Spain and 4 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
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.
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 GondolaBio Inquiries (650-249-2108 ext. 2178, patientadvocacy@gondolabio.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Plasma Protoporphyrin IX (PPIX) Levels Over Time (time frame: Screening; Baseline; Weeks 4, 8, 12, 16, 20, 24). The study lists 5 primary outcomes in all. 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 5 May 2026.