Erythropoietic ProtoporphyriaPhase 2/3NCT05883748
HELIOS: Open-Label, Long-Term Extension Study to Investigate the Safety, Tolerability, and Efficacy of DISC-1459 (Bitopertin) in Participants With EPP or XLP
A Phase 2/3 study testing DISC-1459 in people with Erythropoietic Protoporphyria, run by Disc Medicine, Inc at 26 sites in 11 countries.
Trial summary
This is an open-label, long-term extension study to investigate the safety, tolerability and efficacy of DISC-1459 in participants with EPP. Read more about this study
- Who is it for?
- Ages 12 years and older
- Conditions the study is for
- Erythropoietic Protoporphyria
- What is being tested?
- DISC-1459
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 230 participants
- Where
- 26 sitesin 11 countries
- Study dates
- 31 Aug 2023to Jun 2028
- Phase
- Phase 2/3
- 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
Who may be able to join
- Participants with diagnosis of EPP who are participating (or who have participated) in a prior Disc Medicine bitopertin study and who have completed the randomized treatment phase and End-of-Study visit
- Aged ≥12 years upon study consent
- Body weight ≥32 kg for participants <18 years of age and BMI ≥18.5 kg/m2 for adult participants
- Willing to practice highly effective methods of birth control (both males who have partners of childbearing potential and females of childbearing potential during the study, while taking study drug, and for at least 30 days after the last dose of study drug.
- Negative urine or serum pregnancy test (females of childbearing potential).
- Able to understand the study aims, procedures, and requirements, and provide written informed consent (and assent if necessary).
- Able to comply with all study procedures.
Who cannot join
- Participants who have an ongoing SAE from a clinical study that is assessed by the investigator as related to bitopertin
- Other medical or psychiatric condition or laboratory finding not specifically noted above that, in the judgement of the Investigator or Sponsor, would put the participant at unacceptable risk or otherwise preclude participation in the study
- Condition or concomitant medication that would confound the ability to interpret clinical, clinical laboratory, or participant diary data, including a major psychiatric condition that has had an exacerbation or required hospitalization in the last 6 months
- Planned treatment with afamelanotide or dersimelagon during the study
- Planned use of any drugs or herbal remedies known to be strong inhibitors or inducers of cytochrome p450 (CYP)3A4 enzymes throughout the study
- If female, pregnant, or breastfeeding
Show all 9Show fewer
- Participation in any other clinical protocol or investigational trial, other than Disc Medicine bitopertin trials, that involves administration of experimental therapy and/or therapeutic devices within 30 days of Day 1
- Score of PHQ-8 ≥10 at screening or imminent suicidal risk identified by the C-SSRS as defined as suicidal ideation with intent (Grade 4 or 5) within the last year or any suicidal behavior within the last 5 years.
- Consumption of grapefruit/Seville orange and products containing these for 14 days prior to first dose of study drug and throughout the study
Trial locations and contacts
26 sites in 11 countries. Contact the study team or a site near you to ask about taking part.
26 sites in 11 countries
United States11 sites
University of Alabama Hospital
Birmingham, Alabama, 35233
Massachusetts General Hospital
Boston, Massachusetts, 02114
MetroBoston Clinical Partners
Boston, Massachusetts, 02135
Remington-Davis Clinical Research
Columbus, Ohio, 43215
University of Texas
Galveston, Texas, 77550
University of Miami Miller School of Medicine
Miami, Florida, 33136
Mount Sinai Hospital
New York, New York, 10029
Einstein Medical Center
Philadelphia, Pennsylvania, 19141
University of California San Francisco
San Francisco, California, 94117
Fred Hutchinson Cancer Center
Seattle, Washington, 98109
Atrium Health Wake Forest Baptist
Winston-Salem, North Carolina, 27157
United Kingdom3 sites
Clinical Research Centre, Ninewells Hospital & Medical School , NHS Tayside
Dundee, Scotland, DD1 9SY
Guy's and St Thomas' NHS Foundation Trust
London, England, SE1 9RT
Photobiology Unit, Salford Royal Hospital
Salford, M6 8HD
Australia2 sites
Royal Prince Alfred Hospital
Camperdown, New South Wales, 2050
The Royal Melbourne Hospital
Parkville, Victoria, 3050
France2 sites
CHU de Nantes - Hôtel Dieu, Service de dermatologie
Nantes, France, 44093
Centre d'Investigation Clinique (CIC) Hôpital Bichat - Claude-Bernard
Paris, France, 75018
Germany2 sites
Charité - Universitätsmedizin Berlin, Institute of Allergology
Berlin, Germany, 12203
Klinikum Chemnitz gGmbH
Chemnitz, Saxony, 09116
Italy1 site
Instituto Dermatologico San Gallicano Istituti Fisioterapici Ospitalieri IRCCS
Roma, 53-00144
About this study
Official title: HELIOS: An Open-Label, Long-Term Study to Investigate the Safety, Tolerability, and Efficacy of DISC-1459 (Bitopertin) in Participants With Erythropoietic Protoporphyria (EPP) or X-Linked Protoporphyria (XLP)
This is an open-label, long-term extension study to investigate the safety, tolerability and efficacy of DISC-1459 in participants with EPP.
- Conditions
- Erythropoietic Protoporphyria
- Being tested
- DISC-1459
- Keywords
- EPP, DISC-1459, porphyria, RO4917838
- Medical subject headings
- Protoporphyria, Erythropoietic, Porphyrias
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DISC-1459Drug
Also called Bitopertin, RO4917838
DISC-1459 dose level 1
DISC-1459Drug
Also called Bitopertin, RO4917838
DISC-1459 dose level 2
| Study group | Role | What they receive |
|---|---|---|
| DISC-1459 Oral Dose Level 1 | Experimental | Oral dose, once a day Receives: Drug: DISC-1459 |
| DISC-1459 Oral Dose Level 2 | Experimental | Oral dose, once a day Receives: Drug: DISC-1459 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of treatment-emergent adverse events
Measured: up to 5 Years
Incidence of clinically abnormal vital signs
Measured: up to 5 Years
Incidence of clinically abnormal physical exam
Measured: up to 5 Years
Incidence of abnormal laboratory test results
Measured: up to 5 Years
Assessment of Patient Health Questionnaire (PHQ-8)
The Patient Health Questionnaire (PHQ-8), an 8-item participant-report measure for screening for depression and for establishing depression severity. The total score ranges from 0-24, with a higher score indicating greater depression symptom severity.
Measured: up to 5 Years
Assessment of C-SSRS
The C-SSRS is a clinician-rated scale that assesses suicidality from ideation to behaviors and monitors the potential emergence of suicidality in clinical studies.
Measured: up to 5 Years
Secondary outcomes (3)
Change from baseline in daily daylight tolerance, as assessed by total hours spent in the sunlight without pain and average time to first prodromal syndrome in sunlight
Measured: up to 5 Years
Change from baseline in whole blood metal-free PPIX levels
Measured: up to 5 Years
Plasma Bitopertin Concentrations
Measured: up to 5 Years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jun 2023
- Study start31 Aug 2023
- Primary completionJun 2028 (estimated)
- Study completionJun 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Erythropoietic ProtoporphyriaStudies 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
- Interventional
- Phase
- Phase 2/3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 230 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Disc Medicine, Inc
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Will Savage, MD PhD, Study director, Disc Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05883748
- Sponsor's protocol ID
- DISC-1459-501
- Status last verified
- Dec 2025
- First submitted
- 22 May 2023
- Last updated
- 9 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
- Expanded access
- Available
Study at a glance
From the registry record, last updated by the sponsor on 9 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- HELIOS: An Open-Label, Long-Term Study to Investigate the Safety, Tolerability, and Efficacy of DISC-1459 (Bitopertin) in Participants With Erythropoietic Protoporphyria (EPP) or X-Linked Protoporphyria (XLP)
- ClinicalTrials.gov ID
- NCT05883748
- Acronym / sponsor ID
- DISC-1459-501
- Conditions
- Erythropoietic Protoporphyria
- Keywords
- EPP, DISC-1459, porphyria, RO4917838
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 230 participants (estimated)
- Lead sponsor
- Disc Medicine, IncIndustry (pharma, biotech, devices)
- Study start
- 31 Aug 2023 (actual)
- Primary completion
- Jun 2028 (estimated)
- Study completion
- Jun 2028 (estimated)
- First posted
- 1 Jun 2023 (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.
This is an open-label, long-term extension study to investigate the safety, tolerability and efficacy of DISC-1459 in participants with EPP.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| DISC-1459 Oral Dose Level 1 | Experimental | Drug: DISC-1459Oral dose, once a day |
| DISC-1459 Oral Dose Level 2 | Experimental | Drug: DISC-1459Oral dose, once a day |
Who may qualify
- Ages
- 12 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (7 listed)
- Participants with diagnosis of EPP who are participating (or who have participated) in a prior Disc Medicine bitopertin study and who have completed the randomized treatment phase and End-of-Study visit
- Aged ≥12 years upon study consent
- Body weight ≥32 kg for participants <18 years of age and BMI ≥18.5 kg/m2 for adult participants
- Willing to practice highly effective methods of birth control (both males who have partners of childbearing potential and females of childbearing potential during the study, while taking study drug, and for at least 30 days after the last dose of study drug.
- Negative urine or serum pregnancy test (females of childbearing potential).
Key exclusion criteria (9 listed)
- Participants who have an ongoing SAE from a clinical study that is assessed by the investigator as related to bitopertin
- Other medical or psychiatric condition or laboratory finding not specifically noted above that, in the judgement of the Investigator or Sponsor, would put the participant at unacceptable risk or otherwise preclude participation in the study
- Condition or concomitant medication that would confound the ability to interpret clinical, clinical laboratory, or participant diary data, including a major psychiatric condition that has had an exacerbation or required hospitalization in the last 6 months
- Planned treatment with afamelanotide or dersimelagon during the study
- Planned use of any drugs or herbal remedies known to be strong inhibitors or inducers of cytochrome p450 (CYP)3A4 enzymes throughout the study
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 |
|---|---|---|
| DISC-1459Also: Bitopertin, RO4917838DISC-1459 dose level 1 | Drug | DISC-1459 Oral Dose Level 1 |
| DISC-1459Also: Bitopertin, RO4917838DISC-1459 dose level 2 | Drug | DISC-1459 Oral Dose Level 2 |
Primary outcome
Incidence of treatment-emergent adverse events
Time frame: up to 5 Years
Incidence of clinically abnormal vital signs
Time frame: up to 5 Years
Incidence of clinically abnormal physical exam
Time frame: up to 5 Years
Incidence of abnormal laboratory test results
Time frame: up to 5 Years
Assessment of Patient Health Questionnaire (PHQ-8)
Time frame: up to 5 Years
The Patient Health Questionnaire (PHQ-8), an 8-item participant-report measure for screening for depression and for establishing depression severity. The total score ranges from 0-24, with a higher score indicating greater depression symptom severity.
Assessment of C-SSRS
Time frame: up to 5 Years
The C-SSRS is a clinician-rated scale that assesses suicidality from ideation to behaviors and monitors the potential emergence of suicidality in clinical studies.
3 secondary outcomes
Change from baseline in daily daylight tolerance, as assessed by total hours spent in the sunlight without pain and average time to first prodromal syndrome in sunlight
Time frame: up to 5 Years
Change from baseline in whole blood metal-free PPIX levels
Time frame: up to 5 Years
Plasma Bitopertin Concentrations
Time frame: up to 5 Years
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 Oct 2026.
- Individual participant dataSharing planned: No
Related trials for Erythropoietic Protoporphyria
RecruitingPhase 2/3
A Study to Investigate PORT-77 Oral Dosing Compared With Placebo in Participants With Erythropoietic Protoporphyria (EPP) or X-linked Protoporphyria (XLP)
Erythropoietic Protoporphyria (EPP), X-Linked Protoporphyria (XLP)
Active, not recruitingPhase 3
Extension Study to Evaluate Safety and Tolerability of Oral Dersimelagon (MT-7117) in Subjects With Erythropoietic Protoporphyria (EPP) or X-Linked Protoporphyria (XLP)
EPP, XLP
RecruitingObservational study
Longitudinal Study of the Porphyrias
Acute Porphyrias, Cutaneous Porphyrias
RecruitingObservational study
Observational Study of Adults and Adolescents With Erythropoietic Protoporphyria (EPP) and X-linked Porphyria (XLP)
Erythropoietic Protoporphyria (EPP), X-Linked Porphyria (XLP)
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.
Will Savage, MD PhD study director
Disc Medicine
26 sites in 11 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing DISC-1459 in people with Erythropoietic Protoporphyria, run by Disc Medicine, Inc at 26 sites in 11 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 7 inclusion and 9 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: enrolling by invitation, as of the sponsor's last update on 9 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 26 sites in United States, United Kingdom, Australia, France, Germany and 6 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.
What does this combined 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.
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of treatment-emergent adverse events (time frame: up to 5 Years). The study lists 6 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 9 Oct 2026.