HELIOS: Open-Label, Long-Term Extension Study to Investigate the Safety, Tolerability, and Efficacy of DISC-1459 (Bitopertin) in Participants With EPP or XLP

September 9, 2026 updated by: Disc Medicine, Inc

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Enrolling by invitation

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
230

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 3

Expanded Access

Expanded Access

A way for patients with serious diseases or conditions who cannot participate in a clinical trial to gain access to a medical product that has not been approved by the U.S. Food and Drug Administration (FDA). Also called compassionate use. There are different expanded access types.
Available

Available

  • Available: Expanded access is currently available for this investigational treatment, and patients who are not participants in the clinical study may be able to gain access to the drug, biologic, or medical device being studied.
  • No longer available: Expanded access was available for this intervention previously but is not currently available and will not be available in the future.
  • Temporarily not available: Expanded access is not currently available for this intervention but is expected to be available in the future.
  • Approved for marketing: The intervention has been approved by the U.S. Food and Drug Administration for use by the public.
 outside the clinical trial. See expanded access record.

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Australia
    • New South Wales
      • Camperdown, New South Wales, Australia, 2050
        • Royal Prince Alfred Hospital
    • Victoria
      • Parkville, Victoria, Australia, 3050
        • The Royal Melbourne Hospital
  • Belgium
      • Leuven, Belgium, 3000
        • UZ Leuven
  • France
    • France
      • Nantes, France, France, 44093
        • CHU de Nantes - Hôtel Dieu, Service de dermatologie
      • Paris, France, France, 75018
        • Centre d'Investigation Clinique (CIC) Hôpital Bichat - Claude-Bernard
  • Germany
    • Germany
      • Berlin, Germany, Germany, 12203
        • Charité - Universitätsmedizin Berlin, Institute of Allergology
    • Saxony
      • Chemnitz, Saxony, Germany, 09116
        • Klinikum Chemnitz gGmbH
  • Ireland
      • Dublin, Ireland, D12N512
        • Children's Health Ireland (CHI)
  • Italy
      • Roma, Italy, 53-00144
        • Instituto Dermatologico San Gallicano Istituti Fisioterapici Ospitalieri IRCCS
  • Netherlands
      • Rotterdam, Netherlands, 3015 GD
        • Erasmus MC
  • Spain
    • Spain
      • Barcelona, Spain, Spain, 08036
        • Hospital Clinic de Barcelona
  • Sweden
    • Sweden
      • Stockholm, Sweden, Sweden, 141 86
        • Karolinska University Hospital
  • United Kingdom
      • Salford, United Kingdom, M6 8HD
        • Photobiology Unit, Salford Royal Hospital
    • England
      • London, England, United Kingdom, SE1 9RT
        • Guy's and St Thomas' NHS Foundation Trust
    • Scotland
      • Dundee, Scotland, United Kingdom, DD1 9SY
        • Clinical Research Centre, Ninewells Hospital & Medical School , NHS Tayside
  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35233
        • University of Alabama Hospital
    • California
      • San Francisco, California, United States, 94117
        • University of California San Francisco
    • Florida
      • Miami, Florida, United States, 33136
        • University of Miami Miller School of Medicine
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital
      • Boston, Massachusetts, United States, 02135
        • MetroBoston Clinical Partners
    • New York
      • New York, New York, United States, 10029
        • Mount Sinai Hospital
    • North Carolina
      • Winston-Salem, North Carolina, United States, 27157
        • Atrium Health Wake Forest Baptist
    • Ohio
      • Columbus, Ohio, United States, 43215
        • Remington-Davis Clinical Research
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19141
        • Einstein Medical Center
    • Texas
      • Galveston, Texas, United States, 77550
        • University of Texas
    • Washington
      • Seattle, Washington, United States, 98109
        • Fred Hutchinson Cancer Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 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.

Exclusion Criteria:

  • 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
  • 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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: DISC-1459 Oral Dose Level 1
Oral dose, once a day
Drug: DISC-1459
DISC-1459 dose level 1
Other Names:
  • Bitopertin
  • RO4917838
Drug: DISC-1459
DISC-1459 dose level 2
Other Names:
  • Bitopertin
  • RO4917838
Experimental: DISC-1459 Oral Dose Level 2
Oral dose, once a day
Drug: DISC-1459
DISC-1459 dose level 1
Other Names:
  • Bitopertin
  • RO4917838
Drug: DISC-1459
DISC-1459 dose level 2
Other Names:
  • Bitopertin
  • RO4917838

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Incidence of treatment-emergent adverse events
Time Frame: up to 5 Years
up to 5 Years
Incidence of clinically abnormal vital signs
Time Frame: up to 5 Years
up to 5 Years
Incidence of clinically abnormal physical exam
Time Frame: up to 5 Years
up to 5 Years
Incidence of abnormal laboratory test results
Time Frame: up to 5 Years
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.
up to 5 Years
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.
up to 5 Years

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
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
up to 5 Years
Change from baseline in whole blood metal-free PPIX levels
Time Frame: up to 5 Years
up to 5 Years
Plasma Bitopertin Concentrations
Time Frame: up to 5 Years
up to 5 Years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Disc Medicine, Inc

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Will Savage, MD PhD, Disc Medicine

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 31, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 22, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 22, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 1, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 10, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 9, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • DISC-1459-501

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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