BITOPERTIN for Erythropoietic protoporphyria | X-linked protoporphyria

Stratification factors

• Sunlight exposure time to prodromal symptom (<30 minutes or ≥30 minutes)
• Geographical region

Inclusion criteria

• {"criterion_text":"- 1. Aged 12 years or older at the time of study consent."}
• {"criterion_text":"- 10. Able to comply with all study procedures."}
• {"criterion_text":"- 2. Diagnosis of EPP or XLP, based on medical history by ferrochelatase (FECH) or aminolevulinic acid synthase 2 (ALAS2) genotyping or by biochemical porphyrin analysis."}
• {"criterion_text":"- 3. Minimum daily Sun Exposure Diary compliance ≥85% on Days [CCI] through Day [CCI], inclusive, during screening, and at least 1 successfully completed Sun Exposure Challenge (adults only, as this assessment is optional for adolescents) or historical recall of time to prodrome."}
• {"criterion_text":"- 4. Body weight ≥32 kg (ages 12 to <18 years), body mass index ≥18.5 kg/m2 (ages ≥18 years) at screening."}
• {"criterion_text":"- 5. Washout of at least 2 months prior to screening of afamelanotide and dersimelagon, if applicable."}
• {"criterion_text":"- 6. Aspartate aminotransferase and alanine transaminase <3× upper limit of normal (ULN) and total bilirubin <2× ULN (unless documented Gilbert syndrome) at screening. Albumin >lower limit of normal (LLN)."}
• {"criterion_text":"- 7. Willing to practice highly effective methods of birth control (both males who have partners of childbearing potential and females of childbearing potential during screening, while taking study drug, and for at least 30 days after the last dose of study drug."}
• {"criterion_text":"- 8. Negative pregnancy test (females of childbearing potential) at screening (Days [CCI] to [CCI]) AND baseline (Day 1), prior to dosing."}
• {"criterion_text":"- 9. Able to understand the study aims, procedures, and requirements, and provide written informed consent (and assent if necessary)."}

Exclusion criteria

• {"criterion_text":"- 1. Major surgery within 8 weeks before screening or incomplete recovery from any previous surgery."}
• {"criterion_text":"- 10. Prior exposure to bitopertin."}
• {"criterion_text":"- 11. Concurrent or planned treatment with afamelanotide or dersimelagon during the study period."}
• {"criterion_text":"- 12. Treatment with opioids for any period >7 days in the 2 months prior to screening or anticipated to require opioid use for >7 days at any point during the study."}
• {"criterion_text":"- 13. New treatment for anemia, including initiation of iron supplementation, within 1 month of screening."}
• {"criterion_text":"- 14. Current or planned use of any drugs or herbal remedies known to be strong or moderate inhibitors or inducers of cytochrome P450 (CYP)3A4 enzymes for [CCI} days prior to the first dose and throughout the study."}
• {"criterion_text":"- 15. Current or planned treatment with antipsychotic medication."}
• {"criterion_text":"- 16. Hemoglobin <10 g/dL at screening."}
• {"criterion_text":"- 17. Participation in other interventional clinical studies within 30 days prior to screening."}
• {"criterion_text":"- 18. If female, pregnant, planning to become pregnant, or breastfeeding."}
• {"criterion_text":"- 2. Other than EPP or XLP, an inherited intrinsic or extrinsic red cell disease associated with anemia, eg, G6PD, hemoglobinopathy, membranopathy, or immune or nonimmune hemolytic anemia. Any comorbid hematologic disease must be deemed acceptable by the Sponsor."}
• {"criterion_text":"- 3. Known hypersensitivity to any component of the study drug."}
• {"criterion_text":"- 4. History of liver transplantation or anticipated need for liver transplantation."}
• {"criterion_text":"- 5. History of alcohol dependence or excessive alcohol consumption, as assessed by the Investigator."}
• {"criterion_text":"- 6. Active human immunodeficiency virus (HIV), active hepatitis B or C. A positive HIV or viral hepatitis test result should be discussed between the Investigator and Sponsor prior to enrollment."}
• {"criterion_text":"- 7. [CCI]"}
• {"criterion_text":"- 8. Other medical or psychiatric condition or laboratory finding not specifically noted above that, in the judgment of the Investigator or Sponsor, would put the participant at unacceptable risk or otherwise preclude the participant from participating in the study."}
• {"criterion_text":"- 9. 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."}

Primary endpoints

• {"endpoint_text":"- Average monthly total time in sunlight on days without pain from a phototoxic reaction between 10:00 to 18:00 (10:00 AM to 6:00 PM) after 6 months (24 weeks) of treatment","definition_or_measurement_approach":"Measured as average monthly total time in sunlight on days without pain between 10:00 and 18:00 (10:00 AM to 6:00 PM) after 6 months (24 weeks) of treatment (using Sun Exposure Diary / assessments)."}
• {"endpoint_text":"- Percent change from baseline in whole-blood metal-free PPIX levels at 6 months","definition_or_measurement_approach":"Calculated percent change from baseline in whole-blood metal-free protoporphyrin IX (PPIX) levels at 6 months."}
• {"endpoint_text":"- Safety and tolerability, as assessed by adverse events (AEs) and laboratory results, over the 6-month treatment period","definition_or_measurement_approach":"Assessed by recording adverse events (AEs) and clinical laboratory results throughout the 6-month treatment period."}

Secondary endpoints

• {"endpoint_text":"- Occurrence of phototoxic reactions over the 6-month treatment period","definition_or_measurement_approach":"Occurrence of phototoxic reactions recorded during the 6-month treatment period (safety/efficacy monitoring)."}
• {"endpoint_text":"- Cumulative total time in sunlight on days without pain from a phototoxic reaction between 10:00 to 18:00 (10:00 AM to 6:00 PM) over the 6-month (24-week) treatment period","definition_or_measurement_approach":"Measured as cumulative total time in sunlight on pain-free days between 10:00 and 18:00 over the 24-week treatment period (derived from Sun Exposure Diary)."}
• {"endpoint_text":"- Change from baseline in 2-week average daily sunlight exposure time (minutes) to first prodromal symptom (eg, burning, tingling, itching, or stinging) associated with sunlight exposure between 1 hour post-sunrise and 1 hour pre-sunset at 6 months","definition_or_measurement_approach":"Change from baseline in the 2-week average daily sunlight exposure time (minutes) until first prodromal symptom associated with sunlight exposure (measured between 1 hour after sunrise and 1 hour before sunset) at 6 months."}

Other endpoints

• {"endpoint_text":"- Further Objectives (exploratory) are visible in the study protocol","definition_or_measurement_approach":"Exploratory objectives and endpoints are detailed in the study protocol (refer to protocol document for definitions and measurement approaches)."}

Ireland

Earliest CTIS Part Ii Submission Date

12-09-2025

Latest Decision Or Authorization Date

24-02-2026

Processing Time Days

165

Number Of Sites

1

Number Of Participants

5

Netherlands

Earliest CTIS Part Ii Submission Date

08-09-2025

Latest Decision Or Authorization Date

24-02-2026

Processing Time Days

169

Number Of Sites

1

Number Of Participants

15

Sweden

Earliest CTIS Part Ii Submission Date

08-09-2025

Latest Decision Or Authorization Date

24-02-2026

Processing Time Days

169

Number Of Sites

1

Number Of Participants

6

Norway

Earliest CTIS Part Ii Submission Date

06-09-2025

Latest Decision Or Authorization Date

20-03-2026

Processing Time Days

195

Number Of Sites

1

Number Of Participants

4

Germany

Earliest CTIS Part Ii Submission Date

15-09-2025

Latest Decision Or Authorization Date

24-02-2026

Processing Time Days

162

Number Of Sites

2

Number Of Participants

10

Italy

Earliest CTIS Part Ii Submission Date

15-09-2025

Latest Decision Or Authorization Date

24-02-2026

Processing Time Days

162

Number Of Sites

2

Number Of Participants

3

France

Earliest CTIS Part Ii Submission Date

16-09-2025

Latest Decision Or Authorization Date

23-02-2026

Processing Time Days

160

Number Of Sites

2

Number Of Participants

20

Belgium

Earliest CTIS Part Ii Submission Date

18-09-2025

Latest Decision Or Authorization Date

23-02-2026

Processing Time Days

158

Number Of Sites

1

Number Of Participants

5

Spain

Earliest CTIS Part Ii Submission Date

19-09-2025

Latest Decision Or Authorization Date

02-03-2026

Processing Time Days

164

Number Of Sites

1

Number Of Participants

3

Primary sponsor

Full Name

Disc Medicine Inc.

Organisation Type

Pharmaceutical company

Country Of Registered Address

United States

Contract research organisations

Name

Worldwide Clinical Trials Limited

Responsibilities

Operational and vendor responsibilities (values listed in sponsor duties: reduction; vendor management; conducting exit interview in UK and Ireland; plus multiple operational codes).

Name

Almac Clinical Services Limited

Responsibilities

QP release site; other supply/logistics duties

Name

Suvoda LLC

Responsibilities

Clinical trial technology / (responsibilities listed under sponsor duties without free-text values).

Third parties

• {"country":"United Kingdom","full_name":"Triumph Research Intelligence Limited","duties_or_roles":"Risk Based Quality Management","organisation_type":"Non-Pharmaceutical company"}
• {"country":"United States","full_name":"Medidata Solutions Inc.","duties_or_roles":"","organisation_type":"Non-Pharmaceutical company"}
• {"country":"United States","full_name":"Suvoda LLC","duties_or_roles":"","organisation_type":"Non-Pharmaceutical company"}
• {"country":"United States","full_name":"Resolian Bioanalytics","duties_or_roles":"longterm sample storage","organisation_type":"Industry"}
• {"country":"United Kingdom (Northern Ireland)","full_name":"Almac Clinical Services Limited","duties_or_roles":"QP release site","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Scisafe Inc.","duties_or_roles":"longterm sample storage","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Ledger Run","duties_or_roles":"Grant Payment","organisation_type":"Industry"}
• {"country":"United Kingdom","full_name":"Worldwide Clinical Trials Limited","duties_or_roles":"Responsibilities listed include: reduction; vendor management; conducting exit interview in UK and Ireland (multiple operational roles listed in sponsor duties)","organisation_type":"Pharmaceutical company"}
• {"country":"Switzerland","full_name":"BSI Business Systems Integration AG","duties_or_roles":"CTMS","organisation_type":"Non-Pharmaceutical company"}
• {"country":"United States","full_name":"Professional Case Management Clinical Trials LLC","duties_or_roles":"Home Health Care","organisation_type":"Laboratory/Research/Testing facility"}
• {"country":"United Kingdom","full_name":"Acm Global Central Laboratory Limited","duties_or_roles":"central laboratory sample registration/distribution; sub-contracted lab coordination","organisation_type":"Laboratory/Research/Testing facility"}
• {"country":"United States","full_name":"Scout Clinical","duties_or_roles":"Patients Travel and Micropayments","organisation_type":"Hospital/Clinic/Other health care facility"}
• {"country":"United States","full_name":"Clario Medical Imaging Inc.","duties_or_roles":"ePRO/diaries","organisation_type":"Pharmaceutical company"}