What is the mechanism of action of this treatment?

Erythropoietic Protoporphyria (EPP) is treated by targeting the underlying genetic defects in heme biosynthesis that cause photosensitivity. Cimetidine, a histamine H2 receptor antagonist, is being studied for its potential to reduce protoporphyrin levels, thereby decreasing photosensitivity and improving the quality of life for EPP patients. Cimetidine works by inhibiting the action of histamine on H2 receptors in the stomach, reducing acid production, and potentially influencing heme metabolism. This matters for EPP patients as it offers a non-invasive treatment option that could mitigate the painful cutaneous symptoms associated with light exposure.

What side effects are associated with this type of intervention?

Common treatments for Erythropoietic Protoporphyria (EPP) include beta-carotene, afamelanotide, and cimetidine. Cimetidine, a Histamine H2 Receptor Antagonist, is generally well-tolerated but can cause side effects such as headaches, dizziness, diarrhea, and fatigue. Other treatments like beta-carotene may cause skin discoloration and gastrointestinal discomfort, while afamelanotide can lead to nausea, headache, and skin reactions at the implant site.

What prior FDA approvals exist?

There is no specific mention of prior FDA approvals for the treatment of Erythropoietic Protoporphyria (EPP) in the provided context. The document discusses a study on the efficacy and safety of oral cimetidine for EPP, but does not reference other FDA-approved treatments or similar drugs. Therefore, it is not possible to provide a detailed summary of prior FDA approvals for EPP based on the given information.

What other types of research exist?

One promising novel alternative to Cimetidine for Erythropoietic Protoporphyria (EPP) patients is Afamelanotide. Afamelanotide is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH) that has been shown to increase melanin production, providing photoprotection and reducing pain associated with light exposure in EPP patients. It has been approved in some regions and has demonstrated efficacy and safety in clinical trials.

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Histamine H2 Receptor Antagonist

Cimetidine for Protoporphyria

Phase 2

Recruiting

Led By Amy K Dickey, MD

Research Sponsored by Amy K. Dickey, M.D.

Eligibility Criteria Checklist

Specific guidelines that determine who can or cannot participate in a clinical trial

Must have

Prior enrollment or co-enrollment in the Longitudinal Study of the Porphyrias (PC Study 7201) with a confirmed diagnosis of EPP or XLP

Must not have

Individuals with elevations of porphyrins in plasma or erythrocytes due to other diseases (i.e., secondary porphyrinemia) such as liver and bone marrow diseases

Women who are pregnant, breastfeeding, or actively planning to become pregnant

Timeline

Screening 3 weeks

Treatment Varies

Follow Up before and after each 3-month treatment period

Awards & highlights

Summary

This trial tests if cimetidine, a common stomach medicine, can help people with EPP and XLP who suffer from painful light sensitivity. The drug might work by stopping the body from making too much of a substance that causes this sensitivity. Cimetidine is often prescribed for hospitalized patients requiring intravenous nutritional support and has been used to prevent excessive fluid and electrolyte loss in patients with short-bowel syndrome.

Who is the study for?

This trial is for individuals at least 15 years old with a confirmed diagnosis of Erythropoietic Protoporphyria (EPP) or X-linked Protoporphyria (XLP), who have a history of skin sensitivity to light but are not using other experimental therapies. Participants must be willing to use their smartphone for the study and expose themselves to light weekly.

What is being tested?

The trial is testing if oral Cimetidine can treat protoporphyrias by reducing protoporphyrin levels, improving tolerance to light, and enhancing quality of life. It's compared against a placebo, with outcomes measured through questionnaires and blood tests.

What are the potential side effects?

Cimetidine may cause side effects such as headaches, dizziness, gastrointestinal issues like diarrhea or constipation, tiredness, and in rare cases more serious reactions like heart rhythm problems or allergic reactions.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below

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I am diagnosed with EPP or XLP and enrolled in the PC Study 7201.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:

Select...

I have high porphyrin levels due to liver or bone marrow disease.

Select...

I am pregnant, breastfeeding, or planning to become pregnant soon.

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I have moderate to severe problems with my kidneys.

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I have had a liver or bone marrow transplant or significant liver issues.

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I don't have a smartphone or won't use it for the study.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ before and after each 3-month treatment period

Screening ~ 3 weeks

Treatment ~ Varies

Follow Up ~before and after each 3-month treatment period

This trial's timeline: 3 weeks for screening, Varies for treatment, and before and after each 3-month treatment period for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.

Primary study objectives

Erythrocyte total protoporphyrin level

Secondary study objectives

Light dose

Patient-reported quality of life

Phototoxic episodes

+1 more

Trial Design

2Treatment groups

Active Control

Placebo Group

Group I: CimetidineActive Control1 Intervention

Cimetidine 800mg orally twice daily

Group II: PlaceboPlacebo Group1 Intervention

Placebo capsule orally twice daily

0 / 6Eligibility criteria met

Research Highlights

Information in this section is not a recommendation. We encourage patients to speak with their healthcare team when evaluating any treatment decision.

Mechanism Of Action

Side Effect Profile

Prior Approvals

Other Research

Erythropoietic Protoporphyria (EPP) is treated by targeting the underlying genetic defects in heme biosynthesis that cause photosensitivity. Cimetidine, a histamine H2 receptor antagonist, is being studied for its potential to reduce protoporphyrin levels, thereby decreasing photosensitivity and improving the quality of life for EPP patients. Cimetidine works by inhibiting the action of histamine on H2 receptors in the stomach, reducing acid production, and potentially influencing heme metabolism. This matters for EPP patients as it offers a non-invasive treatment option that could mitigate the painful cutaneous symptoms associated with light exposure.

[Infantile pyknocytosis: A cause of noenatal hemolytic anemia. Is recombinant erythropoietin an alternative to transfusion?].