Cimetidine for Protoporphyria
What You Need to Know Before You Apply
What is the purpose of this trial?
This trial tests whether cimetidine (also known as Tagamet) can help individuals with erythropoietic protoporphyria (EPP) or X-linked protoporphyria (XLP). These conditions cause painful skin reactions to sunlight. The trial aims to determine if cimetidine can reduce these reactions and improve quality of life. Participants must have a history of painful skin reactions to light without blistering and must have participated in a previous study related to these conditions. As a Phase 2 trial, the research focuses on measuring the treatment's effectiveness in an initial, smaller group of people.
Will I have to stop taking my current medications?
The trial protocol does not specify if you must stop taking your current medications, but it mentions that any drugs or supplements that might interfere with safety or study objectives could be restricted. It's best to discuss your current medications with the study team.
Is there any evidence suggesting that cimetidine is likely to be safe for humans?
Research has shown that cimetidine is safe for people with porphyria, a group of disorders affecting the skin and nervous system. Studies and patient feedback suggest it is generally safe. However, concerns exist about long-term use. Safety information indicates that prolonged or repeated use might harm organs like the liver, kidneys, and testis. Most reports indicate that during cimetidine treatment, patients experienced reduced skin sensitivity to light, which benefits those with protoporphyria. Overall, while cimetidine is mostly well-tolerated, monitoring during treatment is important to ensure safety.12345
Why do researchers think this study treatment might be promising?
Researchers are excited about using Cimetidine for protoporphyria because it offers a unique approach compared to existing treatments. Most current therapies focus on managing symptoms or minimizing triggers, but Cimetidine, an H2-receptor antagonist commonly used to reduce stomach acid, may help by altering the metabolism of porphyrins, the compounds that accumulate in this condition. This novel mechanism could provide a new way to reduce the severity of symptoms in patients with protoporphyria, potentially improving quality of life where other treatments fall short.
What evidence suggests that cimetidine might be an effective treatment for protoporphyria?
Research has shown that cimetidine, which participants in this trial may receive, helps reduce symptoms in patients with other types of porphyria, such as acute intermittent porphyria. One study found that 15 out of 18 patients with erythropoietic protoporphyria who took cimetidine for at least four months experienced a noticeable decrease in symptoms. Cimetidine slows down the production of heme, which can help manage symptoms related to light sensitivity in protoporphyria. While more research is needed specifically for erythropoietic and X-linked protoporphyria, early results suggest it may be beneficial.46789
Who Is on the Research Team?
Amy K Dickey, MD
Principal Investigator
Massachusetts General Hospital
Karl E Anderson, MD
Principal Investigator
University of Texas
Are You a Good Fit for This Trial?
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.Inclusion Criteria
Exclusion Criteria
Timeline for a Trial Participant
Screening
Participants are screened for eligibility to participate in the trial
Treatment Period 1
Participants receive either placebo or cimetidine for 3 months
Wash-out
A 3-month wash-out period to eliminate carry-over effects
Treatment Period 2
Participants receive the alternate treatment (cimetidine or placebo) for 3 months
Follow-up
Participants are monitored for safety and effectiveness after treatment
What Are the Treatments Tested in This Trial?
Interventions
- Cimetidine
- Placebo
Cimetidine is already approved in European Union, United States, Canada, Japan for the following indications:
- Gastroesophageal reflux disease (GERD)
- Peptic ulcer disease
- Zollinger-Ellison syndrome
- Gastroesophageal reflux disease (GERD)
- Peptic ulcer disease
- Zollinger-Ellison syndrome
- Pathological hypersecretory conditions
- Gastroesophageal reflux disease (GERD)
- Peptic ulcer disease
- Zollinger-Ellison syndrome
- Gastroesophageal reflux disease (GERD)
- Peptic ulcer disease
- Zollinger-Ellison syndrome
Find a Clinic Near You
Who Is Running the Clinical Trial?
Amy K. Dickey, M.D.
Lead Sponsor
The University of Texas Medical Branch, Galveston
Collaborator
University of Texas
Collaborator
Wake Forest University Health Sciences
Collaborator