CI

At a glance

ClinicalIndex Comparison Record
Phase 2Completed· 26 enrolled / 26 target
Drug / intervention
Cimetidine +1 moredrug
Likely dose
Cimetidine 800mgfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT05020184
NCT05020184Phase 2CompletedMonitor (0.5/mo)Completion was 14mo ago
CompareCT.gov

Effect of Oral Cimetidine in the Protoporphyrias

Amy K. Dickey, M.D.·interventional·Posted Aug 25, 2021·Updated Jun 29, 2026

In Brief

A Phase 2 clinical trial evaluating Cimetidine and Placebo for Erythropoietic Protoporphyria and X-linked Protoporphyria. Completed, enrolled 26 participants across 3 sites.

Signals

Enrolling slower than its timeline implies

Detailed Summary

Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) result from genetic defects of heme biosynthesis that cause life-long, painful cutaneous sensitivity to light. The objective of this study is to determine the efficacy and safety of oral cimetidine administration for treatment of the protoporphyrias. Efficacy will be based on protoporphyrin levels, photosensitivity, and quality of life questionnaires. Funding Source- FDA OOPD

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
ConditionsErythropoietic Protoporphyria, X-linked Protoporphyria
CountriesUnited States
CollaboratorsWake Forest University Health Sciences, The University of Texas Medical Branch, Galveston

Timeline

Phase 2CompletedFinished
20222023202420252026
First PostedAug 25, 2021
Enrollment StartJun 14, 2022
Primary CompletionApr 24, 2025
TodayJul 2, 2026
Enrollment to primary: 2.9 yearsPosted 4.9 years ago

Arms & Interventions

Cimetidineactive_comparator

Cimetidine 800mg orally twice daily

Drug: Cimetidine
Placeboplacebo_comparator

Placebo capsule orally twice daily

Drug: Placebo

Interventions

Cimetidinedrug

Oral Cimetidine 800mg twice daily.

Placebodrug

Placebo twice daily