Trial · NCT05020184
Effect of Oral Cimetidine in the Protoporphyrias
NCT05020184, Phase 2, Completed, Amy K. Dickey, M.D.
3 sourcestrials-2026-11-12-0.5.0
Cite this record
ConductScience Library. Effect of Oral Cimetidine in the Protoporphyrias. Trials, record NCT05020184. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT05020184
On this page
Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- Effect of Oral Cimetidine in the Protoporphyrias
- NCT number
- NCT05020184
- Status
- Completed
- Phases
- Phase 2
- Enrollment
- 26 participants, actual
- Lead sponsor
- Amy K. Dickey, M.D.
- Conditions
- Erythropoietic Protoporphyria, X-linked Protoporphyria
- Interventions
- Cimetidine, Placebo
- First posted
- 2021-08-25
- Last updated
- 2026-09-04
Source ClinicalTrials.gov
Registered outcomes6
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Percent Change in Erythrocyte Total Protoporphyrin Level | Before and after each 3-month treatment period | Percent change in erythrocyte total protoporphyrin levels after treatment period versus before. |
| Secondary | Time to Prodrome | Last 2 months of each treatment period | Mean daily self-reported outdoor time, in minutes, before EPP/XLP prodrome onset during the last two months of each treatment period, including days without symptoms. |
| Secondary | Change in PROMIS-57 v2 Domain T-scores From Pre-treatment to End of Each 3-month Treatment Period | Immediately before and at the end of the 3-month cimetidine treatment period, and immediately before and at the end of the 3-month placebo treatment period | PROMIS-57 v2 assesses 7 health domains: Physical Function, Anxiety, Depression, Fatigue, Sleep Disturbance, Ability to Participate in Social Roles and Activities, and Pain Interference. Domain scores are converted to standardized T-scores with a U.S. general population mean of 50 and standard deviation of 10. Higher scores indicate worse outcomes for Anxiety, Depression, Fatigue, Sleep Disturbance, and Pain Interference, and better outcomes for Physical Function and Ability to Participate in Social Roles and Activities. PROMIS-57 v2 was administered immediately before and at the end of each 3-month treatment period. End-of-period PROMIS-57 v2 domain T-scores were analyzed using mixed-effects linear models adjusted for the immediately pre-treatment PROMIS-57 v2 domain T-score for that treatment period, with treatment as a fixed effect and participant as a random effect. Reported values represent least squared means for change in T-score for the cimetidine and placebo treatment periods. |
| Secondary | Change in PROMIS-57 v2 Pain Intensity Scores From Pre-treatment to End of Each 3-month Treatment Period | Immediately before and at the end of the 3-month cimetidine treatment period, and immediately before and at the end of the 3-month placebo treatment period | PROMIS-57 v2 Pain Intensity is a single item scored from 0 to 10, with higher scores indicating worse pain intensity. The instrument-defined possible score range is 0 to 10. This question was administered immediately before and at the end of each 3-month treatment period in this crossover trial. End-of-period PROMIS-57 v2 Pain Intensity scores were analyzed using mixed-effects linear models adjusted for the immediately pre-treatment Pain Intensity score for that treatment period, with treatment as a fixed effect and participant as a random effect. Reported values represent least squared means for change in Pain Intensity scores for the cimetidine and placebo treatment periods. |
| Secondary | Number of Phototoxic Reactions Per Participant During the Last 2 Months of Each Treatment Period | Last 2 months of the 3-month cimetidine treatment period and last 2 months of the 3-month placebo treatment period | For each participant, the number of phototoxic reactions during the last 2 months of each 3-month treatment period was recorded. In this crossover trial, the reported outcome compares the number of phototoxic reactions per patient during cimetidine with the number during placebo. |
| Secondary | Blue Light Dose | Last 2 months of each treatment period | Average daily outdoor blue light dose before EPP/XLP prodrome onset during the last two months of each treatment period, including days without symptoms. Dose data for the day were excluded if the patient did not wear the dosimeter for the entire day. |
Source ClinicalTrials.gov
Outcomes0
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
None in this release.
Results by group0
Each measurement the trial posted, group by group, in the words and numbers it posted.
None in this release.
Participant flow0
How many started, completed or left each group, period by period.
None in this release.
Adverse events0
Each adverse event the trial posted, group by group: the participants affected out of those at risk.
None in this release.
Adverse event totals0
The totals the trial posted for each group.
None in this release.
Papers0
The papers the trial lists on ClinicalTrials.gov.
None in this release.
Grants1
The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.
| Project | Title | Principal investigators | Organization | Funder | Fiscal years |
|---|---|---|---|---|---|
| R01FD007287 | Effect of Oral Cimetidine in the Protoporphyrias (IND 153247 submitted 9/2/2020) | YEUNG, AMY KATHRYN; ANDERSON, KARL ELMO | MASSACHUSETTS GENERAL HOSPITAL | FOOD AND DRUG ADMINISTRATION | 2021 to 2025 |
Source NIH RePORTER
Trial comparisons0
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
None in this release.
Tests0
The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.
None in this release.
Data dates
The day each source was copied for this release.
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNo license stated
- NIH RePORTER's clinical studies and project filesPublic domain
Each source's terms
- ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
- ClinicalTrials.govnone stated
- NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)
ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
For software
Read this trial from software.
The record and each of its lists are JSON, twenty rows a page. No key.
GET https://conductscience.org/api/trials/v1/NCT05020184
GET https://conductscience.org/api/trials/v1/NCT05020184/registered