Effect of Oral Cimetidine in the Protoporphyrias

NCT05020184 | Completed Phase 2 DMC FDA Drug

• 3 other identifiers: 2021P002095PC72111R01FD007287-01
• Study Type: interventional
• Target: 26
• Locations: 1 country
• Sites: 3

Brief 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

Conditions

Erythropoietic Protoporphyria; X-linked Protoporphyria

Keywords

Erythropoietic Protoporphyria; X-linked Protoporphyria; EPP; Cimetidine; Photosensitivity

Outcome Measures

Primary Outcomes (1)

• Erythrocyte total protoporphyrin level

  Percent change in erythrocyte total protoporphyrin level post-treatment relative to pre-treatment

  Before and after each 3-month treatment period

Secondary Outcomes (4)

• Time to prodrome

  Last 2 months of each treatment period

• Patient-reported quality of life

  Before and after each 3-month treatment period

• Phototoxic episodes

  Last 2 months of each treatment period

• Light dose

  Last 2 months of each treatment period

Study Arms (2)

Cimetidine

ACTIVE COMPARATOR

Cimetidine 800mg orally twice daily

Drug: Cimetidine

Placebo

PLACEBO COMPARATOR

Placebo capsule orally twice daily

Drug: Placebo

Interventions

Cimetidine DRUG

Oral Cimetidine 800mg twice daily.

Also known as: Tagament

Cimetidine

Placebo DRUG

Placebo twice daily

Placebo

Eligibility Criteria

• Age: 15 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Prior enrollment or co-enrollment in the Longitudinal Study of the Porphyrias (PC Study 7201) with a confirmed diagnosis of EPP or XLP
• Male or female age ≥15 years at screening
• Characteristic history of non-blistering cutaneous photosensitivity
• Willing and capable of giving informed consent and following procedures described in the protocol

You may not qualify if:

• Participants not willing to expose themselves to light to the point of prodromal symptoms at least weekly
• History of liver or bone marrow transplant or clinically significant liver dysfunction as determined by the Investigator
• Known or suspected allergy or intolerance to cimetidine
• Use of any other experimental therapy in the past 3 months at screening
• Use of cimetidine within the past 3 months at screening
• Individuals with elevations of porphyrins in plasma or erythrocytes due to other diseases (i.e., secondary porphyrinemia) such as liver and bone marrow diseases
• Patients with any clinically significant comorbid conditions, which in the opinion of the Investigator, precludes participation
• Treatment with any drugs or supplements (Appendix 1) that in the opinion of the Investigator can interfere with subject safety or the objectives of the study
• The participant either does not have a smartphone or is not willing to use his/her smartphone for the study
• Women who are pregnant, breastfeeding, or actively planning to become pregnant
• Individuals with moderate to severe renal insufficiency

Sponsors & Collaborators

• The University of Texas Medical Branch, Galveston: collaborator
• Amy K. Dickey, M.D.: lead
• Wake Forest University Health Sciences: collaborator

Study Sites (3)

Massachusetts General Hospital

Boston, Massachusetts, 02114, United States

Location

Atrium Health Wake Forest Baptist Medical Center

Winston-Salem, North Carolina, 27157, United States

Location

University of Texas Medical Branch

Galveston, Texas, 77555, United States

Location

MeSH Terms

Conditions

Protoporphyria, Erythropoietic; Protoporphyria, Erythropoietic, X-Linked Dominant; Photosensitivity Disorders

Interventions

Cimetidine

Condition Hierarchy (Ancestors)

Porphyrias, Hepatic; Liver Diseases; Digestive System Diseases; Skin Diseases, Genetic; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Skin Diseases; Skin and Connective Tissue Diseases; Porphyrias; Metabolic Diseases; Nutritional and Metabolic Diseases

Intervention Hierarchy (Ancestors)

Guanidines; Amidines; Organic Chemicals; Imidazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Study Officials

• Amy K Dickey, MD

  Massachusetts General Hospital

  PRINCIPAL INVESTIGATOR

• Karl Anderson, MD

  University of Texas

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: randomized, double-blind, placebo-controlled
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Instructor of Medicine

Model Details: The study design is a multicenter, prospective, randomized, double-blind, placebo-controlled, crossover trial of oral cimetidine 800mg twice daily versus placebo

Study Record Dates

• First Submitted: July 26, 2021
• First Posted: August 25, 2021
• Study Start: June 14, 2022
• Primary Completion: April 24, 2025
• Study Completion: April 24, 2025
• Last Updated: January 21, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP
• Time Frame: Beginning 9 months and ending 36 months following article publication
• Access Criteria: With whom: Researchers who provide a methodologically sound proposal that is approved by the study investigators For what type of analysis: To achieve the aims of the approved proposal. By what mechanisms will the data be available: Proposals should be directed to adickey@mgh.harvard.edu . To gain access, data requestors will need to sign a data access agreement.

Locations

US (3)