Theophylline for Treatment of Pseudohypoparathyroidism

Open-Label Extension Study of Theophylline for Treatment of Pseudohypoparathyroidism

Pseudohypoparathyroidism is a genetic disorder with limited treatment options, characterized by early-onset obesity, short stature, hormone resistance and cognitive impairment. This phase 2 clinical trial will test the efficacy of theophylline, a phosphodiesterase inhibitor, in pseudohypoparathyroidism. We hypothesize that theophylline will cause weight loss, improve glucose tolerance and decrease hormone resistance in children and young adults.

Study Overview

• Status: Enrolling by invitation
• Conditions: Pseudohypoparathyroidism Type 1a; Albright Hereditary Osteodystrophy; Pseudohypoparathyroidism
• Intervention / Treatment: Drug: Theophylline ER

Detailed Description

Trial Objectives

1. The primary objective of this study is to evaluate the long-term safety of theophylline in patients with PHP.
2. The secondary objectives of this study are to evaluate changes in BMI, hormone resistance and epiphyseal closure associated with theophylline treatment of patients with PHP.

Study Design The proposed study is a single center, 24-month open label extension clinical trial for patients with PHP who complete the randomized clinical trial.

• Study Type: Interventional
• Enrollment (Estimated): 34
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Tennessee
    • Nashville, Tennessee, United States, 37212
      • Vanderbilt University Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 2 years to 99 years (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 1. Successful completion of the randomized clinical trial "Phase 2 Study of Theophylline Treatment of Pseudohypoparathyroidism IND 133103 (11/1/2016)".

Exclusion Criteria:

1. History of a seizure disorder unrelated to hypocalcemia
2. History of a cardiac arrhythmia (not including bradycardia)
3. Hepatic insufficiency including cirrhosis and acute hepatitis (AST or ALT >3x upper limit of normal)
4. Congestive heart failure
5. Current cigarette use or alcohol abuse
6. Pregnancy or intention to become pregnant during the next year
7. Active peptic ulcer disease
8. Current use of medications known to effect theophylline levels
9. History of hypersensitivity to theophylline or other medication components
10. Unable to comply with study procedures in the opinion of the investigator

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Open-label theophylline; Oral theophylline - either once daily capsule or q6h elixir.	Drug: Theophylline ER; Oral theophylline; Other Names: Theophylline elixir

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adverse Events	Treatment-emergent adverse events will be compared before and during treatment	24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
BMI	Change in BMI	24 months

Collaborators and Investigators

• Sponsor: Jaclyn Tamaroff
• Investigators: Principal Investigator: Jaclyn Tamaroff, MD, Vanderbilt University Medical Center

Publications and helpful links

Helpful Links

• Research Group Facebook Page

Study record dates

Study Major Dates

• Study Start (Actual): May 22, 2020
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: January 21, 2020
• First Submitted That Met QC Criteria: January 21, 2020
• First Posted (Actual): January 27, 2020

Study Record Updates

• Last Update Posted (Actual): April 28, 2026
• Last Update Submitted That Met QC Criteria: April 23, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Metabolism, Inborn Errors; Genetic Diseases, Inborn; Metabolic Diseases; Bone Diseases, Metabolic; Metal Metabolism, Inborn Errors; Calcium Metabolism Disorders; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Nutritional and Metabolic Diseases; Pseudohypoparathyroidism; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Enzyme Inhibitors; Neurotransmitter Agents; Purinergic Antagonists; Purinergic Agents; Respiratory System Agents; Anti-Asthmatic Agents; Bronchodilator Agents; Vasodilator Agents; Phosphodiesterase Inhibitors; Purinergic P1 Receptor Antagonists; Theophylline
• Other Study ID Numbers: IND 133013 Extension Study

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data will be shared upon request
• IPD Sharing Time Frame: After publication
• IPD Sharing Access Criteria: University faculty
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No