Safety and Tolerability of Phenylbutyrate in Inclusion Body Myositis

This is a pilot study (phase 1 clinical trial) to evaluate the safety and tolerability of phenylbutyrate in IBM. In this open label study, 10 patients with sporadic inclusion body myositis will be treated with phenylbutyrate (3 gm twice daily) for 3 months. There will be a run-in period, during which certain biomarkers will be measured at baseline and at the end of the run-in period in addition to final measurement at the end of the treatment period.

Study Overview

• Status: Completed
• Conditions: Inclusion Body Myositis; Sporadic Inclusion Body Myositis
• Intervention / Treatment: Drug: Phenylbutyrate Oral Tablet

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Kansas
    • Kansas City, Kansas, United States, 66160
      • University of Kansas Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Fulfill ENMC 2011 diagnostic criteria for IBM
• Age > 18 years
• Women must be post-menopausal (no menses in >12 months) or status post hysterectomy
• Able to give informed consent

Exclusion Criteria:

• Presence of any one of the following medical conditions: chronic infection; chronic renal insufficiency; cancer other than skin cancer less than five years prior; multiple sclerosis or prior episode of central nervous system demyelination; or other chronic serious medical illnesses
• Presence of any of the following on routine blood screening: WBC<3000; Platelets < 100,000; hematocrit < 30%; BUN > 30 mg %; creatine > 1.5 mg%; liver disease with serum albumin < 3 G/DL
• Women who are pregnant or lactating
• History of non-compliance with other therapies
• Coexistence of other muscular disease
• Drug or alcohol abuse within past three months
• Known bleeding disorder
• Known liver disease
• Known congestive heart failure
• Known hypernatremia
• Inability to give informed consent

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: Phenylbutyrate; Open-label phenylbutyrate	Drug: Phenylbutyrate Oral Tablet; Phenylbutyrate, an orally active chemical chaperone approved by the US Food and Drug Administration for treatment of urea cycle disorders, mimics the function of intracellular molecular chaperones in preventing protein aggregation and oligomerization.; Other Names: PBA

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety and Tolerability of Phenylbutyrate Measured by Incidence of Adverse Events	Since this is a Phase I pilot trial, the primary outcome will be testing the safety and tolerability of phenylbutyrate in patients with Inclusion Body Myositis. This will be measured by the incidence of adverse events reported in subjects throughout the treatment period of the trial.	Month 3 - Month 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Inclusion Body Myositis Functional Rating Scale (IBMFRS)	The IBMFRS is a quickly administered (10-minute) ordinal rating scale (ratings 0-40) used to determine patients' assessment of their capability and independence in 10 functional activities. The higher a subject scores on the scale, the better functional ability the subject has.	Month 6

Collaborators and Investigators

• Sponsor: University of Kansas Medical Center
• Investigators: Principal Investigator: Duaa Jabari, MD, University of Kansas Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): August 20, 2020
• Primary Completion (Actual): January 20, 2022
• Study Completion (Actual): January 20, 2022

Study Registration Dates

• First Submitted: May 18, 2020
• First Submitted That Met QC Criteria: June 4, 2020
• First Posted (Actual): June 9, 2020

Study Record Updates

• Last Update Posted (Actual): May 23, 2022
• Last Update Submitted That Met QC Criteria: May 19, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Keywords: PBA; IBM; Inclusion Body Myositis; Phenylbutyrate
• Additional Relevant MeSH Terms: Nervous System Diseases; Musculoskeletal Diseases; Muscular Diseases; Neuromuscular Diseases; Myositis; Myositis, Inclusion Body; Antineoplastic Agents; 4-phenylbutyric acid
• Other Study ID Numbers: PBA in IBM

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No