A Phase 1/2 First-in-human, 2-part Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of Single Ascending Doses (Part 1: Open-label) and Repeat Doses (Part 2: Randomized, Double-blind, Placebo-controlled) of UX053 in Patients With GSD III

  • End date
    Sep 17, 2023
  • participants needed
  • sponsor
    Ultragenyx Pharmaceutical Inc
Updated on 17 October 2022


The primary objective of the study is to evaluate the safety of UX053 in adults with Glycogen Storage Disease Type III (GSD III).


This study is a phase 1/2 first-in-human (FIH), 2-part study to evaluate the safety, tolerability, and pharmacokinetic (PK) of a single ascending dose (SAD; part 1) and repeat doses (RD; part 2) of UX053 in patients with GSD III. Single SAD and RD of UX053 are tested in separate cohorts. The SAD cohorts will be open-label, while the RD dose cohorts will be randomized, double-blind, and placebo-controlled.

Condition Glycogen Storage Disease Type III
Treatment Placebo, UX053, Antipyretic, Antipyretic, H2 Blocker, H2 Blocker, H1 Blocker, H1 Blocker
Clinical Study IdentifierNCT04990388
SponsorUltragenyx Pharmaceutical Inc
Last Modified on17 October 2022


Yes No Not Sure

Inclusion Criteria

Confirmed diagnosis of GSD III by gene sequencing or enzymatic testing
Alanine aminotransferase at or below 5 times normal during the three months prior to dosing
Willing and able to comply with standard dietary management of GSD III

Exclusion Criteria

History of liver transplant or currently awaiting liver transplant
History of cirrhosis
Active Hepatitis B or C
Severe kidney impairment
History of liver cancer or large liver tumors
History of any cancer within the past 3 years
Known history of HIV infection
Known severe allergy to polyethylene glycol (PEG), polysorbate, or mRNA vaccine
Heart failure that causes marked limitation in physical activity
Poorly controlled diabetes
Poorly controlled hypothyroidism
Treatment with immunosuppressive medications such as those used to treat chronic autoimmune conditions and solid organ transplants
Pregnant or nursing, or planning to become pregnant during the study
Note: Additional inclusion/exclusion criteria may apply, per protocol
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