Ultragenyx Pharmaceutical, a biotechnology company focused on developing treatments for rare and ultra-rare genetic disorders, has begun the dosing of the first patient in a phase I study of UX001 for hereditary inclusion body myopathy (HIBM). UX001 is an extended release formulation of sialic acid intended as a substrate replacement therapy for HIBM, a severe, progressive, genetic neuromuscular disease caused by sialic acid deficiency. UX001 is the first program from the company's pipeline to enter the clinic since its founding in 2010.

The phase I clinical study will evaluate the pharmacokinetics (PK) and safety of UX001 in 24 HIBM patients at two centers in New York and Los Angeles. The study will test four different single-dose levels in each group of six subjects. Subjects will then undergo repeat dosing at three dose levels over 7 days to establish the steady-state pharmacokinetics and safety of repeat doses of UX001. 

"HIBM is one of many rare diseases that lack treatment, but for which good science exists on how it might be treated. Ultragenyx's goal is to be a leader in rare disease therapeutics by rapidly and efficiently transforming existing science into effective treatments for rare diseases that have been neglected in the past,” said Emil D. Kakkis, MD, PhD, chief executive officer of Ultragenyx.