Chinese biotech firm 3SBio acquired worldwide rights to EnzymeRx’ pegsitacase (uricase-PEG 20) for $6.25 million. The drug, which is in Phase I clinical development for the treatment of refractory gout and associated tumor lysis syndrome, is a recombinant Candida utilis uricase modified with multiple molecules of PEG. 3SBio says it aims to develop pegsitacase in China, and establish partnerships for development of the drug in other global territories.
In April EnzymeRx reported promising data from a Phase I trial assessing the safety, pharmacokinetics, and pharmacodynamics of single intravenous doses of pegsitacase in 20 subjects. The treatment resulted in rapid, potent, and long-lasting suppression of uric acid, even at the lowest dose tested. All subjects achieved uric acid levels of 1 mg/dL or lower within a day of pegsitacase administration and maintained the same level for at least a week. Twelve of the 16 subjects receiving the highest four doses of pegsitacase still had uric acid levels of 1 mg/dL or lower by day 12, and eight maintained these very low uric acid levels through day 24.
At the time the Phase I data were released, EnzymeRx said it was planning to continue clinical development of pegsitacase as an intravenous agent for tumor lysis syndrome and other indications requiring rapid onset, and as an intramuscular agent for gout and other conditions requiring chronic administration. The drug has received orphan drug designation in the U.S. for the treatment of refractory gout, tumor lysis syndrome, and Lesch-Nyhan syndrome.