Pegtibatinase is currently advancing in a Phase 1/2 dose escalation study to assess its safety, tolerability, pharmacokinetics, pharmacodynamics and clinical effects in patients with classical HCU. Pegtibatinase has been granted Breakthrough Therapy, Rare Pediatric Disease and Fast Track designations by the FDA, as well as Orphan Drug designation in the US and Europe.
In December 2021, the Company announced positive topline results through the first five cohorts of the Phase 1/2 COMPOSE Study, showing that treatment with pegtibatinase at a dose of 1.5 mg/kg BIW resulted in rapid and sustained reductions in tHcy through 12 weeks of treatment. In May 2023, the Company announced positive results in the sixth cohort, showing that treatment with pegtibatinase at a dose of 2.5 mg/kg BIW resulted in a mean relative reduction from baseline of 67.1% (n=4, mean baseline tHcy = 96.8 μM), compared to a 0.6% increase in tHcy levels from baseline for patients receiving placebo in the study (n=6, mean baseline tHcy = 124.8 μM), as well as maintenance of mean tHcy below the clinically meaningful threshold of 100 μM, over weeks 6 to 12. To date in the study, pegtibatinase has been generally well-tolerated. The Company is engaging with regulators on the design of a potential pivotal Phase 3 study with the expectation of initiating a Phase 3 program by the end of 2023.
View a plain language summary of the COMPOSE Study interim data.