Alnylam Pharmaceuticals said this week that it has formally advanced its preclinical hepatic porphyria treatment into its development pipeline.
The drug, called ALN-AS1, is designed to silence ALAS-1, a liver-expressed rate-limiting enzyme upstream of porphobilinogen deaminase. Inhibition of ALAS-1 has been shown to reduce the accumulation of heme precursors that cause the clinical manifestations of acute intermittent porphyria — a form of porphyria Alnylam is focusing on.
The company said that non-human primate data show that multiple subcutaneous doses of a GalNAc conjugate formulation of the drug led to rapid, dose-dependent, and long-lasting knockdown of the ALAS-1 mRNA, with an ED50 of approximately 1.25 mg/kg.
In rodent studies, doses as low as 2.5 mg/kg resulted in a complete blunting of phenobarbital-induced over-production of the toxic heme intermediates PBG and ALA.
Alnylam said that it will now begin investigational new drug application-enabling studies of ALN-AS1, with the goal of filing an IND next year.