Biological Activity
RG3039 (PF-06687859) is an orally bioavailable and brain-penetrant DcpS inhibitor with an IC50 of 0.069 nM.
In Vitro
RG3039 is a dibasic lipophilic molecule that is predicted to accumulate in lysosomes[1]. In motor neurons, RG3039 significantly increases both the average number of cells with gems and average number of gems per cell, which is used as an indirect measure of SMN levels[2].
In Vivo
RG3039 can extend survival and improve function in two SMA mouse models of varying disease severity (Taiwanese 5058 Hemi and 2B/− SMA mice), and positively impacts neuromuscular pathologies. In 2B/− SMA mice, RG3039 provides a >600% survival benefit (median 18 days to >112 days) when dosing began at P4, highlighting the importance of early intervention[2]. RG3039 distributes to central nervous system tissues where it robustly inhibits DcpS enzyme activity, but minimally activates SMN expression or the assembly of small nuclear ribonucleoproteins. RG3039 treated SMA mice shows a dose-dependent increase in survival, weight and motor function and it is associated with improved motor neuron somal and neuromuscular junction synaptic innervation and function and increased muscle size. RG3039 also enhances survival of conditional SMA mice in which SMN has been genetically restored to motor neurons[3].
References & source
Published experimental findings depend on the model and assay conditions. They do not guarantee equivalent performance in every application. For laboratory research use only.
