ML347 is a potent and selective inhibitor of bone morphogenetic protein (BMP) receptor with IC50 value of 32nM against ALK2 [1].

ML347 is discovered as a selective inhibitor of BMP type-I receptor ALK2 versus ALK3 and is identified as a probe molecule. In the in vitro kinase assay, ML347 shows potent inhibitory activities against ALK1 and ALK2 with IC50 values of 46 and 32 nM, respectively. The IC50 value of it for ALK3 is more than 10μM, demonstrating that ML347 is 300-fold more potent against ALK2. Besides that, ML347 exerts no inhibition effect on other related kinases such as ALK6 and KDR. Moreover, ML347 also shows effective inhibition with IC50 value of 152nM in the BMP4 cell based assay using C2C12BRA cells [1].

References:
[1] Engers D W, Frist A Y, Lindsley C W, et al. Synthesis and structure–activity relationships of a novel and selective bone morphogenetic protein receptor (BMP) inhibitor derived from the pyrazolo [1.5-a] pyrimidine scaffold of Dorsomorphin: The discovery of ML347 as an ALK2 versus ALK3 selective MLPCN probe. Bioorganic & medicinal chemistry letters, 2013, 23(11): 3248-3252.