Discovery of highly potent and ALK2/ALK1 selective kinase inhibitors using DNA-encoded chemistry technology.
Jimmidi, R., Monsivais, D., Ta, H.M., Sharma, K.L., Bohren, K.M., Chamakuri, S., Liao, Z., Li, F., Hakenjos, J.M., Li, J.Y., Mishina, Y., Pan, H., Qin, X., Robers, M.B., Sankaran, B., Tan, Z., Tang, S., Vasquez, Y.M., Wilkinson, J., Young, D.W., Palmer, S.S., MacKenzie, K.R., Kim, C., Matzuk, M.M.(2024) Proc Natl Acad Sci U S A 121: e2413108121-e2413108121
- PubMed: 39541346 
- DOI: https://doi.org/10.1073/pnas.2413108121
- Primary Citation of Related Structures:  
9D8E, 9D8F, 9D8Z - PubMed Abstract: 
Activin receptor type 1 (ACVR1; ALK2) and activin receptor like type 1 (ACVRL1; ALK1) are transforming growth factor beta family receptors that integrate extracellular signals of bone morphogenic proteins (BMPs) and activins into Mothers Against Decapentaplegic homolog 1/5 (SMAD1/SMAD5) signaling complexes. Several activating mutations in ALK2 are implicated in fibrodysplasia ossificans progressiva (FOP), diffuse intrinsic pontine gliomas, and ependymomas. The ALK2 R206H mutation is also present in a subset of endometrial tumors, melanomas, non-small lung cancers, and colorectal cancers, and ALK2 expression is elevated in pancreatic cancer. Using DNA-encoded chemistry technology, we screened 3.94 billion unique compounds from our diverse DNA-encoded chemical libraries (DECLs) against the kinase domain of ALK2. Off-DNA synthesis of DECL hits and biochemical validation revealed nanomolar potent ALK2 inhibitors. Further structure-activity relationship studies yielded center for drug discovery (CDD)-2789, a potent [NanoBRET (NB) cell IC 50 : 0.54 μM] and metabolically stable analog with good pharmacological profile. Crystal structures of ALK2 bound with CDD-2281, CDD-2282, or CDD-2789 show that these inhibitors bind the active site through Van der Waals interactions and solvent-mediated hydrogen bonds. CDD-2789 exhibits high selectivity toward ALK2/ALK1 in KINOMEscan analysis and NB K192 assay. In cell-based studies, ALK2 inhibitors effectively attenuated activin A and BMP-induced Phosphorylated SMAD1/5 activation in fibroblasts from individuals with FOP in a dose-dependent manner. Thus, CDD-2789 is a valuable tool compound for further investigation of the biological functions of ALK2 and ALK1 and the therapeutic potential of specific inhibition of ALK2.
Organizational Affiliation: 
Center for Drug Discovery, Baylor College of Medicine, Houston, TX 77030.