XMD15-44 is a RET kinase inhibitor.XMD15-44 has a growth-inhibitory effect on RET/C634R and RET/M918T transformed RAT1 cells, with IC 50 values of 11.5 nM and 8.3 nM, respectively. XMD15-44 can inhibit RET kinase and signaling in human thyroid cancer cell lines carrying oncogenic RET alleles, reducing cell proliferation.