THZ2, an analogue of THZ1 with improved pharmacokinetic features, is a potent, selective CDK7 inhibitor with IC50 of 13.9 nM, displays a 5-fold improved half-life in vivo compared with THZ1.

THZ1 2HCl is a selective, covalent, and allosteric inhibitor of CDK7 with an IC50 of 3.2 nM. THZ1 2HCl has antiproliferative effects on a variety of cancer cell lines.

Amsilarotene inhibits the phosphorylation of retinoblastoma gene product (RB) and increases the presence of 2 cyclin-dependent kinases (CDK) inhibitors resulting in cell cycle arrest.