Discovery of PF-06873600, a CDK2/4/6 Inhibitor for the Treatment of Cancer

Control
of the cell cycle through selective pharmacological inhibition
of CDK4/6 has proven beneficial in the treatment of breast cancer.
Extending this level of control to additional cell cycle CDK isoforms
represents an opportunity to expand to additional tumor types and
potentially provide benefits to patients that develop tumors resistant
to selective CDK4/6 inhibitors. However, broad-spectrum CDK inhibitors
have a long history of failure due to safety concerns. In this approach,
we describe the use of structure-based drug design and Free–Wilson
analysis to optimize a series of CDK2/4/6 inhibitors. Further, we
detail the use of molecular dynamics simulations to provide insights
into the basis for selectivity against CDK9. Based on overall potency,
selectivity, and ADME profile, PF-06873600 (22) was identified
as a candidate for the treatment of cancer and advanced to phase 1
clinical trials.