PHA-793887 is an intravenously-administered, inhibitor of cyclin dependent kinases CDK2, CDK5, CDK7, at IC50s of 8 nM, 5 nM, and 10 nM, respectively. [1] As a multi-CDK isoform inhibitor, it was postulated that PHA-793887 might overcome resistance-based mechanisms and lead to enhanced tumor suppression. PHA-793881 was found in Phase I dose-ranging studies to induce severe dose-related hepatotoxicity, thus halting clinical studies. [2]

Additionally, PHA-793887 was found to impair TLR signaling, thus suppressing cytokine production (type 1 interferon, interleukin-6, -10, -12, and TNFa), thereby increasing susceptibility of cancer patients to diseases such as herpes viridae. [3]

PHA-793887 was found to be an effective tool compound for the monitoring of the E2F gene signature pathway. [4]