TP-0903 Is Active in Preclinical Models of Acute Myeloid Leukemia with Mutation/Deletion.

Acute myeloid leukemia (AML) with mutations in the tumor suppressor gene TP53 confers a dismal prognosis with 3-year overall survival of <5%. While inhibition of kinases involved in cell cycle regulation induces synthetic lethality in a variety of TP53 mutant cancers, this strategy has not been evaluated in mutant TP53 AML. Previously, we demonstrated that TP-0903 is a novel multikinase inhibitor with low nM activity against AURKA/B, Chk1/2, and other cell cycle regulators.

Intentional Modulation of Ibrutinib Pharmacokinetics through CYP3A Inhibition.

Ibrutinib (Imbruvica; PCI-32765) is an orally administered inhibitor of Bruton's tyrosine kinase that has transformed the treatment of B-cell malignancies. However, ibrutinib has very low oral bioavailability that contributes to significant variability in systemic exposure between patients, and this has the potential to affect both efficacy and toxicity. We hypothesized that the oral bioavailability of ibrutinib is limited by CYP3A isoform-mediated metabolism, and that this pathway can be inhibited to improve the pharmacokinetic properties of ibrutinib.

TP-0903 is active in models of drug-resistant acute myeloid leukemia.

Effective treatment for AML is challenging due to the presence of clonal heterogeneity and the evolution of polyclonal drug resistance. Here, we report that TP-0903 has potent activity against protein kinases related to STAT, AKT, and ERK signaling, as well as cell cycle regulators in biochemical and cellular assays. In vitro and in vivo, TP-0903 was active in multiple models of drug-resistant FLT3 mutant AML, including those involving the F691L gatekeeper mutation and bone marrow microenvironment-mediated factors.

Development and validation of a sensitive UHPLC-MS/MS analytical method for venetoclax in mouse plasma, and its application to pharmacokinetic studies.

A rapid and sensitive analytical method was developed to quantify venetoclax, an oral BH3-mimetic that blocks the anti-apoptotic protein BCL-2, in mouse plasma using ultra-high-performance liquid chromatography with electrospray ionization tandem mass spectrometric detection. Plasma protein precipitation was performed on 5 µL samples, and separation of the analytes was accomplished on an Accucore aQ column using gradient elution at a flow rate of 0.4 mL/min.