Severe Impact of Omeprazole Timing on pH-Sensitive Dasatinib Absorption: Unveiling Substantial Drug-Drug Interaction.

The absorption and bioavailability of most tyrosine kinase inhibitors are affected by gastrointestinal pH as they are weak basic lipophilic drugs. Hence, concomitant use of acid reducing agents (ARAs) is frequently restricted. Particularly comedication of crystalline dasatinib (Sprycel) and proton-pump inhibitors (PPIs) should be avoided.

Enhanced Bioavailability and Reduced Variability of Dasatinib and Sorafenib with a Novel Amorphous Solid Dispersion Technology Platform.

Despite clinical advances with protein kinase inhibitors (PKIs), oral administration of many PKIs is associated with highly variable plasma exposure and a narrow therapeutic window. We developed a novel hybrid nanoparticle-amorphous solid dispersion (ASD) technology platform consisting of an amorphous PKI embedded in a polymer matrix. The technology was used to manufacture immediate-release formulations of 2 tyrosine kinase inhibitors (TKIs), dasatinib and sorafenib.

Despite warnings, co-medication with proton pump inhibitors and dasatinib is common in chronic myeloid leukemia, but XS004, a novel oral dasatinib formulation, provides reduced pH-dependence, minimizing undesirable drug-drug interactions.

Background: Dasatinib and other tyrosine kinase inhibitors (TKI) have revolutionized the treatment of chronic myeloid leukemia (CML). However, as a lipophilic weak base, crystalline monohydrate, dasatinib (Sprycel®) is poorly soluble, rendering a pH-dependent absorption and a highly variable bioavailability. Thus, co-medication with proton pump inhibitors (PPI) profoundly impairs dasatinib uptake and is clearly recommended against.

Oxidation of protein tyrosine phosphatases as a pharmaceutical mechanism of action: a study using 4-hydroxy-3,3-dimethyl-2H-benzo[g]indole-2,5(3H)-dione.

Growth factor and insulin signal transduction comprise series of protein kinases and protein phosphatases whose combined activities serve to propagate the growth factor signal in a regulated fashion. It was shown previously that such signaling cascades generate hydrogen peroxide inside cells. Recent work has implied that one function of this might be to enhance the feed-forward signal through the reversible oxidation and inhibition of protein tyrosine phosphatases (PTPs).

Synthesis and biological activity of a novel class of pyridazine analogues as non-competitive reversible inhibitors of protein tyrosine phosphatase 1B (PTP1B).

A series of novel pyridazine analogues were prepared and the structure-activity relationship of their behavior as inhibitors of PTP1B was evaluated. Most of the analogues had potencies in the low micromolar range. The in vitro kinetics of this compound series demonstrated that they were reversible non-competitive binders.

Investigation of potential bioisosteric replacements for the carboxyl groups of peptidomimetic inhibitors of protein tyrosine phosphatase 1B: identification of a tetrazole-containing inhibitor with cellular activity.

Protein tyrosine phosphatases (PTPs) constitute a diverse family of enzymes that, together with protein tyrosine kinases, control the level of intracellular tyrosine phosphorylation, thus regulating many cellular functions. PTP1B negatively regulates insulin signaling, in part, by dephosphorylating key tyrosine residues within the regulatory domain of the beta-subunit of the insulin receptor, thereby attenuating receptor kinase activity. Inhibitors of PTP1B would therefore have the potential of prolonging the phosphorylated (activated) state of the insulin receptor and are anticipated to be a novel treatment of the insulin resistance characteristic of type 2 diabetes.

Synthesis and biological activity of a novel class of small molecular weight peptidomimetic competitive inhibitors of protein tyrosine phosphatase 1B.

Protein tyrosine phosphatase 1B (PTP1B) negatively regulates insulin signaling in part by dephosphorylating key tyrosine residues within the regulatory domain of the beta-subunit of the insulin receptor (IR), thereby attenuating receptor tyrosine kinase activity. Inhibition of PTP1B is therefore anticipated to improve insulin resistance and has recently become the focus of discovery efforts aimed at identifying new drugs to treat type II diabetes. We previously reported that the tripeptide Ac-Asp-Tyr(SO(3)H)-Nle-NH(2) is a surprisingly effective inhibitor of PTP1B (K(i) = 5 microM).

Regio- and Stereoselective Reactions of 17-Phenyl-18,19,20-trinorprostaglandin F(2)(alpha) Isopropyl Ester.

Novel prostaglandin F(2)(alpha) derivatives, functionalized at C13 and C14, have been prepared. 17-Phenyl-18,19,20-trinorprostaglandin F(2)(alpha) isopropyl ester [(15S)-1] and its epimer [(15R)-1] were stereoselectively epoxidized, using Sharpless conditions, to produce each of the four diastereomeric epoxides (15S)-2, (15S)-3, (15R)-2, and (15R)-3. Treatment of the four epoxides with LiOH stereospecifically-produced the pentahydroxy substituted analogues 12 and 13.