Progress of proteolysis-targeting chimeras (PROTACs) delivery system in tumor treatment.

Proteolysis targeting chimeras (PROTACs) can use the intrinsic protein degradation system in cells to degrade pathogenic target proteins, and are currently a revolutionary frontier of development strategy for tumor treatment with small molecules. However, the poor water solubility, low cellular permeability, and off-target side effects of most PROTACs have prevented them from passing the preclinical research stage of drug development. This requires the use of appropriate delivery systems to overcome these challenging hurdles and ensure precise delivery of PROTACs towards the tumor site. Therefore, the combination of PROTACs and multifunctional delivery systems will open up new research directions for targeted degradation of tumor proteins. In this review, we systematically reviewed the design principles and the most recent advances of various PROTACs delivery systems. Moreover, the constructive strategies for developing multifunctional PROTACs delivery systems were proposed comprehensively. This review aims to deepen the understanding of PROTACs drugs and promote the further development of PROTACs delivery system.

Development and validation of LC-MS/MS methods for the pharmacokinetic assessment of the PROTACs bavdeglutamide (ARV-110) and vepdegestrant (ARV-471).

Chemically induced, targeted protein degradation with proteolysis targeting chimeras (PROTACs) has shown to be a promising pharmacological strategy to circumvent the poor "druggability" of intracellular targets. However, the favorable pharmacology comes with complex molecular properties limiting the oral bioavailability of these drugs. To foster the translation of PROTACs into the clinics it is of high importance to establish sensitive bioanalytical methods that enable the assessment of absorption, bioavailability, and disposition of PROTACs after oral dosing. In this study, two highly sensitive LC-MS/MS methods (LLOQ = 0.5 ng/mL) were developed and validated for the quantification of bavdeglutamide (ARV-110) and vepdegestrant (ARV-471) in rat plasma. Plasma samples were processed by protein precipitation and separated on a C18 column over a gradient of acetonitrile and water with 0.1 % formic acid. Selected reaction monitoring in positive ESI mode was applied to quantify ARV-110 and ARV-471. Both methods showed linearity, accuracy, and precision as well as matrix effects and carry-over within the predefined acceptance criteria. High stability of the compounds in plasma was demonstrated at long-term storage for seven weeks at -20 °C, three freeze-thaw cycles, up to 20 min at room temperature, and as extracts in the autosampler. The plasma concentration-time curves after intravenous and intraduodenal bolus single-dose administrations in rats could be successfully quantified at clinically relevant doses per body weight. The highly sensitive bioanalytical assays presented in this work enable the application of a broad spectrum of in vivo studies to elucidate the oral absorption, bioavailability, and disposition of PROTACs.

Discovery of a potent CDKs/FLT3 PROTAC with enhanced differentiation and proliferation inhibition for AML.

AML is an aggressive malignancy of immature myeloid progenitor cells. Discovering effective treatments for AML through cell differentiation and anti-proliferation remains a significant challenge. Building on previous studies on CDK2 PROTACs with differentiation-inducing properties, this research aims to enhance CDKs degradation through structural optimization to facilitate the differentiation and inhibit the proliferation of AML cells. Compound C3, featuring a 4-methylpiperidine ring linker, effectively degraded CDK2 with a DC50 value of 18.73 ± 10.78 nM, and stimulated 72.77 ± 3.51 % cell differentiation at 6.25 nM in HL-60 cells. Moreover, C3 exhibited potent anti-proliferative activity against various AML cell types. Degradation selectivity analysis indicated that C3 could be endowed with efficient degradation of CDK2/4/6/9 and FLT3, especially FLT3-ITD in MV4-11 cells. These findings propose that C3 combined targeting CDK2/4/6/9 and FLT3 with enhanced differentiation and proliferation inhibition, which holds promise as a potential treatment for AML.

Design, synthesis, and evaluation of VHL-based EZH2 degraders for breast cancer.

EZH2 (enhancer of zeste homolog 2) is one of the most important histone methyltransferases (HMTs), and overexpression of EZH2 can lead to proliferation, migration and angiogenesis of tumor cells. But most of EZH2 inhibitors are only effective against some hematologic malignancies and have poor efficacy against solid tumors. Here, we report the design, synthesis, and evaluation of highly potent proteolysis targeting chimeric (PROTACs) small molecules targeting EZH2. We developed a potent and effective EZH2 degrader P4, which effectively induced EZH2 protein degradation and inhibited breast cancer cell growth. Further studies showed that P4 can significantly decrease the degree of H3K27me3 in MDA-MB-231 cell line, induce apoptosis and G0/G1 phase arrest in Pfeiffer and MDA-MB-231 cell lines. Therefore, P4 is a potential anticancer molecule for breast cancer treatment.

Progress in the controllability technology of PROTAC.

Proteolysis-targeting chimaera (PROTAC) technology functions by directly targeting proteins and catalysing their degradation through an event-driven mode of action, a novel mechanism with significant clinical application prospects for various diseases. Currently, the most advanced PROTAC drug is undergoing phase III clinical trials (NCT05654623). Although PROTACs exhibit significant advantages over traditional small-molecule inhibitors, their catalytic degradation of normal cellular proteins can potentially cause toxic side effects. Therefore, to achieve targeted release of PROTACs and minimize adverse reactions, researchers are actively exploring diverse controllable PROTACs. In this review, we comprehensively summarize the control strategies to provide a theoretical basis for the innovative application of PROTAC technology.