Preclinical evaluation of avutometinib and defactinib in high-grade endometrioid endometrial cancer.

BACKGROUND: High-grade endometrial cancers (EAC) are aggressive tumors with a high risk of progression after treatment. As EAC may harbor mutations in the RAS/MAPK pathways, we evaluated the preclinical in vitro and in vivo efficacy of avutometinib, a RAF/MEK clamp, in combination with the focal adhesion kinase (FAK) inhibitors defactinib or VS-4718, against multiple primary EAC cell lines and xenografts. METHODS: Whole-exome sequencing (WES) was used to evaluate the genetic landscape of five primary EAC cell lines. The in vitro activity of avutometinib and defactinib as single agents and in combination was evaluated using cell viability, cell cycle, and cytotoxicity assays. Mechanistic studies were performed using Western blot assays while in vivo experiments were completed in UTE10 engrafted mice treated with either vehicle, avutometinib, VS-4718, or their combination through oral gavage. RESULTS: WES results demonstrated multiple EAC cell lines to harbor genetic derangements in the RAS/MAPK pathway including KRAS/PTEN/PIK3CA/BRAF/ARID1A, potentially sensitizing to FAK and RAF/MEK inhibition. Five out of five of the EAC cell lines demonstrated in vitro sensitivity to FAK and/or RAF/MEK inhibition. By Western blot assays, exposure of EAC cell lines to defactinib, avutometinib, and their combination demonstrated decreased phosphorylated FAK (p-FAK) as well as decreased p-MEK and p-ERK. In vivo the combination of avutometinib/VS-4718 demonstrated superior tumor growth inhibition compared to single-agent treatment and controls starting at Day 9 (p < 0.02 and p < 0.04) in UTE10 xenografts. CONCLUSIONS: Avutometinib, defactinib, and to a larger extent their combinations, demonstrated promising in vitro and in vivo activity against EAC cell lines and xenografts. These preclinical data support the potential clinical evaluation of this combination in high-grade EAC patients.

Quantitative characterization of the effects of fulvestrant alone or in combination with taselisib (PI3Kinase inhibitor) on longitudinal tumor growth in patients with estrogen receptor-positive, HER2-negative, PIK3CA-mutant, advanced or metastatic breast cancer.

PURPOSE: Among cases of breast cancer, estrogen receptor-positive (ER +), PIK3CA-mutant, HER2- advanced breast cancer stands as a particularly complex clinical indication where approximately 40% of ER + /HER2- breast carcinomas present mutations in the PIK3CA gene. A significant hurdle in treating ER + breast cancer lies in surmounting the challenges of endocrine resistance. In the clinical setting, a multifaceted approach is essential for this indication, one that not only explores the effectiveness of individual treatments but also delves into the potential gains in therapeutic outcome from combination therapies. METHODS: In the current study, longitudinal tumor growth inhibition (TGI) models were developed to characterize tumor response over time in postmenopausal women with ER + /HER2- advanced or metastatic breast cancer undergoing treatment with fulvestrant alone or in combination with the PI3K inhibitor, taselisib. Impact of clinically relevant covariates on TGI metrics was assessed to identify patient subsets most likely to benefit from treatment with fulvestrant monotherapy or combination with taselisib. RESULTS: Tumor growth rate constant (Kg) was found to increase with increasing baseline tumor size and in the absence of baseline endocrine sensitivity. Further, Kg decreased in the absence of baseline liver metastases both in fulvestrant monotherapy and combination therapy with taselisib. Overall, additive/potentially synergistic anti-tumor effects were observed in patients treated with the taselisib-fulvestrant combination. CONCLUSION: These results have important implications for understanding the therapeutic impact of combination treatment approaches and individualized responses to these treatments. Finally, this work, emphasizes the importance of model informed drug development for targeted cancer therapy. CLINICAL TRIAL REGISTRATION: NCT02340221 Registered January 16, 2015, NCT01296555 Registered February 14, 2011.

Phase Ib dose-escalation trial of taselisib (GDC-0032) in combination with HER2-directed therapies in patients with advanced HER2+ breast cancer.

BACKGROUND: In most patients with advanced human epidermal growth factor receptor-2-positive (HER2+) breast cancer, anti-HER2 therapies fail due to the development of acquired resistance, potentially mediated through phosphoinositide-3-kinase (PI3K) signaling. We investigated adding taselisib, an α-selective potent oral inhibitor of PI3K, to different HER2-directed regimens in order to improve disease control. PATIENTS AND METHODS: Patients (n = 68) with advanced HER2+ breast cancer were enrolled to this open-label, dose-escalation phase Ib study. The primary endpoint was defining the maximal tolerated dose (MTD) for the various taselisib-containing combinations. The secondary endpoint was safety. Exploratory endpoints included circulating tumor DNA analysis. The study included four cohorts: (A) taselisib + trastuzumab emtansine (T-DM1), (C) taselisib + trastuzumab and pertuzumab (TP), (D) taselisib + TP + paclitaxel, and (E) taselisib + TP + fulvestrant. RESULTS: Following dose escalation, the taselisib MTD was defined as 4 mg once daily. Treatment was associated with significant toxicities, as 34 out of 68 patients experienced grade ≥3 adverse events (AEs) attributed to taselisib, the most common all-grade AEs being diarrhea, fatigue, and oral mucositis. At a median follow-up of 43.8 months, median progression-free survival (PFS) for the MTD-treated population in cohorts A, C, and E was 6.3 [95% confidence interval (CI) 3.2-not applicable (NA)] months, 1.7 (95% CI 1.4-NA) months, and 10.6 (95% CI 8.3-NA) months, respectively. The median PFS for patients in cohort A with prior T-DM1 use was 10.4 (95% CI 2.7-NA) months. CONCLUSIONS: PIK3CA targeting with taselisib in combination with HER2-targeted therapies was associated with both promising efficacy and substantial toxicities.

Synthesis and molecular docking simulations of novel azepines based on quinazolinone moiety as prospective antimicrobial and antitumor hedgehog signaling inhibitors.

A series of novel azepine derivatives based on quinazolinone moiety was synthesized through the reaction of quinazolinone chalcones (2a-d) either with 2-amino aniline in acidic medium to give diazepines (3a-d) or with 2-aminophenol to offer oxazepine (4a-d). The structure of the synthesized compounds was confirmed via melting points, elemental analyses, and different spectroscopic techniques. Moreover, these newly compounds mode of action was investigated in-silico using molecular docking against the outer membrane protein A (OMPA), exo-1,3-beta-glucanase for their antimicrobial activity, and against Smoothened (SMO), transcription factor glioma-associated homology (SUFU/GLI-1), the main proteins of Hedgehog signaling pathway to inspect their anticancer potential. Our results showed that, diazepine (3a) and oxazepine (4a) offered the highest binding energy against the target OMPA/ exo-1,3-beta-glucanase proteins and exhibited the potent antimicrobial activities against E. coli, P. aeruginosa, S. aureus, B. subtilis, C. Albicans and A. flavus. As well, diazepine (3a) and oxazepine (4a) achieved the best results among the other compounds, in their binding energy against the target SMO, SUFU/GLI-1 proteins. The in-vitro cytotoxic study was done for them on panel of cancer cell lines HCT-116, HepG2, and MCF-7 and normal cell line WI-38. Conclusively, it was revealed that molecular docking in-silico simulations and the in-vitro experiments were agreed. As a result, our findings elucidated that diazepine (3a) and oxazepine (4a), have the potential to be used as antimicrobial agents and as possible cancer treatment medications.

Theoretical insight into the regioselective formation of pyrazolo[1,4]-oxazepine and -oxazines.

AuCl-, AuCl3-, or AuClPEt3-catalyzed formation mechanisms of pyrazolo[1,4]oxazepines and the NaH-promoted mechanism of pyrazolo[1,4]oxazines were investigated computationally. The structural properties of the reactants were studied in various solvents and with different functionals. The hybrid functionals B3LYP, M06, M06-2X, PBEPBE, and wB97X-D in density functional theory were used to determine and discuss the energetics of the compounds. The electronic properties of groups (R = H or R ≠ H) attached to the alkyne moiety played an essential role in the corresponding 7-endo-dig cyclization or 6-exo-dig cyclization in the presence of a gold catalyst. The regioselectivities of the products were investigated, and the natural bond orbitals of the reactants were determined. Furthermore, a gold-catalyzed alternative mechanism is suggested for synthesizing pyrazolo[1,4]oxazines using a terminal alkyne (R = H) moiety as substrate.

Diversity-Oriented Synthesis of Benzo[f][1,4]oxazepine-, 2H-Chromene-, and 1,2-Dihydroquinoline-Fused Polycyclic Nitrogen Heterocycles under Microwave-Assisted Conditions.

An efficient, diversity-oriented synthesis of oxazepino[5,4-b]quinazolin-9-ones, 6H-chromeno[4,3-b]quinolines, and dibenzo[b,h][1,6]naphthyridines was established involving a substrate-based approach under microwave-assisted and conventional heating conditions in high yields (up to 88%). The CuBr2-catalyzed, chemoselective cascade annulation of O-propargylated 2-hydroxybenzaldehydes and 2-aminobenzamides delivered oxazepino[5,4-b]quinazolin-9-ones involving a 6-exo-trig cyclization-air oxidation-1,3-proton shift-7-exo-dig cyclization sequence. This one-pot process showed excellent atom economy (-H2O) and constructed two new heterocyclic rings (six- and seven-membered) and three new C-N bonds in a single synthetic operation. On the other side of diversification, the reaction between O/N-propargylated 2-hydroxy/aminobenzaldehydes and 2-aminobenzyl alcohols delivered 6H-chromeno[4,3-b]quinolines and dibenzo[b,h][1,6]naphthyridines involving sequential imine formation-[4 + 2] hetero-Diels-Alder reaction-aromatization steps. The influence of microwave assistance was superior to conventional heating, where the reactions were clean, rapid, and completed in 15 min, and the conventional heating required a longer reaction time at a relatively elevated temperature.

Atroposelective Access to 1,3-Oxazepine-Containing Bridged Biaryls via Carbene-Catalyzed Desymmetrization of Imines.

We disclose herein an atroposelective synthesis of novel bridged biaryls containing medium-sized rings via N-heterocyclic carbene organocatalysis. The reaction starts with addition of the carbene catalyst to the aminophenol-derived aldimine substrate. Subsequent oxidation and intramolecular desymmetrization lead to the formation of 1,3-oxazepine-containing bridged biaryls in good yields and excellent enantioselectivities. These novel bridged biaryl products can be readily transformed into chiral phosphite ligands. Preliminary density function theory calculations suggest that the origin of enantioselectivity arises from the more favorable frontier molecular orbital interactions in the transition state leading to the major product.

Pharmacokinetic/Pharmacodynamic Evaluation of the Dipeptidyl Peptidase 1 Inhibitor Brensocatib for Non-cystic Fibrosis Bronchiectasis.

BACKGROUND AND OBJECTIVE: Brensocatib is an investigational, first-in-class, selective, and reversible dipeptidyl peptidase 1 inhibitor that blocks activation of neutrophil serine proteases (NSPs). The NSPs neutrophil elastase, cathepsin G, and proteinase 3 are believed to be central to the pathogenesis of several chronic inflammatory diseases, including bronchiectasis. In a phase II study, oral brensocatib 10 mg and 25 mg reduced sputum neutrophil elastase activity and prolonged the time to pulmonary exacerbation in patients with non-cystic fibrosis bronchiectasis (NCFBE). A population pharmacokinetic (PPK) model was developed to characterize brensocatib exposure, determine potential relationships between brensocatib exposure and efficacy and safety measures, and inform dose selection in clinical studies. METHODS: Pharmacokinetic (PK) data pooled from a phase I study of once-daily brensocatib (10, 25, and 40 mg) in healthy adults and a phase II study of once-daily brensocatib (10 mg and 25 mg) in adults with NCFBE were used to develop a PPK model and to evaluate potential covariate effects on brensocatib pharmacokinetics. PK-efficacy relationships for sputum neutrophil elastase below the level of quantification (BLQ) and reduction in pulmonary exacerbation and PK-safety relationships for adverse events of special interest (AESIs; periodontal disease, hyperkeratosis, and infections other than pulmonary infections) were evaluated based on model-predicted brensocatib exposure. A total of 1284 steady-state brensocatib concentrations from 225 individuals were included in the PPK data set; 241 patients with NCFBE from the phase II study were included in the pharmacodynamic (PD) population for the PK/PD analyses. RESULTS: The PPK model that best described the observed data consisted of two distributional compartments and linear clearance. Two significant covariates were found: age on volume of distribution and renal function on apparent oral clearance. PK-efficacy analysis revealed a threshold brensocatib exposure (area under the concentration-time curve) effect for attaining sputum neutrophil elastase BLQ and a strong relationship between sputum neutrophil elastase BLQ and reduction in pulmonary exacerbations. A PK-safety evaluation showed no noticeable trends between brensocatib exposure and the incidence of AESIs. Based on the predicted likelihood of clinical outcomes for sputum neutrophil elastase BLQ and pulmonary exacerbations, brensocatib doses of 10 mg and 25 mg once daily were selected for a phase III clinical trial in patients with NCFBE (ClinicalTrials.gov identifier: NCT04594369). CONCLUSIONS: PPK results revealed that age and renal function have a moderate effect on brensocatib exposure. However, this finding does not warrant dose adjustments based on age or in those with mild or moderate renal impairment. The PK/PD evaluation demonstrated the clinically meaningful relationship between suppression of neutrophil elastase activity and reduction in exacerbations in brensocatib-treated patients with NCFBE, supporting further development of brensocatib for bronchiectasis.

Microwave-Assisted Copper(II)-Catalyzed Cascade Cyclization of 2-Propargylamino/Oxy-Arylaldehydes and O-Phenylenediamines: Access to Densely Functionalized Benzo[f]Imidazo[1,2-d][1,4]Oxazepines and Benzo[f]Imidazo[1,2-d][1,4]Diazepines.

A highly efficient microwave-assisted copper(II)-catalyzed cyclization cascade was established starting from readily accessible O/N-propargylated 2-hydroxy or 2-aminobenzaldehydes and o-phenylenediamines to synthesize densely functionalized imidazo[1,2-d][1,4]oxazepines and imidazo[1,2-d][1,4]diazepines in high yields (up to 93%). This one-pot two-step process was found to be highly atom economical (-H2O, -H2) and operationally simple and enabled the generation of two new heterocycle rings (seven- and five-membered) and three new C-N bonds in a single synthetic operation. These reactions well tolerated a variety of substituents including electron-donating and electron-withdrawing groups and furnished the desired fused heterocycles in high yields under microwave irradiation in a very short reaction time. The mechanism of the established protocol involves sequential imine formation-intramolecular cyclization-air oxidation followed by 7-exo-dig cyclization steps. A comparative study between the microwave-assisted approach and conventional heating was also performed to demonstrate the advantages of the microwave-assisted protocol in terms of high yield and shorter reaction time.

Safety, Tolerability, and Pharmacokinetic Evaluation of Single and Multiple Doses of the Dipeptidyl Peptidase 1 Inhibitor Brensocatib in Healthy Japanese and White Adults.

Brensocatib, an investigational first-in-class, small-molecule, orally bioavailable, selective, and reversible dipeptidyl peptidase 1 inhibitor that blocks activation of neutrophil serine proteases, is currently under clinical development for the treatment of bronchiectasis and other chronic inflammatory diseases. In a 2-part phase 1 study, the safety, tolerability, and pharmacokinetics of brensocatib were evaluated in healthy Japanese and White adults. In part A, participants received single and multiple once-daily doses of brensocatib (10, 25, or 40 mg) or placebo after an overnight fast. In part B, participants received a single oral dose of brensocatib 40 mg on days 1 and 8, with or without food in a crossover fashion. Following a single dose and at steady state, brensocatib exposure was dose dependent, with low to moderate interindividual variability; systemic exposure between Japanese and White participants was similar. Elimination half-life of brensocatib ranged from 22 to 28 hours, resulting in ≈2-fold accumulation in maximum plasma concentration and area under the plasma concentration-time curve at steady state. In both ethnic groups, the presence of food slightly delayed brensocatib absorption with time to maximum plasma concentration increased by 0.7 to 1.7 hours, but it had no significant effect on brensocatib exposure (maximum plasma concentration and area under the plasma concentration-time curve). Brensocatib was well tolerated in Japanese and White participants. The most frequently reported treatment-emergent adverse events were headache and skin exfoliation. No clinically significant vital signs, laboratory abnormalities, or evidence of renal toxicity were observed. The results from this study demonstrate that brensocatib can be administered with or without food and that dose adjustment is unnecessary for Japanese patients when receiving brensocatib treatment.

Stereoselective Oxidative Mannich Reaction of Ketones with Dihydrodibenzo-Oxazepines via a Merger of Photoredox-/Electro-Catalysis with Organocatalysis.

An enantio- and diastereoselective sp3 -sp3 coupling of acyclic/cyclic ketones with dihydrodibenzo-oxazepines has been developed by merging visible light photo-redox- or electro-catalysis with organocatalysis. This approach parallelly utilizes Eosin Y or graphite electrodes for the co-catalyst-free oxidative conversion of dihydrodibenzo-oxazepines to oxazepines, followed by L-Proline catalyzed direct Mannich-type reaction with ketones. A series of enantioenriched dihydrodibenzo-oxazepines have been prepared in high yields and enantioselectivity. This method shows substantial advantages over the existing protocols by using potentially safer starting materials and cheap commercially available catalysts.

Phase II Study of Taselisib in PIK3CA-Mutated Solid Tumors Other Than Breast and Squamous Lung Cancer: Results From the NCI-MATCH ECOG-ACRIN Trial (EAY131) Subprotocol I.

PURPOSE: PIK3CA mutations frequently contribute to oncogenesis in solid tumors. Taselisib, a potent and selective inhibitor of phosphoinositide 3-kinase, has demonstrated clinical activity in PIK3CA-mutant breast cancer. Whether PIK3CA mutations predict sensitivity to taselisib in other cancer types is unknown. National Cancer Institute-Molecular Analysis for Therapy Choice Arm EAY131-I is a single-arm, phase II study of the safety and efficacy of taselisib in patients with advanced cancers. METHODS: Eligible patients had tumors with an activating PIK3CA mutation. Patients with breast or squamous cell lung carcinoma, or whose cancer had KRAS or PTEN mutations, were excluded. Patients received taselisib 4 mg, orally once daily continuously, until disease progression or unacceptable toxicity. The primary end point was objective response rate. Secondary end points included progression-free survival (PFS), 6-month PFS, overall survival (OS), and identification of predictive biomarkers. RESULTS: Seventy patients were enrolled, and 61 were eligible and initiated protocol therapy. Types of PIK3CA mutations included helical 41 of 61 (67%), kinase 11 of 61 (18%), and other 9 of 61 (15%). With a median follow-up of 35.7 months, there were no complete or partial responses. Six-month PFS was 19.9% (90% CI, 12.0 to 29.3) and median PFS was 3.1 months (90% CI, 1.8 to 3.7). Six-month OS was 60.7% (90% CI, 49.6 to 70.0) and median OS was 7.2 months (90% CI, 5.9 to 10.0). Individual comutations were too heterogeneous to correlate with clinical outcome. Fatigue, diarrhea, nausea, and hyperglycemia were the most common toxicities, and most were grade 1 and 2. CONCLUSION: In this study, taselisib monotherapy had very limited activity in a heterogeneous cohort of heavily pretreated cancer patients with PIK3CA-mutated tumors; the presence of a PIK3CA mutation alone does not appear to be a sufficient predictor of taselisib activity.

[Updates in hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer in 2021]. / Actualités 2021 sur le cancer du sein localement avancé ou métastatique RH+/HER2−.

Overall, 2021 was marked by the confirmation of the major interest of cell cycle inhibitors for hormone receptor (HR) positive/human epidermal growth factor receptor 2 (HER2) negative advanced breast cancers with very high overall survival data exceeding five years for hormone-sensitive disease. Studies have also confirmed the efficacy and safety of this therapeutic class in the elderly population. New cell cycle inhibitors are under development (SHR6390). New combinations are also being evaluated, notably palbociclib with SAR439859 (a new selective estrogen receptor degrader: SERD). Targeting of the Phosphoinositide 3-kinases (PI3K) pathway by taselisib, in hormone-resistant disease with a Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Alpha (PIK3CA) mutation, modestly improves progression-free survival but with a non-negligible toxicity of the treatment.

Development of a Once-Daily Modified-Release Formulation for the Short Half-Life RIPK1 Inhibitor GSK2982772 using DiffCORE Technology.

PURPOSE: GSK2982772 is a selective inhibitor of receptor-interacting protein kinase-1 (RIPK1) with a short 2- to 3-h half-life. In a previous modified-release (MR) study, a matrix monolithic formulation (80% GSK2982772 released over 12 h) provided a once-daily (QD) pharmacokinetic (PK) profile in the fasted state; however, it was susceptible to food effects. The current study evaluated the safety and PK of MR formulations using GSK proprietary DiffCORE™ technology. METHODS: Part A evaluated PK following single-dose (240 mg) fasted and fed (high-fat meal) administration of three DiffCORE MR formulations within pre-defined in vitro extremes of 80% GSK2982772 released over 12 h (MR-12 h) to 80% GSK2982772 released over 18 h (MR-18 h) versus an immediate-release formulation. Part B evaluated MR-16 h (120-960 mg) in different prandial states. RESULTS: Pharmacokinetic profiles for all MR formulations and doses tested in the fasted and fed states were consistent with QD dosing. CONCLUSIONS: The DiffCORE technology overcame the food effect vulnerability observed with the matrix monolithic formulation. The MR-16 h formulation was selected for further clinical development as a QD dosing regimen (NCT03649412 September 26, 2018).

Discovery of 3,4-Dihydrobenzo[f][1,4]oxazepin-5(2H)-one Derivatives as a New Class of Selective TNIK Inhibitors and Evaluation of Their Anti-Colorectal Cancer Effects.

The Traf2- and Nck-interacting protein kinase (TNIK) is a downstream signal protein of the Wnt/ß-catenin pathway and has been thought of as a potential target for the treatment of colorectal cancer (CRC) that is often associated with dysregulation of Wnt/ß-catenin signaling pathway. Herein, we report the discovery of a series of 3,4-dihydrobenzo[f][1,4]oxazepin-5(2H)-one derivatives as a new class of TNIK inhibitors. Structure-activity relationship (SAR) analyses led to the identification of a number of potent TNIK inhibitors with compound 21k being the most active one (IC50: 0.026 ± 0.008 µM). This compound also displayed excellent selectivity for TNIK against 406 other kinases. Compound 21k could efficiently suppress CRC cell proliferation and migration in in vitro assays and exhibited considerable antitumor activity in the HCT116 xenograft mouse model. It also showed favorable pharmacokinetic properties. Overall, 21k could be a promising lead compound for drug discovery targeting TNIK and deserves further studies.

RTK-Dependent Inducible Degradation of Mutant PI3Kα Drives GDC-0077 (Inavolisib) Efficacy.

PIK3CA is one of the most frequently mutated oncogenes; the p110a protein it encodes plays a central role in tumor cell proliferation. Small-molecule inhibitors targeting the PI3K p110a catalytic subunit have entered clinical trials, with early-phase GDC-0077 studies showing antitumor activity and a manageable safety profile in patients with PIK3CA-mutant breast cancer. However, preclinical studies have shown that PI3K pathway inhibition releases negative feedback and activates receptor tyrosine kinase signaling, reengaging the pathway and attenuating drug activity. Here we discover that GDC-0077 and taselisib more potently inhibit mutant PI3K pathway signaling and cell viability through unique HER2-dependent mutant p110a degradation. Both are more effective than other PI3K inhibitors at maintaining prolonged pathway suppression. This study establishes a new strategy for identifying inhibitors that specifically target mutant tumors by selective degradation of the mutant oncoprotein and provide a strong rationale for pursuing PI3Kα degraders in patients with HER2-positive breast cancer. SIGNIFICANCE: The PI3K inhibitors GDC-0077 and taselisib have a unique mechanism of action; both inhibitors lead to degradation of mutant p110a protein. The inhibitors that have the ability to trigger specific degradation of mutant p110a without significant change in wild-type p110a protein may result in improved therapeutic index in PIK3CA-mutant tumors.See related commentary by Vanhaesebroeck et al., p. 20.This article is highlighted in the In This Issue feature, p. 1.

A novel class of oxazepine-based anti-cancer agents induces cell death in primary human CLL cells and efficiently reduces tumor growth in Eµ-TCL1 mice through the JNK/STAT4/p66Shc axis.

Survival and expansion of malignant B cells in chronic lymphocytic leukemia (CLL) are highly dependent both on intrinsic defects in the apoptotic machinery and on the interactions with cells and soluble factors in the lymphoid microenvironment. The adaptor protein p66Shc is a negative regulator of antigen receptor signaling, chemotaxis and apoptosis whose loss in CLL B cells contributes to their extended survival and poor prognosis. Hence, the identification of compounds that restore p66Shc expression and function in malignant B cells may pave the way to a new therapeutic approach for CLL. Here we show that a novel oxazepine-based compound (OBC-1) restores p66Shc expression in primary human CLL cells by promoting JNK-dependent STAT4 activation without affecting normal B cells. Moreover, we demonstrate that the potent pro-apoptotic activity of OBC-1 in human leukemic cells directly correlates with p66Shc expression levels and is abrogated when p66Shc is genetically deleted. Preclinical testing of OBC-1 and the novel analogue OBC-2 in Eµ-TCL1 tumor-bearing mice resulted in a significantly longer overall survival and a reduction of the tumor burden in the spleen and peritoneum. Interestingly, OBCs promote leukemic cell mobilization from the spleen to the blood, which correlates with upregulation of sphingosine-1-phosphate receptor expression. In summary, our work identifies OBCs as a promising class of compounds that, by boosting p66Shc expression through the activation of the JNK/STAT4 pathway, display dual therapeutic effects for CLL intervention, namely the ability to mobilize cells from secondary lymphoid organs and a potent pro-apoptotic activity against circulating leukemic cells.

Mevalonate Kinase Deficiency and Squalene Synthase Inhibitor (TAK-475): The Balance to Extinguish the Inflammation.

Mevalonate Kinase Deficiency (MKD) is a rare inborn disease belonging to the family of periodic fever syndromes. The MKD phenotype is characterized by systemic inflammation involving multiple organs, including the nervous system. Current anti-inflammatory approaches to MKD are only partially effective and do not act specifically on neural inflammation. According to the new emerging pharmacology trends, the repositioning of drugs from the indication for which they were originally intended to another one can make mechanistic-based medications easily available to treat rare diseases. According to this perspective, the squalene synthase inhibitor Lapaquistat (TAK-475), originally developed as a cholesterol-lowering drug, might find a new indication in MKD, by modulating the mevalonate cholesterol pathway, increasing the availability of anti-inflammatory isoprenoid intermediates. Using an in vitro model for MKD, we mimicked the blockade of the cholesterol pathway and evaluated the potential anti-inflammatory effect of Lapaquistat. The results obtained showed anti-inflammatory effects of Lapaquistat in association with a low blockade of the metabolic pathway, while this effect did not remain with a tighter blockade. On these bases, Lapaquistat could be configured as an effective treatment for MKD's mild forms, in which the residual enzymatic activity is only reduced and not almost completely absent as in the severe forms.

Computer-Aided Design and Synthesis of a New Class of PEX14 Inhibitors: Substituted 2,3,4,5-Tetrahydrobenzo[F][1,4]oxazepines as Potential New Trypanocidal Agents.

African and American trypanosomiases are estimated to affect several million people across the world, with effective treatments distinctly lacking. New, ideally oral, treatments with higher efficacy against these diseases are desperately needed. Peroxisomal import matrix (PEX) proteins represent a very interesting target for structure- and ligand-based drug design. The PEX5-PEX14 protein-protein interface in particular has been highlighted as a target, with inhibitors shown to disrupt essential cell processes in trypanosomes, leading to cell death. In this work, we present a drug development campaign that utilizes the synergy between structural biology, computer-aided drug design, and medicinal chemistry in the quest to discover and develop new potential compounds to treat trypanosomiasis by targeting the PEX14-PEX5 interaction. Using the structure of the known lead compounds discovered by Dawidowski et al. as the template for a chemically advanced template search (CATS) algorithm, we performed scaffold-hopping to obtain a new class of compounds with trypanocidal activity, based on 2,3,4,5-tetrahydrobenzo[f][1,4]oxazepines chemistry. The initial compounds obtained were taken forward to a first round of hit-to-lead optimization by synthesis of derivatives, which show activities in the range of low- to high-digit micromolar IC50 in the in vitro tests. The NMR measurements confirm binding to PEX14 in solution, while immunofluorescent microscopy indicates disruption of protein import into the glycosomes, indicating that the PEX14-PEX5 protein-protein interface was successfully disrupted. These studies result in development of a novel scaffold for future lead optimization, while ADME testing gives an indication of further areas of improvement in the path from lead molecules toward a new drug active against trypanosomes.

Development of bozepinib-loaded nanocapsules for nose-to-brain delivery: preclinical evaluation in glioblastoma.

Aim: To develop and characterize bozepinib-loaded lipid-core nanocapsules (BZP-LNC+) as a potential treatment for glioblastoma (GBM). Methods: Characterization of nanocapsules was performed by diameter, polydispersity index, Zeta potential, pH and encapsulation efficiency. GBM cell viability, cell cycle and Annexin/PI were evaluated after BZP-LNC+ treatment. Synergism between BZP-LNC+ and temozolomide (TMZ) was performed by CompuSyn software and confirmed in vitro and in vivo. Results: BZP-LNC+ showed adequate particle sizes, positive Zeta potential, narrow size distribution and high encapsulation efficiency. BZP-LNC+ reduces GBM growth by inducing apoptosis. BZP-LNC+ and TMZ showed synergistic effect in vitro and reduced the in vivo glioma growth by approximately 81%. Conclusion: The present study provides proof-of-principle insights for the combination of these drugs for GBM treatment.