The impact of COVID-19 on the cancer care of adolescents and young adults and their well-being: Results from an online survey conducted in the early stages of the pandemic.

BACKGROUND: Because of the global spread of coronavirus disease 2019 (COVID-19), oncology departments across the world have rapidly adapted their cancer care protocols to balance the risk of delaying cancer treatments and the risk of COVID-19 exposure. COVID-19 and associated changes may have an impact on the psychosocial functioning of patients with cancer and survivors. This study was designed to determine the impact of the COVID-19 pandemic on young people living with and beyond cancer. METHODS: In this cross-sectional study, 177 individuals, aged 18 to 39 years, were surveyed about the impact of COVID-19 on their cancer care and psychological well-being. Participants also reported their information needs with respect to COVID-19. Responses were summarized with a content analysis approach. RESULTS: This was the first study to examine the psychological functioning of young patients and survivors during the first weeks of the COVID-19 pandemic. A third of the respondents reported increased levels of psychological distress, and as many as 60% reported feeling more anxious than they did before COVID-19. More than half also wanted more information tailored to them as young patients with cancer. CONCLUSIONS: The COVID-19 pandemic is rapidly evolving and changing the landscape of cancer care. Young people living with cancer are a unique population and might be more vulnerable during this time in comparison with their healthy peers. There is a need to screen for psychological distress and attend to young people whose cancer care has been delayed. As the lockdown begins to ease, the guidelines about cancer care should be updated according to this population's needs.

Synthesis and biochemical evaluation of new 3-amido-4-substituted monocyclic ß-lactams as inhibitors of penicillin-binding protein(s).

In the final phases of bacterial cell wall synthesis, penicillin-binding proteins (PBPs) catalyze the cross-linking of peptidoglycan. For many decades, effective and non-toxic ß-lactam antibiotics have been successfully used as mimetics of the d-Ala-d-Ala moiety of the natural substrate and employed as irreversible inhibitors of PBPs. In the years following their discovery, the emergence of resistant bacteria led to a decline in their clinical efficacy. Using Staudinger cycloaddition, we synthesized a focused library of novel monocyclic ß-lactams in which different substituents were introduced at the C4 position of the ß-lactam ring, at the C3 amino position, and at the N1 lactam nitrogen. In biochemical assays, the compounds were evaluated for their inhibitory effect on the model enzyme PBP1b from Streptococcus pneumoniae. Upon investigation of the antibacterial activity of the newly prepared compounds against ESKAPE pathogens, some compounds showed moderate inhibition. We also examined their reactivity and selectivity in a biochemical assay with other enzymes that have a catalytic serine in the active site, such as human cholinesterases, where they also showed no inhibitory activity, highlighting their specificity for bacterial targets. These compounds form the basis for further work on new monocyclic ß-lactams with improved antibacterial activity.

Conjugates of monocyclic ß-lactams and siderophore mimetics: a patent evaluation (WO2023023393).

INTRODUCTION: ß-Lactams, which include monobactams, remain the most important class of antibiotics worldwide. Aztreonam, the only monobactam in clinical use, has remarkable activity against many Gram-negative bacteria, but limited activity against some of the most problematic multidrug-resistant (MDR) pathogens, such as MDR Pseudomonas aeruginosa and Acinetobacter baumannii co-expressing extended-spectrum- and metallo-ß-lactamases, which can inactivate aztreonam by hydrolysis. AREAS COVERED: Structurally novel siderophore-conjugated aztreonam derivatives with improved antibacterial properties against several high-priority pathogens are claimed. This invention reports that sidechain extension of aztreonam is tolerated; the coupling of its aminothiazoloxime carboxylic acid part with a siderophore mimetic significantly improved the antibacterial activity against several problematic strains, including MDR A. baumannii isolates with carbapenemase/cephalosporinase activity. EXPERT OPINION: Finding new strategies to tackle bacterial resistance to ß-lactam antibiotics is critical. Considering that ß lactams are validated and safe drugs, this research may stimulate the field to develop new ideas in the arena of antimicrobial drug discovery, particularly with respect to siderophore mimetics.

Structural Basis of Prolyl Hydroxylase Domain Inhibition by Molidustat.

Human prolyl-hydroxylases (PHDs) are hypoxia-sensing 2-oxoglutarate (2OG) oxygenases, catalysis by which suppresses the transcription of hypoxia-inducible factor target genes. PHD inhibition enables the treatment of anaemia/ischaemia-related disease. The PHD inhibitor Molidustat is approved for the treatment of renal anaemia; it differs from other approved/late-stage PHD inhibitors in lacking a glycinamide side chain. The first reported crystal structures of Molidustat and IOX4 (a brain-penetrating derivative) complexed with PHD2 reveal how their contiguous triazole, pyrazolone and pyrimidine/pyridine rings bind at the active site. The inhibitors bind to the active-site metal in a bidentate manner through their pyrazolone and pyrimidine nitrogens, with the triazole π-π-stacking with Tyr303 in the 2OG binding pocket. Comparison of the new structures with other PHD inhibitor complexes reveals differences in the conformations of Tyr303, Tyr310, and a mobile loop linking ß2-ß3, which are involved in dynamic substrate binding/product release.

High-Throughput Crystallography Reveals Boron-Containing Inhibitors of a Penicillin-Binding Protein with Di- and Tricovalent Binding Modes.

The effectiveness of ß-lactam antibiotics is increasingly compromised by ß-lactamases. Boron-containing inhibitors are potent serine-ß-lactamase inhibitors, but the interactions of boron-based compounds with the penicillin-binding protein (PBP) ß-lactam targets have not been extensively studied. We used high-throughput X-ray crystallography to explore reactions of a boron-containing fragment set with the Pseudomonas aeruginosa PBP3 (PaPBP3). Multiple crystal structures reveal that boronic acids react with PBPs to give tricovalently linked complexes bonded to Ser294, Ser349, and Lys484 of PaPBP3; benzoxaboroles react with PaPBP3 via reaction with two nucleophilic serines (Ser294 and Ser349) to give dicovalently linked complexes; and vaborbactam reacts to give a monocovalently linked complex. Modifications of the benzoxaborole scaffold resulted in a moderately potent inhibition of PaPBP3, though no antibacterial activity was observed. Overall, the results further evidence the potential for the development of new classes of boron-based antibiotics, which are not compromised by ß-lactamase-driven resistance.

Broad Spectrum ß-Lactamase Inhibition by a Thioether Substituted Bicyclic Boronate.

ß-Lactamases comprise the most widely used mode of resistance to ß-lactam antibiotics. Cyclic boronates have shown promise as a new class of ß-lactamase inhibitor, with pioneering potential to potently inhibit both metallo- and serine-ß-lactamases. We report studies concerning a bicyclic boronate ester with a thioether rather than the more typical ß-lactam antibiotic "C-6/C-7" acylamino type side chain, which is present in the penicillin/cephalosporin antibiotics. The thioether bicyclic boronate ester was tested for activity against representative serine- and metallo-ß-lactamases. The results support the broad inhibition potential of bicyclic boronate based inhibitors with different side chains, including against metallo-ß-lactamases from B1, B2, and B3 subclasses. Combined with previous crystallographic studies, analysis of a crystal structure of the thioether inhibitor with the clinically relevant VIM-2 metallo-ß-lactamase implies that further SAR work will expand the already broad scope of ß-lactamase inhibition by bicyclic boronates.

Cyclic boronates as versatile scaffolds for KPC-2 ß-lactamase inhibition.

Klebsiella pneumoniae carbapenemase-2 (KPC-2) is a serine-ß-lactamase (SBL) capable of hydrolysing almost all ß-lactam antibiotics. We compare KPC-2 inhibition by vaborbactam, a clinically-approved monocyclic boronate, and VNRX-5133 (taniborbactam), a bicyclic boronate in late-stage clinical development. Vaborbactam inhibition is slowly reversible, whereas taniborbactam has an off-rate indicating essentially irreversible complex formation and a 15-fold higher on-rate, although both potentiate ß-lactam activity against KPC-2-expressing K. pneumoniae. High resolution X-ray crystal structures reveal closely related binding modes for both inhibitors to KPC-2, with differences apparent only in positioning of the endocyclic boronate ester oxygen. The results indicate the bicyclic boronate scaffold as both an efficient, long-lasting, KPC-2 inhibitor and capable of supporting further iterations that may improve potency against specific enzyme targets and pre-empt the emergence of inhibitor resistant KPC-2 variants.

Bicyclic Boronates as Potent Inhibitors of AmpC, the Class C ß-Lactamase from Escherichia coli.

Resistance to ß-lactam antibacterials, importantly via production of ß-lactamases, threatens their widespread use. Bicyclic boronates show promise as clinically useful, dual-action inhibitors of both serine- (SBL) and metallo- (MBL) ß-lactamases. In combination with cefepime, the bicyclic boronate taniborbactam is in phase 3 clinical trials for treatment of complicated urinary tract infections. We report kinetic and crystallographic studies on the inhibition of AmpC, the class C ß­lactamase from Escherichia coli, by bicyclic boronates, including taniborbactam, with different C-3 side chains. The combined studies reveal that an acylamino side chain is not essential for potent AmpC inhibition by active site binding bicyclic boronates. The tricyclic form of taniborbactam was observed bound to the surface of crystalline AmpC, but not at the active site, where the bicyclic form was observed. Structural comparisons reveal insights into why active site binding of a tricyclic form has been observed with the NDM-1 MBL, but not with other studied ß-lactamases. Together with reported studies on the structural basis of inhibition of class A, B and D ß­lactamases, our data support the proposal that bicyclic boronates are broad-spectrum ß­lactamase inhibitors that work by mimicking a high energy 'tetrahedral' intermediate. These results suggest further SAR guided development could improve the breadth of clinically useful ß-lactamase inhibition.

Will morphing boron-based inhibitors beat the ß-lactamases?

The ß-lactams remain the most important antibacterials, but their use is increasingly compromised by resistance, importantly by ß-lactamases. Although ß-lactam and non-ß-lactam inhibitors forming stable acyl-enzyme complexes with nucleophilic serine ß-lactamases (SBLs) are widely used, these are increasingly susceptible to evolved SBLs and do not inhibit metallo-ß-lactamases (MBLs). Boronic acids and boronate esters, especially cyclic ones, can potently inhibit both SBLs and MBLs. Vaborbactam, a monocyclic boronate, is approved for clinical use, but its ß-lactamase coverage is limited. Bicyclic boronates rapidly react with SBLs and MBLs forming stable enzyme-inhibitor complexes that mimic the common anionic high-energy tetrahedral intermediates in SBL/MBL catalysis, as revealed by crystallography. The ability of boronic acids to 'morph' between sp2 and sp3 hybridisation states may help enable potent inhibition. There is limited structure-activity relationship information on the (bi)cyclic boronate inhibitors compared to ß-lactams, hence scope for creativity towards new boron-based ß-lactamase inhibitors/antibacterials.

Bicyclic Boronate VNRX-5133 Inhibits Metallo- and Serine-ß-Lactamases.

The bicyclic boronate VNRX-5133 (taniborbactam) is a new type of ß-lactamase inhibitor in clinical development. We report that VNRX-5133 inhibits serine-ß-lactamases (SBLs) and some clinically important metallo-ß-lactamases (MBLs), including NDM-1 and VIM-1/2. VNRX-5133 activity against IMP-1 and tested B2/B3 MBLs was lower/not observed. Crystallography reveals how VNRX-5133 binds to the class D SBL OXA-10 and MBL NDM-1. The crystallographic results highlight the ability of bicyclic boronates to inhibit SBLs and MBLs via binding of a tetrahedral (sp3) boron species. The structures imply conserved binding of the bicyclic core with SBLs/MBLs. With NDM-1, by crystallography, we observed an unanticipated VNRX-5133 binding mode involving cyclization of its acylamino oxygen onto the boron of the bicyclic core. Different side-chain binding modes for bicyclic boronates for SBLs and MBLs imply scope for side-chain optimization. The results further support the "high-energy-intermediate" analogue approach for broad-spectrum ß-lactamase inhibitor development and highlight the ability of boron inhibitors to interchange between different hybridization states/binding modes.