High INR on warfarin

The bottom line Clarify the warfarin dose that the patient is taking, and check for co-existing problems (such as liver disease or cancer), dietary changes, and intake of alcohol and other drugs that may increase risk of bleeding or affect international normalised ratio control. Urgently refer all patients with suspected intracranial or gastrointestinal bleeding to secondary care

The RAG Model: a new paradigm for genetic risk stratification in multiple myeloma

Molecular studies have shown that multiple myeloma is a highly genetically heterogonous disease which may manifest itself as any number of diverse subtypes each with variable clinicopathological features and outcomes. Given this genetic heterogeneity, a universal approach to treatment of myeloma is unlikely to be successful for all patients and instead we should strive for the goal of personalised therapy using rationally informed targeted strategies. Current DNA sequencing technologies allow for whole genome and exome analysis of patient myeloma samples that yield vast amounts of genetic data and provide a mutational overview of the disease. However, the clinical utility of this information currently lags far behind the sequencing technology which is increasingly being incorporated into clinical practice. This paper attempts to address this shortcoming by proposing a novel genetically based “traffic-light” risk stratification system for myeloma, termed the RAG (Red, Amber, Green) model, which represents a simplified concept of how complex genetic data may be compressed into an aggregate risk score. The model aims to incorporate all known clinically important trisomies, translocations, and mutations in myeloma and utilise these to produce a score between 1.0 and 3.0 that can be incorporated into diagnostic, prognostic, and treatment algorithms for the patient

Chloroquine and COVID-19 – a potential game changer?

The novel coronavirus SARS-CoV-2, causing the disease COVID-19, first emerged in Wuhan, China in December 2019 and has now spread to 203 countries or territories, infected over 2 million people and caused over 133,000 deaths. There is an urgent need for specific treatments. One potential treatment is chloroquine and its derivatives, including hydroxychloroquine, which have both antiviral and anti-inflammatory effects. These compounds are effective against SARS-CoV-2 in vitro, but in vivo data are lacking. Although some encouraging outcomes have been reported, and these results have been received enthusiastically, we recommend careful and critical evaluation of current evidence only when all methods and data are available for peer review. Chloroquine is safe and cheap. However, further evidence from coordinated multicentre trials is required before it can be confidently said whether it is effective against the current pandemic

The Renin-Angiotensin system – a therapeutic target in COVID-19?

COVID-19, caused by infection with SARS-CoV-2, is a disease characterised by cough, fever and fatigue, which progresses to life-threatening lung injury in approximately 5% of patients. The SARS-CoV-2 virus enters the cell via ACE2. ACE2 is a component of the renin–angiotensin system (RAS) which has an important counterregulatory effect on the classical ACE-dependent pathway. Several antihypertensives increase ACE2 expression or activity, leading to concern that this may facilitate SARS-CoV-2 entry and worsen COVID-19 disease. However, ACE2 is protective against lung injury while ANG II (which is catabolised by ACE2) is associated with lung injury both in mice and humans. We propose that medications which inhibit the RAS ACE-dependent pathway may be beneficial in treating COVID-19 and should be explored in animal models and clinical trials. Here we give an overview of the RAS pathway with respect to COVID-19 and argue that strategies which manipulate this pathway might reduce the destructive lung manifestations of COVID-19 and improve patient outcomes

Dissecting the role of the CXCL12/CXCR4 axis in acute myeloid leukaemia

Acute myeloid leukaemia (AML) is the most common adult acute leukaemia with the lowest survival rate. It is characterised by a build‐up of immature myeloid cells anchored in the protective niche of the bone marrow (BM) microenvironment. The CXCL12/CXCR4 axis is central to the pathogenesis of AML as it has fundamental control over AML cell adhesion into the protective BM niche, adaptation to the hypoxic environment, cellular migration and survival. High levels of CXCR4 expression are associated with poor relapse‐free and overall survival. The CXCR4 ligand, CXCL12 (SDF‐1), is expressed by multiple cells types in the BM, facilitating the adhesion and survival of the malignant clone. Blocking the CXCL12/CXCR4 axis is an attractive therapeutic strategy providing a ‘multi‐hit’ therapy that both prevents essential survival signals and releases the AML cells from the BM into the circulation. Once out of the protective niche of the BM they would be more susceptible to destruction by conventional chemotherapeutic drugs. In this review, we disentangle the diverse roles of the CXCL12/CXCR4 axis in AML. We then describe multiple CXCR4 inhibitors, including small molecules, peptides, or monoclonal antibodies, which have been developed to date and their progress in pre‐clinical and clinical trials. Finally, the review leads us to the conclusion that there is a need for further investigation into the development of a ‘multi‐hit’ therapy that targets several signalling pathways related to AML cell adhesion and maintenance in the BM

Dissecting the impact of bromodomain inhibitors on the IRF4-MYC oncogenic axis in multiple myeloma

B-cell progenitor fate determinant interferon regulatory factor 4 (IRF4) exerts key roles in the pathogenesis and progression of multiple myeloma (MM), a currently incurable plasma cell malignancy. Aberrant expression of IRF4 and the establishment of a positive auto-regulatory loop with oncogene MYC, drives a MM specific gene-expression programme leading to the abnormal expansion of malignant immature plasma cells. Targeting the IRF4-MYC oncogenic loop has the potential to provide a selective and effective therapy for MM. Here we evaluate the use of bromodomain inhibitors to target the IRF4-MYC axis through combined inhibition of their known epigenetic regulators, BRD4 and CBP/EP300. Although all inhibitors induced cell death, we found no synergistic effect of targeting both of these regulators on the viability of MM cell-lines. Importantly, for all inhibitors over a time period up to 72 hours, we detected reduced IRF4 mRNA, but a limited decrease in IRF4 protein expression or mRNA levels of downstream target genes. This indicates that inhibitor-induced loss of cell viability is not mediated through reduced IRF4 protein expression, as previously proposed. Further analysis revealed a long half-life of IRF4 protein in MM cells. In support of our experimental observations, gene network modelling of MM suggests that bromodomain inhibition is exerted primarily through MYC and not IRF4. These findings suggest that despite the autofeedback positive regulatory loop between IRF4 and MYC, bromodomain inhibitors are not effective at targeting IRF4 in MM and that novel therapeutic strategies should focus on the direct inhibition or degradation of IRF4. This article is protected by copyright

Probing BRD inhibition substituent effects in bulky analogues of (+)-JQ1

A series of bulky organometallic and organic analogues of the bromodomain (BRD) inhibitor (+)-JQ1 have been prepared. The most potent, N-[(adamantan-1-yl)methyl]-2-[(9S)-7-(4-chlorophenyl)-4,5,13-trimethyl-3-thia-1,8,11,12-tetraazatricyclo[8.3.0.02,6]trideca-2(6),4,7,10,12-pentaen-9-yl]acetamide, 2e, showed excellent potency with an KD=ca. 130 nm vs. BRD4(1) and a ca. 2-fold selectivity over BRD4(2) (KD=ca. 260 nm). Its binding to the first bromodomain of BRD4 was determined by a protein cocrystal structure

Thrombotic risk in COVID-19: a case series and case-control study

Background: A possible association between COVID-19 infection and thrombosis, either as a direct consequence of the virus or as a complication of inflammation, is emerging in the literature. Data on the incidence of venous thromboembolism (VTE) is extremely limited. Methods: We describe 3 cases of thromboembolism refractory to heparin treatment, the incidence of VTE in an inpatient cohort, and a case-control study to identify risk factors associated with VTE. Results: We identified 274 confirmed (208) or probable (66) COVID-19 patients. 21 (7.7%) were diagnosed with VTE. D-dimer was elevated in both cases (confirmed VTE) and controls (no confirmed VTE) but higher levels were seen in confirmed VTE cases (4.1vs 1.2 µg/mL P <0.001). Conclusion: Incidence of VTE is high in patients hospitalised with COVID-19. Urgent clinical trials are needed to evaluate the role of anticoagulation in COVID-19. Monitoring of D-dimer and anti-factor Xa levels may be beneficial in guiding management

Synthesis and biological investigation of (+)-JD1, an organometallic BET bromodomain inhibitor

(+)-JD1, a rationally designed ferrocene analogue of the BET bromodomain (BRD) probe molecule (+)-JQ1, has been synthesized and evaluated in biophysical, cell-based assays as well as in pharmacokinetic studies. It displays nanomolar activity against BRD isoforms, and its cocrystal structure was determined in complex with the first bromodomain of BRD4 and compared with that of (+)-JQ1, a known BRD4 small-molecule probe. At 1 μM concentration, (+)-JD1 was able to inhibit c-Myc, a key driver in cancer and an indirect target of BRD4