A haploid genetic screen identifies the G1/S regulatory machinery as a determinant of Wee1 inhibitor sensitivity.

The Wee1 cell cycle checkpoint kinase prevents premature mitotic entry by inhibiting cyclin-dependent kinases. Chemical inhibitors of Wee1 are currently being tested clinically as targeted anticancer drugs. Wee1 inhibition is thought to be preferentially cytotoxic in p53-defective cancer cells. However, TP53 mutant cancers do not respond consistently to Wee1 inhibitor treatment, indicating the existence of genetic determinants of Wee1 inhibitor sensitivity other than TP53 status. To optimally facilitate patient selection for Wee1 inhibition and uncover potential resistance mechanisms, identification of these currently unknown genes is necessary. The aim of this study was therefore to identify gene mutations that determine Wee1 inhibitor sensitivity. We performed a genome-wide unbiased functional genetic screen in TP53 mutant near-haploid KBM-7 cells using gene-trap insertional mutagenesis. Insertion site mapping of cells that survived long-term Wee1 inhibition revealed enrichment of G1/S regulatory genes, including SKP2, CUL1, and CDK2. Stable depletion of SKP2, CUL1, or CDK2 or chemical Cdk2 inhibition rescued the γ-H2AX induction and abrogation of G2 phase as induced by Wee1 inhibition in breast and ovarian cancer cell lines. Remarkably, live cell imaging showed that depletion of SKP2, CUL1, or CDK2 did not rescue the Wee1 inhibition-induced karyokinesis and cytokinesis defects. These data indicate that the activity of the DNA replication machinery, beyond TP53 mutation status, determines Wee1 inhibitor sensitivity, and could serve as a selection criterion for Wee1-inhibitor eligible patients. Conversely, loss of the identified S-phase genes could serve as a mechanism of acquired resistance, which goes along with development of severe genomic instability.

An Economic Evaluation of Sacubitril/Valsartan for Heart Failure Patients in the Netherlands.

BACKGROUND: In September 2014, the PARADIGM-HF trial showed the heart failure drug combination sacubitril/valsartan to be superior to enalapril for patients with a reduced ejection fraction. OBJECTIVES: To determine the incremental cost-effectiveness of sacubitril/valsartan compared with enalapril in the Netherlands using the clinical data from the PARADIGM-HF trial. METHODS: To compare sacubitril/valsartan and enalapril in a cost-effectiveness study, a Markov model was developed using the effectiveness data from the PARADIGM-HF trial. A health care payer's perspective was applied in the economic evaluation. The developed model was used to evaluate the cost-effectiveness for sacubitril/valsartan at different per diem prices. RESULTS: The base-case analysis showed that sacubitril/valsartan can be cost-effective at maximum daily costs of €5.50 and €14.14 considering willingness-to-pay thresholds of €20,000 and €50,000 per quality-adjusted life-year (QALY), respectively. Sensitivity analysis demonstrated the robustness of the model, identifying only the price of sacubitril/valsartan and the mortality within the sacubitril/valsartan group as significant drivers of the cost-effectiveness ratio. Sacubitril/valsartan was cost-effective at a willingness-to-pay threshold of €20,000 per QALY (€50,000 per QALY) in more than 80% of the replications with certainty at the price point of €3 (€10). CONCLUSIONS: Sacubitril/valsartan can be considered a cost-effective treatment at a daily price of €5.25. Unless priced lower than enalapril (<€0.045 per day), sacubitril/valsartan is very unlikely to be cost-saving/dominant.

Ticagrelor Removal by CytoSorb® in Patients Requiring Emergent or Urgent Cardiac Surgery: A UK-Based Cost-Utility Analysis.

BACKGROUND: Acute coronary syndrome patients receiving dual antiplatelet therapy who need emergent or urgent cardiac surgery are at high risk of major bleeding, which can impair postoperative outcomes. CytoSorb®, a blood purification technology based on adsorbent polymer, has been demonstrated to remove ticagrelor from blood during on-pump cardiac surgery. OBJECTIVE: The aim of this study was to evaluate the cost utility of intraoperative removal of ticagrelor using CytoSorb versus usual care among patients requiring emergent or urgent cardiac surgery in the UK. METHODS: A de novo decision analytic model, based on current treatment pathways, was developed to estimate the short- and long-term costs and outcomes. Results from randomised clinical trials and national standard sources such as National Health Service (NHS) reference costs were used to inform the model. Costs were estimated from the NHS and Personal Social Services perspective. Deterministic and probabilistic sensitivity analyses (PSAs) explored the uncertainty surrounding the input parameters. RESULTS: In emergent cardiac surgery, intraoperative removal of ticagrelor using CytoSorb was less costly (£12,933 vs. £16,874) and more effective (0.06201vs. 0.06091 quality-adjusted life-years) than cardiac surgery without physiologic clearance of ticagrelor over a 30-day time horizon. For urgent cardiac surgery, the use of CytoSorb was less costly than any of the three comparators-delaying surgery for natural washout without adjunctive therapy, adjunctive therapy with short-acting antiplatelet agents, or adjunctive therapy with low-molecular-weight heparin. Results from the PSAs showed that CytoSorb has a high probability of being cost saving (99% in emergent cardiac surgery and 53-77% in urgent cardiac surgery, depending on the comparators). Cost savings derive from fewer transfusions of blood products and re-thoracotomies, and shorter stay in the hospital/intensive care unit. CONCLUSIONS: The implementation of CytoSorb as an intraoperative intervention for patients receiving ticagrelor undergoing emergent or urgent cardiac surgery is a cost-saving strategy, yielding improvement in perioperative and postoperative outcomes and decreased health resource use.