Ulinastatin inhibits microglia activation in spinal cord via P2Y12 receptor in a rat neuropathic pain model.

Ulinastatin, a broad spectrum of serine protease inhibitor, has been found to alleviate neuropathic pain (NPP). However, its mechanism is not completely clear. Here, a sciatic nerve ligation rat model and BV2 microglial cells were used to investigate the effect of Ulinastatin on the activation of microglia and P2Y12 receptors in vivo and in vitro. Levels of P2Y12 receptor and NF-κB (P65) expression in the dorsal horn of the lumbar enlargement region of the spinal cord and BV2 cells were assessed by immunohistochemistry and double-label immunofluorescence assays. Levels of IL-1ß and TNF-α in cell culture medium and cerebrospinal fluid (CSF) were examined by ELISA. The results showed that Ulinastatin reduced the release of inflammatory IL-1ß and TNF-α by inhibiting the activation of spinal microglia. Ulinastatin down-regulated P2Y12 receptor and NF-κB (P65) expression in the spinal microglia of the chronic constrictive injury model. The results indicated that Ulinastatin may attenuate the activation of spinal microglia after peripheral nerve injury by inhibiting the activation of P2Y12 receptor signal pathway in microglia. NF-kB may play a key role in the mechanism of Ulinastatin.

Inverse agonist efficacy of selatogrel blunts constitutive P2Y12 receptor signaling by inducing the inactive receptor conformation.

Selatogrel is a potent inhibitor of adenosine diphosphate (ADP) binding to the P2Y12 receptor, preventing platelet activation. We have previously shown that the P2Y12 receptor constitutively activates Gi- and Go-protein-mediated signaling in human platelets. Here, we report that selatogrel acts as an inverse agonist of the P2Y12 receptor. Specifically, using bioluminescence resonance energy transfer2 (BRET2) probes, selatogrel, ticagrelor, and elinogrel were shown to stabilize the inactive form of the Gαi/o-Gßγ complex in cells with recombinant expression of the P2Y12 receptor. In dose-response experiments, while selatogrel exhibited a maximal efficacy similar to ticagrelor, selatogrel was approximately 100-fold more potent than ticagrelor. Quantification of relative cyclic adenosine monophosphate (cAMP) levels in cells expressing the cAMP BRET1 sensor (CAMYEL probe) confirmed that selatogrel completely abolished the constitutive activity of the P2Y12 receptor. In agreement, selatogrel increased basal cAMP levels in human platelets, confirming inverse agonism on the endogenous human platelet P2Y12 receptor. In agreement with the biochemical phenotype of inverse agonism efficacy of selatogrel, the 2.8 Angstrom resolution cocrystal structure of selatogrel bound to the P2Y12 receptor confirmed that selatogrel stabilizes the inactive, basal state of the receptor. Selatogrel bound to pocket 1, spanning helix III to VII. Furthermore, the binding mode of selatogrel, suggesting steric overlap with the proposed binding site of ADP and the ADP analog 2-methylthioadenosine diphosphate (2MeSADP), agrees with the functional characterization of selatogrel preventing platelet activation by blocking ADP binding to the P2Y12 receptor.

Inhibiting P2Y12 receptor relieves LPS-induced inflammation and endothelial dysfunction.

BACKGROUND: Acute lung injury (ALI) is characterized by abnormal inflammatory response without effective therapies. P2Y12 receptor (P2Y12R) plays a vital role in inflammatory response. This study intends to explore whether P2Y12R antagonists can inhibit LPS-induced inflammatory injury of human pulmonary microvascular endothelial cells (HPMVECs) and endothelial cell dysfunction. METHODS: Using a cell model of ALI, the role of P2Y12R was investigated in LPS-induced HPMVECs. The expression of P2Y12R was detected by RT-qPCR and Western blot analysis assay and TNF-α, IL-1ß, and IL-6 levels were analyzed by RT-qPCR. NO levels were also analyzed through NO kit. The levels of NF-κB p65, P-IκB-α, and IκB-α, as well as p-AKT and eNOS levels were detected by Western blot analysis assay. Wound healing assay was performed to evaluate HPMVECs migration. FITC-dextran was used to evaluate endothelial cell permeability, and the analysis of adherens junction protein VE-cadherin and endothelial cell tight junction proteins ZO-1, Claudin 5 and Occludin expression was performed by RT-qPCR and Western blot analysis assay. RESULTS: In vitro, LPS increased the expression levels of P2Y12R and pro-inflammatory mediators (TNF-α, IL-1ß, and IL-6), followed by a decrease in HPMVECs migration. In addition, LPS led to an increase in endothelial cell permeability. P2Y12R antagonists Ticagrelor or clopidogrel treatment significantly reversed these effects of LPS. CONCLUSION: The inhibitor of P2Y12R was able to decrease inflammatory response, promote migration and improve endothelial cell function and permeability, suggesting a key role of P2Y12R in ALI.

P2Y12 receptor antagonism inhibits proliferation, migration and leads to autophagy of glioblastoma cells.

Glioblastoma (GBM) is the most aggressive and lethal among the primary brain tumors, with a low survival rate and resistance to radio and chemotherapy. The P2Y12 is an adenosine diphosphate (ADP) purinergic chemoreceptor, found mainly in platelets. In cancer cells, its activation has been described to induce proliferation and metastasis. Bearing in mind the need to find new treatments for GBM, this study aimed to investigate the role of the P2Y12R in the proliferation and migration of GBM cells, as well as to evaluate the expression of this receptor in patients' data obtained from the TCGA data bank. Here, we used the P2Y12R antagonist, ticagrelor, which belongs to the antiplatelet agent's class. The different GBM cells (cell line and patient-derived cells) were treated with ticagrelor, with the agonist, ADP, or both, and the effects on cell proliferation, colony formation, ADP hydrolysis, cell cycle and death, migration, and cell adhesion were analyzed. The results showed that ticagrelor decreased the viability and the proliferation of GBM cells. P2Y12R antagonism also reduced colony formation and migration potentials, with alterations on the expression of metalloproteinases, and induced autophagy in GBM cells. Changes were observed at the cell cycle level, and only the U251 cell line showed a significant reduction in the ADP hydrolysis profile. TCGA data analysis showed a higher expression of P2Y12R in gliomas samples when compared to the other tumors. These data demonstrate the importance of the P2Y12 receptor in gliomas development and reinforce its potential as a pharmacological target for glioma treatment.

Pleiotropic effects of clopidogrel.

Clopidogrel is a widely prescribed prodrug with anti-thrombotic activity through irreversible inhibition of the P2Y12 receptor on platelets. It is FDA-approved for the clinical management of thrombotic diseases like unstable angina, myocardial infarction, stroke, and during percutaneous coronary interventions. Hepatic clopidogrel metabolism generates several distinct metabolites. Only one of these metabolites is responsible for inhibiting the platelet P2Y12 receptor. Importantly, various non-hemostatic effects of clopidogrel therapy have been described. These non-hemostatic effects are perhaps unsurprising, as P2Y12 receptor expression has been reported in multiple tissues, including osteoblasts, leukocytes, as well as vascular endothelium and smooth muscle. While the "inactive" metabolites have been commonly thought to be biologically inert, recent findings have uncovered P2Y12 receptor-independent effects of clopidogrel treatment that may be mediated by understudied metabolites. In this review, we summarize both the P2Y12 receptor-mediated and non-P2Y12 receptor-mediated effects of clopidogrel and its metabolites in various tissues.

Canine Cancer Cells Activate Platelets via the Platelet P2Y12 Receptor.

In addition to their well-known functions in haemostasis, anucleated platelets have a critical role in cancer biology. Many human and non-human cancer types can directly interact with and activate platelets, promoting cancer malignancy and progression. Although naturally occurring canine neoplastic diseases mimic the biologically complex conditions of human cancers more closely than laboratory-bred mice, studies evaluating the relationship between cancer cells and platelets in dogs are scarce, and the effects of tumour cells on platelets in these animals are unknown. To evaluate whether cancer cells could activate canine platelets, we assessed the response of platelet-rich plasma to cultured canine cancer cells using light transmittance aggregometry. Similar to human and murine cancer cell research, we demonstrated that both canine osteosarcoma and mammary carcinoma cells activated canine platelets in vitro, resulting in platelet aggregation. The degree of aggregation was most pronounced at a cancer cell to platelet ratio of 1:200 for most cell lines. Mechanistic studies revealed that the platelet adenosine diphosphate (ADP) receptor P2Y12 is essential for canine platelet aggregation induced by canine cancer. ADP receptor blockage on platelets inhibited >50% of cancer cell-induced maximum platelet aggregation in all cell lines evaluated. As in other species, our results suggest that canine cancers may activate canine platelets in vivo. This mechanism is likely relevant for the biology and progression of cancer in the dog.

G-protein coupled purinergic P2Y12 receptor interacts and internalizes TauRD-mediated by membrane-associated actin cytoskeleton remodeling in microglia.

In Alzheimer's disease, the microtubule-associated protein, Tau misfolds to form aggregates and filaments in the intra- and extracellular region of neuronal cells. Microglial cells are the resident brain macrophage cells involved in constant surveillance and activated by the extracellular deposits. Purinergic receptors are involved in the chemotactic migration of microglial cells towards the site of inflammation. From our recent study, we have observed that the microglial P2Y12 receptor is involved in phagocytosis of full-length Tau species such as monomers, oligomers and aggregates by actin-driven chemotaxis. This study shows the interaction of repeat-domain of Tau (TauRD) with the microglial P2Y12 receptor and the corresponding residues for interaction have been analysed by various in-silico approaches. In the cellular studies, TauRD was found to interact with microglial P2Y12R and induces its cellular expression confirmed by co-immunoprecipitation and western blot analysis. Furthermore, the P2Y12R-mediated TauRD internalization has demonstrated activation of microglia with an increase in the Iba1 level, and TauRD becomes accumulated at the peri-nuclear region for the degradation. Similarly, immunofluorescence microscopic studies emphasized that TauRD is phagocytosed by microglial P2Y12R via the membrane-associated actin remodeling as filopodia extension. Upon internalization, we have demonstrated the P2Y12R signaling-mediated degradation of accumulated TauRD by lysosomal pathway. Altogether, microglial P2Y12R interacts with TauRD and mediates directed migration and activation for its internalization and degradation.

G protein-coupled purinergic P2Y receptor oligomerization: Pharmacological changes and dynamic regulation.

P2Y receptors (P2YRs) are a δ group of rhodopsin-like G protein-coupled receptors (GPCRs) with many essential functions in physiology and pathology, such as platelet aggregation, immune responses, neuroprotective effects, inflammation, and cellular proliferation. Thus, they are among the most researched therapeutic targets used for the clinical treatment of diseases (e.g., the antithrombotic drug clopidogrel and the dry eye treatment drug diquafosol). GPCRs transmit signals as dimers to increase the diversity of signalling pathways and pharmacological activities. Many studies have frequently confirmed dimerization between P2YRs and other GPCRs due to their functions in cardiovascular and cerebrovascular processes in vivo and in vitro. Recently, some P2YR dimers that dynamically balance physiological functions in the body were shown to be involved in effective signal transduction and exert pathological responses. In this review, we summarize the types, pharmacological changes, and active regulators of P2YR-related dimerization, and delineate new functions and pharmacological activities of P2YR-related dimers, which may be a novel direction to improve the effectiveness of medications.

Pharmacokinetics, mass balance, and metabolism of [14C]vicagrel, a novel irreversible P2Y12 inhibitor in humans.

Vicagrel, a novel irreversible P2Y12 receptor inhibitor, is undergoing phase III trials for the treatment of acute coronary syndromes in China. In this study, we evaluated the pharmacokinetics, mass balance, and metabolism of vicagrel in six healthy male Chinese subjects after a single oral dose of 20 mg [14C]vicagrel (120 µCi). Vicagrel absorption was fast (Tmax = 0.625 h), and the mean t1/2 of vicagrel-related components was ~38.0 h in both plasma and blood. The blood-to-plasma radioactivity AUCinf ratio was 0.55, suggesting preferential distribution of drug-related material in plasma. At 168 h after oral administration, the mean cumulative excreted radioactivity was 96.71% of the dose, including 68.03% in urine and 28.67% in feces. A total of 22 metabolites were identified, and the parent vicagrel was not detected in plasma, urine, or feces. The most important metabolic spot of vicagrel was on the thiophene ring. In plasma pretreated with the derivatization reagent, M9-2, which is a methylated metabolite after thiophene ring opening, was the predominant drug-related component, accounting for 39.43% of the radioactivity in pooled AUC0-8 h plasma. M4, a mono-oxidation metabolite upon ring-opening, was the most abundant metabolite in urine, accounting for 16.25% of the dose, followed by M3-1, accounting for 12.59% of the dose. By comparison, M21 was the major metabolite in feces, accounting for 6.81% of the dose. Overall, renal elimination plays a crucial role in vicagrel disposition, and the thiophene ring is the predominant metabolic site.

Switching a Xanthine Oxidase Inhibitor to a Dual-Target Antagonist of P2Y1 and P2Y12 as an Oral Antiplatelet Agent with a Wider Therapeutic Window in Rats than Ticagrelor.

ADP-mediated platelet aggregation is signaled through G protein-coupled receptors P2Y1 and P2Y12 on the platelet. The clinical effectiveness of inhibiting P2Y12 has been well established, and preclinical studies indicated that the inhibition of P2Y1 could provide equivalent antithrombotic efficacy as P2Y12 antagonists and reduce bleeding risks. On the basis of the 2-phenyl-1H-imidazole scaffold of our previously reported xanthine oxidase inhibitor WSJ-557, we first achieved the transition from the xanthine oxidase inhibitors to dual-target antagonists against P2Y1 and P2Y12. We described the structure-activity relationships of the 2-phenyl-1H-imidazole compounds, which led to the identification of the most potent antiplatelet agents, 24w and 25w, both showing a rapid onset of action in pharmacokinetic study. Furthermore, the rat model suggested that 24w demonstrated a wider therapeutic window than ticagrelor, displaying equivalent and dose-dependent antithrombotic efficacy with lower blood loss compared to ticagrelor at same oral dose. These results supported that 24w and 25w could be promising drug candidates.

Influences of Smoking Status on Effectiveness of Cytochrome P450 Enzyme System Metabolized Medications in Reducing In-Hospital Death in 14 658 Patients With Acute Myocardial Infarction: Data From CPACS-3 Study.

BACKGROUND: The benefit of cytochrome P450 (CYP450) enzyme system metabolized medications, especially clopidogrel, was reported more pronounced in smoking than nonsmoking patients, but limited evidence was available from Asian patients. We analyzed data from a large registry-based study of Chinese patients with acute myocardial infarction (AMI) to understand if the above finding could be reproduced. METHODS: A total of 14 658 patients with AMI were prospectively recruited from 101 hospitals across China. Generalized estimating equation was applied to assess the association between CYP450 enzyme system metabolized medications (clopidogrel, statins, calcium channel blockers) and in-hospital death in smoking and nonsmoking patients, separately, adjusting for hospital clustering effects and propensity score of using the medication in question. RESULTS: There were 86%, 93%, and 10% of study patients who received clopidogrel, statins, and calcium channel blockers during the hospitalization. Compared with patients not receiving clopidogrel, patients receiving the drug had a significantly lower risk of in-hospital death (adjusted relative risk [RR] = 0.61, 95% confidence interval [CI]: 0.40-0.91) in current smokers but an insignificant lower risk (adjusted RR = 0.85, 95% CI: 0.71-1.01) in nonsmokers, and the P for interaction was <.01. The corresponding adjusted RR was 0.45 (95% CI: 0.24-0.86) in current smokers and 0.94 (95% CI: 0.68-1.29) in nonsmokers (P for interaction <.01) for statins use and 1.00 (95% CI: 0.53-1.89) in current smokers and 0.66 (95% CI: 0.48-0.90) in nonsmokers (P for interaction = .23) for calcium channel blockers use. CONCLUSIONS: Our study in a large cohort of Chinese patients with AMI found that the treatment effect in reducing risk of in-hospital death was significantly larger in smokers than in nonsmokers as for clopidogrel and statins but not for calcium channel blockers.

P2Y12 receptor antagonists and AR receptor agonists regulates Protein Disulfide Isomerase secretion from platelets and endothelial cells.

Secretion of PDI from platelets and endothelial cells is an important step of all thrombotic events. In the absence of extracellular PDI thrombus formation and fibrin generation may be impaired. Thrombin-mediated PDI secretion is regulated by the stimulation of P2Y12 receptors. This paper provides evidences that P2Y12 antagonists or AR agonists may modulate release of PDI molecules from platelets and with less efficiency from endothelial cells. Moreover P2Y12 antagonization or AR agonization modulates platelet-endothelial interaction. We prove that combinations of P2Y12 antagonists and AR agonists inhibit platelet-dependent adhesion of cancer cells to endothelium and attenuate cancer cell invasiveness, but longer exposition to AR agonists may stimulate migration of invasive breast cancer cells through endothelium thus leading to increased metastasis.

Impact of Continuous P2Y12 Inhibition Tailoring in Acute Coronary Syndrome and Genetically Impaired Clopidogrel Absorption.

Clopidogrel is still widely used in acute coronary syndrome despite the development of more potent P2Y12 inhibitors. Previously, we conducted a trial that evaluated serial clopidogrel dose adjustment based on platelet function testing in acute coronary syndrome patients with initial high on-treatment platelet reactivity (HTPR). In this substudy, we performed post hoc analysis of the effect of ABCB1 genetic variants C3435T and G2677T/A on platelet inhibition and outcomes. There were no differences in the proportion of HTPR patients among C3435T carriers and noncarriers in both interventional and control group. G2677T carriers expressed significantly higher proportion of HTPR pattern throughout 12-month follow-up in the control group with no difference in the interventional group. There was no difference in ischemic outcomes between C3435T and G2677T carriers and noncarriers in both groups of patients. The results indicate that ABCB1 genotyping is not useful to guide clopidogrel therapy tailoring to improve high-risk patient management.

Prasugrel effectively reduces the platelet reactivity units in patients with genetically metabolic dysfunction of cytochrome P450 2C19 who are treated with long-term dual antiplatelet therapy after undergoing drug-eluting stent implantation.

Dual antiplatelet therapy (DAPT) with aspirin and P2Y12 inhibitor is administered following percutaneous coronary intervention (PCI) with coronary stent implantation. Several studies have reported the effects of switching between P2Y12 inhibitors on platelet reactivity (P2Y12 reaction units: PRU), from acute to late phase after PCI. However, the effect of switching at very late phase is unknown. This study examined the effect on PRU in Japanese coronary heart disease patients with long-term DAPT (aspirin + clopidogrel) when switching from clopidogrel to prasugrel. Ninety-six patients were enrolled in this study. The median DAPT duration at enrollment was 1824.0 days. Twenty-three patients with PRU ≥ 208 at enrollment were randomly assigned into either continuing to receive clopidogrel (Continued Group; n = 11) or switching to prasugrel (Switched Group; n = 12). The primary endpoint was the rate of patients who achieved PRU < 208 at the end of 12 weeks of treatment, which was significantly higher in Switched Group relative to Continued Group (90.0% vs. 36.4%; P = 0.024). The secondary endpoint was the PRU at week 12 in groups subdivided according to cytochrome P450 (CYP) 2C19 genotypes. At week 12, extensive metabolizers (EM Group) had 202.3 ± 60.0 and 174.5 ± 22.3 in Continued Group and Switched Group (P = 0.591), respectively; intermediate and poor metabolizers (non-EM Group) had 229.4 ± 36.9 and 148.4 ± 48.4 in Continued Group and Switched Group (P = 0.002), respectively. The PRU for non-EM Group was significantly reduced in Switched Group. Thus, for patients with long-term DAPT (aspirin + clopidogrel) after PCI with coronary stent implantation, switching from clopidogrel to prasugrel resulted in a stable reduction in PRU, regardless of CYP2C19 polymorphism.

Incidence, predictors, and prognosis of premature discontinuation or switch of prasugrel or ticagrelor: the ATLANTIS - SWITCH study.

Aim of the present study was to investigate the frequency and predictors of premature discontinuation or switch of ADP receptor blockers and its association with serious adverse events. For this purpose 571 consecutive ACS patients receiving ticagrelor (n = 258, 45%) or prasugrel (n = 313, 55%) undergoing PCI were enrolled in this prospective, observational, multicenter ATLANTIS-SWITCH substudy. Predictors of premature discontinuation or switch of antiplatelet therapy and their association with major adverse cardiovascular events and TIMI bleeding events were evaluated. Premature stop/switch was found in 72 (12.6%) patients: 34 (5.9%) stopped and 38 (6.7%) switched the ADP blocker. Ticagrelor treated patients were significantly more likely to stop/switch therapy as compared to prasugrel (15.9% vs. 9.2%, p = 0.016). We identified 4 independent predictors for stop/switch of ADP blocker: major surgery, need for oral anticoagulation (OAC), TIMI major bleeding and drug intolerance. TIMI major bleeding was a driver of stop/switch actions and occurred in 4.3% vs 0.2% in patients with vs without stop/switch (p = 0.001). The majority of stop/switch actions (75%) were physicians driven decisions. Importantly, stop/switch of therapy was not associated with increased risk of MACE (p = 0.936). In conclusion premature switch/stop of ADP blockers appears to be safe when mainly driven by physician's decision and clinical indication.

Prediction of Ticagrelor and its Active Metabolite in Liver Cirrhosis Populations Using a Physiologically Based Pharmacokinetic Model Involving Pharmacodynamics.

Ticagrelor, a P2Y12 receptor antagonist, has been highly recommended for use in acute coronary syndrome. The major active metabolite (AM) is similar to the parent drug, which exhibits antiplatelet activity. The inhibition of platelet aggregation (IPA) is used as an assay to demonstrate the anticoagulant efficacy of ticagrelor. In this study, we developed a physiologically based pharmacokinetic (PBPK) model to predict the pharmacokinetics of ticagrelor and its AM and combined this model with a pharmacodynamics model to reflect potential pharmacodynamic alterations in liver cirrhosis populations. The simulated results obtained using the PBPK model were validated by fold error values, which were all smaller than 2. Comparisons of exposure in different classifications of liver cirrhosis indicated that exposure to ticagrelor increased significantly with an increase in the degree of cirrhosis severity, whereas exposure to AM was decreased. The total concentration of ticagrelor and AM was related to the IPA included in the Sigmoid Emax model. The PBPK model of ticagrelor and AM could predict the pharmacokinetics of all populations, and a combination of PD models was used to extrapolate for predicting unknown scenarios. Liver cirrhosis may result in prolonged IPA, depending on the severity degree of this disease. The combined PBPK model including IPA can reveal changes in pharmacokinetics and pharmacodynamics in populations affected by liver cirrhosis and indicate the risk potential.

Distinct Signaling Patterns of Allosteric Antagonism at the P2Y1 Receptor.

Traditionally, G protein-coupled receptor antagonists are classified as competitive or noncompetitive and surmountable or insurmountable based on functional antagonism. P2Y1 receptor (P2Y1R) structures showed two antagonists binding to two spatially distinct sites: nucleotide MRS2500 (orthosteric, contacting the helical bundle) and urea BPTU (allosteric, on the external receptor surface). However, the nature of their P2Y1R antagonism has not been characterized. Here we characterized BPTU antagonism at various signaling pathways activated by structurally diverse agonists. BPTU rightward shifted the concentration-response curves of both 2-methylthioadenosine 5'-diphosphate trisodium salt and MRS2365 (5'-diphosphates) in some signaling events, such as extracellular signal-regulated kinase 1/2 and label free, in a parallel manner without affecting the maximum agonist effect (Emax) but antagonized insurmountably (suppressed agonist Emax) in signaling events such as guanosine 5'-3-O-(thio)triphosphate binding and ß-arrestin2 recruitment. However, with dinucleotide Ap4A as an agonist, BPTU suppressed the Emax insurmountably in all signaling pathways. By comparison, MRS2500 behaved as surmountable antagonist rightward-shifting concentration-response curves of all three agonists in a parallel manner for all signaling pathways measured. Thus, we demonstrated a previously undocumented phenomenon that P2Y1R antagonism patterns could vary in different signaling pathways, which could be related to conformational selection, signaling amplification, and probe dependence. This phenomenon may apply generally to other receptors considering that antagonism by a specific ligand is often not compared at multiple signaling pathways. Thus, antagonism can be surmountable or insurmountable depending on the signaling pathways measured and the agonists used, which should be of broad relevance to drug discovery and disease treatment.

From UTP to AR-C118925, the discovery of a potent non nucleotide antagonist of the P2Y2 receptor.

The G protein-coupled P2Y2 receptor, activated by ATP and UTP has been reported as a potential drug target for a wide range of important clinical conditions, such as tumor metastasis, kidney disorders, and in the treatment of inflammatory conditions. However, pharmacological studies on this receptor have been impeded by the limited reported availability of stable, potent and selective P2Y2R antagonists. This article describes the design and synthesis of AR-C118925, a potent and selective non-nucleotide antagonist of the P2Y2 receptor discovered using the endogenous P2Y2R agonist UTP as the chemical starting point.

CYP2C19 LOF and GOF-Guided Antiplatelet Therapy in Patients with Acute Coronary Syndrome: A Cost-Effectiveness Analysis.

PURPOSE: This study aimed to examine the cost-effectiveness of CYP2C19 loss-of-function and gain-of-function allele guided (LOF/GOF-guided) antiplatelet therapy in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). METHODS: A life-long decision-analytic model was designed to simulate outcomes of three strategies: universal clopidogrel (75 mg daily), universal alternative P2Y12 inhibitor (prasugrel 10 mg daily or ticagrelor 90 mg twice daily), and LOF/GOF-guided therapy (LOF/GOF allele carriers receiving alternative P2Y12 inhibitor, wild-type patients receiving clopidogrel). Model outcomes included clinical event rates, quality-adjusted life-years (QALYs) gained and direct medical costs from perspective of US healthcare provider. RESULTS: Base-case analysis found nonfatal myocardial infarction (5.62%) and stent thrombosis (1.2%) to be the lowest in universal alternative P2Y12 inhibitor arm, whereas nonfatal stroke (0.72%), cardiovascular death (2.42%), and major bleeding (2.73%) were lowest in LOF/GOF-guided group. LOF/GOF-guided arm gained the highest QALYs (7.5301 QALYs) at lowest life-long cost (USD 76,450). One-way sensitivity analysis showed base-case results were subject to the hazard ratio of cardiovascular death in carriers versus non-carriers of LOF allele and hazard ratio of cardiovascular death in non-carriers of LOF allele versus general patients. In probabilistic sensitivity analysis of 10,000 Monte Carlo simulations, LOF/GOF-guided therapy, universal alternative P2Y12 inhibitor, and universal clopidogrel were the preferred strategy (willingness-to-pay threshold = 50,000 USD/QALY) in 99.07%, 0.04%, and 0.89% of time, respectively. CONCLUSIONS: Using both CYP2C19 GOF and LOF alleles to select antiplatelet therapy appears to be the preferred antiplatelet strategy over universal clopidogrel and universal alternative P2Y12 inhibitor therapy for ACS patients with PCI.

Cardiovascular Pharmacogenomics--Implications for Patients With CKD.

CKD is an independent risk factor for cardiovascular disease (CVD). Thus, patients with CKD often require treatment with cardiovascular drugs, such as antiplatelet, antihypertensive, anticoagulant, and lipid-lowering agents. There is significant interpatient variability in response to cardiovascular therapies, which contributes to risk for treatment failure or adverse drug effects. Pharmacogenomics offers the potential to optimize cardiovascular pharmacotherapy and improve outcomes in patients with CVD, although data in patients with concomitant CKD are limited. The drugs with the most pharmacogenomic evidence are warfarin, clopidogrel, and statins. There are also accumulating data for genetic contributions to ß-blocker response. Guidelines are now available to assist with applying pharmacogenetic test results to optimize warfarin dosing, selection of antiplatelet therapy after percutaneous coronary intervention, and prediction of risk for statin-induced myopathy. Clinical data, such as age, body size, and kidney function have long been used to optimize drug prescribing. An increasing number of institutions are also implementing genetic testing to be considered in the context of important clinical factors to further personalize drug therapy for patients with CVD.