CB1 receptor antagonist AM4113 reverts the effects of cannabidiol on cue and stress-induced reinstatement of cocaine-seeking behaviour in mice.

No pharmacological treatments are yet approved for patients with cocaine use disorders. Cannabidiol, a constituent of the C. sativa plant has shown promising results in rodent models of drug addiction. However, the specific effects and mechanisms of action of cannabidiol in rodent operant models of extinction-based abstinence and drug-seeking relapse remain unclear. Cannabidiol (10 and 20 mg/kg, i.p.) was injected during extinction training to male CD-1 mice previously trained to self-administer cocaine (0.75 mg/kg/infusion). Then, we evaluated the reinstatement of cocaine seeking induced by cues and stressful stimuli (footshock). We found that cannabidiol (10 and 20 mg/kg) did not modulate extinction learning. After cannabidiol 20 mg/kg treatment, increased levels of CB1 receptor protein were found in the prelimbic and orbitofrontal regions of the prefrontal cortex, and in the ventral striatum; an effect paralleled by a reduction of striatal ∆FosB accumulation and an increment of GluR2 AMPA receptor subunits. Furthermore, cue-induced reinstatement of cocaine seeking was attenuated by cannabidiol. Unexpectedly, cannabidiol 20 mg/kg facilitated stress-induced restoration of cocaine-seeking behaviour. To ascertain the participation of CB1 receptors in these behavioural changes, we administered the CB1 antagonist AM4113 (5 mg/kg) before each reinstatement session. Both, the attenuation of cue-induced reinstatement and the facilitation of stress-induced reestablishment were abolished by AM4113 in cannabidiol 20 mg/kg-treated mice. Our results reveal a series of complex CB1-related changes induced by cannabidiol with a varying impact on the reinstatement of cocaine-seeking behaviour that could limit its therapeutic applications.

FOXM1 drives HPV+ HNSCC sensitivity to WEE1 inhibition.

Head and neck squamous cell carcinoma (HNSCC) associated with high-risk human papilloma virus (HPV) infection is a growing clinical problem. The WEE1 kinase inhibitor AZD1775 (WEE1i) overrides cell cycle checkpoints and is being studied in HNSCC regimens. We show that the HPV16 E6/E7 oncoproteins sensitize HNSCC cells to single-agent WEE1i treatment through activation of a FOXM1-CDK1 circuit that drives mitotic gene expression and DNA damage. An isogenic cell system indicated that E6 largely accounts for these phenotypes in ways that extend beyond p53 inactivation. A targeted genomic analysis implicated FOXM1 signaling downstream of E6/E7 expression and analyses of primary tumors and The Cancer Genome Atlas (TCGA) data revealed an activated FOXM1-directed promitotic transcriptional signature in HPV+ versus HPV- HNSCCs. Finally, we demonstrate the causality of FOXM1 in driving WEE1i sensitivity. These data suggest that elevated basal FOXM1 activity predisposes HPV+ HNSCC to WEE1i-induced toxicity and provide mechanistic insights into WEE1i and HPV+ HNSCC therapies.

Chromatin mapping and single-cell immune profiling define the temporal dynamics of ibrutinib response in CLL.

The Bruton tyrosine kinase (BTK) inhibitor ibrutinib provides effective treatment for patients with chronic lymphocytic leukemia (CLL), despite extensive heterogeneity in this disease. To define the underlining regulatory dynamics, we analyze high-resolution time courses of ibrutinib treatment in patients with CLL, combining immune-phenotyping, single-cell transcriptome profiling, and chromatin mapping. We identify a consistent regulatory program starting with a sharp decrease of NF-κB binding in CLL cells, which is followed by reduced activity of lineage-defining transcription factors, erosion of CLL cell identity, and acquisition of a quiescence-like gene signature. We observe patient-to-patient variation in the speed of execution of this program, which we exploit to predict patient-specific dynamics in the response to ibrutinib based on the pre-treatment patient samples. In aggregate, our study describes time-dependent cellular, molecular, and regulatory effects for therapeutic inhibition of B cell receptor signaling in CLL, and it establishes a broadly applicable method for epigenome/transcriptome-based treatment monitoring.

Real-world utilization of andexanet alfa.

OBJECTIVE: In 2018, the FDA approved andexanet alfa for the reversal of life-threatening hemorrhages in patients anticoagulated with apixaban or rivaroxaban. Yet, cost-effective factor Xa inhibitor reversal remains controversial. The objective of this study was to describe real world utilization of andexanet alfa. METHODS: This was a retrospective case series of patients receiving andexanet alfa between July 28, 2018 and April 29, 2019 at a large academic health system. Baseline demographics, anticoagulant type and reversal, as well as brain imaging were collected. Primary endpoints were stability of hematoma for intracranial hemorrhage (ICH), and hemostatic effectiveness for patients undergoing surgical procedures. Secondary endpoints were thromboembolism and 30 day mortality. RESULTS: Of the 25 patients evaluated, 13 received andexanet alfa for ICH. Eleven of the 13 had follow-up imaging available and stability was observed in 90.9%. Three patients received andexanet alfa for reversal prior to surgical procedures, and 100% hemostatic effectiveness was achieved. Nine patients received andexanet alfa for reversal of extracranial bleeding, including gastrointestinal bleed (n=4). There were no thrombotic events in our cohort, and 30 day mortality was 24%. Sixty-four percent of patients would have met exclusion criteria for the ANNEXA-4 trial. CONCLUSION: This is the largest series to date describing real-world utilization of andexanet alfa. Our series showed hemostatic efficacy in 90.9% of patients with ICH, and 100% in patients undergoing surgical procedures. There were no thrombotic complications. Yet, larger and comparative studies are needed to clarify the optimal agent and patient selection for reversal of factor Xa inhibitors.

Activated prothrombin complex concentrate to reverse the factor Xa inhibitor (apixaban) effect before emergency surgery: a case series.

BACKGROUND: The lack of an antidote against factor Xa inhibitors in case of major bleeding or need for urgent surgery is a concern to clinicians. Guidelines on managing major bleeding in patients under anticoagulation with a factor Xa inhibitor suggest several hemostatic agents to reverse the effect, but there is no consensus regarding the choice of drug or appropriate dose. The ability of prothrombin complex concentrate, activated prothrombin complex concentrate, and recombinant factor VIIa to reverse the effect of factor Xa inhibitors has been evaluated in animal studies, in vitro studies, and healthy volunteers, but not yet in randomized clinical studies. CASE PRESENTATION: We report a consecutive case series of patients under factor Xa inhibitor (apixaban) treatment who received activated prothrombin complex concentrate to reverse the anticoagulation effect before emergency cardiovascular surgery. Patient 1, a 63-year-old white man, was operated with replacement of the aortic valve; patient 2, a 65-year-old white man, underwent heart transplantation; patient 3, a 68-year-old white man, was operated for acute type A aortic dissection. They all received activated prothrombin complex concentrate 25 IU/kg immediately before surgery. In two of the cases, the global coagulation assay thromboelastometry (ROTEM™) was performed before and after administering activated prothrombin complex concentrate. The ROTEM™ clotting time was reduced from 1900 seconds to 740 seconds and from 1482 to 807 seconds, respectively, after administering a dose of 25 IU/kg activated prothrombin complex concentrate. The apixaban concentration before reversal was within the range considered to be the therapeutic level in all cases. No bleeding complications occurred during surgery, but one case was complicated with bleeding postoperatively. No thromboembolic complications were observed during or after surgery. CONCLUSIONS: Activated prothrombin complex concentrate 25 IU/kg reversed the anticoagulation effect of apixaban effectively and safely before emergency cardiovascular surgery.

Long-Lasting In Vivo Effects of the Cannabinoid CB1 Antagonist AM6538.

AM6538 is a cannabinoid antagonist that binds CB1 receptors expressed in HEK-293 cells in a wash-resistant manner. The effects of AM6538 in live animals has not previously been established. We characterized the antagonist effects of AM6538 in male mice, using a warm-water tail-withdrawal assay, and in male squirrel monkeys trained to discriminate the CB1 agonist AM4054 from vehicle. The cannabinoid agonists WIN 55,212, Δ9-tetrahydrocannabinol (THC), and AM4054 all produced 100% maximum possible antinociceptive effects in mice following vehicle pretreatment. One-hour pretreatment with increasing doses of AM6538 (0.1-10 mg/kg) produced first rightward, then downward shifts of the agonist dose-effect functions. Rimonabant, 1-10 mg/kg, produced parallel rightward shifts of the AM4054 dose-effect functions, and baseline effects of AM4054 were nearly recovered within 24 hours following 10 mg/kg of rimonabant. In contrast, in mice treated with 10 mg/kg of AM6538, antagonism of THC or AM4054 lasted up to 7 days. AM6538 also antagonized the discriminative stimulus effects of AM4054 in squirrel monkeys in a dose-related manner, and the effects of 3.2 mg/kg of AM6538 endured for more than 7 days. The effective reduction in CB1 receptor reserve was used to calculate the relative efficacy (tau values) of WIN 55,212, THC, and AM4054 in mice and of AM4054 monkeys, with results indicating that THC has a lower efficacy than WIN 55,212 or AM4054 in mice. These results demonstrate that AM6538 is a long-acting CB antagonist in vivo, and further suggest that differences in CB efficacy can be revealed in behavioral assays following AM6538 treatment.

Reversal agents for oral anticoagulants.

For more than half a century, warfarin, a vitamin K antagonist, has been the anticoagulant of choice. However, direct oral anticoagulants are rapidly gaining in popularity, which poses the need for efficacious reversal agents. This review article summarizes the strategies and agents used to reverse oral anticoagulants.

Reversal of Direct Oral Anticoagulants: Current Status and Future Directions.

Direct oral anticoagulants (DOACs) are increasingly used for prevention and treatment of venous thromboembolism and for prevention of stroke in patients with nonvalvular atrial fibrillation. In phase III clinical trials that included more than 100,000 patients, the DOACs were at least as effective as vitamin K antagonists (VKAs) and were associated with less serious bleeding, particularly less intracranial bleeding. Real-world evidence supports these outcomes. Despite this, some physicians and patients are concerned about serious bleeding or emergencies unless specific reversal agents for the DOACs are available. However, in clinical trials performed without reversal agents, the outcome of major bleeds was similar or better in patients receiving DOACs than in those taking VKAs. Because of their short half-lives, supportive measures are sufficient to manage most bleeds in patients receiving DOACs. Anticoagulant reversal should only be considered with life-threatening bleeds, with bleeds that fail to respond to usual measures and in patients requiring urgent surgery. Idarucizumab is licensed for dabigatran reversal and andexanet alfa is likely to be soon licensed for reversal of rivaroxaban, apixaban, and edoxaban. To ensure responsible use of these agents, every hospital needs a bleeding management algorithm that identifies patients eligible for reversal and outlines appropriate dosing regimens.

Clinical implications of reversal agents for direct oral anticoagulants.

Direct oral anticoagulants (DOACs) are effective in preventing and treating venous thromboembolism, and preventing stroke in atrial fibrillation. Until recently, there has been no specific reversal agent for DOACs. Now, a specific antidote for the direct thrombin inhibitor, dabigatran has been approved for use, and antidotes for factor Xa inhibitors (rivaroxaban, apixaban and edoxaban) are being developed. We review the evidence for currently used and emerging reversal strategies, and discuss possible clinical implications, including increased prescription of DOACs, use of DOACs in clinical situations previously felt to pose too great a risk of bleeding, and use of reversal agents beyond currently approved indications.

[NOAC: Real-life data and the role of antidotes for the treatment of bleeding]. / NOAK: Real-life-Daten und Therapie von Blutungen mit Antidots.

The non-vitamin K antagonists (NOAC) are an integral component of our antithrombotic prevention and therapy. For four of the NOAC, their non-inferiority or even superiority versus vitamin K antagonists (VKA) has been proven. Thus, the management of special patient cohorts or the management of active bleeding complications is a focus of current discussion.In addition to prospective trials, numerous retrospective analyses of health insurers or public health provider data have been analyzed and published as "real life" or "real-world evidence" data. In almost all data sets the results of the NOAC approval trials were confirmed, demonstrating their non-inferiority or even superiority versus VKA. Attempts to compare the various NOAC with each other must be viewed critically since the real-world evidence (RWE) analysis provides very divergent results depending on the cohorts analyzed. Thus, a substantial prescriber-bias must be taken into account and never be excluded.In order to improve the management of bleeding complications, NOAC antidotes were developed. While the factors Xa antidote, andexanet alpha, a modified coagulation factor deleted of an intrinsic activity, will not be available before 2018, the dabigatran antidote idarucizumab is already in clinical use. Idarucizumab, a monoclonal antibody fragment directed against dabigatran, is able to completely antagonize the effect of dabigatran within minutes. Therefore, the drug has the potential to terminate life-threatening bleeding complications earlier and make emergency surgical or interventional procedures possible without an elevated bleeding risk.

Factor Eight Inhibitor Bypassing Agent (FEIBA) for Reversal of Target-Specific Oral Anticoagulants in Life-Threatening Intracranial Bleeding.

INTRODUCTION: As increasing number of patients present to emergency departments with life threatening hemorrhages, particularly intracranial hemorrhage on anticoagulation physicians must be cognizant of the limitations of the available reversal options. Based upon the available literature, our institution formulated a reversal algorithm for patients with life-threatening bleeding on factor Xa inhibitors by administering factor eight inhibitor bypassing agent (FEIBA) 20 units/kg. METHODS: A retrospective chart review was performed to include all patients who received FEIBA per institutional protocol. This case series excluded patients who received FEIBA for reversal of dabigatran. Pre and post FEIBA CT scans were compared for changes. Finally, patients were stratified by estimated mortality rates calculated based on pre-intervention characteristics via published risk models. RESULTS: Thirteen patients were initially included in this study yet two patients were excluded because they were on dabigatran. Fifty-five percent of patients demonstrated stable ICH on CT scan after FEIBA administration while thirty-six percent showed worsening scans. Two patients developed thrombotic events after FEIBA administration. DISCUSSION: FEIBA is a treatment option in patients on a TSOA with acute intracranial hemorrhage with evidence of at least partial pharmacologic reversal of their anticoagulation status. There does not appear to be any major risk of thromboembolic complications associated with FEIBA. Much larger study sizes will be necessary to establish statically significant clinical efficacy for FEIBA use in this patient population. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency medicine physicians are first-line caretakers for patients with life threatening intracranial hemorrhages whether spontaneous or traumatic. FEIBA is a potentially safe option to reverse TSOA in this patient population.

Idarucizumab and factor Xa reversal agents: role in hospital guidelines and protocols.

As expected with all antithrombotic agents, there is a risk of bleeding complications in patients receiving direct oral anticoagulants (DOACs) because of the DOAC itself, acute trauma, invasive procedures, or underlying comorbidities. For many bleeding events, a prudent course of action will be to withdraw the DOAC, then "wait and support" the patient, with the expectation that the bleeding event should resolve with time. Likewise, DOAC therapy may be interrupted ahead of a planned procedure, the stopping time being dependent on the agent involved and the patient's renal function. However, urgent reversal of anticoagulation is required in patients with serious or life-threatening bleeding or in those requiring urgent surgery or procedures. Novel specific reversal agents, either under development or recently approved, will need to be incorporated into local anticoagulation reversal protocols. For dabigatran-treated patients, idarucizumab recently has been approved for clinical use in cases of life-threatening or uncontrolled bleeding or when patients require emergency surgery or urgent procedures, both associated with a high risk of bleeding. As clinical experience with individual specific reversal agents grows, their roles in managing major bleeding events in DOAC-treated patients will become better defined. Future research, as well as ongoing use of idarucizumab, should help establish when it is appropriate to re-dose with idarucizumab, coadminister with prothrombin complex concentrates, or re-initiate DOAC after idarucizumab use. Ongoing trials should help identify the appropriate doses and expected durations of effect for andexanet alfa and ciraparantag, which are likely to vary depending on the individual oral anticoagulants.

Optimizing the safety of treatment for venous thromboembolism in the era of direct oral anticoagulants.

Direct oral anticoagulants (DOACs) are rapidly replacing vitamin K antagonists (VKAs) for treatment of venous thromboembolism (VTE). The DOACs include dabigatran, which inhibits thrombin, and rivaroxaban, apixaban, and edoxaban, which inhibit factor Xa. When compared with conventional VTE treatment consisting of a parenteral anticoagulant followed by a VKA, the DOACs were equally effective for prevention of recurrence, but were associated with less bleeding. With similar efficacy, better safety, and the convenience of fixed dosing without the need for routine coagulation monitoring, guidelines now recommend DOACs over VKAs for VTE treatment in patients without active cancer. Nonetheless, measures are needed to optimize the safety of DOACs. Focusing on these measures, this paper summarizes the results of phase III trials evaluating DOACs for VTE treatment; identifies which VTE patients are or are not candidates for DOACs; provides guidance on how to choose among DOACs; lists the licensed dosing information for DOACs; discusses the optimal treatment duration for VTE; describes periprocedural management of DOACs in patients requiring surgery or intervention; and finally, reviews the management of bleeding, including the role for specific reversal agents.

[Perioperative coagulation management during ascending aorta replacement on apixaban]. / Perioperatives Gerinnungsmanagement bei Ersatz der Aorta ascendens unter Apixaban.

The direct oral anticoagulants (DOACs) present a valid therapeutic alternative to vitamin K antagonists in patients with non-valvular atrial fibrillation, for the prevention of venous thromboembolism, and for the treatment and prevention of the recurrence of pulmonary embolisms and deep vein thrombosis. Despite Idarucizumab as an antagonist of Dabigatran there are no other specific antidotes available yet. Therefore, perioperative coagulation management by DOACs is challenging in patients undergoing emergency surgical procedures with a high risk of bleeding complications. This case study describes the perioperative procedure during ascending aorta replacement after aortic dissection with apixaban administration.

Enhanced discriminative stimulus effects of Δ(9)-THC in the presence of cannabidiol and 8-OH-DPAT in rhesus monkeys.

BACKGROUND: Cannabidiol, a therapeutic with potential serotonin (5-hydroxytryptamine; 5-HT) 5-HT1A receptor agonist activity, is the second most prevalent cannabinoid in Cannabis after Δ(9)-THC. The extent to which cannabidiol modifies the effects of Δ(9)-THC has not been firmly established, especially with respect to abuse-related effects in rhesus monkeys where previously antagonistic interactions have been reported for some behavioral outcomes. METHODS: Cannabidiol and the 5-HT1A receptor agonist (±)-8-hydroxy-2-(dipropylamino)tetralin hydrobromide (8-OH-DPAT) were tested in two separate discrimination assays in rhesus monkeys. One group (n=6) discriminated Δ(9)-tetrahydrocannabinol (Δ(9)-THC; 0.1mg/kg i.v.); a second group (n=6) discriminated the cannabinoid antagonist rimonabant (1mg/kg i.v.) while receiving Δ(9)-THC daily (1mg/kg/12hs.c.). Responding was maintained under a fixed ratio 5 schedule of stimulus-shock termination. RESULTS: Both training drugs dose-dependently increased the percentage of responses on the respective drug-associated levers. Cannabidiol (up to 17.8mg/kg) and 8-OH-DPAT (up to 0.178mg/kg) did not substitute for either training drug; however, both significantly increased the potency of Δ(9)-THC to produce discriminative stimulus effects. Moreover, 8-OH-DPAT significantly attenuated the discriminative stimulus effects of rimonabant, whereas cannabidiol did not modify the rimonabant discriminative stimulus. CONCLUSIONS: These results, which are consistent with cannabidiol lacking CB1 receptor agonist or antagonist activity in vivo, demonstrate enhancement of the effects of Δ(9)-THC by cannabidiol, albeit at cannabidiol amounts larger than those in Cannabis or cannabidiol-based therapeutics (nabiximols). In addition to showing that cannabidiol and a 5-HT1A receptor agonist have overlapping behavioral effects, the current results suggest that 5-HT1A agonism enhances the CB1 receptor-mediated effects of Δ(9)-THC.

Bleeding management in patients with new oral anticoagulants.

New oral anticoagulants (NOACs) have been developed in recent years and are increasingly used in clinical practice. Dabigatran is a direct thrombin (factor II) inhibitor while rivaroxaban, apixaban and edoxaban are direct inhibitors of factor Xa. The European Medicines Agency (EMA) currently approves these NOACs for different clinical uses. NOACs do not require routine monitoring of coagulation although an assessment of anticoagulation activity in these patients may be required in different conditions. NOACs show a similar or lower incidence of bleeding compared with conventional therapies in phase III trials. In case of bleeding, non-specific reversal strategies are available while specific reversal agents are the subject of ongoing trials. The role of this review is to summarize the current knowledge on NOCAs focusing on bleeding management in the perioperative period.