edoxaban and Prostatic-Neoplasms

Enzalutamide, a novel, oral androgen receptor antagonist used for the treatment of metastatic, castration-resistant prostate cancer, has been shown to improve overall and progression-free survival, prolong time to initiation of chemotherapy, reduce skeletal-related events, and carry a favorable adverse effect profile. Metastatic prostate cancer is a disease of older men, a population with an increased incidence of medical comorbidities warranting anticoagulation. Prostate cancer itself, along with some of its therapies, is also prothrombotic. Enzalutamide interacts with several anticoagulants through various mechanisms, making their concurrent use clinically challenging. As such, complex decisions about anticoagulation in these patients are frequently encountered by treating physicians. In this review, we describe the potential interactions between enzalutamide and various anticoagulants, and suggest management paradigms based on the current body of knowledge for patients with atrial fibrillation, venous thromboembolism, and mechanical heart valves.

Topics: Androgen Receptor Antagonists; Anticoagulants; Atrial Fibrillation; Benzamides; Dabigatran; Drug Interactions; Embolism; Heart Valve Prosthesis; Heparin, Low-Molecular-Weight; Humans; Male; Nitriles; Phenylthiohydantoin; Prostatic Neoplasms; Pyrazoles; Pyridines; Pyridones; Rivaroxaban; Thiazoles; Venous Thromboembolism; Warfarin

Background Anticoagulation in patients with malignancy and atrial fibrillation is challenging because of enhanced risks for thrombosis and bleeding and the frequent need for invasive procedures. Data on direct oral antagonists in such patients are sparse. Methods and Results The ENGAGE AF - TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction Study 48) trial randomized 21 105 patients with atrial fibrillation to edoxaban or warfarin. Patients with malignancy, defined as a postrandomization new diagnosis or recurrence of remote cancer, were followed up over a median of 2.8 years. Adjusted Cox proportional hazard models were used to evaluate the safety and efficacy of edoxaban versus warfarin. Over a median of 495 days (interquartile range, 230-771 days), 1153 patients (5.5%) were diagnosed with new or recurrent malignancy, most commonly involving the gastrointestinal tract (20.6%), prostate (13.6%), and lung (11.1%). Malignancy was associated with increased risk of death (adjusted hazard ratio [HR], 3.12; 95% confidence interval [CI], 2.78-3.50) and major bleeding (adjusted HR, 2.45; 95% CI, 2.07-2.89), but not stroke/systemic embolism (adjusted HR, 1.08; 95% CI, 0.83-1.42). Relative outcomes with higher-dose edoxaban versus warfarin were consistent regardless of malignancy status for stroke/systemic embolism ( HR , 0.60 [95% CI, 0.31-1.15] for malignancy versus HR , 0.89 [95% CI, 0.76-1.05] for no malignancy; interaction P=0.25) and major bleeding ( HR , 0.98 [95% CI, 0.69-1.40] for malignancy versus HR , 0.79 [95% CI, 0.69-1.05] for no malignancy; interaction P=0.31). There was, however, a significant treatment interaction for the composite ischemic end point (ischemic stroke/systemic embolism/myocardial infarction), with greater efficacy of higher-dose edoxaban versus warfarin in patients with malignancy ( HR , 0.54; 95% CI, 0.31-0.93) compared with no malignancy ( HR , 1.02; 95% CI, 0.88-1.18; interaction P=0.026). Conclusions In patients with atrial fibrillation who develop malignancy, the efficacy and safety profile of edoxaban relative to warfarin is preserved, and it may represent a more practical alternative.

Topics: Aged; Anticoagulants; Atrial Fibrillation; Comorbidity; Embolism; Factor Xa Inhibitors; Female; Gastrointestinal Neoplasms; Hemorrhage; Humans; Lung Neoplasms; Male; Middle Aged; Neoplasms; Proportional Hazards Models; Prostatic Neoplasms; Pyridines; Stroke; Thiazoles; Warfarin