Potential Drug Interactions between Recombinant Interleukin-2 and Direct Oral Anticoagulants: Indirect Evidence from In Vivo Animal Studies.

Recombinant interleukin-2 (rIL-2) is indicated for metastatic renal cell carcinoma and melanoma. Over recent years low-dose rIL-2 has been studied for the treatment of autoimmune diseases and acute coronary syndrome because of its ability to expand and activate T regulatory (Treg) cells. However, several medical conditions potentially benefiting from rIL-2 administrations are characterized by an intrinsic prothrombotic risk, thus requiring concurrent anticoagulation. In our systematic review of the literature, we investigated the potential for drug interactions between oral anticoagulants and rIL-2 by assessing the influence of rIL-2 administration on transporters and cytochromes determining the pharmacokinetics of (direct) oral anticoagulants. We extracted data from 12 studies, consisting of 11 animal studies and one study in humans. Eight studies investigated the pharmacokinetics of P-glycoprotein (P-gp) substrates and reported that the intraperitoneal rIL-2 administration may inhibit intestinal P-gp. Four studies on hepatic cytochrome P450 yielded conflicting results. The only human study included in this systematic review concluded that rIL-2 suppresses the hepatic cytochrome P450, but only if given at higher doses. Based on the results from animal studies, the co-administration of rIL-2 and dabigatran etexilate, a substrate of intestinal P-gp, may lead to higher dabigatran plasma concentrations and bioavailability. Human studies should confirm whether this potential interaction is clinically relevant.

Safety of low-dose subcutaneous recombinant interleukin-2: systematic review and meta-analysis of randomized controlled trials.

Standard-dose intravenous recombinant interleukin-2 (rIL-2) is indicated for the treatment of some subtypes of cancer; however, severe adverse events, including venous thromboembolism (VTE), may complicate its administration. Low-dose subcutaneous rIL-2 is being studied for the management of immune-mediated diseases, since it can modulate the immunological response by specifically targeting T regulatory (Treg) cells; importantly, it is supposed to cause fewer or no complications. In this systematic review and meta-analysis of phase II-III randomized controlled trials (RCTs), we investigated the safety of low-dose (<6 Million International Unit [MIU]/day) and ultra-low-dose (≤1 MIU/day) rIL-2 for severe adverse events (grade III-V) with a focus on VTE. Data of 1,321 patients from 24 RCTs were analysed: 661 patients were randomized to the rIL-2 arm (on top of standard of care) and 660 patients to standard of care alone or placebo. Two studies reported higher rates of thrombocytopenia in the low-dose rIL-2 arm. Ultra-low-dose rIL-2 was reported to be well tolerated in 6 studies with a negligible rate of severe adverse events. Symptomatic VTE events were not reported in any of the study arms (absolute risk difference 0% [95%CI -0.1%; +0.1%]). Our results may facilitate the study and introduction in clinical practice of low-dose rIL-2 for potentially new indications.

Dabigatran after Short Heparin Anticoagulation for Acute Intermediate-Risk Pulmonary Embolism: Rationale and Design of the Single-Arm PEITHO-2 Study.

Patients with intermediate-risk pulmonary embolism (PE) may, depending on the method and cut-off values used for definition, account for up to 60% of all patients with PE and have an 8% or higher risk of short-term adverse outcome. Although four non-vitamin K-dependent direct oral anticoagulants (NOACs) have been approved for the treatment of venous thromboembolism, their safety and efficacy as well as the optimal anticoagulation regimen using these drugs have not been systematically investigated in intermediate-risk PE. Moreover, it remains unknown how many patients with intermediate-high-risk and intermediate-low-risk PE were included in most of the phase III NOAC trials. The ongoing Pulmonary Embolism International Thrombolysis 2 (PEITHO-2) study is a prospective, multicentre, multinational, single-arm trial investigating whether treatment of acute intermediate-risk PE with parenteral heparin anticoagulation over the first 72 hours, followed by the direct oral thrombin inhibitor dabigatran over 6 months, is effective and safe. The primary efficacy outcome is recurrent symptomatic venous thromboembolism or death related to PE within the first 6 months. The primary safety outcome is major bleeding as defined by the International Society on Thrombosis and Haemostasis. Secondary outcomes include all-cause mortality, the overall duration of hospital stay (index event and repeated hospitalizations) and the temporal pattern of recovery of right ventricular function over the 6-month follow-up period. By applying and evaluating a contemporary risk-tailored treatment strategy for acute PE, PEITHO-2 will implement the recommendations of current guidelines and contribute to their further evolution.

Home treatment of patients with low-risk pulmonary embolism with the oral factor Xa inhibitor rivaroxaban. Rationale and design of the HoT-PE Trial.

Pulmonary embolism (PE) is a potentially life-threatening acute cardiovascular syndrome. However, more than 95 % of patients are haemodynamically stable at presentation, and among them are patients at truly low risk who may qualify for immediate or early discharge. The Home Treatment of Pulmonary Embolism (HoT-PE) study is a prospective international multicentre single-arm phase 4 management (cohort) trial aiming to determine whether home treatment of acute low-risk PE with the oral factor Xa inhibitor rivaroxaban is feasible, effective, and safe. Patients with confirmed PE, who have no right ventricular dysfunction or free floating thrombi in the right atrium or ventricle, are eligible if they meet none of the exclusion criteria indicating haemodynamic instability, serious comorbidity or any condition mandating hospitalisation, or a familial/social environment unable to support home treatment. The first dose of rivaroxaban is given in hospital, and patients are discharged within 48 hours of presentation. Rivaroxaban is taken for at least three months. The primary outcome is symptomatic recurrent venous thromboembolism or PE-related death within three months of enrolment. Secondary outcomes include quality of life and patient satisfaction, and health care resource utilisation compared to existing data on standard-duration hospital treatment. HoT-PE is planned to analyse 1,050 enrolled patients, providing 80 % power to reject the null hypothesis that the recurrence rate of venous thromboembolism is >3 % with α≤0.05. If the hypothesis of HoT-PE is confirmed, early discharge and out-of-hospital treatment may become an attractive, potentially cost-saving option for a significant proportion of patients with acute PE.

CRP and CD14 polymorphisms correlate with coronary plaque volume in patients with coronary artery disease--IVUS substudy of the ENCORE trials.

BACKGROUND: Several proinflammatory single-nucleotide polymorphisms (SNPs) have been linked to the progression of atherosclerosis and coronary artery disease (CAD). Plaque size and its destabilization by inflammatory processes are major determinants of ischemia and acute coronary syndromes. Intravascular ultrasound (IVUS) allows for quantification of plaque size in vivo. We therefore investigated the relation of plaque size with mutations of proinflammatory genes in patients with CAD. METHODS: In 196 patients with stable CAD enrolled in the ENCORE trials coronary plaque and vessel volume was assessed by IVUS. 173 patients were successfully genotyped for polymorphisms of proinflammatory genes CD14 C(-260)T and CRP C(+1444)T using the single-nucleotide polymorphism polymerase chain reaction (SNP PCR) approach. RESULTS: Baseline characteristics were comparable for all genotype groups. Higher ratios of plaque volume/vessel volume were observed in patients with the CRP 1444TT (n=11) and CD14 260TT (n=33) genotypes (p=0.016 and p=0.026, respectively). CONCLUSION: In patients with stable coronary artery disease the CRP 1444TT and CD14 260TT variants are associated with larger coronary plaque volume independently of concomitant cardiovascular risk factors.

Asymmetrical dimethylarginine (ADMA) and coronary endothelial function in patients with coronary artery disease and mild hypercholesterolemia.

OBJECTIVE: To investigate the association of the endogenous nitric oxide synthase inhibitor asymmetrical dimethylarginine (ADMA) and coronary endothelial function. METHODS AND RESULTS: In 289 patients with coronary artery disease we assessed coronary endothelium-dependent and -independent vascular responses to intracoronary infusion of acetylcholine, adenosine, and nitroglycerin, respectively, and determined plasma ADMA and l-arginine concentrations by HPLC. After 6 months of treatment with either cerivastatin, nifedipine, cerivastatin+nifedipine, or placebo, coronary vascular function testing as well as ADMA and l-arginine determinations were repeated. We observed no correlation of plasma ADMA or l-arginine concentration and coronary response to acetylcholine, adenosine or nitroglycerin baseline, and no correlation of changes of ADMA or l-arginine plasma concentration with changes in coronary function (all r and rho<0.3, all p>0.05). CONCLUSION: At physiological plasma concentrations ADMA appears to have only little impact on coronary endothelial function.

Long-term effects of darusentan on left-ventricular remodelling and clinical outcomes in the EndothelinA Receptor Antagonist Trial in Heart Failure (EARTH): randomised, double-blind, placebo-controlled trial.

BACKGROUND: Endothelin-receptor blockade provides haemodynamic benefit in experimental and clinical heart failure. We aimed to measure the effects of long-term endothelin-blockade on left-ventricular (LV) remodelling and clinical outcomes in patients with chronic heart failure. METHODS: 642 patients with chronic heart failure were assigned the oral endothelin(A)-antagonist darusentan at 10, 25, 50, 100, or 300 mg daily or placebo for 24 weeks in addition to standard therapy in a randomised, double-blind, placebo-controlled trial. In the 50-300 mg groups, darusentan was uptitrated over 6 weeks. Primary endpoint was change in LV end-systolic volume (LVESV) at 24 weeks from baseline, measured by MRI. All patients for whom assessable MRI scans were available at baseline and follow-up were included in the analysis. FINDINGS: Darusentan was well tolerated. LVESV could be assessed in 485 (76%) patients with paired MRI data at baseline and 6 months. The change in LVESV was not significantly different from that with placebo at any dose (mean difference from placebo 1.27 mL [95% CI -9.9 to 12.4] with 10 mg dose, -1.84 mL [-13.0 to 9.3] with 25 mg, -5.68 mL [-16.9 to 5.6] with 50 mg, -4.05 mL [-15.5 to 7.4] with 100 mg, and -4.34 mL [-15.7 to 7.0] with 300 mg). Heart failure worsened in 71 (11.1%) patients, and 30 (4.7%) died during the study with no difference between groups. INTERPRETATION: Endothelin(A) blockade with darusentan did not improve cardiac remodelling or clinical symptoms or outcomes in patients with chronic heart failure receiving an angiotensin-converting-enzyme inhibitor, beta blocker, or aldosterone antagonist. Thus, endothelin(A) blockade is unlikely to be useful as an add-on treatment in such patients.