New research focusing on VTE presented at ASH Annual Meeting

November 29, 2015

This study analyzed data from the Einstein-DVT and the Einstein-Extension studies. The Einstein-DVT study compared rivaroxaban, an oral anticoagulant, with enoxaparin followed by oral vitamin K antagonist (VKA), the current standard therapy for DVT, for either three, six, or 12 months. The purpose of this study was to investigate the efficacy and safety of rivaroxaban and determine whether the new therapy was at least as effective as and easier to use than current treatment. Patients diagnosed with acute DVT without symptomatic pulmonary embolism (PE) were randomized to receive either oral rivaroxaban (1,731 patients) or enoxaparin (1,718 patients). In the Einstein-Extension study, patients that completed six to 12 months of anticoagulant treatment were randomized to receive rivaroxaban (602 patients) or placebo (594 patients) for an additional six to 12 months. In this study, the investigators sought to prove that rivaroxaban was superior to no treatment (placebo), with the exception of bleeding risk. For both studies, the primary efficacy outcome was recurrent non-fatal or fatal symptomatic VTE, and the principal safety outcome was major or clinically relevant non-major bleeding in Einstein-DVT and major bleeding the Einstein-Extension study.

Results from the Einstein-DVT study revealed 36 (2.1 percent) VTE events in the rivaroxaban group versus 51 (3.0 percent) cases of VTE in the enoxaparin/VKA treatment group. In both groups, major or clinically relevant non-major bleeding occurred in 8.1 percent of subjects while major bleeding occurred in 0.8 percent (one fatal) and 1.2 percent (five fatal) of the rivaroxaban and enoxaparin/VKA patients, respectively.

Results from the Einstein-Extension study demonstrated eight (1.3 percent) VTE events among rivaroxaban recipients and 42 events (7.1 percent) in the placebo group. Major bleeding occurred in 0.7 percent (none fatal) of rivaroxaban recipients and in none of the placebo patients. Clinically relevant non-major bleeding occurred in 5.4 percent of rivaroxaban and 1.2 percent of placebo recipients, respectively. Results from both studies prove rivaroxaban is an effective therapy against DVT and reduces major bleeding risk.

"These study outcomes may possibly change the way that patients with DVT are treated," said lead study author Harry R. Buller, MD, PhD, Professor of Medicine at the Academic Medical Center at the University of Amsterdam in Amsterdam, Netherlands. "This new treatment regimen of oral rivaroxaban can potentially make blood clot therapy easier than the current standard treatment for both the patient and the physician with a single-drug and simple fixed-dose approach."

Dr. Buller will present this study in an oral presentation on Monday, December 6, at 7:00 a.m. in Room 230.

Outpatient Treatment in Patients With Acute Pulmonary Embolism: The Hestia Study [LBA 1]

Pulmonary embolism (PE), which occurs when a blood clot detaches from its point of origin and travels to the lungs where it prevents adequate blood flow, affects approximately 200,000 people per year in the United States. Currently, patients with PE are initially treated in the hospital with low-molecular-weight heparin (LMWH), but several previous studies suggest that outpatient treatment may also be effective and safe for some PE patients. Clinicians need a way to identify those patients who may benefit from outpatient treatment, but validated selection criteria for this purpose are lacking.

With the goal of providing clinicians with a reliable evaluation tool, a group of researchers developed the Hestia criteria, an 11-point questionnaire, and studied its efficacy and safety in determining eligibility for outpatient treatment for patients with acute PE. A total of 297 patients in 12 hospitals in the Netherlands were identified with the Hestia criteria and treated on an outpatient basis with weight-adjusted therapeutic doses of LMWH followed by vitamin K antagonists (VKA). They were sent home from the hospital within 24 hours after being diagnosed with PE. Venous thromboembolism re-occurred in six patients (2 percent; PE in five patients and DVT in one), two patients experienced major bleeding (0.7 percent), and three patients died in the three months following treatment, although none as a result of fatal PE.

"Results from this study show that the Hestia criteria are efficacious and safe in helping doctors determine which acute PE patients can receive outpatient anticoagulant treatment safely," said Menno Huisman, MD, PhD, Associate Professor of Medicine, Chair, Section of Vascular Medicine in the Department of Medicine at Leiden University Medical Center in Leiden, Netherlands. "This set of criteria serves as an easy-to-use model for clinicians who treat PE patients."

Dr. Huisman's co-author Dr. Wendy Zondag will present this study in the Late-Breaking Abstracts Session on Tuesday, December 7, at 7:30 a.m. in Hall D.

SOURCE American Society of Hematology