Tenecteplase Shows Benefit for Intermediate-Risk Patients With Pulmonary Embolism

March 11, 2013—Findings from the PEITHO (Pulmonary Embolism Thrombolysis) study, which tested the addition of a thrombolytic drug, tenecteplase, to standard treatment with heparin, were presented at the 62nd annual scientific session of the American College of Cardiology (ACC) in San Francisco, California.

According to the ACC announcement, the double-blind PEITHO study enrolled 1,006 patients in 13 countries. The patients were randomized to heparin plus placebo or heparin plus tenecteplase. Tenecteplase prevents death or circulatory collapse in a subgroup of patients with a blood clot in the lungs and appears to be especially useful in patients aged less than 75 years, noted the ACC's press release.

In PEITHO, the combined primary endpoint was death from any cause or hemodynamic collapse after 7 days. Hemodynamic collapse was defined as at least one of the following: needing CPR due to a loss of blood pressure; systolic blood pressure of less than 90 mm Hg or a decrease of more than 40 mm Hg for at least 15 minutes; or the need for drugs called catecholamines, which boost circulation.

The primary endpoint was reduced by 56% in patients treated with tenecteplase and heparin, compared with the heparin-only group.

Stavros Konstantinides, MD, professor for clinical trials at the Center for Thrombosis and Hemostasis at the University of Mainz, Germany, is the PEITHO study's coprincipal investigator. In the ACC announcement, Dr. Konstantinides commented, “In patients with intermediate-risk pulmonary embolism, thrombolytic treatment significantly reduced the primary endpoint. Overall, the study strongly supports the concept that risk stratification of patients makes sense and that these patients need something to prevent deterioration.”

Hemodynamic collapse occurred in 1.6% of patients receiving tenecteplase versus 5% receiving placebo, a significant reduction. Actual death rates were low and not significantly different between groups: 1.2% in the tenecteplase group versus 1.8% in the placebo group. Additionally, major bleeding was significantly increased with tenecteplase: 6.3% versus 1.5% in the placebo group. There were 10 hemorrhagic strokes in the tenecteplase group and one in the placebo group, reported the ACC.

Dr. Konstantinides added, “This is more or less the rate that we have seen in previous thrombolytic trials. Patients who were younger than 75 years old had most of the benefit and a tendency toward fewer hemorrhagic strokes. Our future priorities are now to refine our risk stratification concept even further to better identify those patients who will benefit most with less risk of bleeding. Also, the dose of the drug that we used could be lowered in older patients, and alternative methods of delivering thrombolytics could be explored.”