The European Medicines Agency (EMA) released a draft of an upcoming guidance pertaining to the clinical investigation of medicinal products used to prevent venous thromboembolism (VTE) in patients preparing to undergo surgery for the condition.
In the 30 May 2012 draft guidance, EMA explains the upcoming revision to the guidance-the second since it was first issued in 2006-contains a number of small but important changes to the guidance.
"This second revision includes an updated definition of major bleeding and its assessment," wrote EMA. "It also proposes a definition for clinically relevant minor bleeding and inclusion of other secondary endpoints related to the reporting of surgical blood loss, blood transfusions, wound complications, functional outcomes, hepatic and cardiovascular events.
VTE is a condition in which one or more blood clots develop within a vein inside a patient, which can later dislodge and become life-threatening. A medical class of drugs known as thromboprophylaxis can reduce morbidity and mortality related to pulmonary embolisms as the result of VTE in surgical settings. A common and high-risk side effect of these drugs is bleeding and blood loss, which EMA's guidance further defines.
So-called "major bleeding" instances are the most dangerous for patients and involve potentially fatal bleeding, critical bleeding, clinical overt bleeding resulting in a significant drop in haemoglobin levels, bleeding requiring two or more units of whole blood or packed cells or bleeding located at the surgical site and requiring re-operation or another non-routine medical intervention.
EMA recommends clinical trials studying VTE treatments look at three types of composite bleeding endpoints: clinical relevant bleeding, non-major bleeding and total bleeding.
Other clinical parameters include haemaglobin plasma levels, haematocrit and red cell count changes during the treatment period, operative blood loss, percent of patients with post-operative drain, calculated blood loss, post-operative wound drainage, bleeding index, transfusion volume and wound complications.
EMA - Draft guideline on clinical investigation of medicinal products for prevention of venous thromboembolism (VTE) in patients undergoing high VTE-risk surgery