Bloodsuckers such as leeches and bats are providing models for genetically engineered blood thinners, including one derived from leech saliva that was found to reduce the risk of blood clots in some surgery patients.
The study found that treatment with the saliva-based thinner reduced the risk of dangerous clots in patients undergoing hip replacement surgery by 40 percent when compared to a standard medicine.The genetically engineered drug, called desirudin, is one of several new medicines in development to replace heparin and warfarin, which have been the standby therapies for many years.
Blood clots in the legs are a common complication of hip replacements. Without blood thinners, as many as half of patients may have them. The clots are especially dangerous if they break loose and become lodged in the lungs.
Dr. Bengt Eriksson at Sahlgrenska-Ostra University Hospital in Goteborg, Sweden, directed a study of desirudin on 2,079 hip replacement patients at 31 hospitals in 10 European countries. The study was financed by Novartis, a Swiss pharmaceutical company that is developing desirudin.
Patients were randomly assigned to get either desirudin or low molecular weight heparin, a newly developed form of heparin that is easier to administer than the standard variety.
Five percent of patients getting desirudin suffered deep-vein thrombosis after their surgery, compared with 8 percent getting heparin.
Still in the works are genetically engineered versions of other natural blood thinners derived from bats, sand flies and other bloodsucking creatures.