NOVO NORDISK LOGIPARIN SUPERIOR TO WARFARIN FOR PREVENTION OF DEEP VEIN THROMBOSIS

NOVO NORDISK LOGIPARIN SUPERIOR TO WARFARIN FOR PREVENTION OF DEEP VEIN THROMBOSIS in a study of 1,436 hip- or knee- replacement surgeries. The study, conducted by Russell Hull, University of Calgary, et al., and published in the Nov. 4 New England Journal of Medicine, found that 31.4% of patients treated with Novo Nordisk's low-molecular-weight heparin Logiparin experienced deep vein thrombosis compared to 37.4% of patients treated with DuPont-Merck's Coumadin (warfarin). "The reduction in the rate of venous thrombosis with low- molecular-weight heparin, as compared with warfarin, is offset by an increase in the number of bleeding complications and wound hematomas," the article states. The incidence of major bleeding among warfarin-treated patients was 1.2% compared to 2.8% in the Logiparin group. Rates of uncomplicated wound hematoma were 3.6% on warfarin and 6.7% on Logiparin. The advantage of Logiparin therapy was most pronounced in the 641 knee surgery patients. The rate of DVT in warfarin-treated knee surgery patients was 54.9% compared to 45% in the Logiparin group. For hip surgery patients, the DVT rates were 23.2% in the warfarin group and 20.8% in the Logiparin group, not a statistically significant difference. The first low-molecular-weight heparin product approved in the U.S., Rhone-Poulenc Rorer's Lovenox (enoxaparin), was launched in April ("The Pink Sheet" April 12, T&G-4). Lovenox' approval was based on a comparison of the drug to placebo in hip-replacement surgery. Lovenox reduced DVT rates from 46% on placebo to 10% on drug. Introducing their study, Hull et al. wrote: "To date, there are few data comparing less intense prophylaxis using warfarin sodium with prophylaxis using a low-molecular-weight heparin fraction. A comparison of effectiveness and safety would be important, given the widespread acceptance and use of less intense warfarin sodium prophylaxis to treat orthopedic patients in North America." The study compared standard individually-titrated warfarin therapy to a fixed dose of 75 international units of anti-Factor Xa per kilogram of Logiparin. The low-molecular-weight heparin product was administered in once-daily subcutaneous injections, beginning 18-24 hours after surgery unless there were signs of excessive bleeding from the wound. Patients were treated for 14 days or until discharge from the hospital, and presence of DVT was assessed by bilateral ascending radiocontrast venography. "At this time, it is unclear which of these approaches will be more cost effective," Hull et al. wrote. "Although low-molecular- weight heparin offers the advantage of simplicity because this antithrombotic agent is administered in a daily subcutaneous injection without the need for monitoring, it may prove to be more costly than warfarin," the authors suggested. "Warfarin is inexpensive, but the cost of its administration is increased by the need for monitoring of the international normalized ratio." Rhone-Poulenc Rorer supported its $23/day launch price for Lovenox with estimates of the relative costs of treating DVT and savings from reduced hospitalization following surgery in comparison to no prophylaxis ("The Pink Sheet" April 19, T&G-5). Novo-Nordisk has said it plans to file an NDA for Logiparin by the end of 1993 ("The Pink Sheet" Aug. 23, p. 16).