NCIt definition : An ultralow-molecular-weight heparin (ULMWH) (Mw: 2000-3000 daltons)consisting of
a polydisperse mixture of oligomeric heparin fragments with potential anticoagulant
activity. Ultralow-molecular-weight heparin AVE5026 binds to and activates antithrombin
III (ATIII), which may result in the inhibition of activated factor Xa and, to a much
lesser extent, factor IIa (thrombin) and so the inhibition of fibrin formation. Compared
to low-molecular-weight heparins (LMWHs), AVE5026 exhibits an even higher ratio of
anti-Factor Xa to anti-Factor IIa activity ( 30:1). Compared to unfractionated heparins,
the use of LMWHs is associated with lower incidences of major bleeding, osteoporosis
and heparin-induced thrombocytopenia. Like LMWHs, this agent may inhibit tumor growth
by regulating angiogenesis and apoptosis. AVE5026 is prepared by partial depolymerization
of unfractionated porcine mucosal heparin.;