Centocor Inc.'s ReoPro abciximab chimeric monoclonal antibody, which is marketed for cardiovascular indications, inhibits the platelet integrin glycoprotein IIb/IIIa. But ReoPro also blocks the integrin receptor alpha(v)beta(3), which binds another extracellular matrix protein called vitronectin. Now a review article in last week's New England Journal of Medicine has suggested that antibodies targeting alpha(v)beta(3) also could be useful to treat sickle cell anemia.

While the sickling of deoxygenated red blood cells characterizes the disease, vaso-occlusion in sickle cell patients results from other factors as well, including adhesion of sickle cells (both oxygenated and deoxygenated) to the vascular endothelium. Non-specific lubricating agents are being tested, such as Flocor, a purified version of RheothRx poloxamer 188 in Phase III development by CytRx Corp. (CYTR, Atlanta, Ga.). But more specific agents may be useful.