In:
Blood, American Society of Hematology, Vol. 94, No. 2 ( 1999-07-15), p. 587-599
Abstract:
Most clinical trials with fibrinogen receptor antagonists (FRAs) have been associated with thrombocytopenia. This report describes the occurrence of thrombocytopenia in one chimpanzee and one rhesus monkey upon administration of potent FRAs. Chimpanzee A-264 experienced profound thrombocytopenia on two occasions immediately upon intravenous administration of two different potent FRAs, L-738,167 and L-739,758. However, an equally efficacious antiaggregatory dose of another potent antagonist, L-734,217, caused no change in platelet count. These compounds did not affect platelet count in five other chimpanzees or numerous other nonhuman primates. Flow cytometric analysis showed drug-dependent antibodies (DDAbs) in the plasma of chimpanzee A-264 that bound to platelets of chimpanzees, humans, and all other primates tested only in the presence of the compounds that induced thrombocytopenia. Rhesus monkey 94-R021 experienced thrombocytopenia upon administration of a different antagonist, L-767,679, and several prodrugs that are converted into the active form, L-767,679, in the blood. More than 20 other FRAs, including those that induced thrombocytopenia in chimpanzee A-264, had no effect on platelet count in this monkey. Flow cytometric measurements again identified DDAbs that reacted with platelets of all primates tested and required the presence of L-767,679. Screening for DDAbs in the plasma of 1,032 human subjects with L-738,167 and L-739,758 demonstrated that the incidence of these preexisting antibodies in this population was 0.8% ± 0.6% and 1.1% ± 0.6%, respectively.
Type of Medium:
Online Resource
ISSN:
1528-0020
,
0006-4971
DOI:
10.1182/blood.V94.2.587.414a28_587_599
Language:
English
Publisher:
American Society of Hematology
Publication Date:
1999
detail.hit.zdb_id:
1468538-3
detail.hit.zdb_id:
80069-7
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