Recombinant nematode anticoagulant protein c2 in patients with non-ST-segment elevation acute coronary syndrome: the ANTHEM-TIMI-32 trial.
OBJECTIVE
We sought to evaluate the safety and efficacy of recombinant nematode anticoagulant protein c2 (rNAPc2) in patients with non-ST-segment elevation acute coronary syndrome (nSTE-ACS).


BACKGROUND
Recombinant NAPc2 is a potent inhibitor of the tissue factor/factor VIIa complex that has the potential to reduce ischemic complications mediated by thrombin generation.


METHODS
A total of 203 patients were randomized 4:1 to double-blinded intravenous rNAPc2 or placebo every 48 h for a total of 1 to 3 doses in 8 ascending panels (1.5 to 10 microg/kg). All patients received aspirin, unfractionated heparin (UFH), or enoxaparin and early catheterization; clopidogrel and glycoprotein IIb/IIIa blockers were encouraged. Two subsequent open-label panels evaluated 10 mug/kg rNAPc2 with half-dose UFH (n = 26) and no UFH (n = 26). The primary end point was the rate of major plus minor bleeding. Pharmacokinetics, pharmacodynamics, continuous electrocardiography, and clinical events were assessed.


RESULTS
Recombinant NAPc2 did not significantly increase major plus minor bleeding (3.7% vs. 2.5%; p = NS) despite increasing the international normalized ratio in a dose-related fashion (trend p < or = 0.0001). Higher-dose rNAPc2 (> or =7.5 microg/kg) suppressed prothrombin fragment F1.2 generation compared with placebo and reduced ischemia by >50% compared to placebo and lower-dose rNAPc2. Thrombotic bailout requiring open-label anticoagulant occurred in 5 of 26 patients treated without UFH, but none in the half-dose UFH group (19% vs. 0%; p = 0.051).


CONCLUSIONS
In patients with nSTE-ACS managed with standard antithrombotics and an early invasive approach, additional proximal inhibition of the coagulation cascade with rNAPc2 was well tolerated. rNAPc2 doses > or =7.5 microg/kg suppressed F1.2 and reduced ischemia, though some heparin may be necessary to avoid procedure-related thrombus formation. (Anticoagulation With rNAPc2 to Eliminate MACE/TIMI 32; http://www.clinicaltrial.gov/ct/show/NCT00116012?order=1; NCT00116012).
Giugliano
Robert P
RP
TIMI Study Group, Boston, Massachusetts 02115, USA. rgiugliano@partners.org
Wiviott
Stephen D
SD
Stone
Peter H
PH
Simon
Daniel I
DI
Schweiger
Marc J
MJ
Bouchard
Alain
A
Leesar
Massoud A
MA
Goulder
Michael A
MA
Deitcher
Steven R
SR
McCabe
Carolyn H
CH
Braunwald
Eugene
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D015801:Helminth Proteins / Q000008:administration & dosage*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000188:drug therapy* / Q000401:mortality; D010865:Pilot Projects; D011994:Recombinant Proteins / Q000008:administration & dosage; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome
D015801:Helminth Proteins; D011994:Recombinant Proteins; C400226:anti-coagulant protein C2, Ancylostoma caninum