Initial experience with an intravenous P2Y12 platelet receptor antagonist in patients undergoing percutaneous coronary intervention: results from a 2-part, phase II, multicenter, randomized, placebo- and active-controlled trial.
BACKGROUND
Platelet-initiated acute thrombosis and coronary embolization are fundamental in the pathophysiology of complications during percutaneous coronary intervention (PCI). Cangrelor (formerly AR-C69931MX) is a novel, rapidly acting, intravenous, specific antagonist of platelet aggregation via binding to the adenosine diphosphate (ADP) P2Y12 receptor subtype. The primary aims of this study were to assess the initial safety and pharmacodynamics of cangrelor in patients undergoing PCI.


METHODS
In part 1, patients undergoing PCI were randomized to an 18- to 24-hour of either placebo, 1-, 2-, or 4-microg/kg per minute cangrelor in addition to aspirin and heparin beginning before PCI. In part 2, patients were randomized to receive either cangrelor (4 microg/kg per minute) or abciximab before PCI. The primary end point was the composite incidence of major and minor bleeding through 7 days. Secondary end points included the occurrence of major adverse coronary events (death, MI, and unplanned repeat coronary intervention) through 30 days plus ex vivo platelet aggregation and bleeding times.


RESULTS
Two hundred patients (3 dosage groups and placebo) were studied in part 1, and 199 additional patients were then randomized in the second part, comparing 1 dose of cangrelor and abciximab. Combined major and minor bleeding occurred in 13% of those receiving cangrelor and in 8% in those randomized to placebo (P = non significant [NS]) during part 1 and in 7% receiving cangrelor compared with 10% randomized to abciximab (P = NS), during part 2. The 30-day composite incidence of adverse cardiac events was similar between those receiving cangrelor and those receiving abciximab during part 2 (7.6% vs 5.3%, respectively, P = NS). Mean inhibition of ex vivo platelet aggregation in response to 3 micromol/L ADP at steady state was 100% for both cangrelor 4 microg/kg per minute and abciximab groups in part 2. After termination of infusion, platelet aggregation returned to baseline response more rapidly with cangrelor compared with abciximab. There was a trend toward longer bleeding time prolongation and lower platelet count with abciximab compared with cangrelor.


CONCLUSIONS
This initial experience with intravenous cangrelor during PCI suggests an acceptable risk of bleeding and adverse cardiac events while achieving rapid, reversible inhibition of platelet aggregation via competitive binding to the ADP P2Y12 platelet receptor with less prolongation of bleeding time then the glycoprotein IIb/IIIa receptor antagonist abciximab.
Greenbaum
Adam B
AB
Henry Ford Heart and Vascular Institute, Detroit, MI, USA. agreenb1@hfhs.org
Grines
Cindy L
CL
Bittl
John A
JA
Becker
Richard C
RC
Kereiakes
Dean J
DJ
Gilchrist
Ian C
IC
Clegg
Jane
J
Stankowski
Jill E
JE
Grogan
Donna R
DR
Harrington
Robert A
RA
Emanuelsson
Hakan
H
Weaver
W Douglas
WD
D000077284:Abciximab; D000249:Adenosine Monophosphate / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D003327:Coronary Disease / Q000628:therapy*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*
D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D000249:Adenosine Monophosphate; C117446:cangrelor; D000077284:Abciximab