The Medicines Company announced the data from 13,941 patients treated in the discontinued Champion phase-III programme of cangrelor. While cangrelor did not show superiority to 600 mg clopidogrel given orally for the pre-specified primary endpoint comprising death, MI, or ischemia driven revascularization (IDR) at 48 hours, full analysis of the Champion program data revealed strong evidence of pharmacological effects, clinical effectiveness and suitable safety in patients undergoing percutaneous coronary intervention (PCI). In fact, cangrelor significantly reduced the composite endpoint of death, Q-wave myocardial infarction (MI) and IDR.
Two separate presentations on the results of the Champion PCI and Champion Platform trials will be given today at the American Heart Association Scientific Sessions 2009 in Orlando, Florida, by Robert A Harrington, professor of Medicine at Duke University Medical Center, Director of the Duke Clinical Research Institute and Deepak L Bhatt, chief of Cardiology at the VA Boston Healthcare System, Director of the Integrated Interventional Cardiovascular Program at Brigham and Women's Hospital and the VA Boston Healthcare System. The speakers are the lead authors of two papers on these results published in the New England Journal of Medicine, which became available online.
Champion programme data were analyzed after the program's discontinuation in May 2009 when 98% of targeted patients in Champion PCI and 84 per cent in Champion Platform had been enrolled. At that time, the program's independent interim analysis review committee reported to the company and the principal investigators that the Champion Platform trial was not expected to meet its primary endpoints.
Cangrelor was superior to clopidogrel (600 mg given orally before PCI) in inhibiting platelet aggregation measured by a range of laboratory tests (p-value < 0.0001) during the first 2 hours of treatment, resulting in more rapid and greater effect than that of clopidogrel. The antiplatelet effects of cangrelor are quickly reversible, enabling smooth transition to oral clopidogrel with no evidence of attenuation of clopidogrel effect.
The risk of the composite endpoint of death, Q-wave MI or IDR was 39 per cent lower on cangrelor than on 600 mg clopidogrel given immediately before or immediately after PCI (p-value = 0.0049). Similarly, the risk of the composite endpoint of death, Q-wave MI or stent thrombosis was 45% lower (p-value = 0.0028).
In Champion PCI, cangrelor was not superior to 600 mg clopidogrel loading dose in the 37 per cent of patients who entered the trial on clopidogrel maintenance therapy. However, cangrelor was superior to a 600 mg clopidogrel loading dose in remaining 63 per cent thienopyridine-naive patients with a relative risk reduction for death/Q-MI/IDR of 43 per cent (p-value = 0.04). In Champion Platform, all patients were thienopyridine-naive and cangrelor showed a relative risk reduction for death/Q-MI/IDR of 45 per cent (p-value = 0.0028).
"Although these endpoints were a pre-specified component of the primary endpoint, their combinations were devised post-hoc and so the data cannot be deemed conclusive," said Deepak L Bhatt, MPH. "But these findings are biologically plausible and suggest superior antiplatelet effects and clinical potential."
"The platelet sub-study of the Champion PCI trial provides evidence of rapid, potent antiplatelet effect," said Robert A Harrington. "This is particularly important in specific patient groups, such as those urgently requiring PCI or surgery, those who cannot receive oral medication, those who are known not to respond well to clopidogrel."
There was no significant increase with cangrelor in usual measures of bleeding, including no increase in TIMI major or minor bleeding; no increase in GUSTO severe or moderate bleeding; and no increase in the incidence of blood product transfusions. Access site hematomas were more frequent in patients on cangrelor than on comparators. Infrequent (~1%) and reversible episodes of breathlessness were also reported more frequently among patients given cangrelor.
Cangrelor is uniquely positioned in the hospital setting where patients require rapid onset, direct and rapidly reversible platelet inhibition. This may translate into important advantages for patients undergoing PCI, patients undergoing other procedures and those with conditions associated with arterial thrombosis such as acute coronary syndromes.
"We are very excited by cangrelor's promising pharmacological data, substantial improvement of important clinical endpoints, and suitable safety. It is important that cangrelor was superior to a 600 mg clopidogrel loading dose in thienopyridine-naive patients. Our market research and Champion PCI data show that this is the majority of patients undergoing PCI," stated Clive Meanwell, chief executive officer of The Medicines Company. "We intend to continue our dialogue with the FDA and initiate discussions with European regulators to devise the most efficient and expeditious development path forward. We will be able to plan additional large clinical studies as well as timelines for cangrelor reaching the market after completing discussions with the regulators. In the meantime, we will commit resources to regulatory submissions and preparation of commercial-scale manufacturing. "
The company will continue enrolment in the BRIDGE study -- a trial testing cangrelor as a platelet inhibitor in patients with coronary stents who need to discontinue clopidogrel prior to planned surgery. The company also will initiate various other clinical pharmacology studies.
In summary, the pharmacological effects, clinical effectiveness and suitable safety of cangrelor make this a highly attractive drug candidate for short-term platelet inhibition in hospital patients. The compound is a valuable asset, and the company remains committed to its further development.
Cangrelor is an investigational intravenous antiplatelet agent exclusively licensed in December 2003 from AstraZeneca.
The Medicines Company is focused on advancing the treatment of critical care patients through the delivery of innovative, cost-effective medicines to the worldwide hospital marketplace.