Blood Thinner Apixaban Trials Halted After Increase In Bleeding
Trials for experimental anticoagulant (blood thinner) drug apixaban were stopped because the increasing in bleeding for acute coronary syndrome patients was deemed greater than any possible benefits. The 10,800 patients in 40 countries will come off the medication, Bristol-Myers Squibb and Pfizer jointly announced.
Bristol-Myers and Pfizer said they will continue seeking approval for apixaban for the prevention of strokes in patients with atrial fibrillation, as well as the prevention of blood clots for patients undergoing knee and hip replacements. A trial in 2007 demonstrated that apixaban prevented thrombosis in knee replacement patients as well as enoxaparin/open-label heparin did.
Brian Daniels, M.D., senior vice president, Global Development and Medical Affairs, Bristol-Myers Squibb, said:
“We remain committed to the development of apixaban in other patient populations. We are focused on the rolling submission of data for the prevention of stroke in patients with atrial fibrillation who are expected or demonstrated to be unsuitable for treatment with warfarin to the Food and Drug Administration and the application to the European Medicines Agency for venous thromboembolism (VTE) prevention. Other ongoing studies investigating apixaban in different patient populations are being monitored by independent data monitoring committees and are continuing.”
Acute coronary syndrome (ACS) refers to any condition in which blood flow to the heart is suddenly reduced. It can describe the chest pain felt by people during a heart attack, or the chest pain felt by those with unstable angina, a pain that may be experienced while resting or doing light physical activity. Typically, ACS is diagnosed in emergency rooms or hospitals. If diagnosed quickly it is treatable; if not, a heart attack will probably occur. Symptoms, which may be similar to those of a heart attack, can include chest pain, chest pressure, chest tightness which lasts at least for several minutes, referred pain (somewhere else in the body, such as the jaw or upper arm), nausea, dyspnea (shortness of breath), vomiting, and diaphoresis (sudden and heavy sweating).
The Phase 3 Appraise-2 clinical trial was being tested on patients with recent ACS, they were randomly selected to be given either apixaban or a placebo in combination with mono or dual antiplatelet therapy. Bristol-Myers said there was clear evidence of an increase in bleeding among the apixaban patients. The increase in bleeding was thought to create more problems than the benefits of a reduction in ischemic events.
Robert Harrington, M.D., Duke Clinical Research Institute, and co-chair of the APPRAISE-2 Steering Committee, said:
“Our recommendation to discontinue APPRAISE-2 concerns only the population of high-risk ACS patients receiving anti-platelet therapy enrolled in APPRAISE-2. Recent Phase 3 clinical trials of apixaban have demonstrated promising results in patients with VTE and atrial fibrillation. We look forward to reviewing the complete APPRAISE-2 data, when it is available, to better understand this apparently different risk profile in patients with ACS.”
Pfizer and Bristol-Myers Squibb agreed on a global collaboration to develop and market apixaban, which was discovered by Bristol-Myers Squibb.