Disappointment for Pfizer and Bristol-Myers Squibb's Eliquis (apixaban) in anticoagulant trial
Pfizer and Bristol-Myers Squibb suffered a disappointment yesterday after a study indicated their anticoagulant Eliquis performed no better than a reference drug in preventing venous thromboembolism (VTE) in patients with acute medically ill patients.
The results of the ADOPT trial - presented at the American Heart Association meeting in Orlando - compared a 30-day course of orally-administered Eliquis (apixaban) to a shorter (6- to 14-day) course of Sanofi's Lovenox (enoxaparin) given by subcutaneous injection.
The aim was to see if extending the duration of prophylactic anticoagulant treatment in a broad population of medically-ill patients could reduce the chances of them developing a VTE after hospital discharge. Around 2.7 per cent of Eliquis-treated patients developed VTE, compared to 3.1 per cent of those on Lovenox, which was not a statistically significant difference.
While the overall rate of bleeding complications was around the same in both Eliquis and Lovenox groups, Eliquis was associated with a statistically higher rate of major bleeding episodes. The results have also been published in the New England Journal of Medicine (October 13, 2011).
Expectations for ADOPT were not overwhelmingly high, given the failure of earlier trials of enoxaparin and Bayer and Johnson & Johnson's rival compound Xarelto (rivaroxaban) to provide a clinical benefit when administered as extended prophylaxis for VTE. Both these trials (EXCLAIM and MAGELLAN, respectively) showed lower rates of VTE that were offset by significant increases in bleeding complications.
Post-hospital VTE is however a major public health issue, accounting for around half of all VTE cases, and effective therapies are needed to protect patients during the critical three-month period after discharge.
The authors of the ADOPT study, led by Samuel Goldhaber of Brigham and Women's Hospital in Boston, said the trial was underpowered but did indicate a trend towards a reduction in VTE with the Pfizer/BMS drug. Moreover, Lovenox was given for a longer period than is now common in medical practice, mainly because these days hospital stays tend to be shorter.
They suggest that it may be possible to identify subpopulations of medically-ill patients who would gain a significant benefit from Eliquis.
Eliquis is already marketed in Europe for the prevention of VTE in adults who have undergone hip and knee replacement surgeries, and has been filed for approval as a means of preventing stroke in atrial fibrillation (AF) patients.
The AF indication is expected to hold the greatest promise for Eliquis, with analysts at Leerink Swann recently predicting that sales of the drug could reach more than $4bn by 2017, ahead of Xarelto and another rival, Boehringer Ingelheim's Pradaxa (dabigatran).