GlaxoSmithKline’s highly anticipated new coronary heart disease (CHD) drug candidate darapladib has disappointed in a phase III trial.
Top-line results from the STABILITY study revealed that the Lp-PLA2 inhibitor was unable to achieve a significant reduction in major cardiovascular events, including heart attack, stroke and cardiovascular death, compared to placebo.
Darapladib is designed to prevent the rupture of atherosclerotic plaques, a process which leads to heart attacks and strokes in patients with CHD, and was one of the compounds that prompted GSK’s $3bn acquisition of Human Genome Sciences (HGS) in 2012.
If effective, the drug would be a candidate for the millions of people worldwide who do not get a strong enough response from statin drugs, which could make darapladib a blockbuster with sales of several billion dollars a year.
GSK’s head of pharmaceutical R&D Patrick Vallance noted there were some trends towards a benefit in secondary measures in STABILITY and said further analysis is ongoing.
“Given the level of patient need in this area, we continue to investigate the role of Lp-PLA2 inhibition in coronary heart disease and other disease,” he said, adding the company will continue to examine the data and wait for the results of a second phase III trial of darapladib in acute coronary syndrome (ACS).
Analysts were not overwhelmingly hopeful of a positive outcome, however, given that darapladib failed a phase II study looking at its ability to resolve plaques while another drug with a similar mode of action – Anthera Pharmaceuticals’ varespladib – was found to be infective in a phase III ACS trial last year.
Panmure Gordon downgraded GSK from ‘Buy’ to ‘Hold’ on the news yesterday, with analyst Savvas Neophytou saying that even if the ACS trial (SOLID-TIMI 52) is successful “we believe it will be difficult to gain market registration on one trial alone”.
This is the second big disappointment in GSK’s late-stage pipeline this year after its melanoma immunotherapy MAGE-A3 missed its targets.