WASHINGTON, March 30 (Reuters) - An experimental heart drug being developed by GlaxoSmithKline, which failed the main goal of a Phase III study of patients with chronic but well-treated heart disease, showed signs of potential benefit, the trial's co-leader said Sunday.
The results presented at the American College of Cardiology scientific meeting in Washington provided a glimmer of hope that the medicine may have value.
"I'm convinced there is a signal here of efficacy," said Dr. Harvey White, co-chair of the Glaxo-sponsored international study.
The real test of the drug, darapladib, is likely to come from a second, late stage study in far less stable patients who received the medicine within 30 days of a heart attack.
A positive result in that study could put the drug back on track, after it was largely discounted by analysts and investors following the first Phase III failure.
The stakes are high for the British drugmaker as gaining full control of darapladib was one of the reasons behind its $3.6 billion acquisition of Human Genome Sciences in 2012.
Human Genome had rejected an earlier $2.6 billion offer, on the grounds that Glaxo was underestimating the blockbuster sales potential of darapladib.
Glaxo had previously said darapladib did no better than a placebo in decreasing the risk of a combination of cardiovascular death, heart attack and stroke in the trial called Stability.
That trial involved 15,828 patients followed for a median of 3.7 years.
For those taking the Glaxo pill, 9.7 percent had one of the major adverse events compared with 10.4 percent for placebo, which was not a statistically significant difference.
A lack of any impact on stroke prevention appears to have contributed to the failure of the study, researchers surmised.
In addition, the effect of the Glaxo drug may have been muted by the high level of care the patients were receiving.
Almost all were taking statins and aspirin and nearly 80 percent were on blood pressure drugs - all known to decrease the risk of heart attacks, strokes and death.
The drug's impact on a pair of composite secondary goals of the study was deemed "nominally significant" by researchers, meaning they saw the potential of a clinically meaningful effect despite falling short of statistical significance.
(Reporting by Bill Berkrot; Editing by Sophie Hares)