GlaxoSmithKline has halted the development of SRT501, an experimental drug based on resveratrol, but that doesn’t mean the pharmaceutical firm is no longer developing medicines based on the compound.
Glaxo announced last week that it would be halting all trials of the drug, after SRT501 failed to make a significant impact on patients with cancer and even aggravated some kidney problems. “Resveratrol, which is the main ingredient of SRT501, has been studied extensively and shows multiple beneficial effects in animals,” said Melinda Stubbee, director of research and development communications at GlaxoSmithKline. “Unfortunately, the doses of this compound that have been shown to be beneficial in [animals] are relatively impractical in human studies.”
The health benefits of resveratrol have been the focus of multiple studies in recent years. Researchers discovered that the compound, found in grapes as well as other foods such as peanuts, blueberries and cranberries, can extend the lifespan of mice while protecting them from several diseases. The compound is part of the grapevine’s immune system and helps fight off invaders. Since it's absorbed into red wine during the fermentation process, researchers have debated whether resveratrol is at least partially responsible for wine's health benefits. Some of the first experimental drugs based on resveratrol were developed by Sirtris, a Massachusetts-based company. The results looked promising enough that Glaxo snapped the company up for $720 million in 2008.
GlaxoSmithKline recently reviewed the trial studies of SRT501, noting that after comprehensive analysis, the drug was found to be only minimally effective. Further, they reviewed the cases of renal failure in study patients. While the kidney complications were due to the underlying disease, not the drug, the drug’s side effects indirectly led to dehydration, which accelerated kidney failure.
However, GlaxoSmithKline is not discontinuing all work on resveratrol-based drugs. Stubbee explained that the company is now focusing efforts on synthetic molecules that activate the same proteins inside cells that resveratrol activates. “Currently we have two of these latest generation compounds, SRT2104 and SRT2379, in several exploratory clinical trials,” Stubbee said. “The compounds have no chemical relationship to SRT501 and more favorable drug-like properties.”