One of the compounds for which GlaxoSmithKline paid $720 million when it scooped up Sirtris Pharmaceutical two years ago (see here) had a setback. A clinical trial that was supposed to tap the anti-aging effects of red wine was halted for ‘unexpected safety events,’ according to ClinicalTrials.gov.

The stoppage comes three months after a flap over the value of the compounds was hotly debated on In The Pipeline, which first reported that the trial is on hold. For those not following this topic, Sirtris develops drugs that activate sirtuins, a class of enzymes involved in aging, and its most advanced compound is a formulation of resveratrol, a substance found in red wine and plants.

The Glaxo trial was testing the SRT501 compound in combination with the Velcade cancer drug in people with multiple myeloma in the UK and Denmark, according to the web site, which says the trial was to have run from March 2009 through December 2010, and that 61 patients were enrolled. It’s worth noting, however, that other trials testing this compound have been completed (see here).

A Glaxo spokeswoman writes us to say that an unspecified number of patients developed a complication generally associated with myeloma and that Glaxo is analyzing the data. Meanwhile, she adds, that “investigators and regulators in the UK and Denmark were notified of the decision to temporarily hold further enrollment while determining next steps for this particular trial.”