On the Prospects for Intermittent Late-Life Use of Rapamycin

Researchers here discuss the evidence for intermittent use of rapamycin, an mTOR inhibitor that has undesirable side-effects, to be a path forward to producing benefits in older people. We should probably weigh the animal evidence for this class of therapy against the recent failure of a phase III trial for a related form of mTOR inhibition designed to bypass the side-effects of rapamycin. The beneficial effect sizes in humans may be too small to be worth the cost and time of development at the end of the day, and this is somewhat characteristic of interventions, such as mTOR inhibition, that upregulate cellular stress responses such as autophagy. The effect sizes scale down with increased species life span. This is perhaps best illustrated by calorie restriction, an intervention that also acts through increased autophagy. While the practice of calorie restriction can extend life span by up to 40% in short-lived mice, it adds a few years at best in long-lived humans.

Rapamycin is arguably the best-studied pharmaceutical intervention for reliable lifespan and healthspan extension in a wide array of model organisms. These consistent results are encouraging for those eager to develop interventions for prolonging human lifespan or healthspan. Until recently publications of rapamycin treatment in animal models focused on near lifelong treatment, a scenario that is unrealistic to apply to improving the human condition. However, this is beginning to change. A few groups hav...

Source: Fight Aging! - March 23, 2020 Category: Research Authors: Reason Tags: Daily News Source Type: blogs